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Garvey KA, Edwards MA, Blacker LS, Hecht CE, Parks JL, Patel AI. A Comprehensive Examination of the Contaminants in Drinking Water in Public Schools in California, 2017-2022. Public Health Rep 2024; 139:369-378. [PMID: 37667618 PMCID: PMC11037221 DOI: 10.1177/00333549231192471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023] Open
Abstract
OBJECTIVES Reports of unsafe school drinking water in the United States highlight the importance of ensuring school water is safe for consumption. Our objectives were to describe (1) results from our recent school drinking water sampling of 5 common contaminants, (2) school-level factors associated with exceedances of various water quality standards, and (3) recommendations. METHODS We collected and analyzed drinking water samples from at least 3 sources in 83 schools from a representative sample of California public schools from 2017 through 2022. We used multivariate logistic regression to examine school-level factors associated with lead in drinking water exceedances at the American Academy of Pediatrics (AAP) recommendation level (1 part per billion [ppb]) and state action-level exceedances of other contaminants (lead, copper, arsenic, nitrate, and hexavalent chromium). RESULTS No schools had state action-level violations for arsenic or nitrate; however, 4% had ≥1 tap that exceeded either the proposed 10 ppb action level for hexavalent chromium or the 1300 ppb action level for copper. Of first-draw lead samples, 4% of schools had ≥1 tap that exceeded the California action level of 15 ppb, 18% exceeded the US Food and Drug Administration (FDA) bottled water standard of 5 ppb, and 75% exceeded the AAP 1 ppb recommendation. After turning on the tap and flushing water for 45 seconds, 2%, 10%, and 33% of schools exceeded the same standards, respectively. We found no significant differences in demographic characteristics between schools with and without FDA or AAP exceedances. CONCLUSIONS Enforcing stricter lead action levels (<5 ppb) will markedly increase remediation costs. Continued sampling, testing, and remediation efforts are necessary to ensure drinking water meets safety standards in US schools.
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Affiliation(s)
- Kelly A. Garvey
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Marc A. Edwards
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | | | - Christina E. Hecht
- Division of Agriculture and Natural Resources, Nutrition Policy Institute, University of California, Oakland, Oakland, CA, USA
| | - Jeffrey L. Parks
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Anisha I. Patel
- Department of Pediatrics, Stanford University, Palo Alto, CA, USA
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2
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Kriss RB, Smith E, Byrd G, Schock M, Edwards MA. Considering a Utility-Centric Framework Based on "Minimum Orthophosphate" Criteria for Mitigation of Elevated Cuprosolvency in Drinking Water. Environ Sci Technol 2024; 58:5606-5615. [PMID: 38470122 DOI: 10.1021/acs.est.4c00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Gaps in the United States Environmental Protection Agency (US EPA) Lead and Copper Rule (LCR) leave some consumers and their pets vulnerable to high cuprosolvency in drinking water. This study seeks to help proactive utilities who wish to mitigate cuprosolvency problems through the addition of orthophosphate corrosion inhibitors. The minimum doses of orthophosphate necessary to achieve acceptable cuprosolvency in relatively new copper pipe were estimated as a function of alkalinity via linear regressions for the 90th, 95th, and 100th percentile copper tube segments (R2 > 0.98, n = 4). Orthophosphate was very effective at reducing cuprosolvency in the short term but, in some cases, resulted in higher long-term copper concentrations than the corresponding condition without orthophosphate. Alternatives to predicting "long-term" results for copper tubes using simpler bench tests starting with fresh Cu(OH)2 solids showed promise but would require further vetting to overcome limitations such as maintaining water chemistry and orthophosphate residuals and to ensure comparability to results using copper tube.
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Affiliation(s)
- Rebecca B Kriss
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Emily Smith
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Grace Byrd
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | | | - Marc A Edwards
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
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3
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Liu Q, Zhuang Y, Li G, Zhang Y, Edwards MA, Shi B. Understanding the initial use stage of cement mortar lining in drinking water distribution systems: Silicon and aluminum as stability indicators. J Environ Sci (China) 2024; 135:495-505. [PMID: 37778821 DOI: 10.1016/j.jes.2023.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/29/2023] [Accepted: 01/29/2023] [Indexed: 10/03/2023]
Abstract
The cement mortar lining (CML) of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use, but the behavioral characteristics of different elements release from the CML in this stage is still unclear. In this study, dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity conditions. The results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water, which consequently greatly impacted the release/precipitation behaviors of calcium, aluminum and silicon. The pH and aluminum concentration of the effluent water could reach 11.5 and 700 µg/L within 24 hr of hydraulic retention time, respectively, under conditions of relatively lower hardness and alkalinity. Due to the pH elevation, calcium carbonate precipitation could occur even at much lower feed water alkalinity. Whereas the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels, and their release rate depended on the amount of calcium carbonate precipitation. Thus, aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation potential. Appropriate feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed: hardness > 40 mg/L (CaCO3), alkalinity > 100 mg/L (CaCO3).
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Affiliation(s)
- Qiaozhi Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Zhuang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Guiwei Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yao Zhang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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4
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Cullom A, Spencer MS, Williams MD, Falkinham JO, Brown C, Edwards MA, Pruden A. Premise Plumbing Pipe Materials and In-Building Disinfectants Shape the Potential for Proliferation of Pathogens and Antibiotic Resistance Genes. Environ Sci Technol 2023; 57:21382-21394. [PMID: 38071676 DOI: 10.1021/acs.est.3c05905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
In-building disinfectants are commonly applied to control the growth of pathogens in plumbing, particularly in facilities such as hospitals that house vulnerable populations. However, their application has not been well optimized, especially with respect to interactive effects with pipe materials and potential unintended effects, such as enrichment of antibiotic resistance genes (ARGs) across the microbial community. Here, we used triplicate convectively mixed pipe reactors consisting of three pipe materials (PVC, copper, and iron) for replicated simulation of the distal reaches of premise plumbing and evaluated the effects of incrementally increased doses of chlorine, chloramine, chlorine dioxide, and copper-silver disinfectants. We used shotgun metagenomic sequencing to characterize the resulting succession of the corresponding microbiomes over the course of 37 weeks. We found that both disinfectants and pipe material affected ARG and microbial community taxonomic composition both independently and interactively. Water quality and total bacterial numbers were not found to be predictive of pathogenic species markers. One result of particular concern was the tendency of disinfectants, especially monochloramine, to enrich ARGs. Metagenome assembly indicated that many ARGs were enriched specifically among the pathogenic species. Functional gene analysis was indicative of a response of the microbes to oxidative stress, which is known to co/cross-select for antibiotic resistance. These findings emphasize the need for a holistic evaluation of pathogen control strategies for plumbing.
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Affiliation(s)
- Abraham Cullom
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Matheu Storme Spencer
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Myra D Williams
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Joseph O Falkinham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Connor Brown
- Department of Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
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5
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Cullom A, Spencer MS, Williams MD, Falkinham JO, Pruden A, Edwards MA. Influence of pipe materials on in-building disinfection of P. aeruginosa and A. baumannii in simulated hot water plumbing. Water Res X 2023; 21:100189. [PMID: 38098877 PMCID: PMC10719577 DOI: 10.1016/j.wroa.2023.100189] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 04/20/2023] [Accepted: 06/12/2023] [Indexed: 12/17/2023]
Abstract
A framework is needed to account for interactive effects of plumbing materials and disinfectants on opportunistic pathogens (OPs) in building water systems. Here we evaluated free chlorine, monochloramine, chlorine dioxide, and copper-silver ionization (CSI) for controlling Pseudomonas aeruginosa and Acinetobacter baumannii as two representative OPs that colonize hot water plumbing, in tests using polyvinylchloride (PVC), copper-PVC, and iron-PVC convectively-mixed pipe reactors (CMPRs). Pipe materials vulnerable to corrosion (i.e., iron and copper) altered the pH, dissolved oxygen, and disinfectant levels in a manner that influenced growth trends of the two OPs and total bacteria. P. aeruginosa grew well in PVC CMPRs, poorly in iron-PVC CMPRs, and was best controlled by CSI disinfection, whereas A. baumannii showed the opposite trend for pipe material and was better controlled by chlorine and chlorine dioxide. Various scenarios were identified in which pipe material and disinfectant can interact to either hinder or accelerate growth of OPs, illustrating the difficulties of controlling OPs in portions of plumbing systems experiencing warm, stagnant water.
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Affiliation(s)
- Abraham Cullom
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061
| | - Mattheu Storme Spencer
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061
| | - Myra D. Williams
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Joseph O. Falkinham
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061
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6
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Song Y, Finkelstein R, Rhoads W, Edwards MA, Pruden A. Shotgun Metagenomics Reveals Impacts of Copper and Water Heater Anodes on Pathogens and Microbiomes in Hot Water Plumbing Systems. Environ Sci Technol 2023; 57:13612-13624. [PMID: 37643149 PMCID: PMC10501123 DOI: 10.1021/acs.est.3c03568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/31/2023]
Abstract
Hot water building plumbing systems are vulnerable to the proliferation of opportunistic pathogens (OPs), including Legionella pneumophila and Mycobacterium avium. Implementation of copper as a disinfectant could help reduce OPs, but a mechanistic understanding of the effects on the microbial community under real-world plumbing conditions is lacking. Here, we carried out a controlled pilot-scale study of hot water systems and applied shotgun metagenomic sequencing to examine the effects of copper dose (0-2 mg/L), orthophosphate corrosion control agent, and water heater anode materials (aluminum vs magnesium vs powered anode) on the bulk water and biofilm microbiome composition. Metagenomic analysis revealed that, even though a copper dose of 1.2 mg/L was required to reduce Legionella and Mycobacterium numbers, lower doses (e.g., ≤0.6 mg/L) measurably impacted the broader microbial community, indicating that the OP strains colonizing these systems were highly copper tolerant. Orthophosphate addition reduced bioavailability of copper, both to OPs and to the broader microbiome. Functional gene analysis indicated that both membrane damage and interruption of nucleic acid replication are likely at play in copper inactivation mechanisms. This study identifies key factors (e.g., orthophosphate, copper resistance, and anode materials) that can confound the efficacy of copper for controlling OPs in hot water plumbing.
