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House dust has been identified as a major exposure medium for lead (Pb) in children. High levels of Pb in soil and house dust have been recorded at the Bunker Hill Superfund Site (BHSS) in northern Idaho, an historic mining and smelting district. Soil and dust remediation at the site was required; however, regional background soil and dust Pb levels had not been well characterized. The objective of this survey was to determine background house dust Pb levels and to compare those levels with concentrations, and dust and Pb loading rates measured at the BHSS. Soil and house dust samples were collected in five towns demographically similar to the BHSS but unaffected by the mining industry. The background concentrations and loading rates were significantly lower than those observed at the site. House age was a significant factor affecting background soil and house dust Pb concentrations and loading rates.

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The recognition of the hazards to young children of low-level lead intoxication and the widespread distribution of lead in the urban environment have resulted in massive federal, state, and local lead awareness and abatement programs. Two of the most significant exposure routes of lead to young children are the soils and dusts found within the child's home. Most state and federal lead abatement programs deal with lead-based paint contamination but often do not address the issue of soft-surface contamination, such as that of carpets, furniture, and draperies. Carpets can be a reservoir of contaminated soils and dusts; currently, there exists no standard method to test carpeted surfaces for lead contamination.This paper describes a study that uses X-ray fluorescence (XRF) to test carpeted surfaces for lead contamination. XRF technology is the standard technology used in lead-based paint testing and is known to be an accurate technique to test for lead in soils. This study uses a controlled laboratory atmosphere to evaluate this technology; the objectives are to determine: (1) a lower limit of detection for the instrument; and (2) whether soil loading levels can be differentiated by XRF using trace elements also present in the soil. Results indicate that XRF can easily differentiate soil loading levels (g soil/m(2) carpet). The lower limit of detection of soil lead concentration on the carpet is a function of both soil lead concentration and soil loading; therefore, lead loading (mg Pb/m(2)) is a better indicator of detection limit than soil lead concentration. Lead loading detection levels from 108-258 mg Pb/m(2) were obtained, as compared to a level of 10 000 mg/m(2) (1 mg/cm(2)) for lead on painted surfaces as required by theLead-Based Paint Poisoning Prevention Act.XRF technology has the potential to be a fast, inexpensive screening technique for the evaluation of lead contamination on carpeted surfaces.