Respiratory health of two cohorts of terminal grain elevator workers studied 30 years apart.

Introduction We evaluated the respiratory health of two cohorts of grain terminal elevator workers who participated in one of either respiratory health surveys undertaken in 1978 and 2008. Methods Questionnaire and spirometry data from 584 workers from the 1978 survey and 215 workers from the 2008 survey were compared using logistic regression and general linear modeling. Results The geometric means of area samples of grain dust averaged 8.28 mg/m(3) in 1978 and 2.06 mg/m(3) in 2008. Workers in the 1978 survey had a significantly higher prevalence of respiratory symptoms (with the largest adjusted odds ratio of 3.78, 95% CI 2.07-7.25, for shortness of breath), a lower prevalence of atopic conditions and lower mean lung function. Conclusion Current grain workers had a lower risk of respiratory health consequences and a greater prevalence of atopic conditions than workers surveyed 30 years prior, most likely associated with reduced exposure to grain dust in the terminal elevator environment. Am. J. Ind. Med. 54:263-268, 2011. (C) 2010 Wiley-Liss, Inc.