Respiratory health effects of ultrafine and fine particle exposure in cyclists.
OBJECTIVE
Monitoring studies have shown that commuters are exposed to high air pollution concentrations, but there is limited evidence of associated health effects. We carried out a study to investigate the acute respiratory health effects of air pollution related to commuting by bicycle.


METHODS
Twelve healthy adults cycled a low- and a high-traffic intensity route during morning rush hour in Utrecht, The Netherlands. Exposure to traffic-related air pollution was characterised by measurements of PM(10), soot and particle number. Before, directly after and 6 h after cycling we measured lung function (FEV(1), FVC, PEF), exhaled NO (FE(NO)) and respiratory symptoms. The association between post- minus pre-exposure difference in health effects and exposure during cycling was evaluated with linear regression models.


RESULTS
The average particle number concentration was 59% higher, while the average soot concentration was 39% higher on the high-traffic route than on the low-traffic route. There was no difference for PM(10). Contrary to our hypothesis, associations between air pollution during cycling and lung function changes immediately after cycling were mostly positive. Six hours after cycling, associations between air pollution exposure and health were mostly negative for lung function changes and positive for changes in exhaled NO, although non-significant.


CONCLUSIONS
We found substantial differences in ultrafine particle number and soot exposure between two urban cycling routes. Exposure to ultrafine particles and soot during cycling was weakly associated with increased exhaled NO, indicative of airway inflammation, and decrements in lung function 6 h after exposure. A limitation of the study was the relatively small sample size.
Institute for Risk Assessment Sciences, Division of Environmental Epidemiology, Utrecht University, PO Box 80178, 3508 TD Utrecht, The Netherlands. m.m.strak@uu.nl
Maciej
M
Strak
Hanna
H
Boogaard
Kees
K
Meliefste
Marieke
M
Oldenwening
Moniek
M
Zuurbier
Bert
B
Brunekreef
Gerard
G
Hoek
D000328:Adult; D001642:Bicycling; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D005541:Forced Expiratory Volume; D006801:Humans; D018986:Motor Vehicles; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D010507:Periodicity; D012120:Respiration Disorders / Q000209:etiology* / Q000503:physiopathology; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*; D014797:Vital Capacity
D052638:Particulate Matter; D001335:Vehicle Emissions