Land application of treated sewage sludge: community health and environmental justice

Odorous emissions of synthetic turf and its relationship with local communities

Synthetic turf has been a mainstay of field sports and local communities for decades, and in that time, has faced both community and government pressure to ensure its safety and fitness for purpose. Considerable research and regulations have been applied to synthetic turf with regards to its safety, construction, potential toxicity, sports impact, as well as environmental considerations. However, very little attention has been paid to reports of odorous impacts from synthetic turf fields. This is problematic as odours are both a source of most complaints by communities towards other industries, as well as the fact that synthetic turf has a unique placement within communities themselves. It is wholly possible that the concerns surrounding synthetic turf are being modulated by the odours that the fields themselves produce through previously identified psychological mechanisms. As a result, ensuring good standards for synthetic turf with regards to odorous emissions should be benchmarked for community acceptability. This review investigates prior research into synthetic turf with regards to identified volatile organic compounds emitted, as well as proposing the means by which community stakeholders engage with synthetic turf, as well as how they should be consulted. From here, this review provides trajectories for future research within this space, and how regulatory bodies should address potential issues. This research space is currently in its infancy and therefore information relating to synthetic turf odour factors must be carefully considered.

Occurrence and Prioritization of Human Androgen Receptor Disruptors in Sewage Sludges Across China

The global practice of reusing sewage sludge in agriculture and its landfill disposal reintroduces environmental contaminants, posing risks to human and ecological health. This study screened sewage sludge from 30 Chinese cities for androgen receptor (AR) disruptors, utilizing a disruptor list from the Toxicology in the 21st Century program (Tox21), and identified 25 agonists and 33 antagonists across diverse use categories. Predominantly, natural products 5α-dihydrotestosterone and thymidine emerged as agonists, whereas the industrial intermediate caprolactam was the principal antagonist. In-house bioassays for identified disruptors displayed good alignment with Tox21 potency data, validating employing Tox21 toxicity data for theoretical toxicity estimations. Potency calculations revealed 5α-dihydrotestosterone and two pharmaceuticals (17β-trenbolone and testosterone isocaproate) as the most potent AR agonists and three dyes (rhodamine 6G, Victoria blue BO, and gentian violet) as antagonists. Theoretical effect contribution evaluations prioritized 5α-dihydrotestosterone and testosterone isocaproate as high-risk AR agonists and caprolactam, rhodamine 6G, and 8-hydroxyquinoline (as a biocide and a preservative) as key antagonists. Notably, 16 agonists and 20 antagonists were newly reported in the sludge, many exhibiting significant detection frequencies, concentrations, and/or toxicities, demanding future scrutiny. Our study presents an efficient strategy for estimating environmental sample toxicity and identifying key toxicants, thereby supporting the development of appropriate sludge management strategies.

Residents' experiences during a hydrogen sulfide crisis in Carson, California

BACKGROUND

In early October 2021, thousands of residents in Carson, California began complaining of malodors and headaches. Hydrogen sulfide (H2S), a noxious odorous gas, was measured at concentrations up to 7000 parts per billion (ppb) and remained above California's acute air quality standard of 30 ppb for a month. Intermittent elevations of H2S continued for 3 months. After 2 months of malodor in this environmental justice community, a government agency attributed the H2S to environmental pollution from a warehouse fire. Research has yielded conflicting results on the health effects of H2S exposure at levels that were experienced during this event. This research fills a critical need for understanding how people perceive and experience emergent environmental health events and will help shape future responses.

METHODS

Through a community-academic partnership, we conducted 6 focus groups with 33 participants who resided in the Carson area during the crisis. We sought to understand how this incident affected residents through facilitated discussion on topics including information acquisition, impressions of the emergency response, health symptoms, and ongoing impacts.

RESULTS

The majority of participants were women (n = 25), identified as Latina/o (n = 19), and rent their homes (n = 21). Participants described difficulty obtaining coherent information about the emergency, which resulted in feelings of abandonment. Most participants felt that local government and healthcare providers downplayed and/or disregarded their concerns despite ongoing odors and health symptoms. Participants described experiencing stress from the odors' unknown health effects and continued fear of future odor incidents. Residents sought to take control of the crisis through information sharing, community networking, and activism. Participants experienced longer term effects from this event, including increased awareness of pollution and reduced trust in local agencies.

DISCUSSION

This study demonstrates the necessity of clear, comprehensive, and prompt responses by relevant decisionmakers to chemical emergencies to appropriately address residents' fears, curb the spread of misinformation, and minimize adverse health effects. Participant responses also point to the benefit of supporting horizontal community networks for improved information sharing. By engaging directly with community members, researchers and disaster responders can better understand the various and complex impacts of chemical disasters and can improve response.

