Assessment of Arsenic Exposure and Carcinogenic Risk in an Endemic Arsenism Area in Inner Mongolia Caused by Exposure to Arsenic in Drinking Water

Seasonal variation of arsenic concentrations is critical for arsenic exposure assessment and related health risks assessment. An endemic arsenism area in Inner Mongolia caused by exposure to arsenic in drinking water was selected as the study area. The arsenic concentrations in drinking water for different seasons were determined. The exposure doses of arsenic through direct ingestion, indirect ingestion and dermal contact were estimated. Moreover, the carcinogenic health risk was assessed. The results show that the average intake of arsenic for male and female in the study area were 1.80 and 1.89 μg·kg^-1·d^-1, while the corresponding values in control area were both 0.08 μg·kg^-1·d^-1. The intake of arsenic from dermal contact for male and female in the study area were 8.89×10^-4 and 1.10×10^-3 μg·kg^-1·d^-1, while the values were 4.18×10^-5 and 4.93×10^-5 μg·kg^-1·d^-1 in control area. More than 99.93% of the total intake of arsenic were from ingestion pathway. Moreover, the total arsenic exposure dose from summer and winter accounts for more than 89.04% of the whole year. Carcinogenic health risks of males and females in the endemic area were 3.75×10^-5 and 3.67×10^-5 a^-1, respectively. It can be concluded that the intake of arsenic through ingestion pathway was the dominate exposure pathway of arsenic in drinking water. In addition, the arsenic exposure dose was the highest in summer. Carcinogenic risk of arsenic exposure through ingestion and dermal contact exceeded the acceptable risk.