AMERICAN JOURNAL OF INDUSTRIAL MEDICINE 50:421–426 (2007) Farming and the Prevalence of Non-Reversible Airways Obstruction—Results From a Population-Based Study B. Lamprecht, MD, 1 L. Schirnhofer, MD, 1 B. Kaiser, 1 M. Studnicka, MD, 1 and A.S. Buist, MD 2 Introduction Occupational exposure to noxious dusts, gases, and fumes most likely contributes to obstructive lung disease. We studied whether self-reported farming work is associated with non-reversible airways obstruction. Methods Following the burden of obstructive lung disease (BOLD) study protocol, we surveyed a gender-stratified population-based sample of 2,200 adults aged 40 years and over. Pre- and post-bronchodilator spirometry, as well as information on smoking, occupation, and reported respiratory disease was recorded. According to GOLD criteria, non-reversible airways obstruction was defined as a post-bronchodilator forced expiratory volume (FEV 1 )/forced vital capacity (FVC) < 0.70. Occupational and smoking history was based on questionnaire. Farming was defined as ever working in this occupation for 3 months or longer. Results For 1,258 participants with complete data (post-bronchodilator spirometry and questionnaire data), 288 (¼22.9%) reported farming. Among the 288 participants reporting farming, the prevalence of non-reversible airways obstruction was 30.2%. Farming was significantly associated with airways obstruction: chronic obstructive pulmonary disease (COPD) GOLD stage I or higher (OR 1.5; 95% CI 1.1–2.0) and COPD GOLD stage II or higher (OR 1.8; 95% CI 1.2–2.7). The latter estimate was unchanged when adjustment for competing risks gender, age, and smoking was done. In this population the risk for non- reversible airways obstruction attributable to farming was 7.7%. Conclusion Farming should be considered a risk factor for non-reversible airways obstruction. Am. J. Ind. Med. 50:421–426, 2007. ß 2007 Wiley-Liss, Inc. KEY WORDS: airways obstruction; farming; COPD; agricultural exposure INTRODUCTION Obstructive airways disease is an important public health problem, affecting millions of people in developing and developed countries. It is estimated that in 2020, non- reversible obstructive airways disease, also termed chronic obstructive pulmonary disease (COPD), will be the fourth leading cause of death world-wide [Murray and Lopez, 1997]. Although this increased burden of disease will mainly be attributed to active cigarette smoking and aging, obstructive airways disease is also prevalent in non-smokers. Chronic exposure to inhalable particles and gases besides active smoking, result from outdoor air-pollution, indoor second-hand smoke exposure, or cooking at open fire-places. Another possible cause of non-reversible obstructive airways disease is occupational exposure [Trupin et al., 2003]. This is particularly true for farming, where dusts and inhalable ß 2007 Wiley-Liss, Inc. 1 Department of Pneumology, Paracelsus Medical University, Salzburg, Austria 2 Department of Pulmonary and Critical Care Medicine,Oregon Health and Science Univer- sity, Portland, Oregon *Correspondence to:B.Lamprecht,Mu« llner Hauptstrasse 48,Department of Pneumology, 5020, Salzburg, Austria. E-mail: b.lamprecht@salk.at Accepted 15 March 2007 DOI10.1002/ajim.20470. Published online in Wiley InterScience (www.interscience.wiley.com)