Dissemination of well water arsenic results to homeowners in Central Maine: influences on mitigation behavior and continued risks for exposure

Improving Private Well Testing Programs: Experimental Evidence from Iowa

Approximately 23 million U.S. households rely on private wells for drinking water. This study first summarizes drinking water behaviors and perceptions from a large-scale survey of households that rely on private wells in Iowa. Few households test as frequently as recommended by public health experts. Around 40% of households do not regularly test, treat, or avoid their drinking water, suggesting pollution exposure may be widespread among this population. Next, we utilize a randomized control trial to study how nitrate test strips and information about a free, comprehensive water quality testing program influence households' behaviors and perceptions. The intervention significantly increased testing, including high-quality follow-up testing, but had limited statistically detectable impacts on other behaviors and perceptions. Households' willingness to pay for nitrate test kits and testing information exceeds program costs, suggesting that the intervention was welfare-enhancing.

A Mixed Methods Approach to Understanding the Public Health Impact of a School-Based Citizen Science Program to Reduce Arsenic in Private Well Water

BACKGROUND

Exposure to arsenic (As) in well water is a well-documented public health issue for Maine and New Hampshire, as well as for other states in the United States and abroad. Arsenic contamination of well water in these locations is primarily attributed to metasedimentary bedrock that leaches As into groundwater. However, As can also enter groundwater reserves from soils contaminated by the historical use of arsenical pesticides. Approximately half of the households in Maine and New Hampshire rely on private wells, many of which have elevated As. Arsenic exposure has been associated with an increased risk of cancer, cardiovascular disease, reduced infection resistance, and lower intelligence quotient in children. Despite these known health impacts, well water testing and treatment are not universal.

OBJECTIVES

We have approached the problem of low well water testing rates in Maine and New Hampshire communities by developing the All About Arsenic (AAA) project, which engages secondary school teachers and students as citizen scientists in collecting well water samples for analysis of As and other toxic metals and supports their outreach efforts to their communities.

METHODS

We assessed this project's public health impact by analyzing student data relative to existing well water quality datasets in both states. In addition, we surveyed private well owners who contributed well water samples to the project to determine the actions taken to mitigate As in well water.

RESULTS

Students collected 3,070 drinking water samples for metals testing, and 752 exceeded New Hampshire's As standard of 5  ppb . The AAA data has more than doubled the amount of information available to public health agencies about well water quality in multiple municipalities across both states. Students also collected information about well types and treatment systems. Their data reveal that some homeowners did not know what type of wells they had or whether they had filtration systems. Those with filtration systems were often unaware of the type of system, what the system was filtering for, or whether the system was designed to remove As. Through interviews with pilot survey participants, we learned that some had begun mitigating their exposure to As and other toxic metals in response to test results from the AAA project.

DISCUSSION

A school-based approach to collecting and analyzing private well water samples can successfully reach communities with low testing rates for toxic elements, such as As and other metals. Importantly, information generated through the program can impact household decision-making, and students can influence local and state policymaking by sharing information in their communities. https://doi.org/10.1289/EHP13421.

Assessing the Influence of Hand-Dug Well Features and Management on Water Quality

Underground water quality can be affected by natural or human-made influences. This study investigates how the management and characteristics of hand-dug wells impact water quality in 3 suburbs of Kumasi, Ghana, using a combination of qualitative and quantitative research methods. Descriptive analysis, including frequency and percentages, depicted the demographic profiles of respondents. Box plot diagrams illustrated the distribution of physicochemical parameters (Total Dissolved Solid [TDS], Electrical Conductivity [EC], Turbidity, Dissolved Oxygen [DO], and Temperature). Factor analysis evaluated dominant factors among these parameters. Cluster analysis (hierarchical clustering) utilized sampling points as variables to establish spatial variations in water physicochemical parameters. Cramer's V correlation test explored relationships between demographic variables and individual perceptions of water management. One-way ANOVA verified significant mean differences among the physicochemical parameters. Logistic regression models assessed the influence of selected well features (e.g., cover and apron) on TDS, pH, Temperature, Turbidity, and DO. The findings revealed that proximity to human settlements affects water quality, and increasing turbidity is associated with unmaintained covers, significantly impacting water quality (P < .05). Over 80% of wells were located within 10 to 30 m of pollution sources, with 65.63% situated in lower ground and 87.5% being unmaintained. Other significant contamination sources included plastic bucket/rope usage (87.50%), defective linings (75%), and apron fissures (59.37%). Presence of E. coli, Total coliform, and Faecal coliform rendered the wells unpotable. Factor analysis attributed 90.85% of time-based and spatial differences to organic particle decomposition factors. However, Cramer's V correlation analysis found establishing association between demographic factor associations with individual perceptions of hand-dug well management difficult. It is encouraged to promote hand-dug well construction and maintenance standards to ensure that wells are properly built and protected from contamination sources.

An overview of the Be Well Home Health Navigator Program to reduce contaminants in well water: Design and methods

BACKGROUND

The Be Well Home Health Navigator Program is a prospective, randomized controlled trial (RCT) implemented to compare a community health navigator program to usual care program to reduce contaminants in drinking water.

DESIGN AND SETTING

This 4-year two-armed RCT will involve well owners in Oregon that have private drinking water wells that contain arsenic, nitrate, or lead above maximum contaminant levels.

INTERVENTION

The intervention leverages the trusted relationship between Cooperative Extension Service (CES) Community Educators and rural well owners to educate, assist and motivate to make decisions and set actionable steps to mitigate water contamination. In this study, CES will serve as home health navigators to deliver: 1) individualized feedback, 2) positive reinforcement, 3) teach-back moments, 4) decision-making skills, 5) navigation to resources, 6) self-management, and 7) repeated contact for shaping and maintenance of behaviors. Usual care includes information only with no access to individual meetings with CES.

MEASURABLE OUTCOMES

Pre-specified primary outcomes include 1) adoption of treatment to reduce exposure to arsenic, nitrate, or lead in water which may include switching to bottled water and 2) engagement with well stewardship behaviors assessed at baseline, and post-6 and 12 months follow-up. Water quality will be measured at baseline and 12-month through household water tests. Secondary outcomes include increased health literacy scores and risk perception assessed at baseline and 6-month surveys.

IMPLICATIONS

The results will demonstrate the efficacy of a domestic well water safety program to disseminate to other CES organizations.

TRIAL REGISTRATION NUMBER

NCT05395663.

Effect of an Arsenic Mitigation Program on Arsenic Exposure in American Indian Communities: A Cluster Randomized Controlled Trial of the Community-Led Strong Heart Water Study Program

BACKGROUND

Chronic arsenic exposure has been associated with an increased risk of cardiovascular disease; diabetes; cancers of the lung, pancreas and prostate; and all-cause mortality in American Indian communities in the Strong Heart Study.

OBJECTIVE

The Strong Heart Water Study (SHWS) designed and evaluated a multilevel, community-led arsenic mitigation program to reduce arsenic exposure among private well users in partnership with Northern Great Plains American Indian Nations.

METHODS

A cluster randomized controlled trial (cRCT) was conducted to evaluate the effectiveness of the SHWS arsenic mitigation program over a 2-y period on a) urinary arsenic, and b) reported use of arsenic-safe water for drinking and cooking. The cRCT compared the installation of a point-of-use arsenic filter and a mobile Health (mHealth) program (3 phone calls; SHWS mHealth and Filter arm) to a more intensive program, which included this same program plus three home visits (3 phone calls and 3 home visits; SHWS Intensive arm).

