Lead exposure in an urban community: investigation of risk factors and assessment of the impact of lead abatement measures.

INTRODUCTION

A battery recycling plant located in an urbanized area contaminated the environment with lead oxides. The Secretary of Environment of the State of São Paulo demanded an evaluation of lead exposure among the population in the vicinity of the plant.

OBJECTIVES

To assess the lead exposure of children, to propose control measures and evaluate the impact of these measures.

METHODS

Cross-sectional study of all children<13 years old in a radius of 1km from the plant responsible for the contamination. Blood lead levels (BLL) were determined for each child and questionnaires were applied to their parents. Mean BLL were compared before and after control measures were implemented. Logistic regression identified risk factors of lead exposure.

RESULTS

Of the 850 investigated children, 311 presented BLL above the action limit established by the World Health Organization. Overall, the median BLL was 7.3 micro g/dL and it varied according to age of children (higher among 1-5 years old) and distance of the residence from the plant. Risk factors identified for BLL>10 micro g/dL were: to live in unpaved areas, parent working in the plant, distance from the plant, to play on the ground, pica, and to drink locally produced milk. After control measures were implemented (closing the plant, soil removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in BLL was observed considering the 241 re-evaluated children with levels >10 micro g/dL.

CONCLUSIONS

This study showed that combined abatement measures were effective in reducing BLL in children living close to a contaminating source. These results informed the decision-making process regarding management of contaminated areas in Brazil.