Residents' experiences during a hydrogen sulfide crisis in Carson, California

Background

In early October 2021, thousands of residents in Carson, California began complaining of malodors and headaches. The odor was identified as hydrogen sulfide (H2S), a noxious odorous gas. H2S was measured at concentrations up to 7000 parts per billion (ppb) and remained above California's acute air quality standard of 30 ppb for a month, with intermittent elevations continuing for 3 months. After 2 months of malodor in this environmental justice community, the H2S was attributed to a warehouse fire. Research has yielded conflicting results on the health effects of H2S exposure at levels that were experienced during this event. There remains a gap in understanding how people perceive and experience odor emergencies such as this H2S event.

Methods

Through a community-academic partnership, we conducted 6 focus groups in Carson with 33 participants who resided in the Carson area during the crisis. We sought to understand how this incident affected residents through facilitated discussion on topics including information acquisition, impressions of the emergency response, physical and mental health symptoms, and ongoing impacts.

Results

The majority of participants were women (n = 25), identified as Latina/o (n = 19), and rent their homes (n = 21). Participants described difficulty obtaining coherent information about the emergency, which resulted in feelings of abandonment. Most participants felt that local government and health care providers downplayed and/or disregarded their concerns despite ongoing odors and health symptoms. Participants described experiencing stress from the odors' unknown health effects and continued fear of future odor incidents. Residents sought to take control of the crisis through information sharing, community networking, and activism. Participants experienced longer term effects from this event, including increased awareness of pollution and reduced trust in local agencies.

Discussion

This study demonstrates the necessity of clear, comprehensive, and prompt responses by relevant decisionmakers to chemical emergencies to appropriately address residents' fears, curb the spread of misinformation, and minimize adverse health effects. Participant responses also point to the benefit of supporting horizontal community networks for improved information sharing. By engaging directly with community members, researchers and disaster responders can better understand the various and complex impacts of chemical disasters and can improve response.

Identifying sources of antibiotic resistance genes in the environment using the microbial Find, Inform, and Test framework

Introduction

Antimicrobial resistance (AMR) is an increasing public health concern for humans, animals, and the environment. However, the contributions of spatially distributed sources of AMR in the environment are not well defined.

Methods

To identify the sources of environmental AMR, the novel microbial Find, Inform, and Test (FIT) model was applied to a panel of five antibiotic resistance-associated genes (ARGs), namely, erm(B), tet(W), qnrA, sul1, and intI1, quantified from riverbed sediment and surface water from a mixed-use region.

Results

A one standard deviation increase in the modeled contributions of elevated AMR from bovine sources or land-applied waste sources [land application of biosolids, sludge, and industrial wastewater (i.e., food processing) and domestic (i.e., municipal and septage)] was associated with 34-80% and 33-77% increases in the relative abundances of the ARGs in riverbed sediment and surface water, respectively. Sources influenced environmental AMR at overland distances of up to 13 km.

Discussion

Our study corroborates previous evidence of offsite migration of microbial pollution from bovine sources and newly suggests offsite migration from land-applied waste. With FIT, we estimated the distance-based influence range overland and downstream around sources to model the impact these sources may have on AMR at unsampled sites. This modeling supports targeted monitoring of AMR from sources for future exposure and risk mitigation efforts.

Social environment characteristics are related to self-rated health in four Latin America countries: Evidence from the SALURBAL Project

We investigated the associations of social and built environment and demographic features of urban areas with self-rated health among adults living in four Latin American countries. We estimated multilevel models with harmonized data from 69,840 adults, nested in 262 sub-cities and 112 cities, obtained from the Salud Urbana en América Latina project. Poor self-rated health was inversely associated with services provision score at the sub-city-level and with social environment index at the city-level. We did not identify associations of built environment and demographic features with self-rated health. Approaches and policies to improve health in Latin American should be urban context-sensitive.

Modeling and Analysis of Air Pollution and Environmental Justice: The Case for North Carolina's Hog Concentrated Animal Feeding Operations

BACKGROUND

Concentrated animal feeding operations (CAFOs) emit pollutants that can cause negative impacts on human health. The concentration of hog production in North Carolina raises concerns regarding the disproportionate exposure of vulnerable communities to air pollution from CAFOs.

OBJECTIVES

We investigated whether exposure to gaseous ammonia (NH 3 ) and hydrogen sulfide (H 2 S ) (in 2019) differs between subpopulations by examining demographics, including race/ethnicity, age, educational attainment, language proficiency, and socioeconomic status.

METHODS

We used an Air Monitoring Station (AMS)/Environmental Protection Agency (EPA) Regulatory Model (AERMOD)-based Human Exposure Model (version 3) to estimate ambient concentrations of NH 3 and H 2 S from hog farms in Duplin County and its surrounding counties in North Carolina and estimate subsequent exposures of communities within 50 km of Duplin County, North Carolina, or the Duplin County Region. We combined estimated exposures with 2016 American Community Summary Census data, at the block group level, using spatial analysis to investigate whether exposures to these pollutants differ by race and ethnicity, age, income, education, and language proficiency. Based on these estimations, we assessed associated exposure risks to the impacted communities and used multivariable regression modeling to evaluate the relationship between average ammonia exposures from Duplin regional hog farms and the presence of vulnerable populations.