RESULTS

A 47% reduction in urinary arsenic [geometric mean  ( GM ) = 13.2  to  7.0 μ g / g creatinine] was observed from baseline to the final follow-up when both study arms were combined. By treatment arm, the reduction in urinary arsenic from baseline to the final follow-up visit was 55% in the mHealth and Filter arm (GM = 14.6  to  6.55 μ g / g creatinine) and 30% in the Intensive arm (GM = 11.2  to  7.82 μ g / g creatinine). There was no significant difference in urinary arsenic levels by treatment arm at the final follow-up visit comparing the Intensive vs. mHealth and Filter arms: GM ratio of 1.21 (95% confidence interval: 0.77, 1.90). In both arms combined, exclusive use of arsenic-safe water from baseline to the final follow-up visit significantly increased for water used for cooking (17% to 53%) and drinking (12% to 46%).

DISCUSSION

Delivery of the interventions for the community-led SHWS arsenic mitigation program, including the installation of a point-of-use arsenic filter and a mHealth program on the use of arsenic-safe water (calls only, no home visits), resulted in a significant reduction in urinary arsenic and increases in reported use of arsenic-safe water for drinking and cooking during the 2-y study period. These results demonstrate that the installation of an arsenic filter and phone calls from a mHealth program presents a promising approach to reduce water arsenic exposure among private well users. https://doi.org/10.1289/EHP12548.

Behavioral determinants of arsenic-safe water use among Great Plains Indian Nation private well users: results from the Community-Led Strong Heart Water Study Arsenic Mitigation Program

BACKGROUND

The objective of this study was to evaluate the behavioral determinants associated with exclusive use of arsenic-safe water in the community-led Strong Heart Water Study (SHWS) arsenic mitigation program.

METHODS

The SHWS is a randomized controlled trial of a community-led arsenic mitigation program designed to reduce arsenic exposure among private well users in American Indian Great Plains communities. All households received point-of-use (POU) arsenic filters installed at baseline and were followed for 2 years. Behavioral determinants selected were those targeted during the development of the SHWS program, and were assessed at baseline and follow-up.

RESULTS

Among participants, exclusive use of arsenic-safe water for drinking and cooking at follow-up was associated with higher self-efficacy for accessing local resources to learn about arsenic (OR: 5.19, 95% CI: 1.48-18.21) and higher self-efficacy to resolve challenges related to arsenic in water using local resources (OR: 3.11, 95% CI: 1.11-8.71). Higher commitment to use the POU arsenic filter faucet at baseline was also a significant predictor of exclusive arsenic-safe water use for drinking (OR: 32.57, 95% CI: 1.42-746.70) and cooking (OR: 15.90, 95% CI: 1.33-189.52) at follow-up. From baseline to follow-up, the SHWS program significantly increased perceived vulnerability to arsenic exposure, self-efficacy, descriptive norms, and injunctive norms. Changing one's arsenic filter cartridge after installation was associated with higher self-efficacy to obtain arsenic-safe water for drinking (OR: 6.22, 95% CI: 1.33-29.07) and cooking (OR: 10.65, 95% CI: 2.48-45.68) and higher perceived vulnerability of personal health effects (OR: 7.79, 95% CI: 1.17-51.98) from drinking arsenic-unsafe water.

CONCLUSIONS

The community-led SHWS program conducted a theory-driven approach for intervention development and evaluation that allowed for behavioral determinants to be identified that were associated with the use of arsenic safe water and changing one's arsenic filter cartridge. These results demonstrate that theory-driven, context-specific formative research can influence behavior change interventions to reduce water arsenic exposure. The SHWS can serve as a model for the design of theory-driven intervention approaches that engage communities to reduce arsenic exposure.

TRIAL REGISTRATION

The SHWS is registered with ClinicalTrials.gov (Identifier: NCT03725592).

Study design and methods of the Wells and Enteric disease Transmission (WET) Trial: a randomised controlled trial

INTRODUCTION

The burden of disease attributed to drinking water from private wells is not well characterised. The Wells and Enteric disease Transmission trial is the first randomised controlled trial to estimate the burden of disease that can be attributed to the consumption of untreated private well water. To estimate the attributable incidence of gastrointestinal illness (GI) associated with private well water, we will test if the household treatment of well water by ultraviolet light (active UV device) versus sham (inactive UV device) decreases the incidence of GI in children under 5 years of age.

METHODS AND ANALYSIS

The trial will enrol (on a rolling basis) 908 families in Pennsylvania, USA, that rely on private wells and have a child 3 years old or younger. Participating families are randomised to either an active whole-house UV device or a sham device. During follow-up, families will respond to weekly text messages to report the presence of signs and symptoms of gastrointestinal or respiratory illness and will be directed to an illness questionnaire when signs/symptoms are present. These data will be used to compare the incidence of waterborne illness between the two study groups. A randomly selected subcohort submits untreated well water samples and biological specimens (stool and saliva) from the participating child in both the presence and absence of signs/symptoms. Samples are analysed for the presence of common waterborne pathogens (stool and water) or immunoconversion to these pathogens (saliva).

ETHICS

Approval has been obtained from Temple University's Institutional Review Board (Protocol 25665). The results of the trial will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04826991.

A critical review of on-site inorganic arsenic screening methods

Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 µg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested. Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (∼10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.

Evaluation of a water arsenic filter in a participatory intervention to reduce arsenic exposure in American Indian communities: The Strong Heart Water Study

Many rural populations, including American Indian communities, that use private wells from groundwater for their source of drinking and cooking water are disproportionately exposed to elevated levels of arsenic. However, programs aimed at reducing arsenic in American Indian communities are limited. The Strong Heart Water Study (SHWS) is a randomized controlled trial aimed at reducing arsenic exposure among private well users in American Indian Northern Great Plains communities. The community-led SHWS program installed point-of-use (POU) arsenic filters in the kitchen sink of households, and health promoters delivered arsenic health communication programs. In this study we evaluated the efficacy of these POU arsenic filters in removing arsenic during the two-year installation period. Participants were randomized into two arms. In the first arm households received a POU arsenic filter, and 3 calls promoting filter use (SHWS mobile health (mHealth) & filter arm). The second arm received the same filter and phone calls, and 3 in-person home visits and 3 Facebook messages (SHWS intensive arm) for program delivery. Temporal variability in water arsenic concentrations from the main kitchen faucet was also evaluated. A total of 283 water samples were collected from 50 households with private wells from groundwater (139 filter and 144 kitchen faucet samples). Ninety-three percent of households followed after baseline had filter faucet water arsenic concentrations below the arsenic maximum contaminant level of 10 μg/L at the final visit during our 2 year study period with no difference between study arms (98 % in the intensive arm vs. 94 % in the mHealth & filter arm). No significant temporal variation in kitchen arsenic concentration was observed over the study period (intraclass correlation coefficient = 0.99). This study demonstrates that POU arsenic filters installed for the community participatory SHWS program were effective in reducing water arsenic concentration in study households in both arms, even with delivery of the POU arsenic filter and mHealth program only. Furthermore, we observed limited temporal variability of water arsenic concentrations from kitchen faucet samples collected over time from private wells in our study setting.

Classification of sub-populations for quantitative risk assessment based on awareness and perception: A cross-sectional population study of private well users in Ontario

Private well users in Ontario are responsible for protective actions, including source maintenance, treatment, and submitting samples for laboratory testing. However, low participation rates are reported, thus constituting a public health concern, as risk mitigation behaviours can directly reduce exposure to waterborne pathogens. The current study examined the combined effects of socio-demographic profile, experience(s), and "risk domains" (i.e., awareness, attitudes, risk perceptions and beliefs) on behaviours, and subsequently classified private well users in Ontario based on cognitive factors. A province-wide online survey (n = 1228) was employed to quantify Ontario well owners' awareness, perceptions, and behaviours in relation to their personal groundwater supply and local contamination sources. A scoring protocol for four risk domains was developed. Two-step cluster analysis was used to classify respondents based on individual risk domain scores. Logistic regression was employed to identify key variables associated with cluster membership (i.e., profile analysis). Overall, 1140 survey respondents were included for analyses. Three distinct clusters were identified based on two risk domains; groundwater awareness and source risk perception. Profile analyses indicate "low awareness and source risk perception" (Low A/SRP) members were more likely male, while "low awareness and moderate source risk perception" (Low A/Mod SRP) members were more likely female and bottled water users. Well users characterised as "high awareness and source risk perception" (High A/SRP) were more likely to report higher educational attainment and previous well water testing. Findings illustrate that socio-cognitive clusters and their components (i.e., demographics, awareness, attitudes, perceptions, experiences, and protective actions) are distinct based on the likelihood, frequency, and magnitude of waterborne pathogen exposures (i.e., risk-based). Risk-based clustering, when incorporated into quantitative microbial risk assessment, enables the development of effective risk management and communication initiatives that are demographically focused and tailored to specific sub-groups.

