The effect of reducing air lead from vehicular sources on the blood lead concentrations in two Norwegian towns - A cohort study.

Blood lead was measured in two populations - one exposed to moderate lead emissions from traffic pollution and another a control low exposure town. Blood lead concentrations were measured in 1983 before the opening of a tunnel that removed the bulk of the traffic from the town and again one year later. Reductions in the concentrations of lead in blood were larger than predicted by factors given in the literature. There was a significant correlation between the reduction in exposure to lead in air and reductions in blood lead concentrations.