Lead exposure in urban and rural school children in Ghana

Human exposure to lead in non industrial urban areas is commonly ascribed to vehicular combustion of leaded gasoline. This belief is based on results of studies in societies with high vehicular density which show emission of lead fumes into the air by automobiles that use gasoline with high lead content. To assess this view, blood lead levels were evaluated in 11 to 15-year old school children in urban and rural communities of the Greater Accra Region, Ghana. Blood lead levels was significantly higher in all the urban children studied (mean +/-SD: 8.3+/- 12.7g/dl) than in their rural counterparts (4.0+/-7.2g/dl) (P<0.002). The trend was the same when only those who tested positive for blood lead were considered (24.1+/- 9.2g/dl, urban compared with 14.6+/- 5.8g/dl, rural). The prevalence of lead exposure was, however, not significantly different between the two groups (34.3. percent, urban and 27.1 per cent, rural). The presence of anaemia and/or increased urine total protein levels was unrelated to the blood lead levels in the children form both communities. Although a set goal to achieve lead free gasoline is desirable, the closeness of the prevalence rate of lead exposure obtained in the study indicate that factors other than leaded gasoline may be important determinant in exposure to lead in the Ghanaian community.