RESULTS

The average [± standard deviation  ( SD ) ] annual estimated concentration of NH 3 and H 2 S in the Duplin County Region is 1.75 ± 2.81   μ g / m 3 and 0.0087 ± 0.014   μ g / m 3 , respectively. The maximum average annual ambient concentrations are estimated at 54.27 ± 4.12   μ g / m 3 and 0.54 ± 0.041   μ g / m 3 for NH 3 and H 2 S , respectively. Our descriptive analysis reveals that people of low income, people of color, people with low educational attainment, and the linguistically isolated in the Duplin Region are disproportionately exposed to higher levels of pollutants than the average exposure for residents. Alternatively, our statistical results suggests that after adjusting for covariates, communities of color are associated with 1.70% (95% CI: - 3.79 , 0.44) lower NH 3 concentrations per 1-SD increase. One-standard deviation increases in the adults with low educational attainment and children < 19 years of age is associated with 1.26% (95% CI: - 0.77 , 3.33) and 1.20% (95% CI: - 0.62 , 3.05) higher NH 3 exposure per 1-SD increase, respectively.

DISCUSSION

Exposures to NH 3 and H 2 S differed by race and ethnicity, educational attainment, language proficiency, and socioeconomic status. The observed associations between exposure to CAFO-generated pollutants and sociodemographic indicators differed among demographics. The disproportionate distribution of hog facilities and resulting pollutant exposures among communities may have adverse environmental and human health impacts, raising environmental justice concerns. https://doi.org/10.1289/EHP11344.

Method for analysis of environmental lead contamination in soils

A method for lead (Pb) detection in soil is presented. Pb is a dangerous environmental pollutant that is present in soils, posing a health risk to millions of people worldwide, and regular monitoring of Pb contamination in soils is essential to public health. Many sensitive methods for detection of heavy metals in solid matrices exist, but they cannot be performed on-site because they are costly (>$30 per sample), require trained personnel, and many classical sample preparation methods are not safe to bring into the field. We describe an alternative process, combining a safer sample preparation method with electrochemical analysis. The process requires minimal training, making it an attractive overall method for regular environmental screening of Pb in soils. Extract obtained from the soil is pH adjusted and analyzed using a stencil-printed carbon electrode and square wave anodic stripping voltammetry. In this work, a study of 15 neighborhood soils examining the concentration of Pb present post-extraction was performed to demonstrate the method. The limit of detection for the electrochemical analysis was calculated to be 16 ppb-well below the United States Environmental Protection Agency's action limit for Pb in soils (400 mg kg^-1 or 4000 ppb)-and third party inductively coupled plasma-optical emission spectroscopy analysis validated the results obtained in this study to within ±17% on average.

Evaluating the biomethane potential from the anaerobic co-digestion of palm oil mill effluent, food waste, and sewage sludge in Malaysia

The ever-increasing organic waste generation in Malaysia is a significant contributor to greenhouse gas (GHG) emissions. However, organic wastes can be utilized to produce biogas by anaerobic digestion, which is a promising option for both energy and material recovery from organic wastes with high moisture content. Therefore, this study was formulated to investigate the feasibility of anaerobic co-digestion of three types of organic wastes generated in significantly huge quantities in Malaysia, namely palm oil mill effluent (POME), food waste (FW), and sewage sludge (SWS). The biomethane potential (BMP) test was used to evaluate the biomethane potential from these organic wastes under mesophilic conditions to establish a stable and balanced microbial community, which may lack in mono-digestion, to improve biogas production. Comparative performance was made at different food to microorganism (F/M) ratios to investigate methane production in three groups of assays, namely A, B, and C. In groups A and B, the effect of F/M ratio variation on methane production was investigated, while in group C, the effect of varying the co-substrate mixture on methane yield was examined. The findings showed that the highest methane yields achieved for mono-digestion of POME and SWS in group A were 164.44 mL-CH₄/g-COD_added and 65.34 mL-CH₄/g-COD_added, respectively, at an F/M ratio of 0.8 and 197.90 mL-CH₄/g-COD_added for FW in group B at an F/M ratio of 0.5. In addition, the highest methane yield achieved from the anaerobic co-digestion was at 151.47 mL-CH₄/g-COD_added from the co-digestion of the POME and SWS (50:50) at an F/M ratio of 1.7 in group A. Both AD and AcoD were tested to fit into two kinetic models: the modified Gompertz and the transfer function models. The results showed that the modified Gompertz model had a better fit and was more adjusted to the experimental results for both AD and AcoD. The importance of this research lies in the economics of anaerobically co-digesting these abundance feedstocks and the variations in their characteristics which were found to increase their methane yield and process efficiency in anaerobic co-digestion.

The relative effects of self-reported noise and odour annoyance on psychological distress: Different effects across sociodemographic groups?