Targeted Private Well Outreach Following a Change in Drinking Water Standard: Arsenic and the New Jersey Private Well Testing Act

CONTEXT

When the New Jersey Private Well Testing Act (PWTA) became effective in 2002, the maximum contaminant level (MCL) for arsenic in the United States was 50 μg/L. In 2006, the federal and New Jersey MCLs were lowered to 10 μg/L and 5 μg/L, respectively.

OBJECTIVE

To notify and provide free arsenic water testing for homeowners who had a PWTA arsenic result that passed for the MCL in 2006 or earlier but would exceed under the more health protective MCL enacted in 2006, which is still in effect as of this publication date.

DESIGN

About 1200 homeowners with PWTA arsenic results between 5 μg/L and 50 μg/L were offered free arsenic water testing. More than 400 homeowners requested tests and 292 returned samples.

SETTING

New Jersey, United States.

PARTICIPANTS

Homeowners with a passing PWTA arsenic result before 2006 that would have failed under the New Jersey arsenic MCL enacted in 2006.

MAIN OUTCOME MEASURES

Return rate of testing kits; number of tests exceeding arsenic MCL; and participant survey results.

RESULTS

Untreated well water samples (n = 279) were collected and 62.4% exceeded the New Jersey MCL. Treated well water samples (n = 102) were collected and 11.8% exceeded the current New Jersey MCL. In all, about 40% of drinking water samples from the tap, including those with or with no arsenic treatment, exceeded the New Jersey MCL. A survey of participants (n = 69) found that although many (67%) respondents reported that they at least had some idea that wells in their area are vulnerable to naturally occurring contaminants, such as arsenic, many (68%) reported that they had little or no idea that the New Jersey arsenic MCL had been lowered from 50 μg/L to 5 μg/L in 2006.

CONCLUSIONS

This effort further illuminates the necessity and significance of public health outreach for private well water users, especially after drinking water standards change.

Naturally occurring metals in unregulated domestic wells in Nevada, USA

The dominant source of drinking water in rural Nevada, United States, is privately-owned domestic wells. Because the water from these wells is unregulated with respect to government guidelines, it is the owner's responsibility to test their groundwater for heavy metals and other contaminants. Arsenic, lead, cadmium, and uranium have been previously measured at concentrations above Environmental Protection Agency (EPA) guidelines in Nevada groundwater. This is a public health concern because elevated levels of these metals are known to have negative health effects. We recruited individuals through a population health study, the Healthy Nevada Project, to submit drinking water samples from domestic wells for testing. Water samples were returned from 174 households with private wells. We found 22 % had arsenic concentrations exceeding the EPA maximum contaminant level (MCL) of 10 μg/L. Additionally, federal, state, or health-based guidelines were exceeded for 8 % of the households for uranium and iron, 6 % for lithium and manganese, 4 % for molybdenum, and 1 % for lead. The maximum observed concentrations of arsenic, uranium, and lead were ∼80, ∼5, and ∼1.5 times the EPA guideline values, respectively. 41 % of households had a treatment system and submitted both pre- and post-treatment water samples from their well. The household treatments were shown to reduce metal concentrations, but concentrations above guideline values were still observed. Many treatment systems cannot reduce the concentration below guideline values because of water chemistry, treatment failure, or improper treatment techniques. These results show the pressing need for continued education and outreach on regular testing of domestic well waters, proper treatment types, and health effects of metal contamination. These findings are potentially applicable to other arid areas where groundwater contamination of naturally occurring heavy metals occurs.

Do health risk perceptions motivate water - and health-related behaviour? A systematic literature review

Health-related risk perceptions are important determinants of health behaviours and components of behaviour change theories. What someone thinks or feels will motivate or hinder their intention or hesitancy to implement a certain behaviour. Thus, a perceived potential risk to our health and well-being can influence our health-promoting and/or health-seeking behaviour. We aimed to review and synthesize available peer-reviewed literature to better understand the links between water and health-related risk perceptions and behaviours. We conducted the first systematic review of peer-reviewed literature on risk perceptions and behaviours in the context of water and health, published between 2000 and 2021. A total of 187 publications met the inclusion criteria. We extracted data relating to study characteristics and categorized our results according to the major themes emerging from the literature, namely drinking water, sanitation, hygiene and wasterelated topics, health risk factors, diseases and mental health implications, and preventative measures. Our review shows that the literature has grown over the past twenty years, reporting information from different countries belonging to different income groups around the globe, conducted in various settings and contexts, among different target populations, from various disciplinary angles, using different methods, theories and approaches. Our review provides evidence of health risk perceptions determining behaviour particularly related to drinking water sources and water safety. Evidence on disease prevention, health seeking, variations and changes in perception and behaviour over space, geography, socioeconomic differences and time, and the relevance of cultural context is provided. Our review shows that risk perception studies are vital for WASH governance in terms of policy, raising awareness, education and behaviour change. In order to make risk perception and behaviour studies even more relevant to effective public health planning and health messaging, future research needs to increasingly focus on early culturally sensitive interventions and changes in perceptions and behaviours over time.

User experience of point-of-use water treatment for private wells in North Carolina: Implications for outreach and well stewardship

Private well users are potentially exposed to a range of chemical contaminants through their drinking water. Point-of-use (POU) water treatment represents one potential solution to reduce harmful exposures through well water, but well users frequently do not adopt household treatment even if they learn their water is contaminated. This study elucidates the experiences, perceptions, and beliefs of 17 households on private wells in North Carolina that participated in a pilot-scale POU water treatment intervention to better understand the drivers and barriers of POU treatment adoption among well users. The intervention consisted of an under-sink activated carbon block POU filter designed to remove lead and two long-chain perfluoroalkyl acids. Filter effluents and influents were tested monthly for eight months. Questionnaires administered before and after the intervention showed a significant decrease in participants' perceived vulnerability to well water contamination, with 77% feeling vulnerable to poor well water quality before, compared to 23% after the filter was installed. However, the POU filters did not fully eliminate feelings of water insecurity (for example, concerns about exposure to contaminants when bathing remained). Lack of knowledge and skills associated with installing and maintaining POU treatment were important barriers to adoption for some well users. Perceptions of POU treatment were also significantly correlated with the intent to implement other well stewardship behaviors such as well water testing. The results highlight the need for strengthened outreach and support programs that provide technical assistance, education, and financial support for households relying on private wells.

Evaluating the impact of free private well testing outreach on participants' private well stewardship in New Jersey

Over 1 million people in New Jersey (NJ) are estimated to receive drinking water from private wells. The most commonly detected contaminants in NJ private well water are naturally occurring arsenic and gross alpha (8.3 and 10.9%, respectively). Between 2015 and 2018, three free and voluntary private well testing events tested a total of 571 at-risk wells and 226 (40%) were identified as having one or more contaminants exceeding drinking water standards. Participants were invited to complete a survey to evaluate household characteristics, participant experience, and private well stewardship behavior patterns. Of 529 delivered surveys, 211 (40%) participants completed surveys. Among respondents, 63% reported plans to test their private wells in the future. Among failed wells, 45% of households reported performing mitigative action in response to the event, either through the installation of water treatment system or switching to bottled water. The survey evaluation identified previous knowledge of well contamination risks and discussing test results with a third party as important factors for promoting self-reported stewardship behavior. The evaluation provides guidance for outreach organizers to develop effective testing events and further considers the private well owners' experience of the outreach events to identify information for 'best practices' and improvements of future programs.

