Greater contribution to blood lead from water than from air

Abstract

Concern about the levels of lead in blood is widespread. There is uncertainty, however, about the relative importance of the various environmental sources. Lead in petrol is widely assumed to be one of the most important sources and air and dust have been identified as the main routes to man. Water is regarded as an important source in areas with a plumbosolvent water supply, but of little or no importance in other areas. In order to evaluate the contribution to blood lead by various environmental sources, we have conducted surveys of random samples of women in areas of Wales chosen to represent very different levels of exposure to traffic. We report here that lead in air makes a small, but significant, contribution to blood lead but there is no evidence of any contribution from dust. Although in none of the areas were high levels of lead detected in water, water emerges as an important contributor to blood lead.

The biochemical and clinical consequences of lead poisoning

“…A preliminary survey in Wisbech, East Anglia, which has very hard water (over 300 mg/l hardness) showed much lower levels of blood lead at all levels of water lead than in subjects living in areas in North Wales with soft water s u p p l i e~.~~9 In addition to the low blood lead levels in subjects exposed to relatively high water lead levels in the hard water area, subjects living in dwellings with negligible lead in their water supply also had low blood lead levels in the hard water area. These observations have been confirmed by Pocock et u1.231, Elwood et u1., 224 and Gallacher et ~1…”

Evidence of a fall in cord blood lead levels in South Wales 1984–85

“…Even in areas with levels as low as those we describe for Swansea (Table 1) water can be an important source of lead (Elwood et al, 1984). However, the importance of the data in Table 1 in the context of this report is that there is no evidence of any change in water lead which might explain the changes in blood lead (Figure 1).…”

“…One part of the city, Townhill (population about 8,372) had had a highly plumbosolvent water, and in January 1984 a water treatment plant had been installed. Water is an important source of lead in blood (Elwood et al, 1984) and treatment of a water supply can lower the blood lead levels of residents in an area (Elwood et al, 1983c). Following a reduction in exposure it takes about six months for blood lead levels to stabilize (Thomas et al, 1979).…”

Blood lead determinants of a population living in a former lead mining area in Southern Scotland

“…The involuntary elevation of human lead levels from lead contaminated environments caused by past and present industrial activity has been widely noted in numerous studies (Barltrop et al, 1975;Gallacher et al, 1984;Yankel et al, 1977).…”