Bioaerosols From Biosolids Land Application and Composting Activities

There is a concern that bioaerosols may be emitted and cause health impacts to the public and workers. The issue of potential health effects from bioaerosols often occurs when odors are emitted from biosolids management activities. When odors occur the public becomes concerned that in addition to odors, bioaerosols or other material may be emitted at the same time.Early studies have indicated that during land application bioaerosols could be dispersed for great distances of up to five miles. Recently it has been determined that there were errors in the dispersion model calculations and the potential for dispersion is much less. Subsequently field studies have shown that the dispersion is very local and is primarily in the vicinity of the application. Method of application is also a major factor.Bioaerosols have been measured near biosolids composting sites. Dispersion is usually within 250 to 500 feet from site activities. Certain activities can result in significant dispersion. Both the design of facilities and their operation can impact dispersion and impact to workers. One study showed that under dusty conditions there was a direct correlation between total dust and endotoxin levels.Avoiding odors and practicing good management practices that reduce dust and minimize dispersion of bioaerosols is important so as to avoid public concern.This paper will discuss the health issues pertaining to bioaerosols. Data on dispersion of bioaerosols resulting from land application and composting will be presented. Means of minimizing dispersion and minimizing worker exposure will be presented.