RESUMEN
Sulphur dioxide is widely encountered because of its numerous industrial uses. It is the most prominent gas contributing to atmospheres pollution. Many studies have indicated a great impairments of lung function after chronic exposure to pollution. Pulmonary function is usually estimated by PEFR using Standard Wright Peak Expiration Meter. A 145 male subjects working at the Northern Oil Refinery in Baiji were subjected to a pulmonary function test during of Summer 1994. The study shows that the number of affected subjects were more than those non-affected. [81.37%] was the percentage of the affected subjects. The study shows a significant relationship between height and weight and the performance of the PEFR. Also, there was relationship between the period of employment of the subject in the refinery and the values of the PEFR test. The study shows a significant relationship between subjects without previous chest illness and the pulmonary function test. Also, there was a relationship between the PEFR values and the stats of respiratory discomfort and exhaustion during the daily labor