Environmental lead poisoning among children in Porto Alegre state, Southern Brazil

André Klafke de Lima,Mariana Maleronka Ferron,Paulo Hilário Nascimento Saldiva,Nelson Gouveia

doi:10.1590/s0034-89102012000200004

Abstract

OBJECTIVE: To estimate the prevalence of lead poisoning in children and to identify associated factors, as well as possible local sources of contamination. METHODS: A cross-sectional prevalence study conducted in 2006 with a random sample of 97 children age zero to five years from a neighborhood in Porto Alegre, Southern Brazil. Blood lead levels were measured and a questionnaire administered to collect information on sociodemographics, recycling and dwelling. A preliminary environmental evaluation was carried out with direct analysis of soil and indirect analysis of air pollution with bioindicators to identify possible sources of contamination. To analyze lead concentrations from the different collection sites, for each type of material studied, ANOVA was performed with a Brown-Forsythe adjustment for heteroscedasticity and with Dunnett's T3 procedure for multiple comparisons of unequal variances. RESULTS: Blood lead levels > 10.0 µg/dL was found in 16.5% of children. Recycling of waste at home, low father's education level, and increased age of children were associated with increase blood lead levels. High lead levels were found in soil, and there was little indication of lead air pollution. CONCLUSIONS: A high prevalence of lead poisoning was identified, and the potential sources of contamination in this community appear related to waste recylcing activities. Studies should be conducted with other populations of Brazilian children and evaluate potential sources of local and general contamination, to accurately characterize this issue in Brazil.

Highlights

Environmental exposures are causes of many adverse health effects among children and adolescents, despite uncertainty as to their magnitude and regional distribution
Blood lead levels ≥ 10.0 μg/dL was found in 16.5% of children
Recycling of waste at home, low father’s education level, and increased age of children were associated with increase blood lead levels

Summary

METHODS

A cross-sectional study was carried out with a random sample of 97 children age zero to five years residing in Vila Dique, a district of the city of Porto Alegre, Southern Brazil, in 2006. A questionnaire was administered to the parents or guardians to assess factors associated with lead contamination It contained information on child’s age and gender; the material used in the construction of the house (masonry or wood); the place where the child sleeps (floor or elevated bed); the residence’s location according to micro-areas established by the local health unit (Figure); the mother’s and father’s schooling (in years); the presence of waste recycling in the household and the length of time the family resided in the neighborhood. The spectra were reduced with WinQXAS software, available from the website of the International Atomic Energy Agency.d. Analysis of variance was carried out to assess significant differences in the lead concentrations between collection spots for each type of material studied with Brown-Forsythe correction for heteroscedasticity and with Dunnett’s T3 procedure for multiple comparisons of unequal variances.[11]. This study complied with the Declaration of Helsinki and was approved by the Ethics Research Committees of Grupo Hospitalar Conceição (Process n. 034/05 from July 14/2005) and Faculdade de Medicina da Universidade de São Paulo (Process n. 1031/08 from December 17/2008)

RESULTS

CONCLUSIONS

INTRODUCTION

DISCUSSION