Browsing by Author "Cohen, Alasdair"

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    Assessing the impacts of a water, sanitation, and hygiene (WASH) intervention on changing behavior in Bihar, India
    Wilcox, Emily Rose (Virginia Tech, 2023-06-07)
    Access to safe water, sanitation, and hygiene (WASH) is a fundamental human right and a critical component of public and environmental health. Inadequate access to WASH facilities and practices can give rise to preventable diarrheal and waterborne diseases, which can have severe consequences on individuals' health and well-being. This is especially true in low- and middle-income countries such as India. To address these issues, the S.M. Sehgal Foundation identified water quality and hygiene needs in Bihar, India, and thus launched a behavior change intervention called "WASH for Healthy Homes." The intervention aimed to promote the use of silver-ceramic pot filters and safe handwashing practices in five communities of the Vaishali District. While behavior change is a common approach to address WASH issues, evaluating the outcomes of such interventions is crucial for determining the most effective strategies and conditions under which they can be successful. Therefore, this study assessed the effectiveness of the WASH for Healthy Homes intervention and identified factors that influenced its success. A mixed methods approach was utilized that combined statistical analyses of pre- and post-intervention survey data with a thematic analysis of interview and focus group discussion data. Results demonstrated that the intervention was successful in increasing the adoption of the silver-ceramic pot filter and overall safe handwashing practices within the study communities. Success of the WASH for Health Homes intervention was facilitated by participants' health concerns, trust in the field coordinator and social peers, the aesthetic appeal of the treated water, and repeated intervention messaging. However, adoption of intervention behaviors was hindered by several factors, including economic barriers, gender roles in decision-making, the effects of children and elderly in the household, and low attendance during intervention sessions. The research findings provide valuable insights that can help nonprofits better design and execute behavior change interventions, especially in the face of increasing WASH challenges.
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    Boiled or Bottled: Regional and Seasonal Exposures to Drinking Water Contamination and Household Air Pollution in Rural China
    Cohen, Alasdair; Pillarisetti, Ajay; Luo, Qing; Ling, Hongxing; Zhong, Gemei; Colford, John M., Jr.; Smith, Kirk R.; Ray, Isha; Tao, Yong (National Institute of Environmental Health Sciences, 2020-12-04)
    Background: Inadequate access to safe drinking water remains a global health problem, particularly in rural areas. Boiling is the most commonly used form of point-of-use household water treatment (HWT) globally, although the use of bottled water in low- and middle-income countries (LMICs) is increasing rapidly. Objectives: We assessed the regional and seasonal prevalence of HWT practices (including bottled water use) in low-income rural areas in two Chinese provinces, evaluated the microbiological safety of drinking water and associated health outcomes, and estimated the air pollution burden associated with the use of solid fuels for boiling. Methods: We conducted cross-sectional surveys and collected drinking water samples from 1,033 rural households in Guangxi and Henan provinces. Temperature sensors affixed to pots and electric kettles were used to corroborate self-reported boiling frequencies and durations, which were used to model household air pollution (HAP) in terms of estimated particulate matter ≤2.5μm in aerodynamic diameter (PM2.5) concentrations. Results: Based on summer data collection in both provinces, after controlling for covariates, boiling with electric kettles was associated with the largest log reduction in thermotolerant coliforms (TTCs) (−0.66 log10 TTC most probable number/100mL), followed by boiling with pots (−0.58), and bottled water use (−0.39); all were statistically significant (p<0.001). Boiling with electric kettles was associated with a reduced risk of TTC contamination [risk ratio (RR)=0.25, p<0.001] and reported diarrhea (RR=0.80, p=0.672). TTCs were detected in 51% (n=136) of bottled water samples. For households boiling with biomass, modeled PM2.5 concentrations averaged 79 μg/m3 (standard deviation=21). Discussion: Our findings suggest that where boiling is already common and electricity access is widespread, the promotion of electricity-based boiling may represent a pragmatic stop-gap means of expanding safe water access until centralized, or decentralized, treated drinking water is available; displacing biomass use for water boiling could also reduce HAP concentrations and exposures. Our results also highlight the risks of increasing bottled water use in rural areas, and its potential to displace other sources of safe drinking water, which could in turn hamper efforts in China and other LMICs toward universal and affordable safe water access.
