6-YEAR LONGITUDINAL-STUDY OF RESPIRATORY-FUNCTION IN DAIRY FARMERS INTHE DOUBS PROVINCE

A previous study, carried out in 1986 in France, showed the prevalence of respiratory symptoms and of respiratory function impairment to be higher in dairy farmers than in a control group of nonexposed subjects living in a rural zone. In order to confirm the harmful effect of dai ry farming, the two groups were re-studied 6 yrs later at the same per iod of the year. One hundred and ninety-four (77.6%) farmers and 155 ( 62%) control subjects were available for re-examination. Non-re-evalua ted subjects were comparable to reevaluated subjects for age, sex, smo king and respiratory symptoms and function at initial evaluation. Dair y farmers consistently had more respiratory symptoms and lower levels of respiratory function than did control subjects. In the study popula tions as a whole, the mean annual decline in vital capacity (VC) and f orced expiratory volume in one second (FEV1) was slightly, but nonsign ificantly, higher in farmers than in control subjects: in mL(.)yr(-1) (sD), -43.1 (68.2) versus -37.9 (60.2) for VC and -32.8 (56.7) versus -30 (47.2) for FEV1. There was a positive interaction between farming and age (i.e. duration of exposure in this cohort) on respiratory func tion decline, and in male subjects aged greater than or equal to 45 yr s, dairy farming was associated with an accelerated loss in VC (p<0.05 ) and FEV1 (p<0.05) after controlling for age, smoking, height and geo graphic location in a multiple linear regression model. Initial values of respiratory function, age and pack-years smoked (only for VC) were the other variables found to be significant determinants of decline i n lung function. In conclusion, this study mainly suggests that dairy farming is associated to a very moderate accelerated loss in respirato ry function that increases with duration of exposure and is significan t in older male subjects.