COMPARISON OF A WIPE AND A VACUUM COLLECTION METHOD FOR THE DETERMINATION OF LEAD IN RESIDENTIAL DUSTS

Lead-containing house dust is an important source of childhood lead ex posure. Standard methods for collection of settled dust for evaluation of lead content have not been established. Little is known about the relationships between the various wipe and vacuum-based methods employ ed in past studies, preventing meaningful comparisons of results. This study characterized the relationship between a frequently used wipe d ust collection method and a vacuum-based in-line filter method used to collect dust in a national survey of lead in paint and dust in U.S. h ousing. The correlation coefficient was 0.82 for estimates of lead loa dings (PbD, mg/m(2)) from 71 pairs of side-by-side wipe and vacuum dus t samples collected from uncarpeted floors, window sills, and exterior window wells in six dwellings. Geometric mean (GM) wipe PbD estimates exceeded those for vacuum samples by a factor of 3.9 and 5.7 for floo rs and window sills, respectively, findings consistent with the multip le sources of sample loss associated with the vacuum sampler. For wind ow wells, the GM vacuum PbD estimate exceeded the GM wipe PbD estimate by a factor of 3.4, possibly due to the use of an alternative vacuum nozzle. The resulting increase in the estimated prevalence of U.S. hom es with elevated dust lead loadings had wipe-sampling instead of vacuu m-sampling methods been used in the national survey is discussed. (C) 1994 Academic Press, Inc.