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Affiliation(s)
- Yang Song
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
- Utilities
Department, Town of Cary, 316 N. Academy St., Cary, North Carolina 27512, United States
| | - Rachel Finkelstein
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
- AECOM, 3101 Wilson Boulevard, Arlington, Virginia 22201, United States
| | - William Rhoads
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
- Black
& Veatch, 8400 Ward
Pkwy, Kansas City, Missouri 64114, United States
| | - Marc A. Edwards
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
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7
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Roy S, Dietrich KN, Gomez HF, Edwards MA. Considering Some Negative Implications of an Ever-Decreasing U.S. Centers for Disease Control and Prevention (CDC) Blood Lead Threshold and "No Safe Level" Health Messaging. Environ Sci Technol 2023; 57:12935-12939. [PMID: 37611243 DOI: 10.1021/acs.est.3c04766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Siddhartha Roy
- The Water Institute, Gillings School of Global Public Health, University of North Carolina, 4114 McGavran-Greenberg Hall, Chapel Hill, North Carolina 27516, United States
| | - Kim N Dietrich
- Department of Environmental and Public Health Sciences, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States
| | - Hernan F Gomez
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Emergency Medicine, University of Michigan, Hurley Medical Center, One Hurley Plaza, Flint, Michigan 48503, United States
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, Virginia 24061, United States
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8
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Song Y, Pruden A, Rhoads WJ, Edwards MA. Pilot-scale assessment reveals effects of anode type and orthophosphate in governing antimicrobial capacity of copper for Legionella pneumophila control. Water Res 2023; 242:120178. [PMID: 37307684 DOI: 10.1016/j.watres.2023.120178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/07/2023] [Accepted: 06/05/2023] [Indexed: 06/14/2023]
Abstract
Copper (Cu) is sometimes applied as an antimicrobial for controlling Legionella in hot water plumbing systems, but its efficacy is inconsistent. Here we examined the effects of Cu (0 - 2 mg/L), orthophosphate corrosion inhibitor (0 or 3 mg/L as phosphate), and water heater anodes (aluminum, magnesium, and powered anodes) on both bulk water and biofilm-associated L. pneumophila in pilot-scale water heater systems. Soluble, but not total, Cu was a good predictor of antimicrobial capacity of Cu. Even after months of exposure to very high Cu levels (>1.2 mg/L) and low pH (<7), which increases solubility and enhances bioavailability of Cu, culturable L. pneumophila was only reduced by ∼1-log. Cu antimicrobial capacity was shown to be limited by various factors, including binding of Cu ions by aluminum hydroxide precipitates released from corrosion of aluminum anodes, higher pH due to magnesium anode corrosion, and high Cu tolerance of the outbreak-associated L. pneumophila strain that was inoculated into the systems. L. pneumophila numbers were also higher in several instances when Cu was dosed together with orthophosphate (e.g., with an Al anode), revealing at least one scenario where high levels of total Cu appeared to stimulate Legionella. The controlled, pilot-scale nature of this study provides new understanding of the limitations of Cu as an antimicrobial in real-world plumbing systems.
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Affiliation(s)
- Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061; Utilities Department, Town of Cary, 316 N. Academy St., Cary, NC, 27512.
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061
| | - William J Rhoads
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061; Black & Veatch, 8400 Ward Pkwy, Kansas City, MO, 64114
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061.
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Roy S, Edwards MA. NSF Fellows' perceptions about incentives, research misconduct, and scientific integrity in STEM academia. Sci Rep 2023; 13:5701. [PMID: 37029143 PMCID: PMC10080524 DOI: 10.1038/s41598-023-32445-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 03/28/2023] [Indexed: 04/09/2023] Open
Abstract
There is increased concern about perverse incentives, quantitative performance metrics, and hyper-competition for funding and faculty positions in US academia. Recipients of the prestigious National Science Foundation Graduate Research Fellowships (n = 244) from Civil and Environmental Engineering (45.5%) and Computer Science and Engineering (54.5%) were anonymously surveyed to create a baseline snapshot of their perceptions, behaviors and experiences. NSF Fellows ranked scientific advancement as the top metric for evaluating academics followed by publishing in high-impact journals, social impact of research, and publication/citation counts. The self-reported rate of academic cheating was 16.7% and of research misconduct was 3.7%. Thirty-one percent of fellows reported direct knowledge of graduate peers cheating, and 11.9% had knowledge of research misconduct by colleagues. Only 30.7% said they would report suspected misconduct. A majority of fellows (55.3%) felt that mandatory ethics trainings left them unprepared for dealing with ethical issues. Fellows stated academic freedom, flexible schedules and opportunity to mentor students were the most positive aspects of academia, whereas pressures for funding, publication, and tenure were cited as the most negative aspects. These data may be useful in considering how to better prepare STEM graduate trainees for academic careers.
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Affiliation(s)
- Siddhartha Roy
- Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061, USA.
- The Water Institute at UNC, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27516, USA.
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061, USA
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Roy S, Petrie KJ, Gamble G, Edwards MA. Did a nocebo effect contribute to the rise in special education enrollment following the Flint, Michigan water crisis? Clin Psychol Eur 2023; 5:e9577. [PMID: 37065004 PMCID: PMC10103158 DOI: 10.32872/cpe.9577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 02/21/2023] [Indexed: 04/03/2023] Open
Abstract
Background
Exposure to waterborne lead during the Flint Water Crisis during April 2014-October 2015 is believed to have caused increased special education enrollment in Flint children.
Method
This retrospective population-based cohort study utilized de-identified data for children under six years of age who had their blood lead tested during 2011 to 2019, and special education outcomes data for children enrolled in public schools for corresponding academic years (2011-12 to 2019-20) in Flint, Detroit (control city) and the State of Michigan. Trends in the following crisis-related covariates were also evaluated: waterborne contaminants, poverty, nutrition, city governance, school district policies, negative community expectations, media coverage and social media interactions.
Results
Between 2011 and 2019, including the 2014-15 crisis period, the incidence of elevated blood lead in Flint children (≥ 5µg/dL) was always at least 47% lower than in the control city of Detroit (p < .0001) and was also never significantly higher than that for all children tested in Michigan (p = 0.33). Nonetheless, special education enrollment in Flint spiked relative to Detroit and Michigan (p < .0001). There is actually an inverse relationship between childhood blood lead and special education enrollment in Flint.
Conclusion
This study failed to confirm any positive association between actual childhood blood lead levels and special education enrollment in Flint. Negative psychological effects associated with media predictions of brain damage could have created a self-fulfilling prophecy via a nocebo effect. The findings demonstrate a need for improved media coverage of complex events like the Flint Water Crisis.
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Mapili K, Rhoads WJ, Coughter M, Pieper KJ, Edwards MA, Pruden A. Occurrence of opportunistic pathogens in private wells after major flooding events: A four state molecular survey. Sci Total Environ 2022; 826:153901. [PMID: 35182640 DOI: 10.1016/j.scitotenv.2022.153901] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Private wells can become contaminated with waterborne pathogens during flooding events; however, testing efforts focus almost exclusively on fecal indicator bacteria. Opportunistic pathogens (OPs), which are the leading cause of identified waterborne disease in the United States, are understudied in private wells. We conducted a quantitative polymerase chain reaction survey of Legionella spp., L. pneumophila, Mycobacterium spp., M. avium, Naegleria fowleri, and shiga toxin-producing Escherichia coli gene markers and total coliform and E. coli in drinking water supplied by private wells following the Louisiana Floods (2016), Hurricane Harvey (2017), Hurricane Irma (2017), and Hurricane Florence (2018). Self-reported well characteristics and recovery status were collected via questionnaires. Of the 211 water samples collected, 40.3% and 5.2% were positive for total coliform and E. coli, which were slightly elevated positivity rates compared to prior work in coastal aquifers. DNA markers for Legionella and Mycobacterium were detected in 54.5% and 36.5% of samples, with L. pneumophila and M. avium detected in 15.6% and 17.1%, which was a similar positivity rate relative to municipal system surveys. Total bacterial 16S rRNA gene copies were positively associated with Legionella and Mycobacterium, indicating that conditions that favor occurrence of general bacteria can also favor OPs. N. fowleri DNA was detected in 6.6% of samples and was the only OP that was more prevalent in submerged wells compared to non-submerged wells. Self-reported well characteristics were not associated with OP occurrence. This study exposes the value of routine baseline monitoring and timely sampling after flooding events in order to effectively assess well water contamination risks.
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Affiliation(s)
- Kris Mapili
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA 24061, United States of America
| | - William J Rhoads
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA 24061, United States of America; Eawag - Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Microbiology, Überlandstrasse 133, 8600 Dübendorf, Switzerland.
| | - Mary Coughter
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA 24061, United States of America
| | - Kelsey J Pieper
- Northeastern University, Civil and Environmental Engineering, 360 Huntington Ave., Boston, MA 02115, United States of America.
| | - Marc A Edwards
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA 24061, United States of America
| | - Amy Pruden
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA 24061, United States of America
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12
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Roy S, Edwards MA. Are there excess fetal deaths attributable to waterborne lead exposure during the Flint Water Crisis? Evidence from bio-kinetic model predictions and Vital Records. J Expo Sci Environ Epidemiol 2022; 32:17-26. [PMID: 34267307 DOI: 10.1038/s41370-021-00363-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Flint, Michigan had elevated water lead (Pb) levels during the 2014-15 Flint Water Crisis (FWC) and reports claim the exposures caused excess fetal deaths. OBJECTIVE To model the likelihood of excess fetal deaths occurring from FWC lead exposure and compare results to Vital Records. METHODS We used an established bio-kinetic model to predict relative blood lead trends in pregnant women from characteristic exposure to 90th percentile water lead levels (WLLs), and another established model to then estimate characteristic miscarriage (<20 gestation weeks) odds ratios (OR) in Flint (2011-17). For comparison, we made similar predictions for exposures during (1) Washington DC's worst water lead crisis year (2001), (2) Flint "Resident Zero" home with anomalously high WLLs, and (3) 19th century lead-based abortifacients. Data on stillbirths (≥20 gestation weeks) and total fertility rates were obtained from the State of Michigan. RESULTS The models predicted that pregnant women drinking water with representative 90th percentile WLLs had a miscarriage OR during the worst FWC period (June-August 2014) of 1.21 (95% CI = 1.02,1.60), versus 1.66 (95% CI = 1.07, 3.56) during a time of high water lead 3 years before the FWC and 1.00 (95% CI = 1.00, 1.01) post-FWC. The corresponding predicted OR in late-2001 for Washington D.C. when higher fetal death rates were statistically associated with very high WLLs was 3.01 (95% CI = 1.16, 16.23). No apparent differences were revealed in overall and race-specific stillbirth rates before, during, or after the FWC. Total fertility rates dropped 6.8% during the FWC (April 2014-October 2015 versus April 2012-October 2013), but this is now revealed to be within the normal annual variation (-9.4% to +15%) observed post-FWC when residents were protected from water lead exposure. SIGNIFICANCE Neither model simulations nor Vital Records data are consistent with the hypothesis that there was an uptick in fetal deaths or decreased fertility attributable to water lead exposure during the FWC.
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Affiliation(s)
- Siddhartha Roy
- Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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13
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Affiliation(s)
- Siddhartha Roy
- Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061, USA.
