The effect of ambient cadmium air pollution on the hair mineral content of children.

Hair analyses of 80 children with learning and behavioral problems were assessed by age, sex, season, place of residence, exposure to passive smoke and excess contact with known cadmium air pollutant sources. All children had been exposed for at least 2 years to air pollution from a refuse-derived fuel incineration plant. All of the patients had increased hair cadmium compared with a control group, but there was a strong seasonal influence on hair cadmium. Exposure to cadmium was ubiquitous. A neurobehavioral toxic effect was found in children who showed evidence of inhibition of pyrimidine-5'-nucleotidase by low hair phosphorus levels and low zinc levels in whom there was enhanced lead absorption. Hair analyses appear to be a useful biological monitor for detecting toxic effects from ambient air cadmium levels in subsets of the population at risk for heavy metal toxicity. Air filter measurements appear worthless for detecting environmental contamination with cadmium in air with low levels of lead. Trees, on the other hand, which are more adversely affected by cadmium than other heavy metals, show evidence of inhibition of pyrimidine-5'-nucleosidase by excess seeding.