Occupational bioaerosol exposures associated with poultry farming

Abstract

This study aimed to investigate occupational exposure to particulate dust, endotoxin, and (1-3)-β-D-glucan among workers involved in various poultry farming activities. A total of 298 personal samples were collected from randomly selected individuals from exposure groups based on distinct poultry farming activities comprising broiler farms, rearing, laying, hatchery, and catching activities. Aside from the inhalable particulate dust concentration that was determined, filter extracts were also analyzed for (1-3)-β-D-glucan and endotoxin using the endpoint Glucatell® and Limulus amoebocyte lysate (LAL) assays, respectively. Data were analyzed using STATA 12 and linear regression models developed. The mean (GM) dust particulate concentration was 11.04 mg/m3 (GSD = 3.87); 2298 endotoxin units (EU/m3) (GSD = 10.56) and 149 ng/m3 for (1-3)-β-D-glucan (GSD = 4.62). A modest positive correlation was observed between log-transformed endotoxin and (1-3)-β-D-glucan concentrations (Pearson r = 0.44, p < .001), whilst a moderate negative correlation was observed for inhalable dust particulate and (1-3)-β-D-glucan (Pearson r = -0.33, p < .001). However, there was a very poor correlation between inhalable dust and endotoxin (Pearson r = -0.02, p < .001). In the regression models, exposure group based on the nature of farming activity explained 50% of the variability in dust particulate and glucan levels. For dust particulate, rearing activities were significant predictors of higher dust levels compared to hatchery work, while rearing, laying, broiler and catching activities were significant predictors of higher endotoxin or glucan levels. Furthermore, working in a small broiler was a significant determinant of elevated glucan exposures. Farms using automated laying activities had significantly higher particulate levels compared to those using manual laying activities. This study revealed that workers engaged in poultry farming activities were exposed to significantly high levels of inhalable particulate dust, endotoxin, and (1-3)-β-D-glucan concentrations, posing an increased risk for adverse respiratory health effects in these farm workers.