[Analysis of blood lead levels of preschool children in Zhejiang Province with historical comparison].

Objective: To know the blood lead levels (BLL) of preschool children in Zhejiang Province between 1997 to 2003.

Methods: The BLL of preschool children was investigated in this province with cluster sampling in 2003, and compared with the results with that of 1997. The BLL was determined with graphite oven atom absorption spectrography method.

Result: The average BLL of 2013 preschool children in 2003 was (0.34 +/- 0.13) micromol/L, similar with that of 1997 [(0.35 +/- 0.26)micromol/L (P >0.05)]. There were 274 children with BLL >or= 0.483 micromol/L, and the rate of lead poisoning was 13.61 %, lower than that of 1997 (when there were 448 children with BLL >or= 0.483 micromol/L, and the rate of lead poisoning was 23.84%). In 2003, the rates of lead poisoning among preschool children of Hangzhou, Shangyu, Zhoushan and Changshan were 7.69%, 15.37%, 10.87% and 20.15 %, respectively. There were significant differences among the four areas (P < 0.01). In comparison with the results of 1997, the lead poisoning rates of Hangzhou and Shangyu children decreased significantly, while that of Changshan children increased significantly (P <0.01), and that of Zhoushan children didn't change significantly. The highest rate of lead poisoning was found in children of 4-6 years group as 6 years ago.

Conclusion: The rate of lead poisoning among preschool children has decreased significantly now in Zhejiang Province. But the condition of BLL in preschool children is still far from optimistic. The environmental lead pollution in remote mountain areas and island areas should be highly concerned by the government.