Exposure to traffic air pollutants in taxicabs and acute adverse respiratory effects: A systematic review.

Abstract

Taxi drivers could be at risk regarding their respiratory health due to their constant exposure to traffic related air pollutants (TRAP) inside their vehicles. Therefore, we aimed to review pollutants exposure inside taxi vehicles and its determinants as well as its acute adverse respiratory effects. The literature search was done in Pubmed and in Embase. For additional resources we searched manually articles from the reference lists of the selected papers and from Google Scholar. We included only studies in French or in English language meeting the following eligibility criteria: design: observational and quasi-experimental; study population: taxi drivers or taxi commuters, outcome: pollutants levels in taxicabs and/or acute adverse respiratory effects. Data was extracted using tabulation according to the type of the study (exposure or epidemiological). Out of 1753 articles, 21 studies were included. Exposure studies underlined that TRAP concentrations inside taxicabs were higher than their urban background levels and even exceeded those recorded in buses, in trains and when commuting by active transport modes. Overall, their concentrations varied widely between studies depending on the characteristics of the urban environment and the vehicle fleet of each location. Meteorological parameters and ventilation settings appeared to influence pollutants concentrations inside each vehicle. Otherwise, deficiency in epidemiological studies and inconsistencies in their findings restrain our ability to determine the association between acute respiratory effects and exposure to TRAP inside taxicabs. Although studies are heterogeneous, results have shown a high but variable occupational exposure of taxi drivers to TRAP inside their vehicles. However, future researches are required to study short respiratory impact of taxi drivers' exposure to TRAP inside their vehicles.