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

ABSTRACT

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.