Arsenic, cadmium, lead, antimony bioaccessibility and relative bioavailability in legacy gold mining waste

Bioaccessibility and relative bioavailability of As, Cd, Pb and Sb was investigated in 30 legacy gold mining wastes (calcine sands, grey battery sands, tailings) from Victorian goldfields (Australia). Pseudo-total As concentration in 29 samples was 1.45-148-fold higher than the residential soil guidance value (100 mg/kg) while Cd and Pb concentrations in calcine sands were up to 2.4-fold and 30.1-fold higher than the corresponding guidance value (Cd: 20 mg/kg and Pb: 300 mg/kg). Five calcine sands exhibited elevated Sb (31.9-5983 mg/kg), although an Australian soil guidance value is currently unavailable. Arsenic bioaccessibility (n = 30) and relative bioavailability (RBA; n = 8) ranged from 6.10-77.6% and 10.3-52.9% respectively. Samples containing > 50% arsenopyrite/scorodite showed low As bioaccessibility (<20.0%) and RBA (<15.0%). Co-contaminant RBA was assessed in 4 calcine sands; Pb RBA ranged from 73.7-119% with high Pb RBA associated with organic and mineral sorbed Pb and, lower Pb RBA observed in samples containing plumbojarosite. In contrast, Cd RBA ranged from 55.0-67.0%, while Sb RBA was < 5%. This study highlights the importance of using multiple lines of evidence during exposure assessment and provides valuable baseline data for co-contaminants associated with legacy gold mining activities.

An evaluation of properly operated NSF/ANSI-53 Pb certified drinking water filters in Benton Harbor, MI

Communities across the United States and particularly in the Midwest continue to grapple with the complications associated with aging infrastructure. This includes the presence of lead (Pb)-bearing plumbing components such as lead service lines, downstream galvanized iron pipes, and Pb/tin solder. The community of Benton Harbor, MI, experienced six Pb action level exceedances between 2018 and 2021, leading to increasing community concern and a request from the state of Michigan for the US Environmental Protection Agency involvement. Between 9 November and 17 December 2021, US EPA Region 5 and Office of Research and Development, along with the state of Michigan, conducted a water filter efficacy and Pb-nanoparticulate (<100 nm) study to evaluate the performance of NSF/ANSI-53 Pb-certified drinking water filters and the presence of nanoparticulate. In this study, a total of 199 properly installed and operated drinking water filters (combination of faucet mounted and pitcher) were tested in their residential locations. One hundred percent of the water filters were found to perform to the standard to which they were certified, with filtered drinking water Pb concentrations below 5 ppb (maximum observed was 2.5 ppb). In addition, Pb particulate was identified; however, discrete Pb-containing nanoparticles were not widely found or identified.

Reviewing performance of NSF/ANSI 53 certified water filters for lead removal

Properly certified NSF/ANSI 53 water filters are distributed as a temporary measure to protect residents from risk of exposure to elevated lead (Pb) levels resulting from water system changes and various activities. Water consumers and other stakeholders have raised questions on the performance of these filters in field settings, particularly in cases where water Pb levels exceeded the NSF/ANSI 53 challenge water level of 150 µg/L and when Pb phosphate nanoparticles (≤ 200 nm) were present in drinking water. This literature review summarizes findings from 23 studies that evaluated the ability of NSF/ANSI 53 post-2007 certified filters to reduce soluble and/or particulate Pb from water. The studies in total examined 1,486 faucet-mounted, 25 under-the-sink, and 167 pitcher filters, with 1,528 filters used in field studies and 150 filters in laboratory studies. This review found that filter performance varied with different filter type, test water source, and initial unfiltered total Pb concentration. 99% (1,512/1,528) of the filters used in field studies removed Pb to at or below the certification benchmark of pre-2019, 10 µg/L or post-2019, 5 µg/L. In contrast, 61% (91/150) of the filters used in laboratory studies reduced Pb to the benchmark. Laboratory filters were often tested under conditions beyond what they were certified to handle. Pb concentration, particle form and size, improper operation and maintenance of certified water filters were attributed to reported filter failures. This information is intended to help water utilities, regulators, and others make decisions regarding the deployment of water filters to the public when drinking water Pb exposure concerns have been raised.

