Indoor- and Outdoor-Derived Contaminants in Urban and Rural Homes in Ottawa, Ontario, Canada

Abstract

Indoor and outdoor air contaminants have largely been treated separately in studies of their respective effects on respiratory and nonrespiratory health. In this paper, we report the results of a comprehensive study of key contaminants in 10 urban and 10 rural homes in Ottawa, Ontario, Canada. The analyses included house dust mite and cat allergens along with the fungal inflammatory polysaccharide ␤1,3-D-glucan in settled dust and fine particulate matter, coarse particulate matter, ergosterol, glucan, and endotoxin from air samples. In addition, black carbon was continuously measured for 7 days. A detailed physical assessment of the house and patterns of use were undertaken, including a careful inspection for mold and water damage, as well as measurements of air leakage. The performance of the houses and the range and distribution of the contaminants measured were largely similar to that of previous Canadian studies. For certain combinations, it is thought that the presence of both allergen and inflammatory materials increases asthma symptoms. House-byhouse comparisons of airborne concentrations of inflammatory compounds measured (endotoxin, fine particulate matter, and fungal glucan) with dust mite allergens indicated that certain houses had relatively higher amounts of both kinds of materials.

Temporal and spatial variation of indoor and outdoor airborne fungal spores, pollen, and (1→3)-β-d-glucan

“…This finding agrees with the results by Miller et al (2007). Considerable differences, however, were found in average indoor room concentrations between Homes A to C; particularly large differences were seen in beta-glucan concentrations measured in the kitchens.…”

“…The investigators concluded that the levels of beta-glucans are higher during the warm seasons, which may be attributed to the seasonal variation of pollen and fungal spores. Miller et al (2007), who measured airborne beta-glucan, ergosterol, and endotoxin in living rooms and bedrooms in 20 Canadian homes using long-term air sampling, reported no difference between the two room types in any of the measured biocontaminants. Chew et al (2001) analyzed beta-glucan in dust samples collected in 23 Dutch homes over a period of a year and found similar variation of its levels within and between homes.…”

Size-Resolved Concentrations of Particulate Matter and Bioaerosols Inside versus Outside of Homes

“…(1→3)-β-D-glucan, glucose polymers with variable molecular weights and degrees of branching (i.e., triple helix, single helix, or random coil structures), are found in most fungi, plants and certain bacteria, and can be used to monitor levels of fungi. Indoor airborne endotoxin, (1→3)-β-D-glucan, and protein concentrations have been reported in the literature as a part of non-industrial indoor environmental studies (Park et al 2000(Park et al , 2001Reynolds et al 2001;Rylander and Beijer 2003;Foarde and Berry 2004;Sohy et al 2005;Chew et al 2006;Lee et al 2006;Solomon et al 2006;Miller et al 2007), epidemiological studies (Rylander et al 1992;Rylander 1997;Rylander et al 1998; Thorn and Rylander 1998;Wan and Li 1999) and toxicological studies (Monn and Becker 1999;Rylander and Lin 2000;Long et al 2001;Soukup and Becker 2001;Beijer et al 2002).…”

Comparison of Two Analytical Methods for Detecting (1-3)-β-D-Glucan in Pure Fungal Cultures and in Home Dust Samples

“…This appears to be the first report on LAL-analyzed (1-3)--D-glucan concentration in a large number of dust samples. The LAL-analyzed dust (1-3)--D-glucan levels measured in this study were lower than those measured in Canadian homes (n=28) of asthmatic children (GM=172 g/g and GM=160 g/m 2 ) [45] and homes perceived as having satisfactory indoor quality (n=20) (median=230 g/m 2 ) [46]. These differences may be due to different geography and/or heating [16] (in colder climate) in the Canadian homes.…”

“…The EIA assay is not commercially available, and is not generally performed in most clinical laboratories. In addition, less data are available on the utility of LAL and EIA assays in the analysis of fungal (1-3)--Dglucan concentration in environmental samples [4,5,45,46]. Thus, the current study is the first one to directly compare the specificity, sensitivity, and accuracy of LAL versus EIA assays in detecting fungal (1-3)--D-glucans.…”