Dust, lead surface sampling

As set forth in U.S. HUD (1995), dust sampling by use of surface wipes is preferred on the basis of ease of use, relative cost, and a generally favorable performance record for routine samplings. For example, children s blood lead levels and dust wipe lead content in the same units are well correlated (Farfel et al., 1994 Lanphear et al., 1995). Certain vacuum collection approaches can also be used with trained operators in research studies. Measuring dust lead loading from hard surfaces is more reliable than firom complex surfaces such as upholstery or carpeting (Ewers et al., 1994). 

A dust-lead hazard is surface dust that contains a mass-per-area concentration of lead equal to or exceeding 40 micrograms per square foot (pg/fC) on floors or 250pg/ft on interior windowsills based on wipe samples. A soil-lead hazard is bare soil that contains total lead equal to or exceeding 400 parts per million (ppm) in a play area or average of 1200 ppm of bare soil in the rest of the yard based on soil samples. 

Demyanek, M.L., G.R. Dunmyre and G.S. Casuccio (1995). Investigation of adhesive lift sampling technology used for evaluation of lead in surface dust, in Lead in Paint, Soil and Dust Health Risks, Exposure Studies, Measurement Methods and Quality Assurance, M.E. Beard and A.S.D. Iske (Eds), American Society for Testing and Materials, West Conshohoken, PA, USA, STP 1226, pp. 249-267. 

Only properly protected workers should be allowed to enter any area where lead-painted surfaces are disrupted until it is thoroughly cleaned up. Pregnant women, children, and pets should not be present in the home during lead hazard control work. Entry should be allowed only if dust samples are taken and come back showing the home is safe. 

Three types of surfaces should be tested for lead dust. Samples of dust are taken using a wet wipe (similar to one used for babies) according to a very specific procedure, and these are analyzed in an EPA-approved laboratory according to specified methods. Dust samples from floors should not have more than 100 p.g of lead per square foot. Samples from interior windowsills should not have more than 500 jig per square foot, and those from window troughs and exterior concrete or other rough surfaces, not more than 800 p,g per square foot. 

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