Dietary exposure to arsenic species in Japan in 2019 using a total diet study based on composite sample with market basket approach at the national level.

To estimate the mean dietary exposure to total As (tAs) and some arsenic species [inorganic arsenic (iAs), methylarsonic acid (MMAs) and dimethylarsinic acid (DMAs), and arsenobetaine (AsB)] across the entire Japanese population (≥1 year old), a national total diet study (TDS) based on composite sample with a market-basket approach was conducted in Japan from 10 regions throughout Japan in 2019. Mean dietary exposure to iAs of 0.251 μg kg^-1 day^-1 showed a slightly lower value compared to the health-based guideline value of 0.30 μg kg^-1 day^-1. The calculated margin of exposure of 1.2-31.9 were lower or similar to the uncertainty factors of 30. Therefore, the possibility of a risk to Japanese people cannot be excluded. This study indicated that consumption of rice and rice products contributed to 64% of the dietary exposure to iAs. Furthermore, results showed that dietary exposure to tAs had been increasing...