Abstract: Based on the investigation of residents DDTsHCHs mixed exposure via different ways in Taihu Lake region, a physiologically based pharmacokinetic (PBPK) model was built to analyze the distribution and accumulation processes of the pesticides in human tissues, and a tissue dose hazard index was used to assess the health risk of the mixed exposure. For the male and female residents, their health risk index was 0.147-2.499 and 0.138-2.223, and the probability of exceeding the acceptable risk was 24.6% and 16.5%, respectively. Comparing with the traditional mixed health risk assessment method,  i.e ., HI method, the PBPKbased tissue dose hazard index (HI _tissue-dose ) could better reflect the development trend of mixed health risk.

Key words: Trace element, Hair, Qinba mountains, Environmental geochemistry