Antioxidant supplementation and respiratory functions among workers exposed to high levels of ozone.
Ozone exposure has been related to adverse respiratory effects, in particular to lung function decrements.
Antioxidant vitamins are free-radical scavengers and could have a protective effect against photo-oxidant exposure.
To evaluate whether acute effects of ozone on lung functions could be attenuated by antioxidant vitamin supplementation, we conducted a randomized trial using a double-blind crossover design.
Street workers (n=47) of Mexico City were randomly assigned to take daily a supplement (75 mg vitamin E, 650 mg vitamin C, 15 mg beta carotene) or a placebo and were followed from March to August 1996.
Pulmonary function tests were done twice a week at the end of the workday.
During the follow-up, the mean 1-h maximum ozone level was 123 ppb (SD=40).
During the first phase, ozone levels were inversely associated with FVC (beta=-1.60 ml/ppb), FEV1 (beta=-2.11 ml/ppb), and FEF25-75 (beta=-4.92 ml/ppb) (p<0.05) in the placebo group but not in the supplement group.
The difference between the two groups was significant for FVC, FEV1, and FEF25-75 (p<0.01).
During the second phase, similar results were observed, but the lung function decrements in the placebo group were smaller, suggesting that the supplementation may have had a residual protective effect on the lung.
These results need to be confirmed in larger supplementation studies.
Mots-clés Pascal : Exposition professionnelle, Ozone, Pollution air, Fonction respiratoire, Exploration, Antioxydant, Chimioprophylaxie, Vitamine, Supplémentation, Etude double insu, Essai croisé, Randomisation, Effet biologique, Santé et environnement, Médecine travail, Prévention, Adulte, Homme, Mâle
Mots-clés Pascal anglais : Occupational exposure, Ozone, Air pollution, Lung function, Exploration, Antioxidant, Chemoprophylaxis, Vitamin, Supplementation, Double blind study, Crossover study, Randomization, Biological effect, Health and environment, Occupational medicine, Prevention, Adult, Human, Male
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0353152
Code Inist : 002B02N. Création : 27/11/1998.