Lead exposure in young school children in South African subsistence fishing communities

摘要

Background: Lead is an established toxic substance, with wide-ranging health effects, including neurode-velopmental decrements and behavioural problems, even at low levels in blood. Anecdotal reports of lead melting to make fishing sinkers in South African subsistence fishing communities prompted the conduct of an epidemiological study in two South African fishing villages to investigate the extent of lead melting and the associated risks in children. Objectives: The objectives of the study were to determine the extent of lead melting, and the blood lead distributions and associated risk factors in children. Methods: Cross-sectional, analytical studies were undertaken among 160 young school children in the fishing villages of Struis Bay and Elands Bay located along the south-eastern and western South African coastline, respectively. Blood samples were collected for lead content analysis, and anthropometric and hemoglobin measurements were taken. Questionnaires were administered to obtain information about socio-economic status and risk factors for lead exposure. Results: Blood lead levels ranged from 22 to 22.4 μg/dl, with the mean blood lead level equalling 7.4. Around 74% of the children had blood lead levels ≥5 μg/dl and 16% had blood lead levels ≥10 μg/dl. Socio-economic factors, and lead melting practices were strongly associated with elevated blood lead levels. Conclusions: Blood lead levels in these remote subsistence fishing communities were unexpectedly elevated, given the absence of local lead industries or other obvious sources of lead exposure. Lead exposure and poisoning is an important, yet neglected, public health concern in South African subsistence fishing communities, and potentially on the entire African continent.