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

Exposure of Taxi Drivers to Ultrafine Particles and Black Carbon Within Their Vehicles: Determinants of In-vehicle Exposure and Short Term Respiratory Impact.

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03839537
Acronym
PUF-TAXI
Enrollment
56
Registered
2019-02-15
Start date
2019-02-01
Completion date
2020-06-11
Last updated
2026-03-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pulmonary Ventilation

Keywords

Ultrafine particles, black carbon, taxi drivers, respiratory function test, occupational exposure

Brief summary

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.

Detailed description

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.

Interventions

OTHERExposure measurement

* 2 measurements per subject (in warm season and in cold season) * Devices placed inside taxi vehicles on the passenger seat in a sampling bag

* 2 measurements per subject - before and after the work shift - in warm and cold seasons * Subject will inhale and exhale in the device

DIAGNOSTIC_TESTExhaled carbon monoxide test

* 2 measurements per subject - before and after the work shift - in warm and cold seasons * Subject will exhale in the device

DIAGNOSTIC_TESTSkin allergy test

\- Performed by a physician during the inclusion clinical examination

DIAGNOSTIC_TESTFractional Exhaled Nitric Oxide Testing

\- Performed by a physician during the inclusion clinical examination

Sponsors

Assistance Publique - Hôpitaux de Paris
Lead SponsorOTHER
University of Paris 5 - Rene Descartes
CollaboratorOTHER
Centre national de la recherche scientifique - Lebanon (CNRS-L)
CollaboratorUNKNOWN
French Environment and Energy Management Agency
CollaboratorUNKNOWN
URC-CIC Paris Descartes Necker Cochin
CollaboratorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SCREENING
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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)

Design outcomes

Primary

MeasureTime frameDescription
Mean number of ultrafine fraction of particles (UFP)6 monthsper cm3 of air \[from 1000 to 1000000 particles (pt)/cm3\] - 8-11 h recording on 1 working day for each subject - repeated measurement in cold and warm seasons (6 months apart)
Mean concentration of black carbon (BC)6 monthsmeasurement of BC exposure concentrations per cubic meter (ng/m3) by the microAeth AE51 - 8-11 h recording on 1 working day for each subject - repeated measurement in cold and warm seasons (6 months apart)
Difference between the values of the forced vital capacity (FVC) measured before and after work shift36 monthsmeasurement of FVC in liters by a portable spirometer before and after the work shift according to procedures described by The European Respiratory Society and the American Thoracic Society (2005) - 2 measurements per subject - before and after the work shift - 1 working day Repeated measurement in cold and warm seasons (6 months apart) Overall period: 2 working days (one in each season) - 36 months
Difference between the values of the forced expiratory volume in one second (FEV1) measured before and after work shift36 monthsmeasurement of FEV1 in liters by a portable spirometer before and after the work shift according to procedures described by The European Respiratory Society and the American Thoracic Society (2005) -2 measurements per subject - before and after the work shift - 1 working day Repeated measurement in cold and warm seasons (6 months apart) Overall period: 2 working days (one in each season) - 36 months
Difference between the values of the forced expiratory flow between 25 and 75 % of FVC (FEF25-75) measured before and after work shift36 monthsmeasurement of FEF25-75 in liters by a portable spirometer before and after the work shift according to procedures described by The European Respiratory Society and the American Thoracic Society (2005). -2 measurements per subject - before and after the work shift - 1 working day Repeated measurement in cold and warm seasons (6 months apart) Overall period: 2 working days (one in each season) - 36 months
Difference between the rates of the peak expiratory flow (PEF) measured before and after work shift36 monthsmeasurement of PEF in liter per second (L.s-1) by a portable spirometer before and after the work shift according to procedures described by The European Respiratory Society and the American Thoracic Society (2005)-2 measurements per subject - before and after the work shift - 1 working day Repeated measurement in cold and warm seasons (6 months apart) Overall period: 2 working days (one in each season) - 36 months
Acute respiratory symptoms through self-administered questionnaire36 monthsby means of a self-completion questionnaire, participants report their acute respiratory symptoms felt during the measurement day - Reported before and after the work shift per subject - In cold and warm seasons (6 months apart)- Overall period: reported during 2 working days (one in each season) - 36 months

Secondary

MeasureTime frameDescription
Characteristics of vehicles recorded by a self-administered questionnaire36 monthsfuel, age and type of the vehicle, air conditioning, air cabin filter reported by a self-administered questionnaire - after the work shift per subject - In cold and warm seasons (6 months apart) Overall period: reported during 2 working days (one in each season) - 36 months
Characteristics of the trips recorded by a self-administered questionnaire36 monthsspeed, opened/closed windows, smoking, breaks, etc. reported by a self-administered questionnaire - after the work shift per subject - In cold and warm seasons (6 months apart) Overall period: reported during 2 working days (one in each season) - 36 months

Countries

France

Contacts

PRINCIPAL_INVESTIGATORLynda BENSEFA-COLAS, MD, PhD

Assistance Publique - Hôpitaux de Paris

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 11, 2026