Dust, indoor sampling methods

The most frequently used methods for sampling indoor surface dust for SVOC/ POM analysis is simply to use dust from a vacuum cleaner dust bag, see for example, Krause, Chutsch and Englert (1989), or a special vacuum cleaner mouthpiece containing a filter, see for example, 0ie, Hersoug and Madsen (1997). Both the mouth-piece and the filter should be cleaned prior to use. It must be assured that the SVOCs and POMs of interest are quantitatively captured by the filter (e.g., phthalates are quantitatively captured by quartz fiber filters (Clausen and Wolkoffi 1997b)) and that the vacuum cleaner exhaust does not contaminate the samples with for example, phthalates. However, the vacuum cleaner sampling method is probably very dependent on the sampling conditions (e.g., carpet or hard floor... 

This review summarizes occurrence and exposure studies for pollutants in house dust and related indoor air exposures. A standard sampling method and control methods to reduce these exposures are discussed, including recommendations for future research. 

The combined EXAFS, /xXRF and pXRD characterization successfully answered the two main questions posed at the outset of the study. First, the methods identified that Pb in the dust mainly occurs as (1) the mineral hydrocerussite commonly used in indoor paint, and (2) adsorbed onto Fe-oxyhydroxides, which is commonly found in soil. This tells us that both indoor and outdoor sources contribute to the elevated Pb concentrations in the home from which this sample was collected. Second, the identification of these two soluble Pb compounds explained the observed high bioaccessibility of the Pb in this sample (95%), as both phases dissolve easily in a dilute HCl solution. Similarly, Casteel et al. (2006) reported that Pb carbonate, Pb carbonate hydroxide and Pb adsorbed onto goethite are readily bioaccessible in gastric juices. Thus, the in situ investigation to determine the Pb speciation by XAFS and /xXRD explained the high Pb bioaccessibility in this sample, while identifying probable sources for the metal. 

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. 

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