Exposure of Taxi Drivers to Ultrafine Particles and Black Carbon Within Their Vehicles

Brief Summary Short description of the protocol intended for the lay public. Include a brief statement of the study hypothesis. (Limit: 5000 characters)

Example: The purpose of this study is to determine whether prednisone, methotrexate, and cyclophosphamide are effective in the treatment of rapidly progressive hearing loss in both ears due to autoimmune inner ear disease (AIED). This project is part of a research field on the role, not yet fully understood, of atmospheric pollution, especially from road traffic, on respiratory health and allergies, particularly on the development / onset of symptoms and functional disturbances. The ultrafine fraction of particles (UFPs - particles smaller than 100 nm in diameter) is of recent interest because of their ability to induce inflammatory effects, oxidative stress and may contribute to the exacerbation of asthma symptoms in susceptible individuals. UFPs, with their high number concentration and surface area and their small diameter are able not only to convey other contaminants, but also to contribute to a high deposition efficiency, into the alveoli in the lungs. Recently it appeared relevant to be interested in black carbon (BC), components of PM2.5 (particulate matter with a diameter less than 2.5 micrometers), suspected of being responsible for their toxicity. Current epidemiological knowledge of the effects of UFPs and BC are few as compared to those on fine particles. Some professionals, such as police, drivers (taxis, truckers ...), delivery men, postal workers, workers on roads and highways, etc. are heavily exposed, during their working hours, to air pollution due to road traffic. These occupational groups appear to be at greater risk for developing respiratory, cardiovascular and neurological diseases than the general population. Occupational exposure to diesel exhaust has been associated with an increased risk of lung cancer mortality and chronic obstructive pulmonary disease. Occupational exposure to UFPs and BC has rarely been measured due to a lack of suitable devices. Therefore, this project's originality consists in measuring UFPs and BC by using portable devices developed in the recent years. The use of these devices, linking their recordings with ventilatory measures and repeating them, offers the rare opportunity to study the short-term respiratory health impact of this occupational exposure, which has never been described in the literature. Our research aims to: 1/ quantify the occupational exposure of taxi drivers to UFP, BC, oxides of carbon (CO, CO2) and to nitrogen dioxide (NO2), 2/ identify spatio-temporal variability and patterns of exposure related to occupational tasks, 3/ study the impact of this occupational exposure to UFP and BC on ventilation performances and respiratory symptoms.

The study is based on a random sampling of 100 taxi drivers, working full-time day shift, in Paris, members of three Trade Unions. It will be conducted over a period of two years in warm and cold season. The research will begin with an inclusion clinical examination. It consists on determining the overall health status of the participants by administering a standardized questionnaire and performing spirometry test, prick test and FENO measurement. The exposure assessment will be based on continuous measurement of UFP, BC, carbon monoxide (CO) and NO2, by portable devices during a working day (± 11 hours). On the same day, two spirometry tests and two measurements of exhaled carbon monoxide will be performed at the beginning and at the end of the shift, using handheld devices. Multivariate analysis will provide spatio-temporal distributions of individual exposures and their determinants. Generalized Estimating Equations (GEE) multivariate models will be used to determine the relation between exposure (UFP, BC) and respiratory symptoms, ventilation performances, adjusting for potential confounding/modifying factors.

Eligibility Criteria:
Inclusion Criteria:

* Age \> 18 years
* Full time licensed taxi driver
* Subjects with more than 6 months of job tenure (as a taxi driver)
* Subjects affiliated to a social security scheme
* Subjects must have signed an informed consent and are willing to participate in the study

Exclusion Criteria:

* Subjects having difficulty to understand the French language
* Subjects with less than 6 months of job tenure (as a taxi driver)