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061, USA
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14
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Ghosh S, Zhu NJ, Milligan E, Falkinham JO, Pruden A, Edwards MA. Mapping the Terrain for Pathogen Persistence and Proliferation in Non-potable Reuse Distribution Systems: Interactive Effects of Biofiltration, Disinfection, and Water Age. Environ Sci Technol 2021; 55:12561-12573. [PMID: 34448580 DOI: 10.1021/acs.est.1c02121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Diverse pathogens can potentially persist and proliferate in reclaimed water distribution systems (RWDSs). The goal of this study was to evaluate interactive effects of reclaimed water treatments and water age on persistence and proliferation of multiple fecal (e.g., Klebsiella, Enterobacter) and non-fecal (e.g., Legionella, mycobacteria) gene markers in RWDSs. Six laboratory-scale RWDSs were operated in parallel receiving the influent with or without biologically active carbon (BAC) filtration + chlorination, chloramination, or no disinfectant residual. After 3 years of operation, the RWDSs were subject to sacrificial sampling and shotgun metagenomic sequencing. We developed an in-house metagenome-derived pathogen quantification pipeline, validated by quantitative polymerase chain reaction and mock community analysis, to estimate changes in abundance of ∼30 genera containing waterborne pathogens. Microbial community composition in the RWDS bulk water, biofilm, and sediments was clearly shaped by BAC filtration, disinfectant conditions, and water age. Key commonalities were noted in the ecological niches occupied by fecal pathogen markers in the RWDSs, while non-fecal pathogen markers were more varied in their distribution. BAC-filtration + chlorine was found to most effectively control the widest range of target genera. However, filtration alone or chlorine secondary disinfection alone resulted in proliferation of some of these genera containing waterborne pathogens.
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Affiliation(s)
- Sudeshna Ghosh
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Ni Joyce Zhu
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Erin Milligan
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Joseph O Falkinham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Marc A Edwards
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
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15
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Roy S, Mosteller K, Mosteller M, Webber K, Webber V, Webber S, Reid L, Walters L, Edwards MA. Citizen science chlorine surveillance during the Flint, Michigan federal water emergency. Water Res 2021; 201:117304. [PMID: 34107367 DOI: 10.1016/j.watres.2021.117304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 04/30/2021] [Accepted: 05/24/2021] [Indexed: 05/12/2023]
Abstract
Rising incidence of waterborne diseases including Legionellosis linked to low chlorine residuals in buildings and the availability of inexpensive testing options, create an opportunity for citizen science chorine monitoring to complement sampling done by water utilities. University researchers and Flint residents coordinated a citizen science chlorine surveillance campaign in Flint, Michigan in 2015-19, that helped expose the nature of two deadly Legionnaires Disease outbreaks in 2014-2015 during the Flint Water Crisis and progress of system recovery during the Federal emergency. Results obtained with an inexpensive color wheel were in agreement with a digital colorimeter (R2 =0.99; p = 2.81 × 10-21) at 15 sites geographically distributed across Flint. Blinded tests revealed good agreement between official (n = 2051) and citizen (n = 654) data in terms of determining whether regulatory guidelines for chlorine were met, but a discovery that the citizen data were statistically lower than the city's (p<0.00001) especially in warm summer months led to recommendations for increased flushing of service lines before measurements. This work suggests that expanded citizen surveillance of chlorine, site specific flushing advice, and guidance on decisions about water heater set point could help consumers reduce Legionella risks in their homes. Citizen science initiatives for chlorine monitoring offer a unique opportunity for mutually beneficial collaborations between consumers and utilities to reduce the main source of waterborne disease in developed countries.
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Affiliation(s)
- Siddhartha Roy
- Civil and Environmental Engineering, Virginia Tech, USA.
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16
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Zhu NJ, Ghosh S, Edwards MA, Pruden A. Interplay of Biologically Active Carbon Filtration and Chlorine-Based Disinfection in Mitigating the Dissemination of Antibiotic Resistance Genes in Water Reuse Distribution Systems. Environ Sci Technol 2021; 55:8329-8340. [PMID: 34080846 DOI: 10.1021/acs.est.1c01199] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Appropriate management approaches are needed to minimize the proliferation of antibiotic resistance genes (ARGs) in reclaimed water distribution systems (RWDSs). Six laboratory-scale RWDSs were operated over 3 years receiving influent with or without biologically active carbon (BAC) filtration + chlorination, chloramination, or no disinfectant residual. Shotgun metagenomic sequencing was applied toward comprehensive characterization of resistomes, focusing on total ARGs, ARG mobility, and specific ARGs of clinical concern. ARGs such as aadA, bacA, blaOXA, mphE, msrE, sul1, and sul2 were found to be particularly sensitive to varying RWDS conditions. BAC filtration with chlorination most effectively achieved and maintained the lowest levels of nearly all metagenomically derived antibiotic resistance indicators. However, BAC filtration or addition of residual disinfectants alone tended to increase these indicators. Biofilm and sediment compartments harbored ARGs in disinfected systems, presenting a concern for their release to bulk water. Relative and absolute abundances of most ARGs tended to decrease with water age (up to 5 days), with notable exceptions in BAC-filtered chloraminated and no residual systems. Superchlorination of unfiltered water especially raised concerns in terms of elevation of clinically relevant and mobile ARGs. This study revealed that BAC filtration and disinfection must be carefully coordinated in order to effectively mitigate ARG dissemination via RWDSs.
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Affiliation(s)
- Ni Joyce Zhu
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Sudeshna Ghosh
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Marc A Edwards
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
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17
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Song Y, Pruden A, Edwards MA, Rhoads WJ. Natural Organic Matter, Orthophosphate, pH, and Growth Phase Can Limit Copper Antimicrobial Efficacy for Legionella in Drinking Water. Environ Sci Technol 2021; 55:1759-1768. [PMID: 33428375 DOI: 10.1021/acs.est.0c06804] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Copper (Cu) is a promising antimicrobial for premise plumbing, where ions can be dosed directly via copper silver ionization or released naturally via corrosion of Cu pipes, but Cu sometimes inhibits and other times stimulates Legionella growth. Our overarching hypothesis was that water chemistry and growth phase control the net effect of Cu on Legionella. The combined effects of pH, phosphate concentration, and natural organic matter (NOM) were comprehensively examined over a range of conditions relevant to drinking water in bench-scale pure culture experiments, illuminating the effects of Cu speciation and precipitation. It was found that cupric ions (Cu2+) were drastically reduced at pH > 7.0 or in the presence of ligand-forming phosphates or NOM. Further, exponential phase L. pneumophila were 2.5× more susceptible to Cu toxicity relative to early stationary phase cultures. While Cu2+ ion was the most effective biocidal form of Cu, other inorganic ligands also had some biocidal impacts. A comparison of 33 large drinking water utilities' field-data from 1990 and 2018 showed that Cu2+ levels likely decreased more dramatically (>10×) than did the total or soluble Cu (2×) over recent decades. The overall findings aid in improving the efficacy of Cu as an actively dosed or passively released antimicrobial against L. pneumophila.
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Affiliation(s)
- Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry Street, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry Street, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry Street, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - William J Rhoads
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry Street, 418 Durham Hall, Blacksburg, Virginia 24061, United States
- Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf 8600, Switzerland
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18
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Abstract
Lead in drinking water remains a significant human health risk. At-home lead in water test kits could provide consumers with a convenient and affordable option to evaluate this risk, but their accuracy and reliability is uncertain. This study examined the ability of at-home lead test kits to detect varying concentrations of dissolved and particulate lead in drinking water. Sixteen brands representing four test kit types (binary color, binary strip, colorimetric vial, and color strip) were identified. Most kits (12 of 16 brands) were not suitable for drinking water analysis, with lead detection limits of 5-20 mg/L. Binary strips detected dissolved lead at drinking water-relevant levels but failed to detect particulate lead. Household acids (lemon juice and vinegar) improved the strip's ability to detect lead by dissolving some of the lead particulates to the point soluble lead exceeded 15 μg/L. These results illustrate the applications of at-home testing kits for drinking water analysis, highlight limitations and areas for possible improvement, and put forth a testing protocol by which new at-home lead test kits can be judged.
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Affiliation(s)
- Rebecca Kriss
- Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Kelsey J Pieper
- Civil and Environmental Engineering, Northeastern University, 467 Snell Engineering Center, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Jeffrey Parks
- Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, Virginia 24061, United States
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19
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Umunna IL, Blacker LS, Hecht CE, Edwards MA, Altman EA, Patel AI. Water Safety in California Public Schools Following Implementation of School Drinking Water Policies. Prev Chronic Dis 2020; 17:E166. [PMID: 33416472 PMCID: PMC7784553 DOI: 10.5888/pcd17.200366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Introduction Recent legislation requires public and charter schools in California to test drinking water for lead. Our objective was to describe 1) results from this testing program in the context of other available water safety data and 2) factors related to schools and water utilities associated with access to safe drinking water in schools. Methods Our study focused on a random sample of 240 California public and charter schools. We used multivariable logistic regression, accounting for clustering of tested water sources in schools, to examine school-level factors associated with failure to meet lead-testing deadlines and any history of water utility noncompliance. Results Of the 240 schools, the majority (n = 174) tested drinking water for lead. Of the schools tested, 3% (n = 6) had at least 1 sample that exceeded 15 parts per billion (ppb) (California action level) and 16% (n = 28) exceeded 5 ppb (bottled water standard). Suburban schools had lower odds of being served by noncompliant water systems (OR = 0.17; CI, 0.05–0.64; P = .009) than city schools. Compared with city schools, rural schools had the highest odds of not participating in the water testing program for lead (OR = 3.43; CI, 1.46–8.05; P = .005). Hallways and common spaces and food services areas were the most frequent school locations tested; one-third of all locations sampled could not be identified. Conclusion In our study, geography influenced access to safe drinking water in schools, including both water utility safety standards and school lead-testing practices. Considerations for improving the implementation of state lead-testing programs include establishing priority locations for sampling, precisely labeling samples, and developing well-defined testing and reporting protocols.
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Affiliation(s)
| | | | - Christina E Hecht
- Nutrition Policy Institute, University of California, Oakland, California
| | | | - Emily A Altman
- University of California, Berkeley School of Public Health, Berkeley, California
| | - Anisha I Patel
- Stanford University. Medical School Office Building, 1265 Welch Rd, Ext 240, Stanford, CA 94305.
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20
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Cullom AC, Martin RL, Song Y, Williams K, Williams A, Pruden A, Edwards MA. Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens. Pathogens 2020; 9:E957. [PMID: 33212943 PMCID: PMC7698398 DOI: 10.3390/pathogens9110957] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/20/2022] Open
Abstract
Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper's interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.