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    Bottled and Well Water Quality in a Small Central Appalachian Community: Household-Level Analysis of Enteric Pathogens, Inorganic Chemicals, and Health Outcomes in Rural Southwest Virginia
    Cohen, Alasdair; Rasheduzzaman, Md; Darling, Amanda; Krometis, Leigh-Anne H.; Edwards, Marc A.; Brown, Teresa; Ahmed, Tahmina; Wettstone, Erin; Pholwat, Suporn; Taniuchi, Mami; Rogawski McQuade, Elizabeth T. (MDPI, 2022-07-15)
    Consumption of unsafe drinking water is associated with a substantial burden of disease globally. In the US, ~1.8 million people in rural areas lack reliable access to safe drinking water. Our objective was to characterize and assess household-level water sources, water quality, and associated health outcomes in Central Appalachia. We collected survey data and water samples (tap, source, and bottled water) from consenting households in a small rural community without utility-supplied water in southwest Virginia. Water samples were analyzed for physicochemical parameters, total coliforms, E. coli, nitrate, sulfate, metals (e.g., arsenic, cadmium, lead), and 30+ enteric pathogens. Among the 69% (n = 9) of households that participated, all had piped well water, though 67% (n = 6) used bottled water as their primary drinking water source. Total coliforms were detected in water samples from 44.4% (n = 4) of homes, E. coli in one home, and enteric pathogens (Aeromonas, Campylobacter, Enterobacter) in 33% (n = 3) of homes. Tap water samples from 11% (n = 1) of homes exceeded the EPA MCL for nitrate, and 33% (n = 3) exceeded the EPA SMCL for iron. Among the 19 individuals residing in study households, reported diarrhea was 25% more likely in homes with measured E. coli and/or specific pathogens (risk ratio = 1.25, cluster-robust standard error = 1.64, p = 0.865). Although our sample size was small, our findings suggest that a considerable number of lower-income residents without utility-supplied water in rural areas of southwest Virginia may be exposed to microbiological and/or chemical contaminants in their water, and many, if not most, rely on bottled water as their primary source of drinking water.
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    Bottled water quality and associated health outcomes: a systematic review and meta-analysis of 20 years of published data from China
    Cohen, Alasdair; Cui, Jingyi; Song, Qingyang; Xia, Qiwen; Huan, Jiexuan; Guo, Yalu; Sun, Yixin; Colford, John M., Jr.; Ray, Isha (IOP Publishing, 2022-01-20)
    Bottled water is a rapidly growing yet relatively understudied source of drinking water globally. In addition to concerns about the safety of bottled water, the adverse environmental health and social impacts associated with bottled water production, distribution, consumption, and reliance are considerable. Our objective was to comprehensively review, analyze, and synthesize ∼20 years of publicly available data on bottled water quality and associated health outcomes in China. We conducted a systematic review and meta-analysis of publicly available studies of bottled water quality and associated health outcomes in China published between 1995 and early 2016 (in Chinese and English). We pre-specified and registered our study protocol, independently replicated key analyses, and followed standardized reporting guidelines. Our search identified 7059 potentially eligible records. Following screening, after full-text review of 476 publications, 216 (reporting results from 625 studies) met our eligibility criteria. Among many findings, 93.7% (SD = 10.1) of 24 585 samples tested for total coliforms (n = 241 studies), and 92.6% (SD = 12.7) of 7261 samples tested for nitrites (n = 85 studies), were in compliance with China’s relevant bottled water standards. Of the studies reporting concentration data for lead (n = 8), arsenic (n = 5), cadmium (n = 3), and mercury (n = 3), median concentrations were within China’s standards for all but one study of cadmium. Only nine publications reported health outcome data, eight of which were outbreak investigations. Overall, we observed evidence of stable or increasing trends in the proportions of samples in compliance over the ∼20 year period; after controlling for other variables via meta-regression, the association was significant for microbiological but not chemical outcomes (p = 0.017 and p = 0.115, respectively). Bottled water is typically marketed as being safe, yet in most countries it is less well-regulated than utility-supplied drinking water. Given the trend of increasing bottled water use in China and globally—and the associated environmental health impacts—we hope this work will help to inform policies and regulations for improving bottled water safety, while further highlighting the need for substantially expanding the provision of safe and affordable utility-supplied drinking water globally.
