Poultry house as point source of intense bioaerosol emission.

Introduction and objective: Intensive poultry farming is usually associated with massive exposure to organic dust, which is largely composed of microbiological origin particulates. The aim of the study is to assess occupational and environmental exposures to airborne bacteria, fungi, and Marek's disease virus emitted by a poultry house.

Material and methods: The concentrations of airborne microorganisms in a poultry house and its vicinity (250-500 m) at 3 different stages of the production cycle (i.e. empty poultry house, with 7-day-old and 42-day-old chickens) were stationary measured using Andersen and MAS impactors, as well as Coriolis and BioSampler impingers. The collected microbiota was taxonomically identified using molecular and biochemical techniques to characterize occupational exposure and its spatial dissemination.

Results: Although Marek's disease virus was not present in the tested air samples, the appearance of reared chickens in the poultry house resulted in an increase in airborne bacterial and fungal concentrations up to levels of 1.26 × 10⁸ CFU/m³ and 3.77 × 10⁴ CFU/m³, respectively. These pollutants spread around through the ventilation system, but their concentrations significantly decreased at a distance of 500 m from the chicken coop. A part of the identified microbiota was pathogens that were successfully isolated from the air by all 4 tested samplers.

Conclusions: The poultry house employees were exposed to high concentrations of airborne microorganisms, including pathogens that may lead to adverse health outcomes. To protect them, highly efficient hygienic and technical measures regarding the poultry house interior and its ventilation, respectively, should be introduced to prevent both unwanted pollution and subsequent emission of microbial contaminants during intensive chicken breeding.