Monitoring of lead in the environment.

Children living near a lead works and children of employees at the works were selected in order to analyse the lead content of their blood as the biological counterpart of a monitoring exercise for lead in the environment. The overall mean for the 262 children in the survey was 0.91 mumol/l and results were within the normal reference range of 0.3 to 1.8 for all except two children. The results compared favourably with similar areas, and with a survey in the same area in 1972. The mean for the 71 children of employees at the lead works was 1.02 mumol/l, significantly higher than the mean for the other children in the survey (0.88 mumol/l). No appreciable differences were found in housing or wind direction. The means for all groups were unexceptional, but some of the differences were significant. Younger children had significantly higher blood lead levels than older children, and the group of 26 children with levels of 1.3 mumol/l or more was doubly weighted with the youngest age group. After careful investigation, no deviations from normal health were found in this group. The weighting of younger children also contributed to the significance of the higher mean found for children living in the central half of the area.