Traffic-related differences in outdoor and indoor concentrations of particles and volatile organic compounds in Amsterdam

Several studies have reported chronic health effects related to living near major roads. Exposure to traffic-related air pollution has generally not been well characterised in these studies. We therefore performed a study to evaluate differences in concentration of air pollutants outside and inside homes in streets with low and high traffic intensity in Amsterdam, the Netherlands. The study was performed in the framework of the Small Area Variation in Air quality and Health (SAVIAH) study. In the first phase of the study, an NO2-map was produced based upon a dense network and traffic intensity information. The present study was also designed to evaluate whether other pollutants exhibited similar spatial variation. Pollutants measured were particulate matter (PM10 and PM2.5), the reflectance ('blackness') of the PM10 and PM2.5 filters, polycyclic aromatic hydrocarbons (PAH) and volatile organic compounds (VOC). Measurements were performed during 19 days in the winter and spring of 1995. Per day two to four homes were measured. In total 36 homes without major indoor sources of air pollution such as smoking were included in the study, 18 in major streets and 18 ill quiet streets. Outdoor PM10 and PM2.5 concentrations were 15-20% higher at homes located in high trams intensity streets compared to low traffic homes, similar to contrasts in predicted NO2. A substantially larger contrast (about a factor two) was found for outdoor concentration of the particulate components BaP, total PAH, absorption coefficient ('soot') and the gas-phase components benzene and total VOC, The contrasts for these pollutants were substantially larger than the estimated contrast in average NO2 (22%). Differences of a similar magnitude were also found in indoor air in these homes, with the exception of the VOCs. We conclude that PM10 and PM2.5 are not specific indicators of exposure to traffic-related air pollution. In the present study the (outdoor) contrasts of BaP, total PAH, absorption coefficient, benzene and total VOC were highly correlated, suggesting that any of these could have been selected to represent exposure to traffic air pollution. Also, the study indicated that the earlier developed NO2-map reflected even larger contrasts in other traffic-related pollutants. (C) 2000 Elsevier Science Ltd. All rights reserved.