Exposure of Paris taxi drivers to automobile air pollutants within their vehicles

Objectives To study the exposure of Parisian taxi drivers to automobile air pollutants during their professional activity. Methods-A cross sectional study was carried out from 27 January to 27 March 1997, with measurements performed in the vehicles of 29 randomly selected drivers. Carbon monoxide (CO) content was measured over an 8 hour period by a CO portable monitor. The fine suspended particles were measured accordin g to the black smoke index (BS), with a flow controlled portable pump provi ded with a cellulose filter. The nitrogen oxides, NO and NO2 were measured with a passive sampler. Results-These drivers are exposed during their professional activity to rel atively high concentrations of pollutants (mean, median (SD) 3.8, 2 (1.7) p pm for CO, 168, 164 (53) mu g/m(3) for BS, 625, 598 (224) mu g/m(3) for NO, and 139, 131 (43) mu g/m(3) for NO2.) For CO the concentrations were clear ly lower than the threshold values recommended by the World Health Organisa tion. The situation is less satisfactory for the other pollutants, especial ly for the BS index. All concentrations of pollutants recorded were noticea bly higher than concentrations in air recorded by the ambient Parisian air monitoring network and were close to, or slightly exceeded, the concentrati ons measured at the fixed stations close to automobile traffic. Pollutant c oncentrations were also influenced greatly by weather conditions. Conclusion-This first French study conducted in taxi drivers shows that the y are highly exposed to automobile pollutants. The results would justify a medical follow up of this occupational group.