In earlier research, both higher levels of noise and odour annoyance have been associated with decreased mental health. Presumably, these perceptions can trigger feelings of threat and stress reactions and in turn evoke psychological distress. There are two important lacunas in the research on this topic: most studies only consider either noise or odour annoyance and not their relative effect on psychological distress and there is scarce evidence about whether different sociodemographic groups experience more psychological distress due to noise and odour annoyance. Starting from the diversity in the available coping resources and in their daily life patterns, we distinguish gender, age and educational level as relevant sociodemographic variables. Using data from the Health Monitor (n = 25236) in Noord-Brabant, we found using Ordinary Least Squares Regression that individuals that reported higher levels of noise and odour annoyance reported higher levels of psychological distress. Furthermore, the effect of noise annoyance was relatively stronger compared to that of odour annoyance. Regarding the interaction effects, we found that younger adults’ psychological distress was more strongly affected by noise annoyance compared to older adults, but not by odour annoyance. The psychological distress of individuals with no or primary education was more strongly affected by both noise and odour annoyance compared those with tertiary education, but not when compared to those who completed lower or higher secondary education. Contrary to our expectations, we did not find different effects between men and women. Though the evidence for the interactions was mixed, classic health inequalities along age and education lines are reinforced when considering the relationship between noise and odour annoyance and psychological distress.

Invisible and unequal: Unincorporated community status as a structural determinant of health

Despite increasing awareness of the importance of political determinants of health, place-based research has not interrogated one of the most common political statuses: the impact of living in a community without municipal incorporation. In 2010 an estimated 37% of the U.S. population lived in an unincorporated area; despite their ubiquity, unincorporated communities are largely absent from the public health literature. Residents of unincorporated areas typically do not have their own local (e.g., city or municipal) government. This lack of representation leads to political exclusion and diminished access to resources, especially for low-income communities of color, Furthermore, by not disaggregating health data to unincorporated communities, residents are subsumed into county or census tract data that may not be reflective of their community's composition or context. Without jurisdictional distinction in research, there is no accountability for the manufacturing of health inequities in unincorporated communities . In the absence of empirical research on unincorporated communities, this paper uses the Commission on Social Determinants of Health (CSDH) Framework of the World Health Organization to argue that lack of municipal status is a structural determinant of health responsible for social conditions which generate cumulative health risks for residents. This includes using existing evidence on social conditions typical of unincorporated communities to describe patterns of residential segregation, neighborhood disadvantage, and environmental hazards that may increase residents' exposure to unhealthy environments in unincorporated communities. Finally, we provide an agenda for future public health research that can begin to address this health and racial equity gap for low-income unincorporated communities of color who have, until now, been absent in health equity discourse.

Investigation of non-community stakeholders regarding community engagement and environmental malodour

Research into industry-community relationships have focused almost exclusively on the ways in which communities responds to actions from industries. This has led to a paucity of understanding with regards to how community engagement and malodour amelioration practices have been adopted by industry personnel, as well as the attitudes and beliefs of non-community stakeholders in general. In this study, a survey to water industry personnel was distributed to three Australian water utilities in South-Eastern Australia and a semi-structured interview process was carried out with plant managers at six wastewater treatment plants. It was observed that best practice has not yet been established with regards to community engagement and odour amelioration, and that water industry personnel in general had a poor understanding of these concepts. Recommendations for how this situation could be improved, and how non-community stakeholders investigated, are discussed.

Sequential "electrochemical peroxidation - Electro-Fenton" process for anaerobic sludge treatment

In this study, we present a sequential electrochemical process for integral treatment of anaerobic sludge, combining for the first time electrochemical peroxidation (ECP) and electro-Fenton (EF). In the first step, ECP (consisting of H₂O₂-assisted electrocoagulation with Fe electrodes) was applied as a conditioning and stabilizing method, whose synergistic electrocoagulation/Fenton oxidation effects considerably reduced the COD, TOC and total suspended solids (TSS) by 89.3%, 75.4% and 85.6%, respectively, under optimized conditions (initial pH of 5, [H₂O₂]/[Fe²⁺] dose ratio of 5, 15.38 mA cm^-2 and 2 h treatment). Furthermore, total coliforms were completely killed within the first hour of treatment. In the second step, EF was successfully applied to mineralize the remaining organic fraction in the liquid effluent after dewatering, achieving 91.6% and 87.2% of COD and TOC removal, respectively, after 4 h of treatment under optimal conditions (pH 3 and 25 mA cm^-2), while almost total COD and TOC removal was attained in 8 h. The Fe sludge generated at the end of the ECP treatment was easily dewatered by filtration and 20.9 g of nutrient-rich dry sludge were produced. The overall cost of the ECP-EF treatment was S$ 0.05 L^-1 sludge. The combined effects of coagulation and Fenton oxidation during ECP revealed that the treatment efficiency is strongly dependent on the rheological properties of the sludge sample.

