A follow-up cross-sectional study of environmental lead exposure in early childhood in urban South Africa

Abstract

Background. Lead exposure has significant detrimental effects on the health and wellbeing of children. In resource-poor countries, information on the extent of lead exposure is often inadequate owing to the lack of surveillance and screening programmes.

Objective. To determine the degree of lead exposure in children residing in South African urban areas.

Methods. A cross-sectional survey was conducted in schools in Johannesburg, Cape Town and Kimberley in 2007 - 2008. Blood lead levels were assessed in a total of 1 349 grade 1 children using the LeadCare Analyser system. Parents completed a structured questionnaire on sociodemographic profiles and risk factors to provide information about socioeconomic status and other risk factors for lead exposure.

Results. Blood lead levels ranged from 0.8 - 32.3 μg/dl. The mean blood lead level in the total sample was 7.97 μg/dl; 74% had blood lead levels ≥5 μg/dl. The highest proportion (84%) of children with blood lead levels ≥5 μg/dl was in Johannesburg. In the multivariate analysis, socioeconomic status was significantly associated with blood lead levels ≥5 μg/dl.

Conclusion. Lead exposure in South African urban areas remains widespread. The risk of lead poisoning in some areas and certain groups of children may be increasing despite the phasing out of lead-containing petrol. Children living in poverty continue to be the most vulnerable.