Small town lead levels: a case study from the homes of pre-schoolers in Mt. Pleasant, Michigan

This study evaluates the relationship between household Pb levels and four variables (home age, distance to road, traffic volume adjacent to the home, and the amount of exposed soil) for 42 homes in a small city. As a whole, Pb levels for the Mt. Pleasant sample were very low compared to large cities. Home age appeared to have the greatest impact on Pb levels as determined by atomic absorption soil = 65 microg g(-1), vacuum dust = 620 microg g(-1), window sill = 291 microg m(-1), indoor play area = 22 microg m(-1), and home entrance = 291 microg m(-1). The correlation coefficient for increasing home age and soil Pb level was r=0.63 (p<0.000). An inverse relationship (r=-0.45, p=0.003) occurred between soil Pb levels and distance from the road. Household Pb levels generally increased both with higher traffic volumes and greater amounts of exposed soil although both trends were not statistically significant. Study participants kept their home in a good to excellent state of repair and resided on lightly trafficked streets; as such, Pb deposition through the weathering of Pb-based paint and the former combustion of leaded gasoline was minimized.