A national survey of lead and other metal(loids) in residential drinking water in the United States

BACKGROUND

Exposure to lead (Pb), arsenic (As) and copper (Cu) may cause significant health issues including harmful neurological effects, cancer or organ damage. Determination of human exposure-relevant concentrations of these metal(loids) in drinking water, therefore, is critical.

OBJECTIVE

We sought to characterize exposure-relevant Pb, As, and Cu concentrations in drinking water collected from homes participating in the American Healthy Homes Survey II, a national survey that monitors the prevalence of Pb and related hazards in United States homes.

METHODS

Drinking water samples were collected from a national survey of 678 U.S. homes where children may live using an exposure-based composite sampling protocol. Relationships between metal(loid) concentration, water source and house age were evaluated.

RESULTS

18 of 678 (2.6%) of samples analyzed exceeded 5 µg Pb L-1 (Mean = 1.0 µg L-1). 1.5% of samples exceeded 10 µg As L-1 (Mean = 1.7 µg L-1) and 1,300 µg Cu L-1 (Mean = 125 µg L-1). Private well samples were more likely to exceed metal(loid) concentration thresholds than public water samples. Pb concentrations were correlated with Cu and Zn, indicative of brass as a common Pb source is samples analyzed.

SIGNIFICANCE

Results represent the largest national-scale effort to date to inform exposure risks to Pb, As, and Cu in drinking water in U.S. homes using an exposure-based composite sampling approach.

IMPACT STATEMENT

To date, there are no national-level estimates of Pb, As and Cu in US drinking water collected from household taps using an exposure-based sampling protocol. Therefore, assessing public health impacts from metal(loids) in drinking water remains challenging. Results presented in this study represent the largest effort to date to test for exposure-relevant concentrations of Pb, As and Cu in US household drinking water, providing a critical step toward improved understanding of metal(loid) exposure risk.

Patient and Parent Well-Being and Satisfaction With Diabetes Care During a Comparative Trial of Mobile Self-Monitoring Blood Glucose Technology and Family-Centered Goal Setting

Patient engagement in the process of developing a diabetes treatment plan is associated with person-centered care and improved treatment outcomes. The objective of the present study was to evaluate the self-reported patient and parent-centered satisfaction and well-being outcomes associated with the three treatment strategies utilized in a comparative effectiveness trial of technology-enhanced blood glucose monitoring and family-centered goal setting. We evaluated data from 97 adolescent-parent pairs at baseline and 6-months during the randomized intervention. Measures included: Problem Areas in Diabetes (PAID) child and parent scales, pediatric diabetes-related quality of life, sleep quality, and satisfaction with diabetes management. Inclusion criteria were 1) ages 12-18 years, 2) a T1D diagnosis for at least six months and 3) parent/caregiver participation. Longitudinal changes in survey responses were measured at 6 months from baseline. Differences between and within participant groups were evaluated using ANOVA. The average age of youth participants was 14.8 ± 1.6 years with half of the participants being female (49.5%). The predominant ethnicity/race was Non-Hispanic (89.9%) and white (85.9%). We found that youth perceived 1) greater of diabetes-related communication when using a meter capable of transmitting data electronically, 2) increased engagement with diabetes self-management when using family-centered goal setting, and 3) worse sleep quality when using both strategies together (technology-enhanced meter and family-centered goal setting). Throughout the study, scores for self-reported satisfaction with diabetes management were higher in youth than parents. This suggests that patients and parents have different goals and expectations regarding their diabetes care management and care delivery. Our data suggest that youth with diabetes value communication via technology and patient-centered goal setting. Strategies to align youth and parent expectations with the goal of improving satisfaction could be utilized as a strategy to improve partnerships in diabetes care management.

