Spatial variations in the concentrations of traffic-related pollutants in indoor and outdoor air in Huddersfield, England

As part of the Small Area Variations in Air Quality and Health (SAVIAH-2) s tudy, monitoring-was carried out for a number of traffic related pollutants (mass and absorbance of PM10, and PM2.5, benzene, B(a)P and PAHs) indoors and outdoors of homes in an area of Huddersfield, England. Homes were selec ted on the basis of their distance from nearby major roads. Monitoring was conducted during two 2-week periods. On each occasion, pollution levels wer e measured in paired 'proximity' (within 50 m of the main road) and 'backgr ound' ( > 50 m from the main road) homes, for a 24 h period, using active p ump samplers. Spatial variations in pollutant concentrations were modest an d in most cases did not show significant associations either with distance from road or modelled NO, concentrations. Neither of these commonly used me asures would thus seem to provide reliable indicators for these traffic-rel ated pollutants in this study area. Several of the measured pollutants show ed significant inter-correlations, but overall absorbance of the fine parti culate fraction displayed the strongest correlations, and would appear to p rovide the best general marker for these pollutants, perhaps reflecting the importance of diesel vehicles as a major emission source. Indoor-outdoor r atios of PM10, PM2.5, and absorbance of these fractions were below 1, but o ther pollutants did not show significant differences between indoor and out door concentrations. However, all the pollutants showed significant positiv e correlations between indoor and outdoor concentrations, strongest correla tions being seen for the absorbance measures of the particulate fraction. T his suggests that outdoor concentrations may give a useful measure of expos ures to traffic-related pollutants for use in epidemiological studies. (C) 2000 Elsevier Science Ltd. All rights reserved.