Isotopic ratios of lead in contemporary environmental material from Scotland.

Lead emitted into the environment, primarily from the combustion of leaded petrol and industrial activities, retains the isotopic signature of the ore(s) from which it is derived. Leaded petrol, atmospheric particulates and street dust sampled in central Edinburgh between February 1989 and December 1991 had mean(206)Pb/(207)Pb ratios of 1.082 ± 0.024, 1.092 ± 0.011 and 1.109 ± 0.016 respectively. These isotope ratios were found to be depleted in(206)Pb compared with a mean of 1.160 ± 0.012 for tap water in contact with lead pipes and %typical ratios of 1.17-1.19 for British lead ore deposits and coal. Paint, with an observed wide range of 20 Pb(207) Pb ratios (1.083-1.183), appears to have significantly influenced house dust and some street dust(206)Pb(207) values. Such overlaps and influences may hinder the quantitative apportionment, via isotope data, of source and route in general population surveys of human exposure to lead.