Effects of tetrakis (hydroxymethyl) phosphonium sulfate pretreatment on characteristics of sewage sludge

Recently, tetrakis(hydroxymethyl)phosphonium sulfate (THPS) was found to play an important role in the sludge pretreatment process. However, the effects of THPS pretreatment on the characteristics of sewage sludge are still insufficiently understood. The properties of sludge after pretreatment with different concentrations of THPS were investigated in this study. The results showed that pH, dewatering ability, and particle size of sludge decreased with increase in THPS concentration. The volatile suspended solids (VSS) and total suspended solids (TSS) of sludge also decreased slightly with increase in THPS concentration. The specific oxygen uptake rate (SOUR) results suggested that lower THPS concentrations (≤1.87 mg/g VSS) enhanced the activity of sludge, but higher concentrations (≥1.87 mg/g VSS) inhibited it. Gram-negative bacteria with peritrichous flagellation (such as Pseudomonas, Escherichia, and Faecalibacterium) were extremely sensitive to THPS. The decrease in specific most probable numbers (MPNs) of pathogens (total coliforms and Escherichia coli) with the increase in THPS concentration also proved the sterilization ability of THPS in the sludge pretreatment process. Pretreatment of sludge with concentrations of THPS higher than 37.41 mg/g VSS would meet the pathogen requirements for land application of Class A biosolids.

"Ag-Gag" Laws: Evolution, Resurgence, and Public Health Implications

The term "ag-gag" refers to state laws that intentionally limit public access to information about agricultural production practices, particularly livestock production. Originally created in the 1990s, these laws have recently experienced a resurgence in state legislatures. We discuss the recent history of ag-gag laws in the United States and question whether such ag-gag laws create a "chilling effect" on reporting and investigation of occupational health, community health, and food safety concerns related to industrial food animal production. We conclude with a discussion of the role of environmental and occupational health professionals to encourage critical evaluation of how ag-gag laws might influence the health, safety, and interests of day-to-day agricultural laborers and the public living proximal to industrial food animal production.

Soil contamination and sources of phthalates and its health risk in China: A review

Phthalates (PAEs) are extensively used as plasticizers and constitute one of the most frequently detected organic contaminants in the environment. With the deterioration of eco-environment in China during the past three decades, many studies on PAE occurrence in soils and their risk assessments have been conducted which allow us to carry out a fairly comprehensive assessment of soil PAE contamination on a nation-wide scale. This review combines the updated information available associated with PAE current levels, distribution patterns (including urban soil, rural or agricultural soil, seasonal and vertical variations), potential sources, and human health exposure. The levels of PAEs in soils of China are generally at the high end of the global range, and higher than the grade II limits of the Environmental Quality Standard for soil in China. The most abundant compounds, di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), display obvious spatial distribution in different provinces. It is noted that urbanization and industrialization, application of plastic film (especially plastic film mulching in agricultural soil) and fertilizer are the major sources of PAEs in soil. Uptake of PAEs by crops, and human exposure to PAEs via ingestion of soil and vegetables are reviewed, with scientific gaps highlighted.

The interplay of contextual layers: A multilevel analysis of income distribution, neighborhood infrastructure, socioeconomic position and self-rated health in Brazil

Our hypothesis is that neighborhood infrastructure modifies the association between state-level income distribution and self-rated health. In our findings neighborhood infrastructure amplifies the association between income equality and self-rated health, yet with a differential impact on health according to sex, race and education level favoring individuals at higher socioeconomic positions. Most of the individual health variation attributed to context happens at neighborhood level, based on random effects analyses. Our findings contribute to a further understanding of health inequalities in Brazil. The demonstrated synergism between state, neighborhood and individual level determinants of health supports inter-sectoral policies and interventions in a clearly multileveled way.

Effect of humic and fulvic acid transformation on cadmium availability to wheat cultivars in sewage sludge amended soil

The high nutrients and organic matter (OM) content of sewage sludge make it an excellent fertilizer to enhance soil fertility and crop production. However, the presence of adsorbed and precipitated forms of heavy metals, especially cadmium (Cd), can be a major problem for such a utilization of sludge. This pot study aims at producing safe food with minimal Cd concentrations from sewage sludge amended soils. Two wheat cultivars (NARC-11 and Shafaq-06) were sown in soil amended with sewage sludge with rates 0, 15 and 30 g kg^-1 soil. Application of sewage sludge resulted in enhancement of wheat grain yield while Cd concentrations in wheat grains of both cultivars remained within permissible limits (24.1 to 58.6 μg kg^-1 dry weight). Fourier transform infrared (FTIR) spectroscopic analysis revealed more spectral changes in fulvic acids than in humic acids, which showed a higher humification degree, making them chemically and biologically more stable for Cd retention. Sequential extraction data of Cd after NARC-11 harvest exhibited a significant decrease in mobile fractions (exchangeable and reducible fractions were reduced by 3.6 and 5.2%, respectively) and increase in immobile fraction (the oxidizable and residual fractions increased by 7 and 1.8%, respectively). It is concluded that sewage sludge application could be useful for the improvement of wheat production due to formation of stable humate complexes and decrease in Cd availability.

