[The blood lead level and its relationship with behavior in school-age children from rural areas of Chongqing].

Objective: To explore the blood lead level and its relationship with behavior in school-age children from rural areas of Chongqing. Methods: A total of 697 students from grades 3 to 6 in the fall semester of 2014 from 14 rural townships in one district of Chongqing was selected by using the random cluster sampling method. Blood were sampled to analyze the lead level. Neurobehavioral tests were performed to determine their personal cognitive and memory ability. Questionnaires and physical examinations were administered to obtain the information of confounding factors. All students were divided into Q1-Q4 groups according to the quartile of their blood lead level. The relationship between the blood lead level and behavior was analyzed by multivariate logistic regression model and restricted spline regression model. Results: The mean age of 697 students was (10.07±1.36) years old, and the median (interquartile range) of their blood lead level was 44.31 (35.42) μg/L. Multivariate logistic regression model showed that after adjusting for age, gender, body mass index and maternal culture level, compared with Q1 group, the OR (95%CI) values of high digit symbol substitution test (DSST) scores and high overall memory quotient (MQ) scores in Q3 group were 1.65 (1.01-2.70) and 2.10 (1.21-3.62), and the OR (95%CI) value of high long term memory (LTM) scores in Q4 group was 0.53 (0.31-0.92). The results of the restricted spline regression model showed that the dose-response curves between the blood lead level and MQ/LTM test scores were both parabolic (P<0.05). Conclusion: The blood lead level of school-age children from rural areas of Chongqing is the same as that from other areas of China, but slightly higher than that from other areas of Chongqing. Children with higher blood lead level have poor long-term memory ability.