Water use
Water arsenic exposure was assessed at the individual level as the self-reported use of arsenic-safe drinking and cooking water sources in the past month at baseline and follow-up visits. Arsenic-safe water sources included the use of the POU arsenic filter faucet, bottled water, or the municipal water system, and arsenic-unsafe sources included use of the kitchen faucet, bathroom faucet, and refrigerator filter or icemaker (if not reported to be connected to the POU arsenic filter faucet). Participants were also asked about the type of water use in the past month for drink and food items. Drink items included homemade tea or coffee; homemade juices (e.g., fruit punch, lemonade, Kool-Aid); powdered milk; and homemade ice. Food items included homemade soup or stew; bread, muffins, pancakes, cake, cookies, or waffles; pasta, grains, or boiled vegetables; rice made with water; and gravy made with water. For analysis, water use was assessed using the following variables: 1) exclusive use of arsenic-safe water for drinking, 2) exclusive use of arsenic-safe water for cooking, and 3) exclusive use of arsenic-safe water for drinking and cooking.