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 b een 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 Neth erlands. The study was performed in the framework of the Small Area Variati on in Air quality and Health (SAVIAH) study. In the first phase of the stud y, 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 p articulate matter (PM10 and PM2.5), the reflectance ('blackness') of the PM 10 and PM2.5 filters, polycyclic aromatic hydrocarbons (PAH) and volatile o rganic compounds (VOC). Measurements were performed during 19 days in the w inter 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 wer e included in the study, 18 in major streets and 18 ill quiet streets. Outd oor PM10 and PM2.5 concentrations were 15-20% higher at homes located in hi gh trams intensity streets compared to low traffic homes, similar to contra sts in predicted NO2. A substantially larger contrast (about a factor two) was found for outdoor concentration of the particulate components BaP, tota l PAH, absorption coefficient ('soot') and the gas-phase components benzene and total VOC, The contrasts for these pollutants were substantially large r than the estimated contrast in average NO2 (22%). Differences of a simila r magnitude were also found in indoor air in these homes, with the exceptio n 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 (out door) contrasts of BaP, total PAH, absorption coefficient, benzene and tota l VOC were highly correlated, suggesting that any of these could have been selected to represent exposure to traffic air pollution. Also, the study in dicated that the earlier developed NO2-map reflected even larger contrasts in other traffic-related pollutants. (C) 2000 Elsevier Science Ltd. All rig hts reserved.