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    The Effectiveness of Point-of-Use Treatment in Improving Home Drinking Water Quality in Rural Households
    Patton, Hannah Elisabeth (Virginia Tech, 2023-07-12)
    Despite claims of nearly 100% access to potable drinking water in the US, issues of drinking water quality, accessibility, and equity persist in many regions of the country. Drinking water is a common health concern in rural communities, where social, geographic, and economic challenges can inhibit the provision of reliable municipal water. Households without access to municipal water often rely on private wells, which are solely the responsibility of the homeowner to test, treat, and maintain, or roadside springs. These water sources often do not employ water treatment and users can therefore be uniquely susceptible to environmental contaminants. The goal of this research was to examine point-of-use (POU) treatment options that can be used by individuals to improve their drinking water quality and reduce exposure to common contaminants prior to consumption. Two drops (~0.10 mL) of unscented, household bleach in one gallon of spring water is a simple, low-cost treatment option that successfully inactivates total coliform and E. coli and provides an appropriate free chlorine residual (> 0.5 mg/L) over a 1-month time period, without exceeding free chlorine taste thresholds (< 2 mg/L). Efforts to distribute information on this disinfection protocol to spring users in southern West Virginia and southwestern Virginia were well-received; however, only 60% of surveyed spring users report that they plan to implement the protocol. POU faucet filters have been successfully implemented in homes reliant on municipal water to reduce metal contaminant levels in drinking water. Few studies have assessed the effectiveness of these filters in improving water quality in homes reliant on private wells. Faucet-mounted POU filters distributed to homes reliant on private wells in Virginia and southern West Virginia statistically significantly lowered levels of Ba, Cd, Cr, Total Coliform, U, Cu, Pb, Al, Fe, Mn, Zn, and Sr in tap water. However, levels of many contaminants of interest still exceeded at least one Safe Drinking Water Act regulation/recommendation in several filtered samples. Additionally, less than half of study participants reported that they liked using the filters with several citing issues with flowrate. Faucet-mounted POU filters can also be a useful tool in assessing exposure to contaminants at the tap. The acid flow-through method of metals recovery has previously proven to be successful in recovering dissolved Pb from dosed filters. In this study, the acid flow-through extraction method was applied to water spiked with high or low levels of Pb, Fe, or Cu. While faucet-mounted activated carbon filters successfully removed Pb and Cu from dosed influent (>91% removal), filter behavior under influent Fe concentrations of greater than 300 ppb was extremely variable. The acid flow-through method of metals extraction provided some recovery from filters dosed with high and low concentrations of Pb (38.9-70.4%). Recovery of Cu and Fe was variable, likely in part due to Fe and Cu leaching from filter media, suggesting that alternative methods of metals extraction and recovery from POU faucet filters dosed with Fe and Cu, or other common water contaminants (e.g., As, Ba, Cd), must be explored. While POU treatment can be useful in improving drinking water quality in rural households, limitations to adoption persist and must be addressed along with efforts to protect drinking water quality in homes in a more permanent, sustainable way.
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    Implications of Bottled Water Use in Rural Central Appalachia
    Albi, Kate Nicole (Virginia Tech, 2024-05-21)
    An increasing number of Americans identify bottled water as their preferred water source to meet household needs, despite additional expenses and less stringent quality reporting requirements. Previous studies note perceptions of poor water quality and/or distrust in public water authorities as the primary drivers of bottled water use. Examinations of Safe Drinking Water Act (SDWA) violation data validate these perceptions and highlight the increased prevalence of drinking water disparities in rural, low-income communities. This effort aims to assess in-home and bottled drinking water throughout rural Central Appalachia: a documented water inequity hotspot. To evaluate the uses, perceptions, motivations, expenditures, and quality related to in-home and bottled water sources, 24 homes in three different Central Appalachian counties were recruited to complete household surveys. Concurrently, 23 in-home (11 municipally and 12 privately sourced), 11 brands of bottled water, and four roadside spring samples identified as preferred drinking water sources were collected and analyzed for regulated (bacteria, inorganic ions) and emerging (per-and polyfluoroalkyl substances (PFAS), microplastics) contaminants via Standard Methods and compared to Safe Drinking Water Act (SDWA) standards (if applicable). The majority of respondents viewed their in-home water quality as satisfactory or less due to negative organoleptic perceptions (taste, odor, appearance). In-home and roadside spring water quality generally aligned with poor perceptions: coliform bacteria, E. coli, aluminum, iron, manganese, and sodium were detected at concentrations above United States Environmental Protection Agency (USEPA) standards and guidelines. Approximately 71 percent of homes reported bottled water as their primary drinking water source. Bottled water samples did not exceed any USEPA health-based regulations. The presence of inorganic ions contaminants varied greatly across the 11 brands of bottled water assessed, and within brand variability was noted in one bottled water brand purchased at two different locations. PFAS compounds were detected in both in-home and bottled water samples, though at relatively low levels. Microplastic particles were found in all samples, regardless of source. Statistical analyses revealed significantly higher concentrations of all contaminants in point-of-use samples compared to bottled water, except total microplastic particle count. Bottled water is a safe drinking water source for those without access to or confidence in their in-home drinking water, though associated time and financial burdens are considerable.