Sludge disinfection using electrical thermal treatment: The role of ohmic heating

Electrical heating has been proposed as a potential method for pathogen inactivation in human waste sludge, especially in decentralized wastewater treatment systems. In this study, we investigated the heat production and E. coli inactivation in wastewater sludge using electrical thermal treatment. Various concentrations of NaCl and NH4Cl were tested as electrolyte to enhance conductivity in sludge mixtures. At same voltage input (18V), sludge treated with direct current (DC) exhibited slower ascent of temperature and lower energy efficiencies for heat production comparing to that using alternate current (AC). However, DC power showed better performance in E. coli inactivation due to electrochemical inactivation in addition to thermal inactivation. Greater than 6log10 removal of E. coli was demonstrated within 2h using 0.15M of NaCl as electrolyte by AC or DC power. The heat production in sludge was modeled using Maxwell-Eucken and effective medium theory based on the effective electrical conductivity in the two-phase (liquid and solid) sludge mixtures. The results showed that the water and heat loss is a critical consideration in modeling of sludge temperature using ohmic heating. The experimental data also suggested that the models are less applicable to DC power because the electrochemical reactions triggered by DC reduce the concentration of NH4+ and other ions that serve as electrolyte. The results of this study contribute to the development of engineering strategies for human waste sludge management.

Survey of the effect of odour impact on communities

In the context of environmental malodour, surveys are valuable as they allow for the relatively detailed analysis of multiple factors pertaining to odour perception and subsequent reaction. However, the causes for an individual to experience odour impact while a neighbour will not are still not understood. The goal of this current survey design was to consolidate varying research paths for surveys within the environmental odour research space. This survey investigated the area of effect for wastewater treatment plants by using stratified random sampling techniques that radiated from the industrial areas. Additionally, this survey provided a "non-alerted" response to environmental malodour that represents a step forward for ecological validity. We found a small number of items relating to odour annoyance and home ownership that can be used in order to predict odour impact for individual community members. However, we also did not find any relationship with odour impact and perceived control. This survey design and analysis reconciles the varied approaches towards community surveys administered in prior literature, as well as providing information to improve future community engagement policies.

Persistence of Ascaris spp. Ova in Tropical Soil Cultivated with Eucalyptus and Fertilized with Municipal Biosolids

In many countries, the main reason for severely restricting or outright banning the land application of class B biosolids is the lack of risk assessment for adverse human health impacts. Among pathogens that are not often studied are helminth ova, including that of the spp. Almost all of the knowledge about the persistence of spp. ova in soils fertilized with biosolids is based on studies developed in North America, Europe, and Asia. These studies have almost always been conducted under temperate climate conditions, which may cause erroneous interpretations when the conclusions are extrapolated to tropical regions such as those found in Brazil. This team evaluated the persistence of viable spp. ova in a sandy Quartzipsamment tropical soil, previously planted with × hybrid () and fertilized with biosolids, over a 52-wk period. During the reporting period, the average temperature of soil and biosolids fluctuated between 15 and 30°C, and the average moisture of biosolids fluctuated between 60 and 90%. The estimated persistence time of viable spp. ova after land application was estimated at close to 7 wk, indicating that ova may not be viable for as long as it has been shown to be in studies of more temperate areas. The relationship of temperature with persistence of viable spp. ova in a tropical soil was stronger than moisture content, suggesting that temperature substantially contributed to their nonviability over the course of the experiment.

Molecular-based detection of potentially pathogenic bacteria in membrane bioreactor (MBR) systems treating municipal wastewater: a case study

Although membrane bioreactor (MBR) systems provide better removal of pathogens compared to conventional activated sludge processes, they do not achieve total log removal. The present study examines two MBR systems treating municipal wastewater, one a full-scale MBR plant and the other a lab-scale anaerobic MBR. Both of these systems were operated using microfiltration (MF) polymeric membranes. High-throughput sequencing and digital PCR quantification were utilized to monitor the log removal values (LRVs) of associated pathogenic species and their abundance in the MBR effluents. Results showed that specific removal rates vary widely regardless of the system employed. Each of the two MBR effluents' microbial communities contained genera associated with opportunistic pathogens (e.g., Pseudomonas, Acinetobacter) with a wide range of log reduction values (< 2 to >5.5). Digital PCR further confirmed that these bacterial groups included pathogenic species, in several instances at LRVs different than those for their respective genera. These results were used to evaluate the potential risks associated both with the reuse of the MBR effluents for irrigation purposes and with land application of the activated sludge from the full-scale MBR system.

Interfering with therapeutic tranquility: Debates surrounding biosolid waste processing in rural Ontario

Uncertainty surrounding potential health effects of techno-industrial facilities continues to result in heightened debate about what are the best and safest options for future generations in rural places regarded by residents for their therapeutic tranquility. This research examines how a proposed biosolid processing facility in rural Ontario producing agricultural fertilizer from primarily urban sewage has in some residents elicited particularly strong concerns about potential health impacts, which are accompanied by perceptions that the tranquil and pastoral nature of their landscape is being altered. However, fueling community conflict between friends and relatives is the contested nature of the landscape's restorative qualities and the facility's disruption of this tranquil place.

