Airborne endotoxins
Today it is known that endotoxins are constituents from the cell wall of gram-negative bacteria. These bacteria are widespread in the environment, but often occur in low concentration only. However, there are locations in which gram-negative bacteria also find favourable growth conditions. Highly increased concentrations are then also recorded here, for example, in agriculture, the food and feedstuff industry, waste industry, wastewater treatment and in technical processes. In very low doses, endotoxins can have an immune system-strengthening effect. However, higher doses cause tachycardia and various immunological reactions through to life-threatening septic shock reactions.
If high endotoxin loads are recorded in the air of workplaces, reduction measures must be taken to prevent health hazards. The TA Luft (German technical instructions on air quality control) also contains the target for many plants requiring approval of reducing endotoxin emissions by taking appropriate, state-of-the-art measures. However, there is currently no standardised investigation method for the emission measurement. Nonetheless, since 2015, the experiences of various investigation bodies – including bifa – have been brought together by the Air Quality Control Commission (Kommission zur Reinhaltung der Luft - KRdL) in order to draw up VDI guidelines. Endotoxins are a very good indicator of increased bioaerosol loads: They are stable in the environment and in test samples for a comparatively long time and can be detected even in very low concentrations.
High levels of airborne endotoxins are particularly relevant for facilities used for animal production. Therefore, for several years now, increased attention has been paid to the emissions from animal housings. bifa assisted in an investigation carried out by the Bavarian State Environmental Agency (Landesamt für Umwelt - LfU) by providing analyses of the endotoxin levels in combined and fine dust samples; the partial results determined in fattened poultry installations were published by the LfU (www.bestellen.bayern.de).
