Chromosomal aberrations in workers professionally exposed to lead

Chromosomes in cultured lymphocytes from the following groups were analyzed: 16 workers from a smelting plant for storage batteries in Lyon, France; 7 workers from a factory where tin dishes are made at Nerem, Belgium; and 20 controls. The choice of the workers was made on the basis of either elevated blood lead (Lyon) or elevated urinary δ‐aminolevulinic acid (Nerem). An increased number of severe aberrations‐rings and dicentrics—were detected in the persons from Lyon, whereas no such aberrations but an increased number of fragments were seen in those from Nerem.