Rot and Human Health

Composting is good for the planet. But is it good for human health? As more cities adopt a mass composting policy, UBC researchers are trying to find the answer. “Even though it is an eco-friendly practice, we know biohazards may be present,” says associate professor Karen Bartlett of UBC’s school of Environmental Health. “There are disease-causing organisms present throughout the process.” The wastes can contain nasty microorganisms such as listeria and salmonella, but these break down as the waste heats up and decomposes.

Researchers at UBC are able to study three different composting technologies used in Vancouver, Kamloops and Kelowna. These also present different environmental conditions for the rocess. “We will be able to make recommendations to the composting industry, which could help prevent both acute effects and chronic lung disease,” says Jim Atwater, an associate professor of civil engineering.

On the front line are the five to 10 workers at each composting site. “Workers are exposed to massive blooms of organisms that can potentially cause lung damage in high doses,” says Bartlett. “We’ve seen studies from countries where composting is a bigger industry than in Canada. They show that some workers experience ill health associated with breathing organic dust.” Chronic health effects can include permanent scarring of the lungs.

Researchers are exploring what bearing different methods of composting have on human exposure to fungal spores, thermophilic spore-forming bacteria and endotoxins, and on the presence of disease-causing microorganisms. They are also considering environmental factors such as temperature and humidity, which have already been shown to make a difference. “The dry air in Kamloops and Kelowna has an impact on the dispersion of microorganisms and a buffer zone between the composting facility and other facilities may be required,” says Bartlett. “On the other hand, the amount of rain in Vancouver has an impact on dispersion and a buffer zone may not be required.” The researchers also want to establish if minimum temperatures for the destruction of disease-causing mircoorganisms are always met.

The project, which is funded by Worksafe BC, will be used to establish work safety practices.

UBC Alumni’s Trek magazine Issue 23, Spring 2009 p 5