From lab to labor - detailed exposure characterization as basis for protective measures in rarely considered occupational settings

摘要

Exposure to fungi is a common situation in the private as well in the occupational settings. While the exposure in the private environment is usually limited, the occupational settings are of particular interest because workers are often exposed over a whole shift and longer periods of time. Some occupational environments like animal confinement, waste recycling or even moldy indoor environments are well recognized. However, there are still occupational settings which occur only seldom in the scientific and public discussion. Such settings are onion sorting, grape processing, processing of hemp, flax, hay, peas, reed etc. Common to all of these examples is that the products usually don't show any signs of fungal growth. Nevertheless, during processing fungi are released of these products to the ambient air in the range of 104 to 108 cfu/m~3. An example for occupational fungal exposure with an increasing importance is the unloading of moldy items from freight containers. A large part of international and intercontinental transport is realized via freight containers. During sea transport, often condensation occurs within the freight containers what creates a sufficient environment for fungal growth especially on organic products. Exposure measurements should not only characterize the level of airborne exposure, but also help the occupational health and safety consultants to improve workplace conditions. Publications about fungal concentrations at certain work places are helpful only if it becomes transparent if the conditions during the measurement are comparable to those at the workplaces which have to be evaluated. Therefore, we need an integrated approach from "lab to labor" covering all aspects of exposure. E.g., the information that workers are exposed to 105 cfu/m~3 in a grain elevator does not help unless it is stated at which task the measurement has been performed, which amount of grain has been handled, if there has been an aeration etc. Other important factors inter alia are the degree of microbial colonization, the tendency to release dust, the intensity of mechanical processing and the size of the products and their specific surface may have an influence. Additionally, exposure is more than the airborne fungal concentration. With respect to the question which protective measures are appropriate also the duration and the frequency of exposure are important factors.