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Affiliation(s)
- Abraham C. Cullom
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Rebekah L. Martin
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
- Civil and Environmental Engineering, Virginia Military Institute, Lexington, VA 24450, USA
| | - Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | | | - Amanda Williams
- c/o Marc Edwards, Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA;
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
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21
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Abstract
Recent water quality crises in the United States, and recognition of the health importance of drinking water in lieu of sugar-sweetened beverages, have raised interest in water safety, access, and consumption. This review uses a socioecological lens to examine these topics across the life course. We review water intakes in the United States relative to requirements, including variation by age and race/ethnicity. We describe US regulations that seek to ensure that drinking water is safe to consume for most Americans and discuss strategies to reduce drinking water exposure to lead, a high-profile regulated drinking water contaminant. We discuss programs, policies, and environmental interventions that foster effective drinking water access, a concept that encompasses key elements needed to improve water intake. We conclude with recommendations for research, policies, regulations, and practices needed to ensure optimal water intake by all in the United States and elsewhere.
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Affiliation(s)
- Anisha I Patel
- Division of General Pediatrics, Stanford University, Palo Alto, California 94305, USA
| | - Christina E Hecht
- Nutrition Policy Institute, Division of Agriculture and Natural Resources, University of California, Berkeley, California 94704, USA;
| | - Angie Cradock
- Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Lorrene D Ritchie
- Nutrition Policy Institute, Division of Agriculture and Natural Resources, University of California, Berkeley, California 94704, USA;
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22
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Martin RL, Harrison K, Proctor CR, Martin A, Williams K, Pruden A, Edwards MA. Chlorine Disinfection of Legionella spp., L. pneumophila, and Acanthamoeba under Warm Water Premise Plumbing Conditions. Microorganisms 2020; 8:E1452. [PMID: 32971988 PMCID: PMC7563980 DOI: 10.3390/microorganisms8091452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/16/2020] [Accepted: 09/19/2020] [Indexed: 11/30/2022] Open
Abstract
Premise plumbing conditions can contribute to low chlorine or chloramine disinfectant residuals and reactions that encourage opportunistic pathogen growth and create risk of Legionnaires' Disease outbreaks. This bench-scale study investigated the growth of Legionella spp. and Acanthamoeba in direct contact with premise plumbing materials-glass-only control, cross-linked polyethylene (PEX) pipe, magnesium anode rods, iron pipe, iron oxide, pH 10, or a combination of factors. Simulated glass water heaters (SGWHs) were colonized by Legionella pneumophila and exposed to a sequence of 0, 0.1, 0.25, and 0.5 mg/L chlorine or chloramine, at two levels of total organic carbon (TOC), over 8 weeks. Legionella pneumophila thrived in the presence of the magnesium anode by itself and or combination with other factors. In most cases, 0.5 mg/L Cl2 caused a significant rapid reduction of L. pneumophila, Legionella spp., or total bacteria (16S rRNA) gene copy numbers, but at higher TOC (>1.0 mg C/L), a chlorine residual of 0.5 mg/L Cl2 was not effective. Notably, Acanthamoeba was not significantly reduced by the 0.5 mg/L chlorine dose.
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Affiliation(s)
- Rebekah L. Martin
- Department of Civil and Environmental Engineering, Virginia Military Institute, Lexington, VA 24450, USA;
| | - Kara Harrison
- Internal Medicine Residency Program, University of Virginia, Charlottesville, VA 22904, USA;
| | - Caitlin R. Proctor
- Department of Environmental and Ecological Engineering, Department of Civil Engineering, Department of Materials Engineering, Department of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA;
| | - Amanda Martin
- Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24450, USA; (A.M.); (K.W.); (A.P.)
| | - Krista Williams
- Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24450, USA; (A.M.); (K.W.); (A.P.)
| | - Amy Pruden
- Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24450, USA; (A.M.); (K.W.); (A.P.)
| | - Marc A. Edwards
- Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24450, USA; (A.M.); (K.W.); (A.P.)
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23
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Spencer MS, Cullom AC, Rhoads WJ, Pruden A, Edwards MA. Replicable simulation of distal hot water premise plumbing using convectively-mixed pipe reactors. PLoS One 2020; 15:e0238385. [PMID: 32936810 PMCID: PMC7494094 DOI: 10.1371/journal.pone.0238385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/14/2020] [Indexed: 11/18/2022] Open
Abstract
A lack of replicable test systems that realistically simulate hot water premise plumbing conditions at the laboratory-scale is an obstacle to identifying key factors that support growth of opportunistic pathogens (OPs) and opportunities to stem disease transmission. Here we developed the convectively-mixed pipe reactor (CMPR) as a simple reproducible system, consisting of off-the-shelf plumbing materials, that self-mixes through natural convective currents and enables testing of multiple, replicated, and realistic premise plumbing conditions in parallel. A 10-week validation study was conducted, comparing three pipe materials (PVC, PVC-copper, and PVC-iron; n = 18 each) to stagnant control pipes without convective mixing (n = 3 each). Replicate CMPRs were found to yield consistent water chemistry as a function of pipe material, with differences becoming less discernable by week 9. Temperature, an overarching factor known to control OP growth, was consistently maintained across all 54 CMPRs, with a coefficient of variation <2%. Dissolved oxygen (DO) remained lower in PVC-iron (1.96 ± 0.29 mg/L) than in PVC (5.71 ± 0.22 mg/L) or PVC-copper (5.90 ± 0.38 mg/L) CMPRs as expected due to corrosion. Further, DO in PVC-iron CMPRs was 33% of that observed in corresponding stagnant pipes (6.03 ± 0.33 mg/L), demonstrating the important role of internal convective mixing in stimulating corrosion and microbiological respiration. 16S rRNA gene amplicon sequencing indicated that both bulk water (Padonis = 0.001, R2 = 0.222, Pbetadis = 0.785) and biofilm (Padonis = 0.001, R2 = 0.119, Pbetadis = 0.827) microbial communities differed between CMPR versus stagnant pipes, consistent with creation of a distinct ecological niche. Overall, CMPRs can provide a more realistic simulation of certain aspects of premise plumbing than reactors commonly applied in prior research, at a fraction of the cost, space, and water demand of large pilot-scale rigs.
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Affiliation(s)
- M. Storme Spencer
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, United States of America
| | - Abraham C. Cullom
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, United States of America
| | - William J. Rhoads
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, United States of America
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, United States of America
| | - Marc A. Edwards
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, United States of America
- * E-mail:
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24
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Mantha A, Tang M, Pieper KJ, Parks JL, Edwards MA. Tracking reduction of water lead levels in two homes during the Flint Federal Emergency. Water Res X 2020; 7:100047. [PMID: 32195459 PMCID: PMC7076093 DOI: 10.1016/j.wroa.2020.100047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/15/2020] [Accepted: 02/20/2020] [Indexed: 06/02/2023]
Abstract
A Federal Emergency was declared in Flint, MI, on January 16, 2016, 18-months after a switch to Flint River source water without phosphate corrosion control. Remedial actions to resolve the corresponding lead in water crisis included reconnection to the original Lake Huron source water with orthophosphate, implementing enhanced corrosion control by dosing extra orthophosphate, a "Flush for Flint" program to help clean out loose leaded sediment from service lines and premise plumbing, and eventually lead service line replacement. Independent sampling over a period of 37 months (January 2016-February 2019) was conducted by the United States Environmental Protection Agency and Virginia Tech to evaluate possible human exposure via normal flow (∼2-3 L/min) sampling at the cold kitchen tap, and to examine the status of loose deposits from the service line and the premise plumbing via high-velocity flushing (∼12-13 L/min) from the hose bib. The sampling results indicated that high lead in water persisted for more than a year in two Flint homes due to a large reservoir of lead deposits. The effects of a large reservoir of loose lead deposits persisted until the lead service line was completely removed in these two anomalous homes. As water conservation efforts are implemented in many areas of the country, problems with mobile lead reservoirs in service lines are likely to pose a human health risk.
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Affiliation(s)
- Anurag Mantha
- Virginia Tech, Charles E. Via, Jr. Department of Civil and Environmental Engineering, 1145 Perry St., 418 Durham Hall, Blacksburg, VA, 24061, United States
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25
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Garner E, Brown CL, Schwake DO, Rhoads WJ, Arango-Argoty G, Zhang L, Jospin G, Coil DA, Eisen JA, Edwards MA, Pruden A. Comparison of Whole-Genome Sequences of Legionella pneumophila in Tap Water and in Clinical Strains, Flint, Michigan, USA, 2016. Emerg Infect Dis 2020; 25:2013-2020. [PMID: 31625848 PMCID: PMC6810188 DOI: 10.3201/eid2511.181032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
During the water crisis in Flint, Michigan, USA (2014-2015), 2 outbreaks of Legionnaires' disease occurred in Genesee County, Michigan. We compared whole-genome sequences of 10 clinical Legionella pneumophila isolates submitted to a laboratory in Genesee County during the second outbreak with 103 water isolates collected the following year. We documented a genetically diverse range of L. pneumophila strains across clinical and water isolates. Isolates belonging to 1 clade (3 clinical isolates, 3 water isolates from a Flint hospital, 1 water isolate from a Flint residence, and the reference Paris strain) had a high degree of similarity (2-1,062 single-nucleotide polymorphisms), all L. pneumophila sequence type 1, serogroup 1. Serogroup 6 isolates belonging to sequence type 2518 were widespread in Flint hospital water samples but bore no resemblance to available clinical isolates. L. pneumophila strains in Flint tap water after the outbreaks were diverse and similar to some disease-causing strains.
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26
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Rhoads WJ, Bradley TN, Mantha A, Buttling L, Keane T, Pruden A, Edwards MA. Residential water heater cleaning and occurrence of Legionella in Flint, MI. Water Res 2020; 171:115439. [PMID: 31940510 DOI: 10.1016/j.watres.2019.115439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/13/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
After the Federal emergency in Flint, MI was declared in early 2016 in response to elevated lead-in-water and incidence of Legionnaires' disease, concerns arose that contaminants in residential water heaters could continue to contribute to poor quality tap water. Here, a comprehensive field survey of residential water heaters (n = 30) and associated water quality was conducted and the subsequent effects of an aggressive manual water heater clean-out was determined, including draining the tank and removing sediments via brushing and flushing. Before cleaning, inorganics accumulated in the tank sediments did not serve as a source of metals measured at hot water outlets. After cleaning, hardness- (calcium, magnesium, silica) and corrosion-associated inorganics (lead, iron, copper, aluminum, zinc) decreased by 64% in samples from sediment cleanout drain valves. Culturable L. pneumophila was only detected in 1 home (3.3%) prior to cleaning and 2 homes (6.7%) after cleaning, thus quantitative polymerase chain reaction was used to quantify potential effects on unculturable strains despite the limitation of differentiating live and dead cells. After the cleaning protocol, Legionella spp. and L. pneumophila gene numbers decreased or remained non-detectable in 83% and 98% of samples, respectively. Homes with less than 0.4 mg/L influent free chlorine tended to have quantifiable Legionella spp. gene numbers in water entering the home and had elevated L. pneumophila and Legionella spp. gene numbers throughout the home plumbing. Also, Legionella spp. and L. pneumophila gene numbers were highest for water heaters set at or below ∼42 °C and significantly decreased >51 °C, consistent with Legionella's preferred temperature range. Examination of the only home that had culturable L. pneumophila both before and after the cleaning protocol revealed that the organism was culturable from several sample locations throughout the home, including in water representative of the water main. Notably, the home was located in close proximity to McLaren Hospital, where an outbreak of Legionnaires disease was reported, and the water heater had a setpoint within the Legionella growth range of 44.2 °C. Considering that other factors were more strongly associated with Legionella occurrence and water heater sediment was not detectably mobilizing to tap water, it was concluded that water heater cleaning had some benefits, but was not an overarching factor contributing to possible human health risks.