A holistic approach to lead pipe scale analysis: Importance, methodology, and limitations

With lead service lines (LSLs) remaining for decades to come, scale analyses are critical to helping limit lead exposure from drinking water. This laboratory has used an integrated suite of analytical techniques to characterize the elemental composition, mineral identification, and physical features of scales, helping the water industry to evaluate, predict, and reduce lead corrosion. The methods used in this laboratory to prepare and analyze the LSL scale, and guidance to achieving reliable and meaningful results, are described. Primary methods include the following: optical microscopy, powder X-ray diffraction, inductively coupled plasma spectroscopy, X-ray fluorescence, scanning electron microscopy with energy dispersive spectroscopy, combustion and coulometric analyses of C and S, and X-ray absorption spectroscopy. Examples of associated pitfalls and ways to avoid them are provided, including pipe excavation/transport, sample preparation, analysis, and data interpretation. Illustrative examples are presented of practical scale analysis questions that could be answered by combinations of pipe scale analyses.

Variability and sampling of lead (Pb) in drinking water: Assessing potential human exposure depends on the sampling protocol

Lead (Pb) in drinking water has re-emerged as a modern public health threat which can vary widely in space and in time (i.e., between homes, within homes and even at the same tap over time). Spatial and temporal water Pb variability in buildings is the combined result of water chemistry, hydraulics, Pb plumbing materials and water use patterns. This makes it challenging to obtain meaningful water Pb data with which to estimate potential exposure to residents. The objectives of this review paper are to describe the root causes of intrinsic Pb variability in drinking water, which in turn impacts the numerous existing water sampling protocols for Pb. Such knowledge can assist the public health community, the drinking water industry, and other interested groups to interpret/compare existing drinking water Pb data, develop appropriate sampling protocols to answer specific questions relating to Pb in water, and understand potential exposure to Pb-contaminated water. Overall, review of the literature indicated that drinking water sampling for Pb assessment can serve many purposes. Regulatory compliance sampling protocols are useful in assessing community-wide compliance with a water Pb regulatory standard by typically employing practical single samples. More complex multi-sample protocols are useful for comprehensive Pb plumbing source determination (e.g., Pb service line, Pb brass faucet, Pb solder joint) or Pb form identification (i.e., particulate Pb release) in buildings. Exposure assessment sampling can employ cumulative water samples that directly capture an approximate average water Pb concentration over a prolonged period of normal household water use. Exposure assessment may conceivably also employ frequent random single samples, but this approach warrants further investigation. Each protocol has a specific use answering one or more questions relevant to Pb in water. In order to establish statistical correlations to blood Pb measurements or to predict blood Pb levels from existing datasets, the suitability of available drinking water Pb datasets in representing water Pb exposure needs to be understood and the uncertainties need to be characterized.

Orthophosphate Interactions with Destabilized PbO2 Scales

This research presents two case studies in which a change in the disinfectant from free chlorine to chloramine caused an increase in lead corrosion. In both systems, the predominantly tetravalent lead (PbO₂) scales destabilized as a result of disinfectant change. Orthophosphate corrosion control was used in both systems, and the effect of this treatment chemical on the destabilized PbO₂ scales was examined. The absence of chemical reactivity between PbO₂ and phosphorus is well known, and this research confirms that phosphorus does not interact with the legacy PbO₂ scales. Instead, phosphorus and calcium were found to permeate through the destabilized PbO₂ material and react with divalent lead [Pb(II)] at the surface of a basal litharge (PbO) layer. This reaction precipitated a crystalline lead phosphate in both systems, which could not be specifically identified by any known powder diffraction files. Further analysis suggested that the compound formed was not the typically modeled hydroxypyromorphite but rather a calcium-substituted hydroxypyromorphite. During scale formation, calcium is frequently bound to the Pb(II) phosphate crystal lattice structure, causing measurable crystal lattice distortion in powder X-ray diffraction patterns. The results of this study illustrate the longevity of legacy scales and how disequilibrium compounds persist long after treatment changes have been made.

