Lead contamination of UK dusts and soils and implications for childhood exposure: An overview of the work of the Environmental Geochemistry Research Group, Imperial College, London, England 1981–1992

Abstract

Over the course of the last decade, research conducted by the Imperial College Environmental Geochemistry Research Group has focused on the nature and effects of lead in UK dusts and soils. An initial nationwide reconnaissance survey demonstrated that approximately 10% of the population is exposed to lead levels in excess of 2,000 μg g(-1) in house-hold dust. Subsequent exposure studies revealed that for 2 year old children in the UK urban environment, approximately 50% of lead intake was from dust ingested as a result of hand-to-mouth activity. Follow-up computer controlled scanning electron microscopy (CCSEM) analysis of urban household dust and particulate material wiped from children's hands showed that important sources of dust lead include lead-based paint, road dust and soils. CCSEM identification of specific soil lead tracer particles (from minewaste contaminated soils) in dusts and on children's hands further documented the important role of soil as a source of exposure. Speciation studies of soil lead of this origin indicated that the form of the lead, which is largely influenced by the soil environment, is the primary control on bioavailability. It appears that although lead of minewaste origin may be present at elevated levels in dusts and soils, it does not necessarily contribute to elevated blood lead levels when the lead is present in relatively insoluble form.

Environmental and potential human health legacies of non-industrial sources of lead in a Canadian urban landscape – the case study of St John's, Newfoundland

“…Ingestion of house dust can be a major contributor (50% or more) to blood lead levels in children (Thornton et al 1994;Lanphear et al 1996;Lanphear and Roghmann 1997;Lanphear et al 1998;Yiin et al 2000). House dust intake rivalled only food intake as the primary component of the total lead exposure for children in Ottawa, ON, accounting for 30-70%, depending on the concentration statistic used (Rasmussen et al 2001).…”

Using environmental forensic microscopy in exposure science

“…The SEM-EDS analysis procedures have played an important role in environmental forensic investigations of various metal contaminants including copper, tin, zinc and lead arsenate (Rybicka et al, 1994;Thornton et al, 1994;Brown et al, 1995;Millette et al, 1995;Pirrie et al, 2003). In these published studies, the chemical composition and sometimes morphology as determined by SEM with x-ray analysis on individual particles played a role in determining the source or distribution of metal particles in environmental samples.…”

Urban geochemical mapping studies: how and why we do them

“…For example, the Environmental Geochemistry Research Group at Imperial College, London, built on its expertise in geochemical mapping and became involved in projects examining sources, processes and effects for some heavy metals (Thornton et al, 1994). Increased environmental awareness and the increased funding for such work, connected with a decline in exploration interest in developed countries, led to more geochemical mapping studies being done in urban areas.…”