Leveraging Health Care Communication Channels for Environmental Health Outreach in New Jersey

Households with pregnancies and young children are a priority group for outreach on private well water screening due to the widespread occurrence and toxicity of common groundwater contaminants such as arsenic. Given the trusted role of health care providers as communicators of health risk, Columbia University investigators and New Jersey government partners collaborated with Hunterdon Healthcare to offer free well testing to residents of Hunterdon County, a hot spot for naturally occurring arsenic in New Jersey. Through practice-based test kit distribution and online patient portal messages, supported by a public multimedia campaign, we tested 433 private wells and alerted 50 families about elevated arsenic found in their drinking water. These health care-facilitated outreach strategies allowed for targeting based on geographic and demographic risk and suggested opportunities to better leverage communication channels, such as incorporating questions on home water source into the electronic medical record.

Methods for Estimating Locations of Housing Units Served by Private Domestic Wells in the United States Applied to 2010

In 1990, the last time the decennial census included a question on domestic drinking water source, it was estimated that private domestic water wells (PDWs) supplied household water to about 15.1 million housing units (15% of the population) in the United States (U.S.). PDWs are not regulated by the Safe Drinking Water Act, and with few exceptions, are not subject to the water quality testing required of public water suppliers. We expanded two methods in estimating housing units reliant on PDWs from an Oklahoma pilot study (Weaver et al. 2017), nationally. Both use 1990 census data on drinking water sources as a baseline. The first method uses housing unit change and private well drilling logs for 20 states. This allows for the rate of well use to change between 1990 and 2010 in these states. The second, based solely on housing unit change, assumes a constant rate of well use. Ordinary least squares regression demonstrated (R ² = 0.78) that the methods yield similar estimates for nationwide well use. Using the housing unit change method, it is estimated that in 2010, 23 million housing units were reliant on PDWs (17% of the population). We provide these estimates at the census block group and census block resolution. This dataset will assist in a better understanding of the reliance on PDWs in the U.S., and position local, tribal, state, and national groups to better protect this water resource from contaminant sources.

RESEARCH IMPACT STATEMENT

The work provides improved estimates of the spatial distribution of housing units reliant on private domestic wells in the United States and a foundation to protect this water supply at all levels of government.

Defining drinking water metal contaminant mixture risk by coupling zebrafish behavioral analysis with citizen science

Contaminated drinking water is an important public health consideration in New England where well water is often found to contain arsenic and other metals such as cadmium, lead, and uranium. Chronic or high level exposure to these metals have been associated with multiple acute and chronic diseases, including cancers and impaired neurological development. While individual metal levels are often regulated, adverse health effects of metal mixtures, especially at concentrations considered safe for human consumption remain unclear. Here, we utilized a multivariate analysis that examined behavioral outcomes in the zebrafish model as a function of multiple metal chemical constituents of 92 drinking well water samples, collected in Maine and New Hampshire. To collect these samples, a citizen science approach was used, that engaged local teachers, students, and scientific partners. Our analysis of 4016 metal-mixture combinations shows that changes in zebrafish behavior are highly mixture dependent, and indicate that certain combinations of metals, especially those containing arsenic, cadmium, lead, and uranium, even at levels considered safe in drinking water, are significant drivers of behavioral toxicity. Our data emphasize the need to consider low-level chemical mixture effects and provide a framework for a more in-depth analysis of drinking water samples. We also provide evidence for the efficacy of utilizing citizen science in research, as the broader impact of this work is to empower local communities to advocate for improving their own water quality.

Development of Privacy Features on Anecdata.org, a Free Citizen Science Platform for Collecting Datasets for Climate Change and Related Projects

The Anecdata website and its corresponding mobile app provide unique features to meet the needs of a wide variety of diverse citizen science projects from across the world. The platform has been developed with the help of continuous feedback from community partners, project leaders, and website users and currently hosts more than 200 projects. Over 8,000 registered users have contributed more than 30,000 images and over 50,000 observations since the platform became open to the public in 2014. From its inception, one of the core tenets of Anecdata's mission has been to make data from citizen science projects freely accessible to project participants and the general public, and in the platform's first few years, it followed a completely open data access model. As the platform has grown, hosting ever more projects, we have found that this model does not meet all project needs, especially where endangered species, property access rights, participant safety in the field, and personal privacy are concerned. We first introduced features for data and user privacy as part of "All About Arsenic," a National Institutes of Health (NIH)/National Institute of General Medical Sciences (NIGMS) Science Education Partnership Award (SEPA)-funded project at MDI Biological Laboratory, which engages middle and high school teachers and students from schools across Maine and New Hampshire in sampling their home well water for analysis of arsenic and other heavy metals. In order to host this project on Anecdata, we developed features for spatial privacy or "geoprivacy" to conceal the coordinates of samplers' homes, partial data redaction tools we call "private fields" to withhold certain sample registration questions from public datasets, and "participant anonymity" to conceal which user account uploaded an observation. We describe the impetus for the creation of these features, challenges we encountered, and our technical approach. While these features were originally developed for the purposes of a public health and science literacy project, they are now available to all project leaders setting up projects on Anecdata.org and have been adopted by a number of projects, including Mass Audubon's Eastern Meadowlark Survey, South Carolina Aquarium's SeaRise, and Coastal Signs of the Seasons (SOS) Monitoring projects.

Recommended Sampling Intervals for Arsenic in Private Wells

Geogenic arsenic in drinking water is a worldwide problem. For private well owners, testing (e.g., private or government laboratory) is the main method to determine arsenic concentration. However, the temporal variability of arsenic concentrations is not well characterized and it is not clear how often private wells should be tested. To answer this question, three datasets, two new and one publicly available, with temporal arsenic data were utilized: 6370 private wells from New Jersey tested at least twice since 2002, 2174 wells from the USGS NAWQA database, and 391 private wells sampled 14 years apart from Bangladesh. Two arsenic drinking water standards are used for the analysis: 10 µg/L, the WHO guideline and EPA standard or maximum contaminant level (MCL) and 5 µg/L, the New Jersey MCL. A rate of change was determined for each well and these rates were used to predict the temporal change in arsenic for a range of initial arsenic concentrations below an MCL. For each MCL and initial concentration, the probability of exceeding an MCL over time was predicted. Results show that to limit a person to below a 5% chance of drinking water above an MCL, wells that are ½ an MCL and above should be tested every year and wells below ½ an MCL should be tested every 5 years. These results indicate that one test result below an MCL is inadequate to ensure long-term compliance. Future recommendations should account for temporal variability when creating drinking water standards and guidance for private well owners.

