PAHs, in house dust

Table 11.9 Concentrations of some polycyclic aromatic hydrocarbons (PAHs) in house dust from Germany and the USA (mgkg"1).

Benzo(a)pyrene was found in 89% of the homes at a median value of 1.12 A g/g- The sum of the medians of the seven B-2 PAHs in house dust was 7.22 yig/g. These B-2 PAHs show strong within-home covariance and were detected in 90% of the homes. Cotinine, which comes from tobacco smoke, was found in the rug dust in 77% of the homes at a median level of... 

Concentrations of PAHs measured in house dust are in the same order of magnitude for American and German homes (see Table 11.9). This holds especially for BaP, the most prominent indicator for PAHs. Values are further in accordance with the median for BaP of 0.2mgkg 1 given by Kersten und Reich (2003) for house dust from 65 apartments in Hamburg (Germany). 

No association was found for BaP in house dust and the indoor air by Dieckow, Ullrich and Seifert (1999). Nor did Fromme et al. (2004b) find an association between concentrations of polycyclic aromatic hydrocarbons in household dust and indoor air. But for fluoranthene, phenanthrene, and pyrene, statistically significant correlations of surface dust loadings (ngcnf2) with personal air and indoor air concentrations were noted (Clayton et al., 2003). As stated by Hansen and Volland (2002), there seems to be no simple relation between PAHs in air and in dust. 

Method performance in air analysis involves terms such as accuracy, storage stability, capacity, sampling rate, recovery, and sensitivity. To evaluate the performance of a developed method, certified reference materials for particulate matter, such as urban dust SRM 1649a particulate matter from NIST (Gaithersburg, MD, USA) can be purchased. In addition, a standard reference material has been recently developed for the determination of organic compounds in house dust the SRM 2585 is intended for using in method validation for the analysis of PAHs, PCBs, chlorinated pesticides, and PBDEs (Poster et al. 2007). 

Those studies conducted to date establish a basis for control of lead, pesticides, PAHs, PCBs, and allergens in indoor air and house dust. Track-in and accumulation of pollutants in rugs is an important source of exposure for children lead in dust is the major source of lead for most toddlers. The established benefits from reduced exposure to lead and allergens justify public education to reduce dust from track-in and inside sources as well as pollutants in indoor air. Action to control lead and allergens will reduce exposure to other pollutants in house dust and indoor air. It is possible that a nonregulatory education and outreach program with emphasis on public participation and pollution prevention will be more effective in the home than use of regulations and other traditional methods of pollution control. 

More research is needed to determine the cause of the rapid increase in childhood asthma in Seattle and the U.S., as well as the source of PAHs and mutagens in house dust. There is a need to use existing data to assess risks and set priorities for risk reduction. Perhaps the highest priority should be given to finding cost-effective methods of public education to reduce home exposures. Such methods may vary with the level of income and education. We recommend the following ... 

Estimate risks for lead, pesticides, PAHs, VOCs, and PCBs in house dust and indoor air using available data. These risk assessments should include synergistic interactions between pollutants that may increase total risk. 

Determine the source of PAHs and mutagens in house dust. Determine the concentration of dioxins in house dust. 

Lewis et al. (1999) prepared a gross house dust sample by combing dust from four vacuum cleaner bags obtained from 25 middle-class homes. The composite dust was separated into seven size fractions ranging from <4 to 500 micrometer in diameter. Ten PAHs were analyzed. All of the ten target PAHs were detected... 

It is desirable to collect as many different matrices from each study participant as is feasible and to process them with consideration of both immediately planned analyses of biomarkers and future uses. For example, several Children s Environmental Health Centers obtained urine, peripheral blood, cord blood, breast milk, meconium, saliva, hair, placental tissue, infant formula, indoor and outdoor air, and house dust from longitudinal birth cohort studies (Eskenazi et al. 2005). The centers have analyzed concentrations of numerous compounds in those biologic and environmental samples, such as pesticides, phthalates, mercury, lead, cotinine, polycyclic aromatic hydrocarbone (PAHs), PAH-DNA adducts, allergens, endotoxin, antioxidant micronutrients, cholinesterase, and thyroid hormones. Most centers also banked samples for future analyses. 

Analytical methods have been developed by the Southwest Research Institute, Battelle-Columbus, and others for analyzing pesticides, PAHs, and PCBs in many environmental matrices, including indoor air and house dust samples (Camann 1994 Chuang et al. 1994). Progress in sampling and analysis make possible improvements in exposure analysis and the epidemiological studies discussed in the following sections. 

House dust in carpets, on sofas, and in air ducts is both a major source and sink of pollutants in the home (Roberts et al. 1994). The lead on surfaces and the lead loading in a carpet (/igPb/m ) are the best predictors of a toddler s blood lead (Davies et al. 1990 Hilts 1994). Dust in carpets can also be a major source of exposure to pesticides and allergens (Lewis et al. 1994 Pope et al. 1993). We believe, but have only partially confirmed, that house dust is also a major source of childhood exposure for PAHs, PCBs, and other persistent pollutants. 

Camann and Buckley (1994) used the HVS3 to collect house dust from the homes of more than 250 children with acute lymphocytic leukemia and 250 control children in nine states Illinois, Indiana, Iowa, Michigan, Minnesota, New Jersey, Ohio, Pennsylvania, and Wisconsin. A preliminary analysis of 28 pesticides, 10 PAHs, and cotinine has been compiled on 362 cases and controls. The most frequently found pesticides, the percentage of homes where found, and median values, respectively, were as follows or//io-phenylphenol, 96%, 0.48 Atg/g chlorpyrifos (Dursban ), 67%, 0.46 Atg/g carbaryl, 32%, 0.54 A g/g DDT, 25%, 0.25 yi>g/g chlordane, 16%, 0.86 Atg/g and dieldrin, 13%, 0.25 iig/g. 

Ltg/g even though only 28 o of Americans smoke. These data are valuable in that the controls were selected at random. They tend to confirm the PAH and pesticide house dust data collected in earlier nine home studies in Florida, Ohio, North Carolina, and Washington (Budd et al. 1990 Chu-ang et al. 1994, 1995 Lewis et al. 1994). However, these data from Camann and Buckley are considered preliminary and subject to revision in that the controls have not been separated from cases and the analysis and quality control process has not been completed on the more than 500 cases and controls that have been collected. 

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