HORIZONTAL AND VERTICAL VARIABILITY OF BE NZENE CONCENTRATIONS IN HOMES

A German study on the epidemiology of asthma will be conducted for the next 10 years in Erfurt, Hamburg, and the Bitterfeld region. The stud y will include an indoor and outdoor exposure assessment of volatile o rganic chemicals. The results of the pilot phase which was conducted i n Erfurt will be presented here using the compound benzene as an examp le. In a well-defined region of Erfurt, during the winter of 1994, pas sive sampling for benzene was conducted in the living room (at 0.7, 1. 2 and 2 m height), bedroom (2 m), kitchen (2 m) and outside the living room window in 20 homes of randomly chosen adults. The 20 houses cons isted of 10 old concrete constructions (''Altbauten'', 1960 1970) and 10 new concrete constructions (''Neubauten'', 1970 - 1980). Despite a certain tendency noted in medians and means no height-dependent differ ences in the concentrations of benzene could be significantly detected , which might influence exposure due to the height of respiration in c hildren and adults and according to the proband's position in the room (laid down, seated, standing). With regard to benzene concentration i n air the bedroom concentrations were closer to the outdoor concentrat ions than to those in the living room and kitchen. Rank correlation co efficients between outdoor to indoor benzene concentrations ranged fro m 0.42 - 0.47, while indoor correlations varied between 0.37 and 0.67. Indoor-outdoor-coefficients for benzene in Erfurt were strongly influ enced by the somewhat higher indoor values encountered in the older co ncrete constructions. Their variability dominates the distribution in the whole data set. Significant differences in benzene indoor concentr ations between the old and new buildings could not be detected.