Lead Particle Size Fractionation and Identification in Newark, New Jersey's Drinking Water

Following a pH reduction in their drinking water over a span of more than 20 years, the City of Newark, New Jersey, has struggled with elevated lead (Pb) release from Pb service lines and domestic plumbing in the zone fed by the Pequannock Water Treatment Plant. In response, Newark initiated orthophosphate addition and provided faucet-mounted point-of-use (POU) filters and pitcher filters certified for Pb and particulate reduction under NSF/ANSI Standards 53 and 42 to residential homes in that zone. Water chemistry analysis and size fractionation sampling were performed at four of these houses. Analysis of the particulate material retained by the fractionation filters revealed that Pb was dominantly present in the water as fine Pb(II) orthophosphate particles. A considerable amount of the particulates occurred as a nanoscale fraction that sometimes passed through the POU faucet or pitcher filtration units. Scanning electron microscopy, transmission electron microscopy, and energy-dispersive spectroscopy analyses showed that the nanoparticles (<100 nm) and their aggregates were composed of Pb, phosphorus, and chlorine, which are consistent with pyromorphite, Pb₅(PO₄)₃Cl. Electron diffraction and X-ray analyses supported the presence of hydroxypyromorphite and chloropyromorphite nanoparticles and the size range estimates from the imaging. This research confirmed that nonadherent Pb(II)-orthophosphate nanoparticles were an important form of Pb in drinking water in the Pequannock water quality zone of Newark.

Water quality-pipe deposit relationships in Midwestern lead pipes

The conventional wisdom of lead-scale solubility has been built over the years by geochemical solubility models, experimental studies, and field sampling utilizing multiple protocols. Rarely, have the mineral phases from scales formed in real-world drinking water lead service lines (LSLs) been compared to theoretical predictions. In this study, model predictions are compared to LSL scales from 22 drinking water distribution systems. The results show that only nine of the 22 systems had LSL scales that followed model predictions. The remaining systems had unpredictable scales some with unknown lead release characteristics demonstrating that predicting scale formation and lead release solely by models cannot be relied on in all cases to protect human health. Therefore, for many systems with LSLs, pilot studies with existing LSL scales will be necessary to evaluate and optimize corrosion control, and correspondingly, appropriate residential water sampling will be needed to demonstrate consistent and optimal system corrosion control.

The new system of review by multicentre research ethics committees: prospective study

OBJECTIVE

To assess the function of the new system of review by multicentre research ethics committees and to highlight areas where improvement is still needed.

DESIGN

Prospectively collected data from a multicentre study was examined with respect to the ethics review process. Administrative, financial, and time elements of the review process were audited.

SETTING

A single multicentre research ethics committee and 125 local ethics committees from six regions of England.

MAIN OUTCOME MEASURES

Time to reply, time to approval, and number of non-local changes to the application requested.

RESULTS

Only 40% of local ethics committees considered our study in the manner specified in the 1998 directive. Less than a third of committees replied within the 21 day period stipulated, although committees acting by executive subcommittee replied more quickly than those not acting by executive subcommittee. There was a tendency for executive subcommittees to approve studies in a shorter time. Local ethics committees asked for a large number of non-local changes to the application. The financial cost of applying to multiple ethics committees remains high, mainly because multiple copies of research applications are being requested.

CONCLUSIONS

The new system of approval by multicentre research ethics committee for multicentre studies was introduced to reduce administrative costs, speed up the process of reviews by multiple research ethics committees, and standardise the conclusions of the local research ethics committees. Since its introduction an improvement has been seen, but the system is not yet universally functioning as intended. Ethics review still remains a hindrance to the financial resources and commencement of national studies. We strongly support the structure of review by multicentre research ethics committees but suggest that the system has yet to achieve its aims.

