Our children in day care: reducing exposure to environmental lead at day care centres

Abstract

The authors characterized the exposure of 5-year-old pre-school children, in two areas of Pretoria, to lead in air and surface soil. The study was conducted at 30 pre-schools in Soshanguve and 24 in Pretoria East during July 2001. Exposure to lead in air, lead concentrations in surface soil and dust, and risk factors associated with inhalation exposure to the metal were determined by means of questionnaires, time- activity diaries, and lead concentrations in air, soil and surface dust. Pre-schools in Soshanguve had smaller playgrounds than in Pretoria East (382 vs 889 m(2) outdoors and 28 vs 70 m(2) indoors), had lower outdoor lead concentrations associated with total suspended particles (0.098 vs 0.145 mug/m(3)), experienced higher lead loadings of indoor dust (173 vs 64 mug/m(2)) and of outdoor soil (17.7 vs 6.9 mug/g), and were more often located adjacent to untarred roads. Pre-schools in Pretoria East were more often situated next to busy roads and were exposed to higher traffic volumes (421 vs 66 vehicles/hour). Mean air lead concentration indoors was lower than outdoors (0.08 vs 0.1 mug/m(3)). Children in Soshanguve spent more time indoors (5.6 vs 5.2 hours/day). We recommend that cleaning practices at schools should not use appliances that disperse dust, to minimize the resuspension of lead contained in surface dust. Pre-schools should be sited away from busy or steeply sloping roads, where motor vehicle emissions are enhanced. Traffic volumes on roads close to where pre-schools are planned should be monitored in advance. If a school is adjacent to a source of lead pollution, the time children spend outdoors should be carefully limited.