Science for Reducing Health Inequalities Emerges From Social Justice Movements

Although the health sciences have investigated economic and social inequalities in morbidity and mortality for hundreds of years, health inequalities persist and are, by some measures, increasing. This is not simply a situation in which the knowledge exists but is not implemented. Rather, science in general and epidemiology in particular have focused on quantifying the effects of specific agents considered in isolation. This approach is powerful, but, in the absence of ecological concepts that connect parts and wholes, contributes to maintaining health inequalities. By joining movements for human rights and social justice, health scientists can identify research questions that are relevant to public health, develop methods that are appropriate to answering those questions, and contribute to efforts to reduce health inequalities.

Wastewater Disposal Wells, Fracking, and Environmental Injustice in Southern Texas

OBJECTIVES

To investigate race and poverty in areas where oil and gas wastewater disposal wells, which are used to permanently inject wastewater from hydraulic fracturing (fracking) operations, are permitted.

METHODS

With location data of oil and gas disposal wells permitted between 2007 and 2014 in the Eagle Ford area, a region of intensive fracking in southern Texas, we analyzed the racial composition of residents living less than 5 kilometers from a disposal well and those farther away, adjusting for rurality and poverty, using a Poisson regression.

RESULTS

The proportion of people of color living less than 5 kilometers from a disposal well was 1.3 times higher than was the proportion of non-Hispanic Whites. Adjusting for rurality, disposal wells were 2.04 times (95% confidence interval = 2.02, 2.06) as common in areas with 80% people of color or more than in majority White areas. Disposal wells are also disproportionately sited in high-poverty areas.

CONCLUSIONS

Wastewater disposal wells in southern Texas are disproportionately permitted in areas with higher proportions of people of color and residents living in poverty, a pattern known as "environmental injustice."

Emission and Dispersion of Bioaerosols from Dairy Manure Application Sites: Human Health Risk Assessment

In this study, we report the human health risk of gastrointestinal infection associated with inhalation exposure to airborne zoonotic pathogens emitted following application of dairy cattle manure to land. Inverse dispersion modeling with the USEPA's AERMOD dispersion model was used to determine bioaerosol emission rates based on edge-of-field bioaerosol and source material samples analyzed by real-time quantitative polymerase chain reaction (qPCR). Bioaerosol emissions and transport simulated with AERMOD, previously reported viable manure pathogen contents, relevant exposure pathways, and pathogen-specific dose-response relationships were then used to estimate potential downwind risks with a quantitative microbial risk assessment (QMRA) approach. Median 8-h infection risks decreased exponentially with distance from a median of 1:2700 at edge-of-field to 1:13 000 at 100 m and 1:200 000 at 1000 m; peak risks were considerably greater (1:33, 1:170, and 1:2500, respectively). These results indicate that bioaerosols emitted from manure application sites following manure application may present significant public health risks to downwind receptors. Manure management practices should consider improved controls for bioaerosols in order to reduce the risk of disease transmission.

We Should Expect More out of Our Sewage Sludge

Sewage sludge and biosolids production and management are a central component of water and sanitation engineering. The culmination of previous incremental technologies and regulations aimed at solving a current treatment problem, rather than developing the practice for the higher goals of sustainability have resulted in sludge becoming an economic and social liability. Sludge management practice must shift from treatment of a liability toward recovery of the embedded energy and chemical assets, while continuing to protect the environment and human health. This shift will require new research, treatment technologies and infrastructure and must be guided by the application of green engineering principles to ensure economic, social, and environmental sustainability.

Community perspectives on the risk of indoor air pollution arising from contaminated groundwater

The migration of volatile contaminants into overlying buildings, known as vapor intrusion, is a health concern for people living above contaminated groundwater. As public health and environmental agencies develop protocols to evaluate vapor intrusion exposure, little attention has been paid to the experiences and opinions of communities likely to be affected by vapor intrusion. Using a community-driven research approach and qualitative interviews, we explored community perspectives on the vapor intrusion pathway and the perceived impact on community health and well-being among neighbors living atop a large, shallow-chlorinated solvent plume in San Antonio, TX. Most participants associated vapor intrusion with health risks, expressing concern about the unavoidable and uncontrollable nature of their exposure. Few were satisfied with the responsiveness of public officials. Above all, participants wanted more accurate, transparent information and additional independent scientific investigations.

Critical review and rethinking of USEPA secondary standards for maintaining organoleptic quality of drinking water

Consumers assess their tap water primarily by its taste, odor, and appearance. Starting in 1979, USEPA promulgated Secondary Maximum Contaminant Levels (SMCLs) as guidance for contaminants with organoleptic effects and also to maintain consumers’ confidence in tap water. This review assesses the basis for the 15 SMCLs (aluminum, chloride, color, copper, corrosivity, fluoride, foaming agents, iron, manganese, odor, pH, silver, sulfate, total dissolved solids, zinc) and summarizes advances in scientific knowledge since their promulgation. SMCLs for aluminum, color, pH, silver, sulfate, total dissolved solids, and zinc are appropriate at current values and remain consistent with sensory science literature. Recent advances in sensory and health sciences indicate that SMCLs for chloride, copper, fluoride, iron, and manganese are too high to minimize organoleptic effects. The SMCLs for corrosivity and foaming agents may be outdated. The SMCL for odor requires rethinking as the test does not correlate with consumer complaints. Since current stresses on source and treated waters include chemical spills, algal blooms, and increased salinization, organoleptic episodes that negatively impact consumer confidence and perception of tap water still occur and may increase. Thus, adherence to SMCLs can help maintain production of palatable water along with consumers’ confidence in their water providers.

