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 7.0µg/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 6.55µg/g creatinine) and 30% in the Intensive arm (GM=11.2 to 7.82µg/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).

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.

Tapwater Exposures, Effects Potential, and Residential Risk Management in Northern Plains Nations.

In the United States (US), private-supply tapwater (TW) is rarely monitored. This data gap undermines individual/community risk-management decision-making, leading to an increased probability of unrecognized contaminant exposures in rural and remote locations that rely on private wells. We assessed point-of-use (POU) TW in three northern plains Tribal Nations, where ongoing TW arsenic (As) interventions include expansion of small community water systems and POU adsorptive-media treatment for Strong Heart Water Study participants. Samples from 34 private-well and 22 public-supply sites were analyzed for 476 organics, 34 inorganics, and 3 in vitro bioactivities. 63 organics and 30 inorganics were detected. Arsenic, uranium (U), and lead (Pb) were detected in 54%, 43%, and 20% of samples, respectively. Concentrations equivalent to public-supply maximum contaminant level(s) (MCL) were exceeded only in untreated private-well samples (As 47%, U 3%). Precautionary health-based screening levels were exceeded frequently, due to inorganics in private supplies and chlorine-based disinfection byproducts in public supplies. The results indicate that simultaneous exposures to co-occurring TW contaminants are common, warranting consideration of expanded source, point-of-entry, or POU treatment(s). This study illustrates the importance of increased monitoring of private-well TW, employing a broad, environmentally informative analytical scope, to reduce the risks of unrecognized contaminant exposures.

The Strong Heart Water Study: Informing and designing a multi-level intervention to reduce arsenic exposure among private well users in Great Plains Indian Nations.

Elevated arsenic exposure from drinking water is associated with an increased risk of cardiovascular disease, diabetes, kidney disease, and skin, lung, and bladder cancer. Arsenic contamination in groundwater supplies disproportionately affects rural populations using private wells. Arsenic mitigation programs for American Indian communities are limited. There is an urgent need for targeted approaches to reduce arsenic exposure for at-risk communities using private wells. Formative research was conducted to inform and design a community-based arsenic mitigation intervention for Lakota and Dakota Nations in the Great Plains Area of the United States, where, in some communities, one-quarter of private wells are estimated to have elevated arsenic. Formative research included semi-structured interviews, a community workshop, intervention-planning workshops, and a pilot study of the developed intervention. Community members prioritize aesthetic qualities of water (e.g. taste, color), safety, and other situational factors (e.g. cost) when considering their drinking and cooking water. Although water safety is a concern, awareness and concern for arsenic vary substantially within communities. To reduce arsenic exposure, community members recommended communication of water test results, home visits for intervention delivery, and reminders to use arsenic-safe water. Findings informed the development of an intervention to prevent arsenic exposure through drinking water and cooking, including health promotion messages and household items to facilitate use of an arsenic removal device (e.g. tankards to store filtered water). The pilot study indicated promising acceptability and operability of the developed intervention. This research provides a model for the development of environmental health interventions in partnership with American Indian and other private well-using communities.