Evaluation of four sampling methods for determining exposure of children to lead-contaminated household dust

Childhood exposure to lead has been demonstrated to result in health effect s and lead-contaminated household dust is a primary exposure source. There is a need to establish reliable methods for sampling surfaces to determine levels of lead contamination, Three vacuums (HVS3, GS80, and MVM) and one w ipe method were evaluated for the collection of household floor dust under field sampling conditions within a Superfund site and demographically simil ar control area, Side-by-side floor samples were taken from three locations within 41 randomly selected households between August and September 1995: a child's bedroom, primary play area, and primary entrance. Analysis was pe l formed to assess the relative collection performance of each sampler, spa tial distribution of lead within a household, and correlation of lead loadi ng with observed blood lead level, and to determine if discrete- or composi tes samples were more predictive of blood lead levels, Approximately 90% of the floor surfaces were carpeted, The rank order of sampling methods from greatest to lowest collection efficiency was HVS3 > GS80 > wipe > MVM, The HVS3 had the highest level of precision (CV = 0.05), with the GS80 and wipe precisions 0.48 and 0.053, respectively, Lead loadings for samples collect ed in bedrooms and living areas and composite samples using the HVS3 and wi pe methods were significantly correlated with blood lead levels. Correlatio ns between blood lead levels and composite samples were stronger for the HV S3 (R-2 = 0.33, P = 0.003) and wipe (R-2 = 0.25, P = 0.002) methods than th e respective discrete samples. Regression analysis indicated that a blood l ead level of 10 mu g/dl corresponds to a carpet wipe sample geometric mean of 68 mu g/ft(2). For ongoing public health purposes, such as screening and clearance testing, use of the wipe sampling method is the most appropriate . This investigation supports findings by others that the present HUD risk levels for lead in floor wipe samples may not be adequate for reducing chil dren's blood lead levels below 10 mu g/dl. (C) 1999 Academic Press.