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Affiliation(s)
- William J Rhoads
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA.
| | - Taylor N Bradley
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Anurag Mantha
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Lauren Buttling
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Tim Keane
- Legionella Risk Management, Chalfont, PA, USA
| | - Amy Pruden
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Marc A Edwards
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA.
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Edwards MA, Robinson DA, Ren H, Cheyne CG, Tan CS, White HS. Nanoscale electrochemical kinetics & dynamics: the challenges and opportunities of single-entity measurements. Faraday Discuss 2019; 210:9-28. [PMID: 30264833 DOI: 10.1039/c8fd00134k] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The development of nanoscale electrochemistry since the mid-1980s has been predominately coupled with steady-state voltammetric (i-E) methods. This research has been driven by the desire to understand the mechanisms of very fast electrochemical reactions, by electroanalytical measurements in small volumes and unusual media, including in vivo measurements, and by research on correlating electrocatalytic activity, e.g., O2 reduction reaction, with nanoparticle size and structure. Exploration of the behavior of nanoelectrochemical structures (nanoelectrodes, nanoparticles, nanogap cells, etc.) of a characteristic dimension λ using steady-state i-E methods generally relies on the well-known relationship, λ2 ∼ Dt, which relates diffusional lengths to time, t, through the coefficient, D. Decreasing λ, by performing measurements at a nanometric length scales, results in a decrease in the effective timescale of the measurement, and provides a direct means to probe the kinetics of steps associated with very rapid electrochemical reactions. For instance, steady-state voltammetry using a nanogap twin-electrode cell of characteristic width, λ ∼ 10 nm, allows investigations of events occurring at timescales on the order of ∼100 ns. Among many other advantages, decreasing λ also increases spatial resolution in electrochemical imaging, e.g., in scanning electrochemical microscopy, and allows probing of the electric double layer. This Introductory Lecture traces the evolution and driving forces behind the "λ2 ∼ Dt" steady-state approach to nanoscale electrochemistry, beginning in the late 1950s with the introduction of the rotating ring-disk electrode and twin-electrode thin-layer cells, and evolving to current-day investigations using nanoelectrodes, scanning nanocells for imaging, nanopores, and nanoparticles. The recent focus on so-called "single-entity" electrochemistry, in which individual and very short redox events are probed, is a significant departure from the steady-state approach, but provides new opportunities to probe reaction dynamics. The stochastic nature of very fast single-entity events challenges current electrochemical methods and modern electronics, as illustrated using recent experiments from the authors' laboratory.
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Affiliation(s)
- M A Edwards
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, USA.
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28
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Roy S, Tang M, Edwards MA. Lead release to potable water during the Flint, Michigan water crisis as revealed by routine biosolids monitoring data. Water Res 2019; 160:475-483. [PMID: 31177077 DOI: 10.1016/j.watres.2019.05.091] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 05/20/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
Routine biosolids monitoring data provides an independent and comprehensive means to estimate water lead release pre-, during and post-Flint Water Crisis (FWC). The mass of potable plumbing-related metals (i.e., lead, cadmium, copper, nickel and zinc) in sewage biosolids strongly correlated with one another during the FWC (p < 0.05). A simple parametric regression model based on 90th percentile potable water lead measurements (WLL90) from five city-wide citizen science sampling efforts August 2015-August 2017 was strongly correlated to corresponding monthly lead mass in biosolids [Biosolids-Pb (kg) = 0.483 x WLL90 (μg/L) + 1.79; R2 = 0.86, p < 0.05]. Although total biosolids lead increased just 14% during the 18 months of the FWC versus the comparable time pre-FWC, 76% of that increase occurred in July-September 2014, and the corresponding percentage of Flint children under 6 years with elevated blood lead ≥ 5 μg/dL (i.e., %EBL5) doubling from 3.45% to 6.61% in those same three months versus 2013 (p < 0.05). %EBL5 was not statistically higher during the remaining months of the FWC compared to pre-FWC or post-FWC. As expected, lead in biosolids during the FWC, when orthophosphate was not added, was moderately correlated with water temperature (R2 = 0.30, p < 0.05), but not at other times pre- and post-FWC when orthophosphate was present. Tripling the orthophosphate dose post-FWC versus pre-FWC and some lead pipe removal, decreased lead in biosolids (and %EBL5) to historic lows (2016-2017 vs. 2012-2013; p < 0.05), supporting the effectiveness of these public health interventions in reducing childhood water lead exposure.
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Affiliation(s)
- Siddhartha Roy
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA, 24061, USA.
| | - Min Tang
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA, 24061, USA
| | - Marc A Edwards
- Virginia Tech, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, VA, 24061, USA
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Pieper KJ, Katner A, Kriss R, Tang M, Edwards MA. Understanding lead in water and avoidance strategies: a United States perspective for informed decision-making. J Water Health 2019; 17:540-555. [PMID: 31313993 DOI: 10.2166/wh.2019.272] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The pervasiveness of lead in drinking water poses a significant public health threat, which can be reduced by implementing preventive measures. However, the causes of elevated lead in water and the benefits of lead in water avoidance strategies are often misunderstood. Based on experiences in the United States, this paper describes an oversimplified 'lead in water equation' to explain key variables controlling the presence of lead in drinking water to better inform public health practitioners, government officials, utility personnel, and concerned residents. We illustrate the application of the equation in Flint, Michigan and explore the primary household-level water lead avoidance strategies recommended during the crisis, including flushing, filtration, bottled water use, and lead pipe removal. In addition to lead reduction, strategies are evaluated based on costs and limitations. While these lead avoidance strategies will reduce water lead to some degree, the costs, limitations, and effectiveness of these strategies will be site- and event-specific. This paper presents a simplified approach to communicate key factors which must be considered to effectively reduce waterborne lead exposures for a wide range of decision makers.
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Affiliation(s)
- Kelsey J Pieper
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA E-mail: ; † These authors contributed equally to the work
| | - Adrienne Katner
- Department of Environmental and Occupational Health Sciences, Louisiana State University Health Science Center, New Orleans, LA 70112, USA; † These authors contributed equally to the work
| | - Rebecca Kriss
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA E-mail:
| | - Min Tang
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA E-mail:
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA E-mail:
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30
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Garner E, Inyang M, Garvey E, Parks J, Glover C, Grimaldi A, Dickenson E, Sutherland J, Salveson A, Edwards MA, Pruden A. Impact of blending for direct potable reuse on premise plumbing microbial ecology and regrowth of opportunistic pathogens and antibiotic resistant bacteria. Water Res 2019; 151:75-86. [PMID: 30594092 DOI: 10.1016/j.watres.2018.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 11/08/2018] [Accepted: 12/03/2018] [Indexed: 06/09/2023]
Abstract
Little is known about how introducing recycled water intended for direct potable reuse (DPR) into distribution systems and premise plumbing will affect water quality at the point of use, particularly with respect to effects on microbial communities and regrowth. The examination of potential growth of opportunistic pathogens (OPs) and spread of antibiotic resistance genes (ARGs), each representing serious and growing public health concerns, by introducing DPR water has not previously been evaluated. In this study, the impact of blending purified DPR water with traditional drinking water sources was investigated with respect to treatment techniques, blending location, and blending ratio. Water from four U.S. utility partners was treated in bench- and pilot-scale treatment trains to simulate DPR with blending. Water was incubated in simulated premise plumbing rigs made of PVC pipe containing brass coupons to measure regrowth of total bacteria (16S rRNA genes, heterotrophic plate count), OPs (Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa), ARGs (qnrA, vanA), and an indicator of horizontal gene transfer and multi-drug resistance (intI1). The microbial community composition was profiled and the resistome (i.e., all ARGs present) was characterized in select samples using next generation sequencing. While regrowth of total bacteria (16S rRNA genes) from the start of the incubation through week eight consistently occurred across tested scenarios (Wilcoxon, p ≤ 0.0001), total bacteria were not more abundant in the water or biofilm of any DPR scenario than in the corresponding conventional potable condition (p ≥ 0.0748). Regrowth of OP marker genes, qnrA, vanA, and intI1 were not significantly greater in water or biofilm for any DPR blends treated with advanced oxidation compared to corresponding potable water (p ≥ 0.1047). This study of initial bacteria colonizing pipes after introduction of blended DPR water revealed little evidence (i.e., one target in one water type) of exacerbated regrowth of total bacteria, OPs, or ARGs in premise plumbing.
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Affiliation(s)
- Emily Garner
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Mandu Inyang
- Southern Nevada Water Authority, Henderson, NV, 89015, United States; Massachusetts Water Resources Authority, Southborough, MA, 01772, United States
| | - Elisa Garvey
- Carollo Engineers, Inc, Walnut Creek, CA, 94598, United States
| | - Jeffrey Parks
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Caitlin Glover
- Southern Nevada Water Authority, Henderson, NV, 89015, United States
| | | | - Eric Dickenson
- Southern Nevada Water Authority, Henderson, NV, 89015, United States
| | | | - Andrew Salveson
- Carollo Engineers, Inc, Walnut Creek, CA, 94598, United States
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, United States.
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31
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Pieper KJ, Tang M, Jones CN, Weiss S, Greene A, Mohsin H, Parks J, Edwards MA. Impact of Road Salt on Drinking Water Quality and Infrastructure Corrosion in Private Wells. Environ Sci Technol 2018; 52:14078-14087. [PMID: 30407803 DOI: 10.1021/acs.est.8b04709] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Increased road salt use and resulting source water contamination has widespread implications for corrosion of drinking water infrastructure, including chloride acceleration of galvanic corrosion and other premature plumbing failures. In this study, we utilized citizen science sampling, bench-scale corrosion studies, and state-level spatial modeling to examine the potential extent of chloride concentrations in groundwater and the resulting impact on private wells in New York. Across the sampled community, chloride levels varied spatially, with the highest levels in private wells downgradient of a road salt storage facility followed by wells within 30 m of a major roadway. Most well users surveyed (70%) had stopped drinking their well water for aesthetic and safety reasons. In the bench-scale experiment, increasing chloride concentration in water increased galvanic corrosion and dezincification of plumbing materials, resulting in increased metal leaching and pipe wall thinning. Our simple spatial analysis suggests that 2% of private well users in New York could potentially be impacted by road salt storage facilities and 24% could potentially be impacted by road salt application. Our research underscores the need to include the damage to public and privately owned drinking water infrastructure in future discussion of road salt management.
