Oslo traffic study - part 1: an integrated approach to assess the combined effects of noise and air pollution on annoyance

Vehicular traffic is a common important source of air pollution, traffic accidents, road traffic noise as well as other environmental exposures. The relationship between each of these exposures and their respective impacts are nevertheless most often studied separately. An integrated alternative approach was adopted in the Oslo traffic study to allow people's environmental annoyances to be studied relative to the indicators of air pollution, road traffic noise and residential traffic. These annoyances include annoyance with the smell of exhaust, with dust and grime, feeling insecure in traffic and being annoyed with road traffic noise. A hypothesis was that multiple exposures typical in city areas have combined impacts - that people exposed to both air pollution and road traffic noise will be more annoyed than in the respective single-exposure situations. Three environmental studies in 1987, 1994 and 1996 each year comprising about 1000 respondents after a response rate of 50%, serve as before-after studies of two tunnel projects. Personal interviews were utilised in the before study in 1987 and telephone interviews in 1994 and 1996. Exposure indicators for air pollution as well as road traffic noise and residential traffic levels were produced for each respondent by comprehensive environmental modelling. Exposure-effect logistic regression models for the probability of people being highly annoyed by the smell of exhaust and by road traffic noise, respectively, were estimated. The results indicate that the higher the road traffic noise levels people are exposed to, the more likely they are to be highly annoyed by exhaust smell at a specified air pollution level. The higher air pollution levels people are exposed to the more likely they are to be annoyed by road traffic noise at a specified noise level. Modifying factors were controlled for. (C) 2000 Elsevier Science Ltd. All rights reserved.