Abstract
Little is known about lead exposure in the general population of young adults. In this study, whole blood lead concentration (PbB) was determined in a sample of the Dunedin Multidisciplinary Health and Development Study, a well-documented birth cohort of New Zealanders aged 21 years in 1993-1994. PbB in those who consented to venipuncture at 21 years of age (n = 779; 411 males, 368 females) was compared to PbB for the same cohort at age 11 years. The PbB at age 21 ranged from 0.4 to 56 g/dl with a geometric mean of 4.5 g/dl (95% CI, 4.3-4.7 g/dl). Only three individuals had a PbB above 30 g/dl. Males had significantly higher PbB than females (geometric mean 6.0 vs. 3.2 g/dl; p<0.0001). The PbB at age 21 was 53% lower than in the same individuals at age 11 (geometric mean 4.8 vs. 10.2 g/dl; p<0.001; n = 480) and the correlation between corresponding values was weak (r = 0.19; p<0.001). PbB at age 21 showed significant associations with high risk occupational activities, recreational exposure, domicile close to a main road, smoking, and male sex. Blood lead concentrations continue to fall in New Zealand, but occupational and recreational activities remain a significant source of lead exposure.