Bioaerosols: Endotoxin - what is it and why measure it?
A recent BOHS meeting in Newcastle focused on the impacts of exposure to bioaerosols on workers in the waste industry. This reflects the growing concern about the effects of this type of exposure in the workplace or more general environment. Endotoxin, a powerful respiratory irritant is an important component of bioaerosol. It is present in the cell wall of some bacteria and may be released in large amounts when the bacteria die. Symptoms associated with short term exposure to endotoxin may include flu-like symptoms, difficulty in breathing and fatigue. In the longer term, repeated exposure to high levels of endotoxin increases the risk of chronic respiratory illness. High exposures to endotoxin may occur in the intensive farming of crops, animals and poultry. Sewage workers, domestic waste handlers, composting operatives, and engineers (via contaminated metal working fluids) are also exposed to high levels. Endotoxin can also be an indoor quality issue as cigarettes and cigarette smoke contain endotoxin.
Measurement of exposure to endotoxin is an important tool in minimising the risks to health. It can identify where and how high exposures arise. It can also be used to assess the effectiveness of any control strategies that have been introduced to minimise exposure. Both the Netherlands and the US have introduced a guideline level for concentrations of endotoxin in workplace air.