VOC source identification from personal and residential indoor, outdoor and workplace microenvironment samples in EXPOLIS-Helsinki, Finland

Principal component analyses (varimax rotation) were used to identify commo n sources of 30 target volatile organic compounds (VOCs) in residential out door, residential indoor and workplace microenvironment and personal 48-h e xposure samples, as a component of the EXPOLIS-Helsinki study. Variability in VOC concentrations in residential outdoor micro environments was dominat ed by compounds associated with long-range transport of pollutants, followe d by traffic emissions, emissions from trees and product emissions. Variabi lity in VOC concentrations in environmental tobacco smoke (ETS) free reside ntial indoor environments was dominated by compounds associated with indoor cleaning products, followed by compounds associated with traffic emissions , long-range transport of pollutants and product emissions. Median indoor/o utdoor ratios for compounds typically associated with traffic emissions and long-range transport of pollutants exceeded 1, in some cases quite conside rably, indicating substantial indoor source contributions. Changes in the m edian indoor/outdoor ratios during different seasons reflected different se asonal ventilation patterns as increased ventilation led to dilution of tho se VOC compounds in the indoor environment that had indoor sources. Variabi lity in workplace VOC concentrations was dominated by compounds associated with traffic emissions followed by product emissions, long-range transport and air fresheners. Variability in VOC concentrations in ETS free personal exposure samples was dominated by compounds associated with traffic emissio ns, followed by long-range transport, cleaning products and product emissio ns. VOC sources in personal exposure samples reflected the times spent in d ifferent microenvironments, and personal exposure samples were not adequate ly represented by any one microenvironment, demonstrating the need for pers onal exposure sampling. (C) 2001 Elsevier Science Ltd. All rights reserved.