Respiratory effects of chronic animal feed dust exposure.

Abstract

The aim of our study was to assess the prevalence of chronic work related respiratory symptoms and to determine lung function abnormalities in animal feed industry workers. 108 workers with a mean age of +/- SD: 32 +/- 7.11 yr employed in the animal feed industry and 108 unexposed subjects as a control group were enrolled in the study. All subjects filled out a questionnaire on their respiratory symptoms. Pulmonary function tests (PFTs) were conducted. Airborne dust (respirable fraction) was sampled during an 8-h work shift. Dust sampling was performed with a Casella AFC 123 machine. A significantly higher prevalence of work related upper and lower respiratory tract symptoms such as cough (12%), dyspnea (5.6%) and sinusitis (8.3%) were found among the workers than in the control group (p=0.001, p=0.04 and p=0.008 respectively). Irritation symptoms such as pruritus of the eyes (11.1%), skin lesions (7.4%) and nose symptoms (8.3%) were also significantly higher among workers that in the control group (p=0.001, p=0.014 and p=0.005 respectively). The mean PFTs (predicted %) of the workers; forced vital capacity (FVC)% +/- SD (85.23 +/- 12.06), 1-s forced expiratory volume (FEV1)% +/- SD (88.73 +/- 13.09), peak expiratory flow (PEF)% +/- SD (70.64 +/- 18.76) and forced expiratory flow rate at 25-75% of the FVC (FEF25-75)% +/- SD (88.42 +/- 25.94) were found significantly lower than in the control group (p<0.0001, p<0.0001, p<0.0001, p<0.0001 respectively). Our data indicate that exposure to animal feed dust is an important factor in the occurrence of respiratory symptoms and decline in lung functions.