Reduction in drinking water arsenic exposure and health risk through arsenic treatment among private well households in Maine and New Jersey, USA

Over 2 million mostly rural Americans are at risk of drinking water from private wells that contain arsenic (As) exceeding the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) of 10 micrograms per liter (μg/L). How well existing treatment technologies perform in real world situations, and to what extent they reduce health risks, are not well understood. This study evaluates the effectiveness of household As treatment systems in southern-central Maine (ME, n = 156) and northern New Jersey (NJ, n = 94) and ascertains how untreated well water chemistry and other factors influence As removal. Untreated and treated water samples, as well as a treatment questionnaire, were collected. Most ME households had point-of-use reverse-osmosis systems (POU RO), while in NJ, dual-tank point-of-entry (POE) whole house systems were popular. Arsenic treatment systems reduced well water arsenic concentrations ([As]) by up to two orders of magnitude, i.e. from a median of 71.7 to 0.8 μg/L and from a mean of 105 to 14.3 μg/L in ME, and from a median of 8.6 to 0.2 μg/L and a mean of 15.8 to 2.1 μg/L in NJ. More than half (53%) of the systems in ME reduced water [As] to below 1 μg/L, compared to 69% in NJ. The treatment system failure rates were 19% in ME (>USEPA MCL of 10 μg/L) and 16% in NJ (>NJ MCL of 5 μg/L). In both states, the higher the untreated well water [As] and the As(III)/As ratio, the higher the rate of treatment failure. POE systems failed less than POU systems, as did the treatment systems installed and maintained by vendors than those by homeowners. The 7-fold reduction of [As] in the treated water reduced skin cancer risk alone from 3765 to 514 in 1 million in ME, and from 568 to 75 in 1 million in NJ.

Private well stewardship within a rural, agricultural Latino community: a qualitative study

BACKGROUND

Nitrate contamination in groundwater disproportionately impacts agricultural Latino communities, creating a significant hazard for Latinos that rely on private wells. Private well users must conduct water testing and other well stewardship behaviors to ensure that their well water is safe to drink. This study sought to identify the key factors impacting private well water testing behavior in rural, agricultural Latino communities.

METHODS

We conducted 4 focus groups with private well users, 2 in Spanish and 2 in English. We recruited 37 participants from the Lower Yakima Valley, Washington State, a rural, agricultural community with a large Latino population and elevated nitrate concentrations in groundwater. A semi-structured interview guide was developed to capture factors impacting testing as guided by the Risk, Attitudes, Norms, Ability, and Self-Regulation (RANAS) model. Inductive thematic analysis was conducted by two coders to identify common themes.

RESULTS

Themes emerged around the factors impacting well stewardship, including well water testing, treatment, and maintenance, and were not specific to nitrate contamination. Private well users reported many of the same factors reported in other communities, with the exception of home repair experience and challenges around landlords and neighbors on shared wells, which have not been reported previously. In addition to landlords and neighbors, lack of actionable information, economic limitations, and lack of technical support emerged as factors that made well stewardship burdensome for individuals. The majority of participants reported using bottled water, including many who used point-of-use or point-of-entry water treatment systems.

CONCLUSIONS

The burden of well stewardship in rural, agricultural Latino communities may suggest the need for interventions at the community, county, or state levels and not at the individual level alone. Additionally, the role of landlords, neighbors on shared wells, and home repair experience in well stewardship represent important areas of exploration for researchers and public health practitioners.

Knowledge and behavioural interventions to reduce human health risk from private groundwater systems: A global review and pooled analysis based on development status

Groundwater contamination constitutes a significant health risk for private well users residing in rural areas. As the responsibility to safeguard rural private domestic groundwater typically rests with non-expert homeowners, interventions promoting risk mitigation and awareness represent the most viable means of preventing supply contamination. However, no global review or pooled analyses of these interventions has been undertaken to date. The current study sought to identify and quantify the performance of private well interventions from 1990 to 2018 via a global systematised review and pooled analysis. The PICO (Population-Intervention-Comparison-Outcome) approach was employed for literature identification. Relevant studies were statistically analysed across two quantitative outcome (performance) types, namely knowledge and behaviour, controlling for intervention characteristics and country development status. Mean behavioural and knowledge attainment across interventions was 53% and 48%, respectively, with interventions in economically developed regions exhibiting higher behavioural outcomes (56% vs. 45%) than those in developing regions. Geographically, interventions were located in southern or southeast Asia (n = 23), North America (n = 15), Central America (n = 1) and Africa (n = 1), with none identified in Australia/Oceania, Europe, or South America. Behavioural outcomes were significantly associated with presence of educational/research coordinator (p = 0.023), with these interventions attaining higher levels of efficacy (+74%) than those implemented by other coordinator types. Findings indicate that instructor-led, practical interventions allied with both large- and local-scale awareness-raising campaigns represent an optimum approach for future private well risk interventions. Subsequent adoption of such interventions may lead to increased levels of private well maintenance and provide a point of reference for myriad water and health communication contexts.

FRESH: Long-Term Outcomes of a Randomized Trial to Reduce Radon and Tobacco Smoke in the Home

Introduction

Tobacco smoke and radon are the leading causes of lung cancer. The FRESH intervention was a randomized controlled trial of 515 homeowners to promote stage of action to reduce radon and air nicotine levels.

Methods

We studied 515 participants, 257 in a treatment group and 258 in a control group. Treatment participants received free radon and air nicotine test kits, report back, and telephone support, and those participants whose homes had high radon levels received a voucher for $600 toward mitigation. Both groups were asked to retest 15 months post intervention. We examined differences in stage of action to test for and mitigate radon and adopt a smoke-free–home policy and in observed radon and air nicotine values by study group over time.

Results

Homeowners in the treatment group scored higher on stage of action to test for radon and air nicotine and to mitigate for radon during follow-up than those in the control group at 3 months and 9 months, but the effect of the intervention diminished after 9 months. We saw no difference between groups or over time in observed radon or air nicotine values. Of homeowners in the treatment group with high radon levels at baseline, 17% mitigated, and 80% of them used the voucher we provided.

Conclusion

The null finding of no significant change in observed radon or air nicotine values from baseline to 15 months may reflect the low proportion of radon mitigation systems installed and the decline in stage of action to adopt a smoke-free home policy. Including a booster session at 9 months post intervention may improve the remediation rate.

Arsenic concentrations after drinking water well installation: Time-varying effects on arsenic mobilization

Chronic exposure to geogenic arsenic via drinking water is a worldwide health concern. However, effects of well installation and operation on arsenic concentrations and mobilization are not well understood. This knowledge gap impacts both reliable detection of arsenic in drinking water and effective public health recommendations to reduce exposure to arsenic. This study examines changes in arsenic and redox geochemistry over one year following installation of 254 new domestic water wells in three regions of the north-central USA that commonly have elevated arsenic concentrations. Our regions' geologic settings share some important characteristics with other high-arsenic aquifers: igneous bedrock aquifers; or late Pleistocene-age glacial sand and gravel aquifers interbedded with aquitards. Over the study, arsenic concentrations increased by 16% or more in 25% of wells in glacial aquifer regions, and the redox conditions changed towards more reducing. In wells in the bedrock region, there was no significant change in arsenic concentrations, and redox conditions changed towards more oxidizing. Our findings illustrate the importance of understanding short- to moderate-term impacts of well installation and operation on arsenic and aqueous chemistry, as it relates to human exposure. Our study informs water quality sampling requirements, which currently do not consider the implications sampling timing with respect to well installation. Evaluating arsenic concentrations in samples from new wells in the context of general regional pH and redox conditions can provide information regarding the degree of disequilibrium created by well drilling. Our analysis approach may be transferable and scalable to similar aquifer settings across the globe.

Factors influencing perceptions of private water quality in North America: a systematic review

BACKGROUND

An estimated four million and 43 million people in Canada and the USA use private water supplies. Private water supplies are vulnerable to waterborne disease outbreaks. Private water supplies in Canada and the USA are often unregulated and private water management is often a choice left to the owner. Perceptions of water quality become important in influencing the adoption of private water stewardship practices, therefore safeguarding public health.

METHODS

We conducted a systematic literature review to understand factors that shape perceptions of water quality among private water users. We searched six computer databases (Web of science, Medline, Scopus, EBSCO, PubMed and Agricola). The search was limited to primary peer-reviewed publications, grey literature and excluded conference proceedings, review articles, and non-peer review articles. We restricted the search to papers published in English and to articles which published data on surveys of private water users within Canada and the USA. The search was also restricted to publications from 1986 to 2017. The literature search generated 36,478 records. Two hundred and four full text were reviewed.

