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Repeated surveillance of lead poisoning among children
A M Silvany-Neto1, F M Carvalho, M E Chaves
1Department of Preventive Medicine, University of Bahia, Brazil.
Insights
A 1985 survey in Santo Amaro found persistent lead poisoning in children near a smelter, despite pollution controls. High soil lead levels and pica remain significant risks, indicating ongoing lead exposure concerns.
Area of Science:
- Environmental Health
- Pediatric Toxicology
- Occupational Health
Background:
- Lead poisoning is a significant public health issue, particularly affecting children in areas with industrial pollution.
- A lead smelter in Santo Amaro, Brazil, was a suspected source of environmental lead contamination.
- Previous studies indicated high lead exposure risks for children living near the smelter.
Purpose of the Study:
- To assess the current levels of lead exposure in children residing near the Santo Amaro lead smelter.
- To evaluate the impact of environmental pollution control measures implemented between 1980 and 1985.
- To identify persistent risk factors for lead poisoning in the study population.
Main Methods:
- A comparative survey of children's blood lead levels (PbB) and zinc protoporphyrin (ZPP) concentrations was conducted in 1980 and 1985.
- The 1985 survey involved 250 children aged 1-9 years living within 900m of the smelter.
- Soil lead content and children's habits (e.g., pica) were assessed as potential exposure factors.
Main Results:
- In 1985, the geometric mean ZPP was 1.17 mumol l-1, and the mean PbB was 1.77 mumol l-1, with 22 children exceeding 1.68 mumol l-1.
- Children living in homes with soil lead >10,000 ppm and those with soil pica exhibited elevated ZPP levels.
- Slight improvements in ZPP and PbB were noted compared to 1980, but new cases of lead poisoning were still identified.
Conclusions:
- Despite industrial improvements, lead exposure remains a concern for children near the Santo Amaro smelter.
- Highly contaminated soil poses a long-lasting risk factor for childhood lead poisoning in the area.
- Continued monitoring and intervention are necessary to mitigate lead exposure and prevent new cases.
Abstract:
In 1980, a survey of lead poisoning was carried out among 592 children aged 1 to 9 years living within 900 m of a lead smelter in Santo Amaro, Brazil. From 1980 to 1985, the lead smelter carried out a number of major improvements aimed at reducing environmental pollution. In January, 1985, a second survey was carried out among a sample of 250 children living in this same geographical area. The geometric mean of zinc protoporphyrin (ZPP) concentration in whole blood was 1.17 (standard deviation = 1.5) mumol l-1. Blood lead concentrations (PbB) determined in a subsample of 53 children had an arithmetic mean and standard deviation of 1.77 +/- 1.00 mumol l-1, with 22 children showing PbB greater than or equal to 1.68 mumol l-1. Twenty-nine (11.6%) of the 250 children lived in houses where the lead content of the soil was greater than 10,000 ppm, and they presented higher ZPP levels than the rest of the population. Children with the habit of pica for soil had elevated ZPP levels. Comparing the results from the 1980 and 1985 surveys, slight improvements in ZPP and PbB levels were observed. However, new cases of lead poisoning are still occurring in the area. The soil is highly contaminated by lead and represents a long-lasting risk factor for child intoxication.