Incidence of clinically confirmed farmer's lung in Finland and its relation to meteorological factors
Terho, E.O.; Heinonen, O.P.; Lammi, S.; Laukkanen, V.
European Journal of Respiratory Diseases. Supplement 152: 47-56
1987
ISSN/ISBN: 0106-4347 PMID: 3499346 Document Number: 288116
This report deals with 1980-82 (inclusive), during which 512 new cases of farmer's lung in Finland were recorded, 186 in 1980, 153 in 1981 and 183 in 1982. The mean age of the patients was 47 yr (range 14-75); 45 yr for men and 48 yr for women. About two-thirds of the patients were women. The mean annual incidence of farmer's lung among the entire farming population (standardized for age and sex to the total population in Finland in 1975) was 44/100 000 persons in farming. Both the standardized mean annual incidence (range 8-60/100 000 persons in farming) and the female/male ratio of the standarized incidence showed distinct regional differences. Most cases of farmer's lung occurred during the indoor feeding season for cattle. The highest frequency of new cases was observed in Apr. and the lowest in Oct. The incidence of farmer's lung was positively correlated with measures of daily rainfall and negatively correlated with days without rainfall and with sunshine during the haymaking period preceding the diagnosis. It is suggested that a rainy haymaking period calls for artificial drying of hay in order to reduce the incidence of farmer's lung.