RESPIRATORY EFFECTS OF LOW-LEVEL PHOTOCHEMICAL AIR-POLLUTION IN AMATEUR CYCLISTS

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 aft er training sessions or competitive races on a number of occasions. Co ntinuous 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 Nation al Monitoring Network, The difference between pre and postexercise lun g function values was related to these ozone concentrations. Ozone con centrations were low on most occasions with an average of 87 mu g/m(3) and a maximum of 195 mu g/m(3). The difference between pre- and poste xercise lung function was found to be negatively related to the ozone concentration during exercise. When all observations obtained at ozone concentrations higher than 120 mu g/m(3) were removed from the analys is, the relationship with ozone was still significant. The data also s uggested that effects of ozone on lung function were stronger in midsu mmer than in the late summer. The difference between pre- and postexer cise 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 vi gorously exercising outdoors, ozone is related to lung function change s and acute respiratory symptom changes at low levels of exposure.