RESULTS

Fifty-two articles were included in the final review. Several factors were found to influence perceptions of water quality including organoleptic preferences, chemical and microbiological contaminants, perceived risks, water well infrastructure, past experience with water quality, external information, demographics, in addition to the values, attitudes, and beliefs held by well owners.

CONCLUSIONS

Understanding the factors that shape perceptions of water quality among private water users is an important step in developing private water management policies to increase compliance towards water testing and treatment in Canada and the USA. As many jurisdictions in Canada and the USA do not have mandatory private water testing or treatment guidelines, delineating these factors is an important step in informing future research and guiding policy on the public health of private water systems.

Arsenic in groundwater in private wells in rural North Dakota and South Dakota: Water quality assessment for an intervention trial

Elevated exposure to arsenic disproportionately affects populations relying on private well water in the United States (US). This includes many American Indian (AI) communities where naturally occurring arsenic is often above 10 µg/L, the current US Environmental Protection Agency safety standard. The Strong Heart Water Study is a randomized controlled trial aiming to reduce arsenic exposure to private well water users in AI communities in North Dakota and South Dakota. In preparation for this intervention, 371 households were included in a community water arsenic testing program to identify households with arsenic ≥10 µg/L by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic ≥10 µg/L was found in 97/371 (26.1%) households; median water arsenic concentration was 6.3 µg/L, ranging from <1-198 µg/L. Silica was identified as a water quality parameter that could impact the efficacy of arsenic removal devices to be installed. A low-range field rapid arsenic testing kit evaluated in a small number of households was found to have low accuracy; therefore, not an option for the screening of affected households in this setting. In a pilot study of the effectiveness of a point-of-use adsorptive media water filtration device for arsenic removal, all devices installed removed arsenic below 1 µg/L at both installation and 9 months post-installation. This study identified a relatively high burden of arsenic in AI study communities as well as an effective water filtration device to reduce arsenic in these communities. The long-term efficacy of a community based arsenic mitigation program in reducing arsenic exposure and preventing arsenic related disease is being tested as part of the Strong Heart Water Study.

Health protective behavior following required arsenic testing under the New Jersey Private Well Testing Act

Exposure to naturally occurring arsenic in groundwater is a public health concern, particularly for households served by unregulated private wells. At present, one of the greatest barriers to exposure reduction is a lack of private well testing due to difficulties in motivating individual private well owners to take protective actions. Policy and regulations requiring testing could make a significant contribution towards universal screening of private well water and arsenic exposure reduction. New Jersey's Private Well Testing Act (PWTA) requires tests for arsenic during real estate transactions; however, the regulations do not require remedial action when maximum contaminant levels (MCLs) are exceeded. A follow-up survey sent to residents of homes where arsenic was measured above the state MCL in PWTA-required tests reveals a range of mitigation behavior among respondents (n = 486), from taking no action to reduce exposure (28%), to reporting both treatment use and appropriate maintenance and monitoring behavior (15%). Although 86% of respondents recall their well was tested during their real estate transaction, only 60% report their test showed an arsenic problem. Treatment systems are used by 63% of households, although half were installed by a previous owner. Among those treating their water (n = 308), 57% report that maintenance is being performed as recommended, although only 31% have tested the treated water within the past year. Perceived susceptibility and perceived barriers are strong predictors of mitigation action. Among those treating for arsenic, perceived severity is associated with recent monitoring, and level of commitment is associated with proper maintenance. Mention of a treatment service agreement is a strong predictor of appropriate monitoring and maintenance behavior, while treatment installed by a previous owner is less likely to be maintained. Though the PWTA requires that wells be tested, this study finds that not all current well owners are aware the test occurred or understood the implications of their arsenic results. Among those that have treatment installed to remove arsenic, poor monitoring and maintenance behaviors threaten to undermine intentions to reduce exposure. Findings suggest that additional effort, resources, and support to ensure home buyers pay attention to, understand, and act on test results at the time they are performed may help improve management of arsenic water problems over the long term and thus the PWTA's public health impact.

Private-well stewardship among a general population based sample of private well-owners

Private well stewardship, including on-going testing and treatment, can ensure private well users are able to maintain source-water quality and prevent exposures to potentially harmful constituents in primary drinking water supplies. Unlike municipal water supplies, private well users are largely responsible for their own testing and treatment and well stewardship is often minimal. The importance of factors influencing regular testing, and treatment behaviors, including knowledge, risk perception, convenience and social norms, can vary by geography and population characteristics. The primary goals of this study were to survey a general statewide population of private well users in Wisconsin in order to quantify testing and treatment patterns and gather data on motivations and barriers to well stewardship. The majority of respondents reported using and drinking well water daily but only about one half of respondents reported testing their wells in the last ten years and of these, only 10% reported testing in the last 12months. Bacteria and nitrates were contaminants most often tested; and, a private laboratory most often conducted testing. The most commonly reported water treatment was a water softener. Living in a particular geographic region and income were the most significant predictors of water testing and treatment. Iron and hardness, which influence water aesthetics but not always safety, were the most commonly reported water quality problems. Health concerns or perceived lack thereof were, respectively, motivators and barriers to testing and treatment. Limited knowledge of testing and treatment options were also identified as barriers. Results confirm previous findings that well stewardship practices are minimal and often context specific. Understanding the target population's perceptions of risk and knowledge are important elements to consider in identifying vulnerable populations and developing education and policy efforts to improve well stewardship.

Effectiveness of table top water pitcher filters to remove arsenic from drinking water

Arsenic contamination of drinking water is a serious threat to the health of hundreds of millions of people worldwide. In the United States ~3 million individuals drink well water that contains arsenic levels above the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10μg/L. Several technologies are available to remove arsenic from well water including anion exchange, adsorptive media and reverse osmosis. In addition, bottled water is an alternative to drinking well water contaminated with arsenic. However, there are several drawbacks associated with these approaches including relatively high cost and, in the case of bottled water, the generation of plastic waste. In this study, we tested the ability of five tabletop water pitcher filters to remove arsenic from drinking water. We report that only one tabletop water pitcher filter tested, ZeroWater®, reduced the arsenic concentration, both As³⁺ and As⁵⁺, from 1000μg/L to < 3μg/L, well below the MCL. Moreover, the amount of total dissolved solids or competing ions did not affect the ability of the ZeroWater® filter to remove arsenic below the MCL. Thus, the ZeroWater® pitcher filter is a cost effective and short-term solution to remove arsenic from drinking water and its use reduces plastic waste associated with bottled water.

Lessons Learned from Arsenic Mitigation among Private Well Households

PURPOSE OF REVIEW

Many thousands of research papers have been published on the occurrence, health effects, and mitigation of arsenic in drinking water sourced from groundwater around the world. Here, an attempt is made to summarize this large body of knowledge into a small number of lessons.

RECENT FINDINGS

This is an opinion paper reflecting on why we are far from the goal of eliminating this silent and widespread poison to protect the health of many millions. The lessons are drawn from research in countries representing a range of economic development and cultural contexts. The replacement of household wells with centralized water supplies has reduced population level exposure to moderate (50-100 μg/L) and high (>100 μg/L) levels of arsenic in drinking water in some countries as they become wealthier. However, there remains a very large rural population in all countries where the exposure to low levels (10-50 μg/L) of arsenic continues due to its dispersed occurrence in the environment and frequent reliance on private well. A set of natural (geological and biological), socioeconomic, and behavioral barriers to progress are summarized as lessons. They range from challenges in identifying the exposed households due to spatially heterogeneous arsenic distribution in groundwater, difficulties in quantifying the exposure let alone reducing the exposure, failures in maintaining compliance to arsenic drinking water standards, to misplaced risk perceptions and environmental justice issues. Environmental health professionals have an ethical obligation to help As mitigation among private well water households, along with physicians, hydrogeologists, water treatment specialists, community organizations, and government.

