Relationship of blood lead in women and children to domestic water lead

Abstract

Humans can be exposed to lead through food, drink, various occupations or hobbies and also some cosmetics^1,2. The contribution of these different exposures to the total body uptake varies between individuals and groups but it is generally accepted that food and drink are the major sources of body lead¹. On average, lead from water contributes markedly less to total intake than does lead from food². It has been suggested, however, that when average lead in water rises above 0.1 mg l⁻¹ the intake from water begins to match or exceed that from food². We have previously reported³ that the mean blood lead levels in mothers and children on a housing estate with lead water pipes were over twice as high as those on an adjacent estate using copper pipes. Here we report that the blood lead levels, even when raised, remained very stable when lead exposures were unchanged. The removal of the lead water pipes produced a drop of approximately 50% in mean blood lead levels, reducing them to levels comparable to those on the copper piped estate. No other changes in lead exposure could be found to explain the variations in blood lead levels between the estates, and therefore the possibility of the large contribution of water lead to blood lead should be considered where the conditions described below are known to occur.