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    Intermittent Water Supply Management, Household Adaptation, and Drinking Water Quality: A Comparative Study in Two Chinese Provinces
    Li, Hongxing; Cohen, Alasdair; Li, Zheng; Lv, Shibo; He, Zuan; Wang, Li; Zhang, Xinyi (MDPI, 2020-05-12)
    Intermittent water supply (IWS) is a relatively common phenomenon across the world as well as in rural and peri-urban areas across China, though there has been little IWS-focused research from China published to date. IWS consumers typically adopt a range of strategies to cope with insufficient water supply, poor drinking water quality, and associated inconveniences. In this study, we collected a range of data from small-scale utilities and households in two IWS systems and two continuous water supply (CWS) systems, as well as from comparison groups, in Shandong and Hubei provinces. Data collection included water quality testing, interviews, and surveys on behavioral adaptations, coping strategies, water-related health perceptions, and other metrics of consumer satisfaction. Overall, we found that the IWS coping strategies employed in northern China (Shandong) were associated with generally safe, but inconvenient, water access, whereas adaptation strategies observed in southern China (Hubei) appeared to improve convenience, but not water quality. Compared to the CWS comparison groups, we did not observe significant differences in water- and sanitation-related behaviors in the IWS groups, suggesting interventions to increase adaptive and protective behaviors at the household level might further improve safe water access for households living with IWS. Overall, although the water supply infrastructure in these study areas appeared to be in relatively good condition, in contrast to reported data on IWS systems in other countries, we observed multiple risk factors associated with the water treatment and distribution processes in these IWS systems. Among policy recommendations, our results suggest that the implementation of Water Safety Plans in China would likely improve the management of drinking water treatment and, by extension, safe drinking water supply under conditions of IWS.
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    Microbiological and chemical drinking water contaminants and associated health outcomes in rural Appalachia, USA: A systematic review and meta-analysis
    Darling, Amanda; Patton, Hannah; Rasheduzzaman, Md; Guevara, Rachel; McCray, Joshua; Krometis, Leigh-Anne H.; Cohen, Alasdair (Elsevier, 2023-09)
    In rural areas of the United States, an estimated ~1.8 million people lack reliable access to safe drinking water. Considering the relative dearth of information on water contamination and health outcomes in Appalachia, we conducted a systematic review of studies of microbiological and chemical drinking water contamination and associated health outcomes in rural Appalachia. We pre-registered our protocols, limiting eligibility to primary data studies published from 2000 to 2019, and searched four databases (PubMed, EMBASE, Web of Science, and the Cochrane Library). We used qualitative syntheses, meta-analyses, risk of bias analysis, and meta-regression to assess reported findings, with reference to US EPA drinking water standards. Of the 3452 records identified for screening, 85 met our eligibility criteria. 93 % of eligible studies (n = 79) used cross-sectional designs. Most studies were conducted in Northern (32 %, n = 27) and North Central (24 %, n = 20) Appalachia, and only 6 % (n = 5) were conducted exclusively in Central Appalachia. Across studies, E. coli were detected in 10.6 % of samples (sample-size-weighted mean percentage from 4671 samples, 14 publications). Among chemical contaminants, sample-size-weighted mean concentrations for arsenic were 0.010 mg/L (n = 21,262 samples, 6 publications), and 0.009 mg/L for lead (n = 23,259, 5 publications). 32 % (n = 27) of studies assessed health outcomes, but only 4.7 % (n = 4) used case-control or cohort designs (all others were cross-sectional). The most commonly reported outcomes were detection of PFAS in blood serum (n = 13), gastrointestinal illness (n = 5), and cardiovascular-related outcomes (n = 4). Of the 27 studies that assessed health outcomes, 62.9 % (n = 17) appeared to be associated with water contamination events that had received national media attention. Overall, based on the number and quality of eligible studies identified, we could not reach clear conclusions about the state of water quality, or its impacts on health, in any of Appalachia's subregions. More epidemiologic research is needed to understand contaminated water sources, exposures, and potentially associated health outcomes in Appalachia.
