Introduction Because children exposed to lead have a very high health risk, surveillance and prevention programs are very important to avoid short- and long-term health effects. Objectives To describe the trend for the blood lead levels over a 12-year period in environmentally exposed children and to document the actions implemented to reduce the blood lead levels. Materials and methods We performed a retrospective cohort study of children aged 0–15 years who were enrolled in the Coahuila Health Secretary's Childhood Blood Lead Level Surveillance program. This database includes children from the city of Torreon, Coahuila, Mexico, where the biggest smelter in Latin America is located. Results A total of 151,322 observations were analyzed in the study. The percentage of samples with elevated blood lead levels decreased from 84.9% to 10.4% during 1998–2010, and the decrease was greater in girls than in boys. Conclusion According to the results of our study, the majority of strategies and activities to decrease blood lead levels in an environmentally exposed population should be focused on children aged 0–5 years, on the home environment, on preventing fugitive emissions from smelters and other sources and on the proper disposal and confinement of industrial residues.
