Respiratory health effects of short-term traffic-related air pollution exposure in cyclists.

There is a scarce amount of knowledge on health effects of short-term,
journey-time exposure to traffic-related air pollution. While the researches on
short-term exposure to air pollution from traffic have been done in recent
years, to our knowledge there exists no study that investigated the health
effects of such type of exposure in a real-world situation.

The objective of the study is to investigate respiratory health effects of
exposure to traffic-related air pollution during commuting by bicycle.

• 4-week study period.
• Two routes - Route 1 (leading from the centre of Utrecht city to IRAS
location at Uithof, largely along major roads) and Route 2 (designed to create
contrast in the exposure to traffic-related air pollution. It will go from the
centre of the city to IRAS as well, but through green areas and small roads
distant from main roads).
• 20 voluntary participants, divided into four groups (a, b, c, d) of 5. Each
group will travel the selected routes eight times in total - four times Route 1
and four times Route 2. Two groups will travel simultaneously on different
routes for 1 hour, during morning rush hours (08:00-09:30), twice a week,
during 4 weeks study period. The measurements of exposure to traffic-related
air pollution will be made on both routes.
• Pre- and post-exposure health measurements will be conducted. The
participants will fill in a baseline questionnaire regarding their respiratory
health status. During the study their lung function (spirometry) and exhaled NO
will be evaluated, they will be also filling in a symptom questionnaire.
• The study design results in 160 measurements in total.

There is a potential risk of traffic accidents during cycling in the morning
rush hours. We will try to minimize this risk by instructing the participants
to strictly follow the existing traffic rules and regulations.