Seasonal variation of concentrations of volatile organic compounds in selected German homes

Knowledge of the occurrence of volatile organic compounds (VOC) in indoor air has been steadily increasing during the last few years. However, information about the extent of the variation of VOC concentrations due to changing seasonal conditions has remained scarce. To fill this gap, VOC concentrations in 12 households in Berlin were followed over one year by exposing passive samplers for 26 two-week periods each. The analysis of VOC included determinations of alkanes, aromatics, halocarbons, and polar compounds. Smokers' and nonsmokers' homes in old and new buildings were chosen for the study. For each sampling period, the test families listed activities and the use of products susceptible to emit VOC. In one part of the study, VOC determinations were completed by measurements of the ventilation rate. In most of the households, the total VOC concentration level in winter was about two to three times higher than in summer. The compounds emanating from intermittent sources could in part be assigned to the activities of the occupants.