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Affiliation(s)
- Kelsey J Pieper
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Min Tang
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - C Nathan Jones
- The National Socio-Environmental Synthesis Center , University of Maryland , 1 Park Place, Suite 300 , Annapolis , Maryland 21401 , United States
| | - Stephanie Weiss
- Citizen Scientist , Town of Orleans , New York 20558 , United States
| | - Andrew Greene
- Citizen Scientist , Town of Orleans , New York 20558 , United States
| | - Hisyam Mohsin
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Jeffrey Parks
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Marc A Edwards
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
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32
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Dai D, Rhoads WJ, Edwards MA, Pruden A. Shotgun Metagenomics Reveals Taxonomic and Functional Shifts in Hot Water Microbiome Due to Temperature Setting and Stagnation. Front Microbiol 2018; 9:2695. [PMID: 30542327 PMCID: PMC6277882 DOI: 10.3389/fmicb.2018.02695] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 10/23/2018] [Indexed: 12/20/2022] Open
Abstract
Hot water premise plumbing has emerged as a critical nexus of energy, water, and public health. The composition of hot water microbiomes is of special interest given daily human exposure to resident flora, especially opportunistic pathogens (OPs), which rely on complex microbial ecological interactions for their proliferation. Here, we applied shotgun metagenomic sequencing to characterize taxonomic and functional shifts in microbiomes as a function of water heater temperature setting, stagnation in distal pipes, and associated shifts in water chemistry. A cross-section of samples from controlled, replicated, pilot-scale hot water plumbing rigs representing different temperature settings (39, 42, and 51°C), stagnation periods (8 h vs. 7 days), and time-points, were analyzed. Temperature setting exhibited an overarching impact on taxonomic and functional gene composition. Further, distinct taxa were selectively enriched by specific temperature settings (e.g., Legionella at 39°C vs. Deinococcus at 51°C), while relative abundances of genes encoding corresponding cellular functions were highly consistent with expectations based on the taxa driving these shifts. Stagnation in distal taps diminished taxonomic and functional differences induced by heating the cold influent water to hot water in recirculating line. In distal taps relative to recirculating hot water, reads annotated as being involved in metabolism and growth decreased, while annotations corresponding to stress response (e.g., virulence disease and defense, and specifically antibiotic resistance) increased. Reads corresponding to OPs were readily identified by metagenomic analysis, with L. pneumophila reads in particular correlating remarkably well with gene copy numbers measured by quantitative polymerase chain reaction. Positive correlations between L. pneumophila reads and those of known protozoan hosts were also identified. Elevated proportions of genes encoding metal resistance and hydrogen metabolism were noted, which was consistent with elevated corrosion-induced metal concentrations and hydrogen generation. This study provided new insights into real-world factors influencing taxonomic and functional compositions of hot water microbiomes. Here metagenomics is demonstrated as an effective tool for screening for potential presence, and even quantities, of pathogens, while also providing diagnostic capabilities for assessing functional responses of microbiomes to various operational conditions. These findings can aid in informing future monitoring and intentional control of hot water microbiomes.
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Affiliation(s)
| | | | | | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
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33
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Garner E, McLain J, Bowers J, Engelthaler DM, Edwards MA, Pruden A. Microbial Ecology and Water Chemistry Impact Regrowth of Opportunistic Pathogens in Full-Scale Reclaimed Water Distribution Systems. Environ Sci Technol 2018; 52:9056-9068. [PMID: 30040385 DOI: 10.1021/acs.est.8b02818] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Need for global water security has spurred growing interest in wastewater reuse to offset demand for municipal water. While reclaimed (i.e., nonpotable) microbial water quality regulations target fecal indicator bacteria, opportunistic pathogens (OPs), which are subject to regrowth in distribution systems and spread via aerosol inhalation and other noningestion routes, may be more relevant. This study compares the occurrences of five OP gene markers ( Acanthamoeba spp., Legionella spp., Mycobacterium spp., Naegleria fowleri, Pseudomonas aeruginosa) in reclaimed versus potable water distribution systems and characterizes factors potentially contributing to their regrowth. Samples were collected over four sampling events at the point of compliance for water exiting treatment plants and at five points of use at four U.S. utilities bearing both reclaimed and potable water distribution systems. Reclaimed water systems harbored unique water chemistry (e.g., elevated nutrients), microbial community composition, and OP occurrence patterns compared to potable systems examined here and reported in the literature. Legionella spp. genes, Mycobacterium spp. genes, and total bacteria, represented by 16S rRNA genes, were more abundant in reclaimed than potable water distribution system samples ( p ≤ 0.0001). This work suggests that further consideration should be given to managing reclaimed water distribution systems with respect to nonpotable exposures to OPs.
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Affiliation(s)
- Emily Garner
- Via Department of Civil and Environmental Engineering , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Jean McLain
- Water Resources Research Center , University of Arizona , Tucson , Arizona 85719 , United States
| | - Jolene Bowers
- Translational Genomics Research Institute , Flagstaff , Arizona 86005 , United States
| | - David M Engelthaler
- Translational Genomics Research Institute , Flagstaff , Arizona 86005 , United States
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering , Virginia Tech , Blacksburg , Virginia 24061 , United States
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34
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Pieper KJ, Martin R, Tang M, Walters L, Parks J, Roy S, Devine C, Edwards MA. Evaluating Water Lead Levels During the Flint Water Crisis. Environ Sci Technol 2018; 52:8124-8132. [PMID: 29932326 DOI: 10.1021/acs.est.8b00791] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In April 2014, the drinking water source in Flint, Michigan was switched from Lake Huron water with phosphate inhibitors to Flint River water without corrosion inhibitors. The absence of corrosion control and use of a more corrosive source increased lead leaching from plumbing. Our city-wide citizen science water lead results contradicted official claims that there was no problem- our 90th percentile was 26.8 μg/L, which was almost double the Lead and Copper Rule action level of 15 μg/L. Back calculations of a LCR sampling pool with 50% lead pipes indicated an estimated 90th percentile lead value of 31.7 μg/L (±4.3 μg/L). Four subsequent sampling efforts were conducted to track reductions in water lead after the switch back to Lake Huron water and enhanced corrosion control. The incidence of water lead varied by service line material. Between August 2015 and November 2016, median water lead reduced from 3.0 to <1 μg/L for homes with copper service lines, 7.2-1.9 μg/L with galvanized service lines, and 9.9-2.3 μg/L with lead service lines. As of summer 2017, our 90th percentile of 7.9 μg/L no longer differed from official results, which indicated Flint's water lead levels were below the action level.
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Affiliation(s)
- Kelsey J Pieper
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Rebekah Martin
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Min Tang
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - LeeAnne Walters
- Citizen Scientist, 212 Browning Avenue , Flint , Michigan 48507 , United States
| | - Jeffrey Parks
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Siddhartha Roy
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Christina Devine
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
| | - Marc A Edwards
- Civil and Environmental Engineering , Virginia Polytechnic Institute and State University , 418 Durham Hall , Blacksburg , Virginia 24061 , United States
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35
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Garner E, Chen C, Xia K, Bowers J, Engelthaler DM, McLain J, Edwards MA, Pruden A. Metagenomic Characterization of Antibiotic Resistance Genes in Full-Scale Reclaimed Water Distribution Systems and Corresponding Potable Systems. Environ Sci Technol 2018; 52:6113-6125. [PMID: 29741366 DOI: 10.1021/acs.est.7b05419] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Water reclamation provides a valuable resource for meeting nonpotable water demands. However, little is known about the potential for wastewater reuse to disseminate antibiotic resistance genes (ARGs). Here, samples were collected seasonally in 2014-2015 from four U.S. utilities' reclaimed and potable water distribution systems before treatment, after treatment, and at five points of use (POU). Shotgun metagenomic sequencing was used to profile the resistome (i.e., full contingent of ARGs) of a subset ( n = 38) of samples. Four ARGs ( qnrA, blaTEM, vanA, sul1) were quantified by quantitative polymerase chain reaction. Bacterial community composition (via 16S rRNA gene amplicon sequencing), horizontal gene transfer (via quantification of intI1 integrase and plasmid genes), and selection pressure (via detection of metals and antibiotics) were investigated as potential factors governing the presence of ARGs. Certain ARGs were elevated in all ( sul1; p ≤ 0.0011) or some ( blaTEM, qnrA; p ≤ 0.0145) reclaimed POU samples compared to corresponding potable samples. Bacterial community composition was weakly correlated with ARGs (Adonis, R2 = 0.1424-0.1734) and associations were noted between 193 ARGs and plasmid-associated genes. This study establishes that reclaimed water could convey greater abundances of certain ARGs than potable waters and provides observations regarding factors that likely control ARG occurrence in reclaimed water systems.
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Affiliation(s)
- Emily Garner
- Via Department of Civil and Environmental Engineering , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Chaoqi Chen
- Department of Crop and Soil Environmental Sciences , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Kang Xia
- Department of Crop and Soil Environmental Sciences , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Jolene Bowers
- Translational Genomics Research Institute , Flagstaff , Arizona 86005 , United States
| | - David M Engelthaler
- Translational Genomics Research Institute , Flagstaff , Arizona 86005 , United States
| | - Jean McLain
- Water Resources Research Center , University of Arizona , Tucson , Arizona 85719 , United States
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering , Virginia Tech , Blacksburg , Virginia 24061 , United States
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Ji P, Rhoads WJ, Edwards MA, Pruden A. Effect of heat shock on hot water plumbing microbiota and Legionella pneumophila control. Microbiome 2018; 6:30. [PMID: 29426363 PMCID: PMC5807837 DOI: 10.1186/s40168-018-0406-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 01/18/2018] [Indexed: 05/25/2023]
Abstract
BACKGROUND Heat shock is a potential control strategy for Legionella pneumophila in hot water plumbing systems. However, it is not consistently effective, with little understanding of its influence on the broader plumbing microbiome. Here, we employed a lab-scale recirculating hot water plumbing rig to compare the pre- and post-"heat shock" (i.e., 40 → 60 → 40 °C) microbiota at distal taps. In addition, we used a second plumbing rig to represent a well-managed system at 60 °C and conducted a "control" sampling at 60 °C, subsequently reducing the temperature to 40 °C to observe the effects on Legionella and the microbiota under a simulated "thermal disruption" scenario. RESULTS According to 16S rRNA gene amplicon sequencing, in the heat shock scenario, there was no significant difference or statistically significant, but small, difference in the microbial community composition at the distal taps pre- versus post-heat shock (both biofilm and water; weighted and unweighted UniFrac distance matrices). While heat shock did lead to decreased total bacteria numbers at distal taps, it did not measurably alter the richness or evenness of the microbiota. Quantitative PCR measurements demonstrated that L. pneumophila relative abundance at distal taps also was not significantly different at 2-month post-heat shock relative to the pre-heat shock condition, while relative abundance of Vermamoeba vermiformis, a known Legionella host, did increase. In the thermal disruption scenario, relative abundance of planktonic L. pneumophila (quantitative PCR data) increased to levels comparable to those observed in the heat shock scenario within 2 months of switching long-term operation at 60 to 40 °C. Overall, water use frequency and water heater temperature set point exhibited a stronger effect than one-time heat shock on the microbial composition and Legionella levels at distal taps. CONCLUSIONS While heat shock may be effective for instantaneous Legionella control and reduction in total bacteria numbers, water heater temperature set point and water use frequency are more promising factors for long-term Legionella and microbial community control, illustrating the importance of maintaining consistent elevated temperatures in the system relative to short-term heat shock.
