A Multimedia Arsenic Exposure Assessment for the Hopi Tribe, AZ, USA

Exposure to arsenic (As), a naturally occurring metalloid, is associated with multiple adverse health effects. The Hopi Tribe is in rural northeastern Arizona where there are health disparities, public concern about As exposures, and limited exposure assessment. Between 2016 and 2020, the Hopi Environmental Health Project (HEHP) recruited a random, cross-sectional sample of households to estimate aggregate daily doses of As for heads of household (n = 76). Environmental and individual sampling occurred during both heating and non-heating seasons using questionnaires (including dietary recalls) and sample collection of air (24-h collection), soil, house dust, water, and a first morning of urine. Total As daily dose (ADD) was estimated for participants by media in µg/kg-day during the heating and non-heating seasons [air/inhalation (median = 1.37E-03; 1.69E-03), soil ingestion (median = 5.00E-07; 4.00E-7), house dust ingestion (median = 9.10E-05; 6.71E-05), drinking water (median = 4.09E-03; 0.00 + 00), and food (median = 3.45E-01; 3.76E-01)]. During the heating season, mean ± sd aggregate As exposure was 0.46 ± 0.52 µg/kg-day (min: 0.07 µg/kg-day, max: 3.72 µg/kg-day). During the non-heating season, the average aggregate As exposure was 0.51 ± 0.42 µg/kg-day (min: 0.09 µg/kg-day, max: 2.00 µg/kg-day). Diet contributed the greatest proportion to the ADD during both seasons and no association was found between modeled As dose and urinary biomarkers. (r² = 0.004). Many studies focus on As exposure through drinking water and overlook the contribution from food. Our study demonstrates that As contained in food can be the major As exposure source.