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    Subsewershed SARS-CoV-2 Wastewater Surveillance and COVID-19 Epidemiology Using Building-Specific Occupancy and Case Data
    Cohen, Alasdair; Maile-Moskowitz, Ayella; Grubb, Christopher; Gonzalez, Raul A.; Ceci, Alessandro; Darling, Amanda; Hungerford, Laura L.; Fricker, Ronald D. Jr.; Finkielstein, Carla V.; Pruden, Amy; Vikesland, Peter J. (American Chemical Society, 2022-05-01)
    To evaluate the use of wastewater-based surveillance and epidemiology to monitor and predict SARS-CoV-2 virus trends, over the 2020-2021 academic year we collected wastewater samples twice weekly from 17 manholes across Virginia Tech's main campus. We used data from external door swipe card readers and student isolation/quarantine status to estimate building-specific occupancy and COVID-19 case counts at a daily resolution. After analyzing 673 wastewater samples using reverse transcription quantitative polymerase chain reaction (RT-qPCR), we reanalyzed 329 samples from isolation and nonisolation dormitories and the campus sewage outflow using reverse transcription digital droplet polymerase chain reaction (RT-ddPCR). Population-adjusted viral copy means from isolation dormitory wastewater were 48% and 66% higher than unadjusted viral copy means for N and E genes (1846/100 mL to 2733/100 mL/100 people and 2312/100 mL to 3828/100 mL/100 people, respectively; n = 46). Prespecified analyses with random-effects Poisson regression and dormitory/cluster-robust standard errors showed that the detection of N and E genes were associated with increases of 85% and 99% in the likelihood of COVID-19 cases 8 days later (incident-rate ratio (IRR) = 1.845, p = 0.013 and IRR = 1.994, p = 0.007, respectively; n = 215), and one-log increases in swipe card normalized viral copies (copies/100 mL/100 people) for N and E were associated with increases of 21% and 27% in the likelihood of observing COVID-19 cases 8 days following sample collection (IRR = 1.206, p < 0.001, n = 211 for N; IRR = 1.265, p < 0.001, n = 211 for E). One-log increases in swipe normalized copies were also associated with 40% and 43% increases in the likelihood of observing COVID-19 cases 5 days after sample collection (IRR = 1.403, p = 0.002, n = 212 for N; IRR = 1.426, p < 0.001, n = 212 for E). Our findings highlight the use of building-specific occupancy data and add to the evidence for the potential of wastewater-based epidemiology to predict COVID-19 trends at subsewershed scales.
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    Vaccine Effectiveness During an Outbreak of COVID-19 Alpha Variant (B.1.1.7) in a Men’s Correctional Facility in Rural Virginia
    Silverman, Rachel A.; Ceci, Alessandro; Cohen, Alasdair; Helmick, Meagan; Short, Erica; Bordwine, Paige; Friedlander, Michael J.; Finkielstein, Carla V. (2022-07)
    In April 2021, a COVID-19 outbreak occurred at a correctional facility in rural Virginia, USA. Eighty-four infections were identified among 854 incarcerated persons by facilitywide testing with reverse transcription quantitative PCR (qRT-PCR). We used whole-genome sequencing to link all infections to 2 employees infected with the B.1.1.7α (UK) variant. The relative risk comparing unvaccinated to fully vaccinated persons (mRNA-1273 [Moderna, https:// www.moderna.com]) was 7.8 (95% CI 4.8–12.7), corresponding to a vaccine effectiveness of 87.1% (95% CI 79.0%–92.1%). Average qRT-PCR cycle threshold values were lower, suggesting higher viral loads, among unvaccinated infected than vaccinated cases for the N, E, and S genes. Vaccination was highly effective at preventing SARS-CoV-2 infection in this high-risk setting. This approach can be applied to similar settings to estimate vaccine effectiveness as variants emerge to guide public health strategies during the ongoing pandemic.
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    Vaccine Effectiveness during Outbreak of COVID-19 Alpha (B.1.1.7) Variant in Men’s Correctional Facility, United States
    Silverman, Rachel A.; Ceci, Alessandro; Cohen, Alasdair; Helmick, Meagan; Short, Erica; Bordwine, Paige; Friedlander, Michael J.; Finkielstein, Carla V. (Centers for Disease Control and Prevention, 2022-07)
    In April 2021, a COVID-19 outbreak occurred at a correctional facility in rural Virginia, USA. Eighty-four infections were identified among 854 incarcerated persons by facilitywide testing with reverse transcription quantitative PCR (qRT-PCR). We used whole-genome sequencing to link all infections to 2 employees infected with the B.1.1.7α (UK) variant. The relative risk comparing unvaccinated to fully vaccinated persons (mRNA-1273 [Moderna, https:// www.moderna.com]) was 7.8 (95% CI 4.8–12.7), corresponding to a vaccine effectiveness of 87.1% (95% CI 79.0%–92.1%). Average qRT-PCR cycle threshold values were lower, suggesting higher viral loads, among unvaccinated infected than vaccinated cases for the N, E, and S genes. Vaccination was highly effective at preventing SARS-CoV-2 infection in this high-risk setting. This approach can be applied to similar settings to estimate vaccine effectiveness as variants emerge to guide public health strategies during the ongoing pandemic.