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Affiliation(s)
- Pan Ji
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - William J Rhoads
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA.
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Rhoads WJ, Garner E, Ji P, Zhu N, Parks J, Schwake DO, Pruden A, Edwards MA. Distribution System Operational Deficiencies Coincide with Reported Legionnaires' Disease Clusters in Flint, Michigan. Environ Sci Technol 2017; 51:11986-11995. [PMID: 28849909 DOI: 10.1021/acs.est.7b01589] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We hypothesize that the increase in reported Legionnaires' disease from June 2014 to November 2015 in Genesee County, MI (where Flint is located) was directly linked to the switch to corrosive Flint River water from noncorrosive Detroit water from April 2014 to October 2015. To address the lack of epidemiological data linking the drinking water supplies to disease incidence, we gathered physiochemical and biological water quality data from 2010 to 2016 to evaluate characteristics of the Flint River water that were potentially conducive to Legionella growth. The treated Flint River water was 8.6 times more corrosive than Detroit water in short-term testing, releasing more iron, which is a key Legionella nutrient, while also directly causing disinfectant to decay more rapidly. The Flint River water source was also 0.8-6.7 °C warmer in summer months than Detroit water and exceeded the minimum Legionella growth temperature of 20 °C more frequently (average number of days per year for Detroit was 63 versus that for the Flint River, which was 157). The corrosive water also led to 1.3-2.2 times more water main breaks in 2014-2015 compared to 2010-2013; such disruptions have been associated with outbreaks in other locales. Importantly, Legionella spp. and Legionella pneumophila decreased after switching back to Detroit water, in terms of both gene markers and culturability, when August and October 2015 were compared to November 2016.
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Affiliation(s)
- William J Rhoads
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Emily Garner
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Pan Ji
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Ni Zhu
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Jeffrey Parks
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - David Otto Schwake
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech , 418 Durham Hall, Blacksburg, Virginia 24061, United States
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Proctor CR, Dai D, Edwards MA, Pruden A. Interactive effects of temperature, organic carbon, and pipe material on microbiota composition and Legionella pneumophila in hot water plumbing systems. Microbiome 2017; 5:130. [PMID: 28978350 PMCID: PMC5628487 DOI: 10.1186/s40168-017-0348-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/20/2017] [Indexed: 05/22/2023]
Abstract
BACKGROUND Several biotic and abiotic factors have been reported to influence the proliferation of microbes, including Legionella pneumophila, in hot water premise plumbing systems, but their combined effects have not been systematically evaluated. Here, we utilize simulated household water heaters to examine the effects of stepwise increases in temperature (32-53 °C), pipe material (copper vs. cross-linked polyethylene (PEX)), and influent assimilable organic carbon (0-700 μg/L) on opportunistic pathogen gene copy numbers and the microbiota composition, as determined by quantitative polymerase chain reaction and 16S rRNA gene amplicon sequencing. RESULTS Temperature had an overarching influence on both the microbiota composition and L. pneumophila numbers. L. pneumophila peaked at 41 °C in the presence of PEX (1.58 × 105 gene copies/mL). At 53 °C, L. pneumophila was not detected. Several operational taxonomic units (OTUs) persisted across all conditions, accounting for 50% of the microbiota composition from 32 to 49 °C and 20% at 53 °C. Pipe material most strongly influenced microbiota composition at lower temperatures, driven by five to six OTUs enriched with each material. Copper pipes supported less L. pneumophila than PEX pipes (mean 2.5 log10 lower) at temperatures ≤ 41 °C, but showed no difference in total bacterial numbers. Differences between pipe materials diminished with elevated temperature, probably resulting from decreased release of copper ions. At temperatures ≤ 45 °C, influent assimilable organic carbon correlated well with total bacterial numbers, but not with L. pneumophila numbers. At 53 °C, PEX pipes leached organic carbon, reducing the importance of dosed organic carbon. L. pneumophila numbers correlated with a Legionella OTU and a Methylophilus OTU identified by amplicon sequencing. CONCLUSIONS Temperature was the most effective factor for the control of L. pneumophila, while microbiota composition shifted with each stepwise temperature increase. While copper pipe may also help shape the microbiota composition and limit L. pneumophila proliferation, its benefits might be constrained at higher temperatures. Influent assimilable organic carbon affected total bacterial numbers, but had minimal influence on opportunistic pathogen gene numbers or microbiota composition. These findings provide guidance among multiple control measures for the growth of opportunistic pathogens in hot water plumbing and insight into the mediating role of microbial ecological factors.
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Affiliation(s)
- Caitlin R. Proctor
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia, 24061 USA
- EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstr 133, CH-8600 Duebendorf, Switzerland
| | - Dongjuan Dai
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia, 24061 USA
| | - Marc A. Edwards
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia, 24061 USA
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia, 24061 USA
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Allen JM, Cuthbertson AA, Liberatore HK, Kimura SY, Mantha A, Edwards MA, Richardson SD. Showering in Flint, MI: Is there a DBP problem? J Environ Sci (China) 2017; 58:271-284. [PMID: 28774618 DOI: 10.1016/j.jes.2017.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/11/2017] [Indexed: 05/19/2023]
Abstract
Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detroit water (Lake Huron) with corrosion control, to Flint River water without corrosion control. Although lead levels are now closer to normal, reports of skin rashes have sparked questions surrounding tap water in some Flint homes. This study investigated the presence of contaminants, including disinfection by-products (DBPs), in the hot tap water used for showering in the homes of residents in Flint. Extensive quantitative analysis of 61 regulated and priority unregulated DBPs was conducted in Flint hot and cold tap water, along with the analysis of 50 volatile organic compounds and a nontarget comprehensive, broadscreen analysis, to identify a possible source for the reported skin rashes. For comparison, chlorinated hot and cold waters from three other cities were also sampled, including Detroit, which also uses Lake Huron as its source water. Results showed that hot water samples generally contained elevated levels of regulated and priority unregulated DBPs compared to cold water samples, but trihalomethanes were still within regulatory limits. Overall, hot shower water from Flint was similar to waters sampled from the three other cities and did not have unusually high levels of DBPs or other organic chemicals that could be responsible for the skin rashes observed by residents. It is possible that an inorganic chemical or microbial contaminant may be responsible.
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Affiliation(s)
- Joshua M Allen
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Amy A Cuthbertson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Hannah K Liberatore
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Susana Y Kimura
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Anurag Mantha
- Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Marc A Edwards
- Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Susan D Richardson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA.
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Wang F, Devine CL, Edwards MA. Effect of Corrosion Inhibitors on In Situ Leak Repair by Precipitation of Calcium Carbonate in Potable Water Pipelines. Environ Sci Technol 2017; 51:8561-8568. [PMID: 28661668 DOI: 10.1021/acs.est.7b01380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Corrosion inhibitors can affect calcium carbonate precipitation and associated in situ and in-service water distribution pipeline leak repair via clogging. Clogging of 150 μm diameter leak holes represented by glass capillary tubes, in recirculating solutions that are supersaturated with calcite (Ωcalcite = 13), demonstrated that Zn, orthophosphate, tripolyphosphate, and hexametaphosphate corrosion/scaling inhibitors hinder clogging but natural organic matter (NOM) has relatively little impact. Critical concentrations of phosphates that could inhibit leak repair over the short-term in one water tested were: tripolyphophate (0.05 mg/L as P) < hexametaphosphate (0.1 mg/L) < orthophosphate (0.3 mg/L). Inhibitor blends (Zn+orthophosphate and Zn+NOM+orthophosphate) had stronger inhibitory effects compared to each inhibitor (Zn, orthophosphate or NOM) alone, whereas Zn+NOM showed a lesser inhibitory effect than its individual component (NOM) alone due to formation of smaller CaCO3 particles with a much more negative zeta-potential. Overall, increased dosing of corrosion inhibitors is probably reducing the likelihood of scaling and in-service leak repair via clogging with calcium carbonate solids in potable water systems.
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Affiliation(s)
- Fei Wang
- The Charles E. Via, Jr. Department of Civil & Environmental Engineering, Virginia Tech Blacksburg, Virginia 24061, United States
| | - Christina L Devine
- The Charles E. Via, Jr. Department of Civil & Environmental Engineering, Virginia Tech Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- The Charles E. Via, Jr. Department of Civil & Environmental Engineering, Virginia Tech Blacksburg, Virginia 24061, United States
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41
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Dai D, Prussin AJ, Marr LC, Vikesland PJ, Edwards MA, Pruden A. Factors Shaping the Human Exposome in the Built Environment: Opportunities for Engineering Control. Environ Sci Technol 2017; 51:7759-7774. [PMID: 28677960 DOI: 10.1021/acs.est.7b01097] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The "exposome" is a term describing the summation of one's lifetime exposure to microbes and chemicals. Such exposures are now recognized as major drivers of human health and disease. Because humans spend ∼90% of their time indoors, the built environment exposome merits particular attention. Herein we utilize an engineering perspective to advance understanding of the factors that shape the built environment exposome and its influence on human wellness and disease, while simultaneously informing development of a framework for intentionally controlling the exposome to protect public health. Historically, engineers have been focused on controlling chemical and physical contaminants and on eradicating microbes; however, there is a growing awareness of the role of "beneficial" microbes. Here we consider the potential to selectively control the materials and chemistry of the built environment to positively influence the microbial and chemical components of the indoor exposome. Finally, we discuss research gaps that must be addressed to enable intentional engineering design, including the need to define a "healthy" built environment exposome and how to control it.
