Distribution of pesticides and polycyclic aromatic hydrocarbons in house dust as a function of particle size.

Abstract

House dust is a repository for environmental pollutants that may accumulate indoors from both internal and external sources over long periods of time. Dust and tracked-in soil accumulate most efficiently in carpets, and the pollutants associated with dust and soil may present an exposure risk to infants and toddlers, who spend significant portions of their time in contact with or in close proximity to the floor and who engage in frequent mouthing activities. The availability of carpet dust for exposure by transfer to the skin or by suspension into the air depends on particle size. In this study, a large sample of residential house dust was obtained from a commercial cleaning service whose clients were homeowners residing in the Raleigh-Durham-Chapel Hill (Research Triangle) area of North Carolina. The composite dust was separated into seven size fractions ranging from < 4 to 500 microm in diameter, and each fraction was analyzed for 28 pesticides and 10 polycyclic aromatic hydrocarbons (PAHs). Over 20% of the fractionated dust sample consisted of particles < 25 microm in diameter. Fourteen pesticides and all 10 of the target PAHs were detected in one or more of the seven size-fractionated samples. Sample concentrations reported range from 0.02 to 22 microg/g; the synthetic pyrethroids cis- and trans-permethrin were the most abundant pesticide residue. The concentrations of nearly all of the target analytes increased gradually with decreasing particle size for the larger particles, then increased dramatically for the two smallest particle sizes (4-25 microm and < 4 microm).ImagesFigure 1Figure 2Figure 3Figure 4

Polycyclic aromatic hydrocarbons: determinants of residential carpet dust levels and risk of non-Hodgkin lymphoma

“…In general, carpet dust PAH concentrations measured in our study were lower than previously reported levels in Durham, NC, USA [44, 45] and Ottawa, Canada [46]. However, measured concentrations in this multicenter study were considerably higher than those measured in the California Childhood Leukemia Study (CCLS), a recent case–control study conducted in the San Francisco Bay area and the Central Valley, USA [47].…”

Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets

“…Previous studies have shown that carpets can harbor large amounts of lead, house dust mite (HDM) allergens, PAHs, and other chemical substances. 2– 5 Without proper cleaning, these contaminants are accessible and potentially harmful to young children. 6–10 …”

Analysis of House Dust and Children?s Hair for Pesticides: A Comparison of Markers of Ongoing Pesticide Exposure in Children

“…Thus, exposure to house dust is a significant pathway for the children’s exposure to pesticides [9,11]. Studies also indicate that more pesticides and higher pesticide concentrations are found in household dust as compared to air, soil, and food [24,35]. …”

“…Carbamates and pyrethroids are semi- or less volatile pesticides that tend to settle in house dust [24]. We expect that these are the pesticides that will accumulate in the dust samples because spray pesticides and slow-burning mosquito coils which contain these pesticides are regularly used in the homes of the subjects [28].…”