Systematic review of differential inorganic arsenic exposure in minority, low-income, and indigenous populations in the United States
Inorganic arsenic (iAs) is carcinogenic in humans and also associated with cardiovascular, respiratory, and skin diseases. Natural and anthropogenic sources contribute to low concentrations of iAs in water, food, soil, and air. Minority and low income populations are often at higher risk of exposure to environmental hazards, yet it is unclear if higher iAs exposure occurs in these groups. We conducted a systematic review to evaluate studies that examined iAs exposure in minority, low-income, and indigenous populations within the United States (US). We included studies that estimated iAs exposure based on environmental concentrations of iAs in water, food, and soil, or iAs biomarkers. We qualitatively integrated data to draw conclusions about increased iAs exposure in these populations. Five studies were identified that estimated exposures and provided demographic information about populations of concern. These studies used arsenic concentrations in water, soil, or food to estimate exposure, with varied evidence of differential exposure. We identified six studies that suggested potential for differential exposure to iAs from environmental sources including soil, rice, private well-water, and fish. However, these studies did not report data stratified by demographic information. While the studies identified suggest potential sources for iAs exposure, the data are limited by the lack of direct exposure measures, speciation data for total arsenic, and comparative demographic data. Based upon these data gaps, there is insufficient evidence to conclude that there is differential exposure to iAs across different minority, indigenous, or low income populations within the United States.