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Affiliation(s)
- Dongjuan Dai
- Via Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg Virginia 24061, United States
| | - Aaron J Prussin
- Via Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg Virginia 24061, United States
| | - Linsey C Marr
- Via Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg Virginia 24061, United States
| | - Peter J Vikesland
- Via Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg Virginia 24061, United States
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg Virginia 24061, United States
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg Virginia 24061, United States
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Rhoads WJ, Pruden A, Edwards MA. Interactive Effects of Corrosion, Copper, and Chloramines on Legionella and Mycobacteria in Hot Water Plumbing. Environ Sci Technol 2017; 51:7065-7075. [PMID: 28513143 DOI: 10.1021/acs.est.6b05616] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Complexities associated with drinking water plumbing systems can result in undesirable interactions among plumbing components that undermine engineering controls for opportunistic pathogens (OPs). In this study, we examine the effects of plumbing system materials and two commonly applied disinfectants, copper and chloramines, on water chemistry and the growth of Legionella and mycobacteria across a transect of bench- and pilot-scale hot water experiments carried out with the same municipal water supply. We discovered that copper released from corrosion of plumbing materials can initiate evolution of >1100 times more hydrogen (H2) from water heater sacrificial anode rods than does presence of copper dosed as soluble cupric ions. H2 is a favorable electron donor for autotrophs and causes fixation of organic carbon that could serve as a nutrient for OPs. Dosed cupric ions acted as a disinfectant in stratified stagnant pipes, inhibiting culturable Legionella and biofilm formation, but promoted Legionella growth in pipes subject to convective mixing. This difference was presumably due to continuous delivery of nutrients to biofilm on the pipes under convective mixing conditions. Chloramines eliminated culturable Legionella and prevented L. pneumophila from recolonizing biofilms, but M. avium gene numbers increased by 0.14-0.76 logs in the bulk water and were unaffected in the biofilm. This study provides practical confirmation of past discrepancies in the literature regarding the variable effects of copper on Legionella growth, and confirms prior reports of trade-offs between Legionella and mycobacteria if chloramines are applied as secondary disinfectant residual.
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Affiliation(s)
- William J Rhoads
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , 418 Durham Hall, Blacksburg, Virginia 24061, United States
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Pieper KJ, Tang M, Edwards MA. Flint Water Crisis Caused By Interrupted Corrosion Control: Investigating "Ground Zero" Home. Environ Sci Technol 2017; 51:2007-2014. [PMID: 28145123 DOI: 10.1021/acs.est.6b04034] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Flint, Michigan switched to the Flint River as a temporary drinking water source without implementing corrosion control in April 2014. Ten months later, water samples collected from a Flint residence revealed progressively rising water lead levels (104, 397, and 707 μg/L) coinciding with increasing water discoloration. An intensive follow-up monitoring event at this home investigated patterns of lead release by flow rate-all water samples contained lead above 15 μg/L and several exceeded hazardous waste levels (>5000 μg/L). Forensic evaluation of exhumed service line pipes compared to water contamination "fingerprint" analysis of trace elements, revealed that the immediate cause of the high water lead levels was the destabilization of lead-bearing corrosion rust layers that accumulated over decades on a galvanized iron pipe downstream of a lead pipe. After analysis of blood lead data revealed spiking lead in blood of Flint children in September 2015, a state of emergency was declared and public health interventions (distribution of filters and bottled water) likely averted an even worse exposure event due to rising water lead levels.
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Affiliation(s)
- Kelsey J Pieper
- Virginia Tech , Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Min Tang
- Virginia Tech , Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Marc A Edwards
- Virginia Tech , Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
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44
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Buse HY, Ji P, Gomez-Alvarez V, Pruden A, Edwards MA, Ashbolt NJ. Effect of temperature and colonization of Legionella pneumophila and Vermamoeba vermiformis on bacterial community composition of copper drinking water biofilms. Microb Biotechnol 2017; 10:773-788. [PMID: 28097816 PMCID: PMC5481522 DOI: 10.1111/1751-7915.12457] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 10/04/2016] [Accepted: 10/22/2016] [Indexed: 11/28/2022] Open
Abstract
It is unclear how the water‐based pathogen, Legionella pneumophila (Lp), and associated free‐living amoeba (FLA) hosts change or are changed by the microbial composition of drinking water (DW) biofilm communities. Thus, this study characterized the bacterial community structure over a 7‐month period within mature (> 600‐day‐old) copper DW biofilms in reactors simulating premise plumbing and assessed the impact of temperature and introduction of Lp and its FLA host, Vermamoeba vermiformis (Vv), co‐cultures (LpVv). Sequence and quantitative PCR (qPCR) analyses indicated a correlation between LpVv introduction and increases in Legionella spp. levels at room temperature (RT), while at 37°C, Lp became the dominant Legionella spp. qPCR analysis suggested Vv presence may not be directly associated with Lp biofilm growth at RT and 37°C, but may contribute to or be associated with non‐Lp legionellae persistence at RT. Two‐way PERMANOVA and PCoA revealed that temperature was a major driver of microbiome diversity. Biofilm community composition also changed over the seven‐month period and could be associated with significant shifts in dissolved oxygen, alkalinity and various metals in the influent DW. Hence, temperature, biofilm age, DW quality and transient intrusions/amplification of pathogens and FLA hosts may significantly impact biofilm microbiomes and modulate pathogen levels over extended periods.
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Affiliation(s)
- Helen Y Buse
- Pegasus Technical Services, Inc c/o US EPA, 26 W Martin Luther King Drive NG-16, Cincinnati, OH, 45268, USA
| | - Pan Ji
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Vicente Gomez-Alvarez
- Pegasus Technical Services, Inc c/o US EPA, 26 W Martin Luther King Drive NG-16, Cincinnati, OH, 45268, USA
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta, Edmonton, AB T6G 2G7, Canada
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Edwards MA, Roy S. Academic Research in the 21st Century: Maintaining Scientific Integrity in a Climate of Perverse Incentives and Hypercompetition. Environ Eng Sci 2017; 34:51-61. [PMID: 28115824 PMCID: PMC5206685 DOI: 10.1089/ees.2016.0223] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/18/2016] [Indexed: 05/10/2023]
Abstract
Over the last 50 years, we argue that incentives for academic scientists have become increasingly perverse in terms of competition for research funding, development of quantitative metrics to measure performance, and a changing business model for higher education itself. Furthermore, decreased discretionary funding at the federal and state level is creating a hypercompetitive environment between government agencies (e.g., EPA, NIH, CDC), for scientists in these agencies, and for academics seeking funding from all sources-the combination of perverse incentives and decreased funding increases pressures that can lead to unethical behavior. If a critical mass of scientists become untrustworthy, a tipping point is possible in which the scientific enterprise itself becomes inherently corrupt and public trust is lost, risking a new dark age with devastating consequences to humanity. Academia and federal agencies should better support science as a public good, and incentivize altruistic and ethical outcomes, while de-emphasizing output.
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Affiliation(s)
- Marc A. Edwards
- Corresponding author: Department of Civil and Environmental Engineering, Virginia Tech, 407 Durham Hall, 1145 Perry Street, Blacksburg, VA 24061. Phone: (540) 231-7236; Fax: (540) 231-7532; E-mail:
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46
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Randhawa H, Edwards MA, Cantle F. WHO ARE OUR ‘CODE-RED’ KIDS? – A URBAN MAJOR TRAUMA CENTRE'S EXPERIENCE OF MAJOR HAEMORRHAGE IN INJURED CHILDREN. Arch Emerg Med 2016. [DOI: 10.1136/emermed-2016-206402.66] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Edwards MA, Pruden A. We Helped Flint Residents Save Themselves and Are Proud of It-Staying in Our Ivory Tower Would Have Perpetuated Injustice. Environ Sci Technol 2016; 50:12057. [PMID: 27934236 DOI: 10.1021/acs.est.6b05347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States
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48
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Edwards MA, Pruden A. The Flint Water Crisis: Overturning the Research Paradigm to Advance Science and Defend Public Welfare. Environ Sci Technol 2016; 50:8935-8936. [PMID: 27532691 DOI: 10.1021/acs.est.6b03573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Marc A Edwards
- Department of Civil and Environmental Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States
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Abstract
Microiontophoresis is a drug delivery method in which an electric current is used to eject molecular species from a micropipette. It has been primarily utilized for neurochemical investigations, but is limited due to difficulty controlling and determining the ejected quantity. Consequently the concentration of an ejected species and the extent of the affected region are relegated to various methods of approximation. To address this, we investigated the principles underlying ejection rates and examined the concentration distribution in microiontophoresis using a combination of electrochemical, chromatographic, and fluorescence-based approaches. This involved a principal focus on how the iontophoretic barrel solution affects ejection characteristics. The ion ejection rate displayed a direct correspondence to the ionic mole fraction, regardless of the ejection current polarity. In contrast, neutral molecules are ejected by electroosmotic flow (EOF) at a rate proportional to the barrel solution concentration. Furthermore, the presence of EOF was observed from barrels containing high ionic strength solutions. In practice, use of a retaining current draws extracellular ions into the barrel and will alter the barrel solution composition. Even in the absence of a retaining current, diffusional exchange at the barrel tip will occur. Thus behavior of successive ejections may slightly differ. To account for this, electrochemical or fluorescence markers can be incorporated into the barrel solution in order to compare ejection quantities. These may also be used to provide an estimate of the ejected amount and distribution provided accurate use of calibration procedures.
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Affiliation(s)
- D C Kirkpatrick
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA.
| | - L R Walton
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA.
| | - M A Edwards
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA.
| | - R M Wightman
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA. and Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA
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50
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Rhoads WJ, Pruden A, Edwards MA. Convective Mixing in Distal Pipes Exacerbates Legionella pneumophila Growth in Hot Water Plumbing. Pathogens 2016; 5:E29. [PMID: 26985908 PMCID: PMC4810150 DOI: 10.3390/pathogens5010029] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/15/2016] [Accepted: 03/01/2016] [Indexed: 11/17/2022] Open
Abstract
Legionella pneumophila is known to proliferate in hot water plumbing systems, but little is known about the specific physicochemical factors that contribute to its regrowth. Here, L. pneumophila trends were examined in controlled, replicated pilot-scale hot water systems with continuous recirculation lines subject to two water heater settings (40 °C and 58 °C) and three distal tap water use frequencies (high, medium, and low) with two pipe configurations (oriented upward to promote convective mixing with the recirculating line and downward to prevent it). Water heater temperature setting determined where L. pneumophila regrowth occurred in each system, with an increase of up to 4.4 log gene copies/mL in the 40 °C system tank and recirculating line relative to influent water compared to only 2.5 log gene copies/mL regrowth in the 58 °C system. Distal pipes without convective mixing cooled to room temperature (23-24 °C) during periods of no water use, but pipes with convective mixing equilibrated to 30.5 °C in the 40 °C system and 38.8 °C in the 58 °C system. Corresponding with known temperature effects on L. pneumophila growth and enhanced delivery of nutrients, distal pipes with convective mixing had on average 0.2 log more gene copies/mL in the 40 °C system and 0.8 log more gene copies/mL in the 58 °C system. Importantly, this work demonstrated the potential for thermal control strategies to be undermined by distal taps in general, and convective mixing in particular.
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Affiliation(s)
- William J Rhoads
- Via Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 401 Durham Hall, Blacksburg, VA 24061, USA.
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 401 Durham Hall, Blacksburg, VA 24061, USA.
| | - Marc A Edwards
- Via Department of Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 401 Durham Hall, Blacksburg, VA 24061, USA.
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