Effect of indoor feeding season for cattle on lung function of dairy farmers.

The effect of the indoor feeding season for cattle on pulmonary function was studied in 91 randomly selected healthy, non-smoking dairy farmers who did not use personal dust respirators. All the farmers lived in the rural municipality of Pielavesi in eastern Finland. The reference group consisted of 90 healthy, non-smoking urban dwellers who were teachers randomly selected from all the teachers employed by the city of Kuopio (situated in the same administrative district as Pielavesi). Studies of pulmonary function included flow-volume spirometry and measurement of pulmonary diffusing capacity. Among farmers, even a follow-up period of only 6 months was long enough to reveal restrictive impairment in lung function; among teachers restrictive impairment was not found. No evidence of impairment of pulmonary diffusing capacity was found in either of the study groups during the follow-up. Among teachers, changes in lung function did not differ from those previously reported as physiologically normal.