Routine use of ultrasound 24 hours before laparoscopic cholecystectomy can predict the need for intraoperative cholangiogram: results of a 12-month prospective audit

Intraoperative cholangiograms and exploration of the common bile duct (CBD) during laparoscopic cholecystectomy are technically more demanding than during open cholecystectomy. This has led to many surgeons using a selective policy for cholangiography. In this study we prospectively assessed whether biliary ultrasound (CBD diameter > or = 6 mm) or one or more abnormal liver function tests (LFTs) performed in the 24 hours preoperatively could predict the need for cholangiography. Forty-five patients were studied (14 male, 31 female), mean age 47.8 years. All patients with one or both tests abnormal preoperatively (19 patients) underwent intraoperative cholangiograms. Seven CBD stones were identified (16%). There was no evidence of CBD stones in patients not undergoing cholangiography at a median follow-up of 18 months. In patients with stones, three underwent open CBD exploration, and four underwent endoscopic retrograde choledochopancreatography (ERCP) and sphincterotomy in the early postoperative period without complications. CBD diameter > or = 6 mm is a useful predictor of CBD stones. These may be treated successfully by postoperative ERCP.

Prandial aspiration and pneumonia in an elderly population followed over 3 years

The purpose of our study was to prospectively determine pneumonia frequency and correlate it with prandial liquid aspiration and feeding status in frail elderly nursing home residents. Initially, 152 patients had video swallowing examinations (81 oropharyngeal dysphagia, 19 thoracic dysphagia, 52 without dysphagia). Those diagnosed with oropharyngeal impairment were subsequently managed with swallowing therapy or artificial feeding modalities. Patients were followed for 3 years (unless they expired earlier) and clinical courses were categorized according to the degree of prandial aspiration and feeding (PAF) status. Subjects with new lung infiltrates persisting for at least 5 days with appropriate clinical findings were diagnosed as having pneumonia and were classified according to the PAF status months in which these findings occurred. Fifty-six pneumonias were diagnosed during 4,280 months with the following frequencies: no aspiration months 0.6%; minor aspiration months 0.9%; major aspiration/oral feeding months 1.3%; major aspiration/artificial feeding months 4.4%, p < 0.001. Our results indicate that there is not a simple and obvious relation between prandial liquid aspiration and pneumonia. Artificial feeding does not seem to be a satisfactory solution for preventing pneumonia in elderly prandial aspirators.

Deglutition in elderly patients with dementia: findings of videofluorographic evaluation and impact on staging and management

Oral and pharyngeal function in 131 institutionalized elderly patients with advanced dementia was evaluated by means of videofluoroscopic deglutition examination (VDE). Findings were normal in only nine (7%) patients. Oral-stage dysfunction was observed in 93 (71%) patients, pharyngeal dysfunction in 56 (43%), and pharyngoesophageal-segment abnormalities in 43 (33%). Multiple-stage dysfunction was noted in 55 (42%) patients. Major aspiration of contrast medium was present in 31 patients, and minor aspiration in 66. Evaluation of VDE findings prompted a change in clinical staging (degree of impairment) in 40 patients and substantial alteration in treatment planning in 28. At clinical bedside evaluation, the degree of bolus misdirection was overestimated in 19 patients with minor aspiration and underestimated in seven with major aspiration. Dementia is often associated with oral and pharyngeal impairment, and VDE can be important in diagnosis and treatment.

Aspiration and the elderly

Aspiration is prevalent in the elderly but its association with impairment of oral intake and gastroesophageal reflux is often misunderstood. This paper describes the causes, pathophysiology, and consequences of aspiration and their unique features in aged persons. It also explains how videofluoroscopic evaluation can assess current function while limiting factors that result in misinformation. The management of aspiration is discussed, emphasizing the importance and difficulties in maintaining functional well-being and possible complications of therapy.