Sampling was conducted in December 2012. A total of four sites in Xiaxi and Aozhai (A, D, E and G) were selected to survey in this study (Fig. 1). Descriptive statistics of the study population and rice consumption information are shown in Table 1. Participantswere recruited based on the criteria that they had been local residents for N3months. The recruitment strategy in the survey was to recruit 10–20% of the entire population at each site. All the participants participated voluntarily. The recruitment period lasted two days. A questionnaire was also conducted to obtain basic information on age, bodyweight, occupation, history of involvement of artisanal Hg mining activity, dental fillings, smoking and alcohol drinking habits, illness and the amount of daily rice consumption.