Respiratory effects of chronic animal feed dust exposure

Abstract

Aim - 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. Method - 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. Results - 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 pruritis 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 (FEV 1)% ± 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 (FEF 25-75)% ± 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.