Human health risk assessment of cadmium exposure through rice consumption in cadmium-contaminated areas of the Mae Tao sub-district, Tak, Thailand.

The Mae Tao sub-district is located in the Mae Tao watershed, an important cadmium (Cd)-contaminated area in Thailand. This study was conducted to (i) determine Cd concentrations in rice collected from households in the area, (ii) assess the Cd exposure and potential health risk (HQ) from rice consumption in local adults and (iii) investigate how the factors of individual characteristics and consumption behavior affect the level of HQ. A total of 159 rice samples were collected from households in all 6 villages of the Mae Tao sub-district for analysis of Cd by inductively coupled plasma mass spectrometry. Biodata information and rice consumption behavior were surveyed from local residents at the same time as rice sample collection. Approximately 19.8% and 19.1% of white rice and sticky rice, respectively, contained total Cd higher than the Codex maximum standard of Cd in rice (0.4 mg kg). Locally grown rice contained an average of 1.5 times more Cd than retail rice. Cd exposure from consuming only sticky rice was the highest (2.26 × 10 mg kg day), followed by the consumption of both types of rice (1.39 × 10 mg kg day) and the consumption of only white jasmine rice (6.30 × 10 mg kg day). The highest and lowest average HQ values were found in the only sticky rice consumption pattern (2.263) and the only white rice consumption pattern (0.630), respectively. The potential health risk from Cd in each rice consumption pattern was mainly influenced by the total Cd concentration in rice and the rice ingestion rate.