Occupational exposure and severe pulmonary fibrosis.
BACKGROUND
External agents, especially metal and wood dust, are believed to be risk factors for development of idiopathic pulmonary fibrosis (IPF). The aim of this case-control study was to investigate which occupational exposure types are associated with development of severe pulmonary fibrosis (PF), and especially IPF.


METHODS
An extensive postal questionnaire including 30 specific items regarding occupational exposure was completed by 181 patients with severe PF and respiratory failure reported to the Swedish Oxygen Register, among whom 140 were judged as having IPF. The questionnaire was also completed by 757 control subjects. We stratified data for age, sex and smoking and calculated odds ratios (ORs).


RESULTS
We found increased risk for IPF in men with exposure to birch dust (OR 2.7, 95% confidence interval (95% CI) 1.30-5.65) and hardwood dust (OR 2.7, 95% CI 1.14-6.52). Men also had slightly increased ORs associated with birds. We did not find any increased risk in association with metal dust exposure.


CONCLUSIONS
Exposure for birch and hardwood dust may contribute to the risk for IPF in men.
Gustafson
Torbjörn
T
Department of Medicine, Skellefteå Hospital, SE-931 86 Skellefteå, Sweden. torbjorn.gustafson@vll.se
Dahlman-Höglund
Anna
A
Nilsson
Kenneth
K
Ström
Kerstin
K
Tornling
Göran
G
Torén
Kjell
K
D016022:Case-Control Studies; D004391:Dust / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals / Q000009:adverse effects*; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D011658:Pulmonary Fibrosis / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014934:Wood / Q000009:adverse effects*
D004391:Dust; D008670:Metals