Relation between lead and cadmium in blood and the involuntary smoking of children.

The blood lead (PbB) and blood cadmium (CdB) levels, as well as the parental smoking habits, of 133 children aged 4 to 11 years were studied. The children were from a town with a lead smeltery and a surrounding rural area. There was a significant association between the higher PbB levels of the children and involuntary (parental) smoking in the home. The CdB levels of the children were not affected by parental smoking habits. The children whose parents did not smoke at home had lower PbB values than those with one smoking parent. These children, in turn, had lower levels than children with two smoking parents. Mothers who smoked had a greater impact than fathers who smoked. There was also a dose-response relationship between the amount of tobacco smoked by the mother and the PbB level of the child. The PbB value was higher for the children living near industrial lead emissions than for children from the rural area. The association between PbB level and involuntary smoking is probably not due to inhalation of lead originating from tobacco smoke. A small airways disease affecting the absorption of inhaled lead particles is proposed as an explanation.