Am. J. Respir. Crit. Care Med., Vol 150, No. 4, Oct 1994, 962-966.
Respiratory effects of low-level photochemical air pollution in amateur cyclists
B Brunekreef, G Hoek, O Breugelmans and M Leentvaar
Department of Epidemiology and Public Health, University of Wageningen, The Netherlands.
A group of male amateur cyclists was studied in the summer of 1991 in the
east of the Netherlands. Lung function was measured before and after
training sessions or competitive races on a number of occasions. Continuous
heart rate monitors were employed to document exercise levels. Heart rate
averaged 161 beats/min during training, and 176 beats/min during races.
Exercise duration averaged 75 min. Ozone concentrations during exercise
were obtained from the nearest stations of the National Monitoring Network.
The difference between pre- and postexercise lung function values was
related to these ozone concentrations. Ozone concentrations were low on
most occasions with an average of 87 micrograms/m3 and a maximum of 195
micrograms/m3. The difference between pre- and postexercise lung function
was found to be negatively related to the ozone concentration during
exercise. When all observations obtained at ozone concentrations higher
than 120 micrograms/m3 were removed from the analysis, the relationship
with ozone was still significant. The data also suggested that effects of
ozone on lung function were stronger in midsummer than in the late summer.
The difference between pre- and postexercise acute symptoms was positively
related to ozone, for shortness of breath, chest tightness, and wheeze.
Cough and eye irritation were not related to ozone. These results indicate
that in healthy young men vigorously exercising outdoors, ozone is related
to lung function changes and acute respiratory symptom changes at low
levels of exposure.