The Case for Universal Screening of Private Well Water Quality in the U.S. and Testing Requirements to Achieve It: Evidence from Arsenic

BACKGROUND

The 1974 Safe Drinking Water Act (SDWA) regulates >170,000 public water systems to protect health, but not >13 million private wells. State and local government requirements for private well water testing are rare and inconsistent; the responsibility to ensure water safety remains with individual households. Over the last two decades, geogenic arsenic has emerged as a significant public health concern due to high prevalence in many rural American communities.

OBJECTIVES

We build the case for universal screening of private well water quality around arsenic, the most toxic and widespread of common private water contaminants. We argue that achieving universal screening will require policy intervention, and that testing should be made easy, accessible, and in many cases free to all private well households in the United States, considering the invisible, tasteless, odorless, and thus silent nature of arsenic.

DISCUSSION

Our research has identified behavioral, situational and financial barriers to households managing their own well water safety, resulting in far from universal screening despite traditional public health outreach efforts. We observe significant socioeconomic disparities in arsenic testing and treatment when private water is unregulated. Testing requirements can be a partial answer to these challenges.

CONCLUSIONS

Universal screening, achieved through local testing requirements complemented by greater community engagement targeting biologically and socioeconomically vulnerable groups, would reduce population arsenic exposure greater than any promotional efforts to date. Universal screening of private well water will identify the dangers hidden in America's drinking water supply and redirect attention to ensure safe water among affected households. https://doi.org/10.1289/EHP629.

Variability in the chemistry of private drinking water supplies and the impact of domestic treatment systems on water quality

Tap water from 497 properties using private water supplies, in an area of metalliferous and arsenic mineralisation (Cornwall, UK), was measured to assess the extent of compliance with chemical drinking water quality standards, and how this is influenced by householder water treatment decisions. The proportion of analyses exceeding water quality standards were high, with 65 % of tap water samples exceeding one or more chemical standards. The highest exceedances for health-based standards were nitrate (11 %) and arsenic (5 %). Arsenic had a maximum observed concentration of 440 µg/L. Exceedances were also high for pH (47 %), manganese (12 %) and aluminium (7 %), for which standards are set primarily on aesthetic grounds. However, the highest observed concentrations of manganese and aluminium also exceeded relevant health-based guidelines. Significant reductions in concentrations of aluminium, cadmium, copper, lead and/or nickel were found in tap waters where households were successfully treating low-pH groundwaters, and similar adventitious results were found for arsenic and nickel where treatment was installed for iron and/or manganese removal, and successful treatment specifically to decrease tap water arsenic concentrations was observed at two properties where it was installed. However, 31 % of samples where pH treatment was reported had pH < 6.5 (the minimum value in the drinking water regulations), suggesting widespread problems with system maintenance. Other examples of ineffectual treatment are seen in failed responses post-treatment, including for nitrate. This demonstrates that even where the tap waters are considered to be treated, they may still fail one or more drinking water quality standards. We find that the degree of drinking water standard exceedances warrant further work to understand environmental controls and the location of high concentrations. We also found that residents were more willing to accept drinking water with high metal (iron and manganese) concentrations than international guidelines assume. These findings point to the need for regulators to reinforce the guidance on drinking water quality standards to private water supply users, and the benefits to long-term health of complying with these, even in areas where treated mains water is widely available.

Arsenic in private well water part 3 of 3: Socioeconomic vulnerability to exposure in Maine and New Jersey

Arsenic is a naturally occurring toxic element often concentrated in groundwater at levels unsafe for human consumption. Private well water in the United States is mostly unregulated by federal and state drinking water standards. It is the responsibility of the over 13 million U.S. households regularly depending on private wells for their water to ensure it is safe for drinking. There is a consistent graded association with health outcomes at all levels of socioeconomic status (SES) in the U.S. Differential exposure to environmental risk may be contributing to this persistent SES-health gradient. Environmental justice advocates cite overwhelming evidence that income and other SES measures are consistently inversely correlated with exposure to suboptimal environmental conditions including pollutants, toxins, and their impacts. Here we use private well household surveys from two states to investigate the association between SES and risks for arsenic exposure, examining the potentially cumulative effects of residential location, testing and treatment behavior, and psychological factors influencing behavior. We find that the distribution of natural arsenic hazard in the environment is socioeconomically random. There is no evidence that higher SES households are avoiding areas with arsenic or that lower SES groups are disproportionately residing in areas with arsenic. Instead, disparities in exposure arise from differing rates of protective action, primarily testing well water for arsenic, and secondly treating or avoiding contaminated water. We observe these SES disparities in behavior as well as in the psychological factors that are most favorable to these behaviors. Assessment of risk should not be limited to the spatial occurrence of arsenic alone. It is important that social vulnerability factors are incorporated into risk modeling and identifying priority areas for intervention, which should include strategies that specifically target socioeconomically vulnerable groups as well as all the conditions which cause these disparities in testing and treatment behavior.

Arsenic in private well water part 1 of 3: Impact of the New Jersey Private Well Testing Act on household testing and mitigation behavior

Regularly ingesting water with elevated arsenic increases adverse health risks. Since September 2002, the NJ Private Well Testing Act (PWTA) has required testing untreated well water for arsenic during real estate transactions in 12 counties. Its implementation provides an opportunity to investigate the effects of policy intervention on well testing and treatment behavior. Here we analyze results of a survey mailed to 1943 random addresses (37% response), including responses from 502 private well households who purchased their homes prior to PWTA commencement and 168 who purchased after. We find the PWTA has significantly increased arsenic testing rates in an area where 21% of wells contain arsenic above the 5μg/L NJ drinking water standard. The PWTA has allowed identification of more wells with arsenic (20% of post-PWTA vs. 4% of pre-PWTA households) and more treatment for arsenic (19% of post-PWTA vs. 3% of pre-PWTA households). Such an Act is a partial answer to significant socioeconomic disparities in testing observed among households for whom it is not required. Additionally residents purchasing homes since 2002 are younger and disproportionately more likely to have children in their household (60% vs. 32%), a priority group given their particular vulnerability to effects of arsenic. Despite more wells tested under the PWTA, post-PWTA well owners forget or misremember arsenic test results more often, are more likely to report not knowing what kind of treatment they are using, and are not reporting better maintenance or monitoring of their treatment systems than pre-PWTA households. This suggests serious challenges to reducing arsenic exposure remain even when testing is a requirement. Furthermore, only a fraction of wells have been tested under the PWTA due to the slow pace of housing turnover. We recommend more public resources be made available to support private well testing among socially and biologically vulnerable groups.

Arsenic and Environmental Health: State of the Science and Future Research Opportunities

BACKGROUND

Exposure to inorganic and organic arsenic compounds is a major public health problem that affects hundreds of millions of people worldwide. Exposure to arsenic is associated with cancer and noncancer effects in nearly every organ in the body, and evidence is mounting for health effects at lower levels of arsenic exposure than previously thought. Building from a tremendous knowledge base with > 1,000 scientific papers published annually with "arsenic" in the title, the question becomes, what questions would best drive future research directions?

OBJECTIVES

The objective is to discuss emerging issues in arsenic research and identify data gaps across disciplines.

METHODS

The National Institutes of Health's National Institute of Environmental Health Sciences Superfund Research Program convened a workshop to identify emerging issues and research needs to address the multi-faceted challenges related to arsenic and environmental health. This review summarizes information captured during the workshop.

DISCUSSION

More information about aggregate exposure to arsenic is needed, including the amount and forms of arsenic found in foods. New strategies for mitigating arsenic exposures and related health effects range from engineered filtering systems to phytogenetics and nutritional interventions. Furthermore, integration of omics data with mechanistic and epidemiological data is a key step toward the goal of linking biomarkers of exposure and susceptibility to disease mechanisms and outcomes.