Odors from sewage sludge and livestock: associations with self-reported health

OBJECTIVES

Class B treated sewage sludge (TSS) contains microbes and toxicants and is applied to land in areas where livestock wastes may be present. We evaluated relationships of reports of TSS and livestock odors with acute symptoms and excessive flies.

METHODS

A total of 158 adults living near liquid TSS application sites, 85 living near cake TSS application sites, and 188 living in comparison areas responded to a household survey regarding odors, health, and demographics. We identified symptom groups using factor analysis. We used generalized estimating equations to fit linear models for associations between factor scores and odors, and Poisson models for associations with specific symptoms.

RESULTS

Most factor scores were similar between exposure groups. Covariate-adjusted z-scores for lower respiratory symptoms were 0.28 (95% confidence interval [CI] -0.10, 0.65) higher among residents who reported moderate to very strong liquid TSS odor than among residents in comparison areas, and 0.28 (95% CI 0.05, 0.50) higher among residents who reported moderate to very strong livestock odor compared with residents reporting no or faint livestock odor. The factor score for dermatologic conditions was higher among residents who reported higher liquid sludge odor (0.27, 95% CI -0.13, 0.68), primarily due to skin rash (prevalence ratio = 2.21, 95% CI 1.13, 4.32). Excessive flies were reported twice as commonly among respondents who reported moderate to very strong TSS odor than among other residents.

CONCLUSIONS

Reported odors from TSS and livestock were associated with some acute symptoms. Health departments should monitor land applications of human and animal wastes and conduct surveillance of health problems reported by neighbors.

The impact of malodour on communities: a review of assessment techniques

Malodours remain the biggest source of complaints regarding environmental issues. This factor is likely to increase, as the urban development steadily encroaches into areas that have malodourous emitting industries (such as wastewater and waste management operations and intensive livestock practices), and has the potential to be both time and fiscally expensive. Despite the enormous amount of research involved in odour detection and abatement, as well as the creation of several distinct methodologies, there has yet been no definitive procedure to evaluate odour impact on communities, as well as community response. This paper is a review of the current methods that explore this problem, as well as a précis of this research field's goals and challenges. The first aim of this review is to illustrate the dichotomy between regulatory-established procedures, such as panellist testing, and methods that are centred around producing a more comprehensive explanation of factors that influence an odour's impact on a community or individual. In that regard, we have addressed several predominant paradigms of inquiry for this field: analytical methods, panellist testing, qualitative research, and survey methods, with associated variants. Secondly, the challenges of measuring and monitoring community impact are discussed. While the quantification of odorants is crucial to appreciating impact, individual-based modifiers of perception have an enormous scope for which to shape the effect of those odours. Perceptual differences are also likely the most dominant variables that influence the elicited behaviour of individuals who have experienced malodour exposure.

Chronic exposure to odorous chemicals in residential areas and effects on human psychosocial health: dose-response relationships

Perceived air pollution, including environmental odor pollution, is known to be an environmental stressor that affects individuals' psychosocial health and well-being. However, very few studies have been able to quantify exposure-response associations based on individual-specific residential exposures to a proxy gas and to examine the mechanisms underlying these associations. In this study, individual-specific exposures in non-urban residential environments during 2005-2010 on a gas released from animal biodegradable wastes (ammonia, NH3) were calculated by the Danish Eulerian long-range transport model and the local-scale transport deposition model. We used binomial and multinomial logistic regression and mediation analyses to examine the associations between average exposures and questionnaire-based data on psychosocial responses, after controlling for person-specific covariates. About 45% of the respondents were annoyed by residential odor pollution. Exposures were associated with annoyance (adjusted odds ratio [ORadj]=3.54, 95% confidence interval [CI]=2.33-5.39), health risk perception (ORadj=4.94; 95% CI=1.95-12.5) and behavioral interference (ORadj=3.28; 95% CI=1.77-6.11), for each unit increase in loge(NH3 exposure). Annoyance was a strong mediator in exposure-behavior interference and exposure-health risk perception relationships (81% and 44% mediation, respectively). Health risk perception did not play a mediating role in exposure-annoyance or exposure-behavioral interference relationships. This is the first study to provide a quantitative estimation of the dose-response associations between ambient NH3 exposures and psychosocial effects caused by odor pollution in non-urban residential outdoor environments. It further shows that these effects are both direct and mediated by other psychosocial responses. The results support the use of NH3 as a proxy gas of air pollution from animal biodegradable wastes in epidemiologic studies.