Dietary exposure to inorganic Arsenic in the Kenya population

Abstract

Inorganic arsenic exposure, mainly resulting from dietary sources, has been associated with a higher risk of cancer due to its genotoxic effects. This study aims to estimate the dietary exposure to inorganic arsenic among the Kenyan population and its associated factors. Consumption data were collected through 24-hour recalls from a convenience sample of the Kenyan population from the Kenya National Micronutrient Survey (n=826; ages 6 months-49 years). Occurrence data on inorganic arsenic in food were obtained from EFSA publications. For the risk characterization, margins of exposure (MOE) for skin cancer outcomes were calculated. To compare inorganic arsenic exposure between groups, the Mann-Whitney U-Test and the Kruskal-Wallis Test were used. For the general study population, the median estimated daily dietary exposure per body weight to inorganic arsenic was 0.12 µg/kg/day, ranging from 0.06 to 0.22 µg/kg/day (25th to 75th percentile), with 1.33 µg/kg/day at the 99th percentile in the Lower Bound (LB) scenario, and 0.31 µg/kg/day, ranging from 0.20 to 0.51 µg/kg/day (25th to 75th percentile), with 2.15 µg/kg/day at the 99th percentile in the Upper Bound (UB) scenario. Children aged 6 months to 5 years had the highest inorganic arsenic exposure (median 0.17 µg/kg/day; 99th percentile 2.39 µg/kg/day in the LB, and 0.52 µg/kg/day; 99th percentile 3.23 µg/kg/day in the UB). For skin cancer outcomes, the median MOE estimated in the LB and UB was 2.48 and 0.67, respectively. In this study, according to the MOE estimates, 78.8% of the population presented a concerning exposure to inorganic arsenic in LB scenario and 97.4% in UB scenario. Rice and grains and grain-based products were the main sources of inorganic arsenic. The current dietary exposure to inorganic arsenic in the Kenyan population raises concerns regarding skin cancer outcomes, since the exposure exceeds the level considered safe. Our results highlight the need to reduce dietary inorganic arsenic exposure, especially among children, adolescents, rural residents, and pregnant and lactating women.