Blood lead levels and poor school performance among children in Mexico City

Objective: To describe the relationship between blood lead levels (BLL) and poor school performance. Material and methods: A cross-sectional study was carried out in 1996 among 792 schoolchildren aged 7-14 years, who attended the outpatient units of five pediatric hospitals of Mexico City. BLL was measured together with lead exposure and academic performance. Results: Reported BLL and geometric means (GM) were 8.6 mu g/dL and 7.7 mu g/dL, respectively. The main source of exposure was the use of glazed pottery (difference of use =1.182; p = 0.000). Among schoolchildren who failed any school year, GM of the BLL was 8.1 mu g/dL, compared with children who did not fail (Gill = 7.6 mu g/dL; p = 0.240). The risk of failing a school year between the 1(st) and 3(rd) grade with a BLL greater than 10 mu g/dL was 1.73 (p = 0.012, IC 95% 1.13-2.66) and from 1(st) to 4(th) grade was 1.62 (p = 0.021, IC 95% 1.07-2.46). Conclusions: Blood lead levels, among other conditions, may contribute to the failure in school performance observed in the children participating in this study.