Text Box: THE TRENDS OF CHILDREN'S BLOOD LEAD LEVELS CHANGES IN SHANGHAI AFTER THE INTRODUCTION OF LEAD FREE GASOLINE Yan C-H, Wu S-H, Shen XM, Jiang F, Xinhua Hospital, Shanghai Second Medical University, Shanghai, China Objective: The purpose of this study is to describe trends in blood lead levels changes for the children aged 1~6 years during the time period between 1997 and 1999 before and after introducing lead free gasoline in Shanghai. Method: Blood lead levels of 1969 children aged 1~6 years were determined by a sampling survey method in five districts in Shanghai in 1997. And the blood lead levels of the same population were re-determined in 1998 and in 1999. We enrolled monthly in the Blood Lead Proficiency Testing Program of Centers for Disease Control in the United States. Our results for testing blood lead samples were with the acceptable ranges during the study. Results: The geometric means of blood lead levels were 83mg/L in 1997, 80mg/L in 1998 and 76mg/L in 1999, respectively. The prevalence rates of childhood lead poisoning were 37.8% in 1997, 25.7% in 1998 and 24.8% in 1999. The extents of average blood lead levels decline in the five districts between the year 1997 and 1999 were 10mg/L, 11mg/L, 6mg/L, 4mg/L, and 2mg/L. Conclusion: Lead poisoning is an entirely preventable disease. The average levels of lead of young children in Shanghai decrease significantly by introducing lead free gasoline in Shanghai. Lead emissions from vehicles running on leaded gasoline is one of important contributor to increasing the children's blood lead levels in Shanghai. 1169