In what sizes and concentrations do bioaerosols from poultry farmingcome?

Background and Objective

When experts in approval procedures for constructions or extensions of livestock plants evaluate the environmental compatibility, they also use computer models to calculate whether bioaerosols emerging from the plants can enter inhabited areas. These calculations assume that bioaerosols are largely smaller than 2.5 microns. However, this does not correspond to reality and also leads to a certain blur in the health assessment. Large bioaerosol particles can also carry a higher number of micro-organisms, but they sediment much faster than small particles and are therefore carried far less distant over the air. Small bio aerosol particles, on the other hand, can be carried much further into the environment and also penetrate deeper into the respiratory tract. In addition, the level of emissions is different during the day and at night. In order to improve the prognoses for the spread and health assessment of bioaerosol emissions, we want to determine the size distribution of bioaerosols from animal husbandry plants more precisely.

Target Group

In order to be able to estimate how emissions from animal populations affect the environment and the population, robust data is needed for the size distribution of bioaerosols. Our results help state authorities, environmental assessors and engineering firms to better assess potential dangers.

Approach

In this research project funded by the Saxonian State Ministry for the Environment and Agriculture (SMUL), bioaerosols are collected at different sizes (aerodynamic diameter) at the immediate interface of barn / environment. For this purpose, the sampling units are specifically adapted to the exhaust air systems of the respective husbandry systems for poultry. In the laboratory, the concentrations of total bacteria and staphylococci are then determined by means of classical culture methods on standard and selective nutrient media. On the basis of the results obtained, the quantities of bacteria-bearing bioaerosol particles can then be compiled for each of the investigated species and husbandry system and thus indicate the average bioaerosol sizes and concentrations which can also be used in the future for dispersion modelling.