Measured Concentrations of VOCs in Several Non-Residential Microenvironments in the United States

Abstract

Individuals spend about 25% of their time in non-residential indoor microenvironments. For some of these microenvironments, particularly stores and restaurants, exposures to volatile organic compounds (VOCs), have not been well characterized. In the Boston Exposure Assessment in Microenvironments (BEAM) study, sampling using scripted activities was conducted in stores, restaurants, and transportation in the summer of 2003 and winters of 2004 and 2005. A suite of VOCs including hydrocarbons, several chlorinated compounds, and aldehydes was analyzed. Nine store types were sampled using a composite design to enable a greater number of stores to be visited. Stores had higher concentrations of formaldehyde, toluene, ethylbenzene, xylenes, and styrene than other microenvironments, particularly in certain store types. Geometric mean formaldehyde levels were highest in the housewares stores, at 53 microg/m3 (95% CI = 43, 66). Geometric mean toluene levels were highest in multipurpose stores, at 76 microg/m3 (95% CI = 50, 118). The levels observed in stores were several times higherthan levels found in transportation microenvironments, and indicate strong indoor sources. In contrast, benzene did not have significantly higher levels in stores than typically found outdoors. Concentrations of formaldehyde and benzene, ethylbenzene, xylenes, and styrene were strongly influenced by the presence of smoking in the dining microenvironment. Chloroform levels were higher in restaurants than in other microenvironments, with a geometric mean of 1.1 microg/m3 (95% CI = 0.7, 1.8). The VOC concentrations found in stores and restaurants in this study are a potentially important source of exposure for sensitive individuals or people who work in these microenvironments.

Contribution to volatile organic compound exposures from time spent in stores and restaurants and bars

“…Restaurant, grocery store, and stores of all other types (non-grocery) concentrations were taken from the Boston Exposure Assessment in Microenvironments (BEAM) study (Loh et al, 2006). This study collected data using personal samplers in a range of store types (e.g.…”

“…), smoking and non-smoking restaurants and bars, and different modes of transportation. Due to the composite method of sampling used, a lognormal distribution was assumed for the stores (Loh et al, 2006). The restaurants/bars were collected as single samples per location, and we were able to then fit distributions to the data for each compound.…”

“…For travel concentrations, no significant differences between modes of transportation were found for most compounds in the BEAM study (Loh et al, 2006), therefore concentrations were averaged across in-vehicle levels in cars, buses, trains, and personal concentrations while walking. The outdoors concentration distributions were developed the same way as the indoor home concentrations, using the corresponding outdoor values reported in the home studies.…”

“…NHAPS includes time spent in restaurants and stores, and separates visits to grocery stores from other stores, which were grouped into a mall/store category. We also separate grocery stores from all other types of stores because grocery stores tended to have lower concentrations of most compounds in comparison (Loh et al, 2006). To preserve the correlation between time spent in various activities throughout a day, we used the amount of time spent in each microenvironment from the same NHAPS individual's diary day.…”

“…These studies include Kim et al, 2001; who examined VOCs in pubs, department stores, cinemas, train stations, bus stations, cars, buses, and trains in Birmingham, UK; Lee et al, 2002; who studied shopping malls, restaurants, and offices and classrooms in Hong Kong; and the Boston Exposure Assessment in Microenvironments (BEAM) study, which investigated VOCs in different types of stores, restaurants, and transportation microenvironments (Loh et al, 2006). Although not all studies were conducted in the United States, these studies found concentrations in stores and restaurants to be much higher for several VOCs, such as toluene, formaldehyde, and styrene, than those outdoors, in transportation microenvironments, and even homes without smokers.…”