CONCLUSIONS

Promising research strategies and technologies for arsenic exposure and adverse health effect mitigation are being pursued, and future research is moving toward deeper collaborations and integration of information across disciplines to address data gaps.

CITATION

Carlin DJ, Naujokas MF, Bradham KD, Cowden J, Heacock M, Henry HF, Lee JS, Thomas DJ, Thompson C, Tokar EJ, Waalkes MP, Birnbaum LS, Suk WA. 2016. Arsenic and environmental health: state of the science and future research opportunities. Environ Health Perspect 124:890-899; http://dx.doi.org/10.1289/ehp.1510209.

Impact of the 2012 extreme drought conditions on private well owners in the United States, a qualitative analysis

BACKGROUND

Extreme hot and dry weather during summer 2012 resulted in some of the most devastating drought conditions in the last half-century in the United States (U.S.). While public drinking water systems have contingency plans and access to alternative resources to maintain supply for their customers during drought, little is known about the impacts of drought on private well owners, who are responsible for maintaining their own water supply. The purpose of this investigation was to explore the public health impacts of the 2012 drought on private well owners' water quality and quantity, identify their needs for planning and preparing for drought, and to explore their knowledge, attitudes, and well maintenance behaviors during drought.

METHODS

In the spring of 2013, we conducted six focus group discussions with private well owners in Arkansas, Indiana, and Oklahoma.

RESULTS

There were a total of 41 participants, two-thirds of whom were men aged 55 years or older. While participants agreed that 2012 was the worst drought in memory, few experienced direct impacts on their water quantity or quality. However, all groups had heard of areas or individuals whose wells had run dry. Participants conserved water by reducing their indoor and outdoor consumption, but they had few suggestions on additional ways to conserve, and they raised concerns about limiting water use too much. Participants wanted information on how to test their well and any water quality issues in their area.

CONCLUSIONS

This investigation identified information needs regarding drought preparedness and well management for well owners.

Methods of conducting effective outreach to private well owners - a literature review and model approach

Educational outreach programs have the potential to increase the occurrence of private well testing and maintenance behaviors, but are not always able to successfully engage the intended audience and overcome their barriers to change. We conducted a review of literature regarding behavior change and risk communication to identify common barriers to private well stewardship and motivational strategies to encourage change, as well as best practices for communicating with well owners. Results indicated that no specific strategy will be appropriate for all audiences, as different groups of well owners will have different barriers to change. For this reason, educators must develop an understanding of their audience so they are able to identify the most significant barriers to change and select motivational strategies that will directly reduce barriers. Implications for private well outreach programs are discussed.

Assessing arsenic exposure in households using bottled water or point-of-use treatment systems to mitigate well water contamination

There is little published literature on the efficacy of strategies to reduce exposure to residential well water arsenic. The objectives of our study were to: 1) determine if water arsenic remained a significant exposure source in households using bottled water or point-of-use treatment systems; and 2) evaluate the major sources and routes of any remaining arsenic exposure. We conducted a cross-sectional study of 167 households in Maine using one of these two strategies to prevent exposure to arsenic. Most households included one adult and at least one child. Untreated well water arsenic concentrations ranged from <10 μg/L to 640 μg/L. Urine samples, water samples, daily diet and bathing diaries, and household dietary and water use habit surveys were collected. Generalized estimating equations were used to model the relationship between urinary arsenic and untreated well water arsenic concentration, while accounting for documented consumption of untreated water and dietary sources. If mitigation strategies were fully effective, there should be no relationship between urinary arsenic and well water arsenic. To the contrary, we found that untreated arsenic water concentration remained a significant (p ≤ 0.001) predictor of urinary arsenic levels. When untreated water arsenic concentrations were <40 μg/L, untreated water arsenic was no longer a significant predictor of urinary arsenic. Time spent bathing (alone or in combination with water arsenic concentration) was not associated with urinary arsenic. A predictive analysis of the average study participant suggested that when untreated water arsenic ranged from 100 to 500 μg/L, elimination of any untreated water use would result in an 8%-32% reduction in urinary arsenic for young children, and a 14%-59% reduction for adults. These results demonstrate the importance of complying with a point-of-use or bottled water exposure reduction strategy. However, there remained unexplained, water-related routes of exposure.

MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic

This report is the outcome of the meeting "Environmental and Human Health Consequences of Arsenic" held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13-15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food, and more than 200 million people ingest arsenic via drinking water at concentrations greater than international standards. Although the US Environmental Protection Agency (EPA) has set a limit of 10 μg/L in public water supplies and the WHO has recommended an upper limit of 10 μg/L, recent studies indicate that these limits are not protective enough. In addition, there are currently few standards for arsenic in food. Those who participated in the Summit support citizens, scientists, policymakers, industry, and educators at the local, state, national, and international levels to (1) establish science-based evidence for setting standards at the local, state, national, and global levels for arsenic in water and food; (2) work with government agencies to set regulations for arsenic in water and food, to establish and strengthen non-regulatory programs, and to strengthen collaboration among government agencies, NGOs, academia, the private sector, industry, and others; (3) develop novel and cost-effective technologies for identification and reduction of exposure to arsenic in water; (4) develop novel and cost-effective approaches to reduce arsenic exposure in juice, rice, and other relevant foods; and (5) develop an Arsenic Education Plan to guide the development of science curricula as well as community outreach and education programs that serve to inform students and consumers about arsenic exposure and engage them in well water testing and development of remediation strategies.

Home Water Treatment Habits and Effectiveness in a Rural Arizona Community

Drinking water quality in the United States (US) is among the safest in the world. However, many residents, often in rural areas, rely on unregulated private wells or small municipal utilities for water needs. These utilities may violate the Safe Drinking Water Act contaminant guidelines, often because they lack the required financial resources. Residents may use alternative water sources or install a home water treatment system. Despite increased home water treatment adoption, few studies have examined their use and effectiveness in the US. Our study addresses this knowledge gap by examining home water treatment in a rural Arizona community. Water samples were analyzed for metal(loid)s, and home treatment and demographic data were recorded in 31 homes. Approximately 42% of homes treated their water. Independent of source water quality, residents with higher income (OR = 1.25; 95%CI (1.00 - 1.64)) and education levels (OR = 1.49; 95%CI (1.12 - 2.12)) were more likely to treat their water. Some contaminant concentrations were effectively reduced with treatment, while some were not. We conclude that increased educational outreach on contaminant testing and treatment, especially to rural areas with endemic water contamination, would result in a greater public health impact while reducing rural health disparities.

Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93-99%) in particulates (>0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560-13,000 mg/kg of As and 14-35% weight/weight of Fe. As/Fe ratios (2.5-20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000-100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ(18)O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater.

At the crossroads: Hazard assessment and reduction of health risks from arsenic in private well waters of the northeastern United States and Atlantic Canada

This special issue contains 12 papers that report on new understanding of arsenic (As) hydrogeochemistry, performance of household well water treatment systems, and testing and treatment behaviors of well users in several states of the northeastern region of the United States and Nova Scotia, Canada. The responsibility to ensure water safety of private wells falls on well owners. In the U.S., 43 million Americans, mostly from rural areas, use private wells. In order to reduce As exposure in rural populations that rely on private wells for drinking water, risk assessment, which includes estimation of population at risk of exposure to As above the EPA Maximum Contaminant Level, is helpful but insufficient because it does not identify individual households at risk. Persistent optimistic bias among well owners against testing and barriers such as cost of treatment mean that a large percentage of the population will not act to reduce their exposure to harmful substances such as As. If households are in areas with known As occurrence, a potentially large percentage of well owners will remain unaware of their exposure. To ensure that everyone, including vulnerable populations such as low income families with children and pregnant women, is not exposed to arsenic in their drinking water, alternative action will be required and warrants further research.