FOLK REMEDIES - A SOURCE OF TRACE METAL EXPOSURE IN HUMANS

Despite efforts to identify and eliminate sources, childhood lead (Pb) and other toxic trace metal exposures remain a problem worldwide. Sources of exposure vary by country and may include contamination of foodstuffs, residences in close proximity to active and inactive mining sites, mineralized soils, lead paint, drinking water, consumer products and ethnic remedies and goods. We have previously characterized and reported on samples of ‘edible’ soils obtained from Kabwe, Zambia, a historic Pb mining area with high levels of Pb poisoning (Plumlee et al, Rev. Mineral Geochem. V. 64). The Kabwe soils contained elevated total and bioaccessible concentrations of Pb in a predominately lead carbonate form. In this presentation, we report on a new source of exposure to Pb and other toxic trace metals in a US city. In an effort to identify the source of an infant’s elevated blood lead level detected during a routine screening visit, we assisted physicians from the Pediatric Environmental Health Center, Boston Children’s Hospital by characterizing a sample of a non-commercial ‘diaper’ or rash powder from Malaysia. An order of magnitude greater than the average Kabwe ‘edible’ soils, ICP-MS analysis revealed the Pb concentration in the sample to be 62% and XRD results indicate litharge (PbO) is the primary source of Pb. The powder also contained high concentrations of arsenic, antimony and thallium. In vitro bioaccessibility extractions using artificial gastric, lung and urine fluids suggest that these toxicants are highly gastric-bioaccessible, and moderate to poorly bioaccessible in lung and urine fluid simulants.