Each year, Quebec produces roughly one million cubic metres of peat. A study on the working conditions of the 700 or so workers in this industry revealed a high level of exposure to dust containing a variety of bacteria and moulds. Peat acts like a reservoir of non-tuberculous mycobacteria. Although not all of these bacteria are pathogenic, some species are known to cause several pulmonary infection and hypersensitivity problems.

Precise measurement of worker exposure to mycobacteria is complicated by the fact that air samples are contaminated with moulds.

A molecular biology approach based on DNA amplification by polymerase has made it possible to improve the assessment of worker exposure to non-tuberculous mycobacteria. The method was originally developed by Canadian Forest Service researchers for the rapid detection of forest pests. It is now being used to detect human pathogens in peat.

This approach allows the detection of up to 10,000 more types of pathogens than conventional sampling methods. In addition, new mycobacteria have been detected, some of which are known to cause health problems.

CFS expertise in the field of molecular diagnostics has therefore helped to enhance the detection of pathogens and gain insight into the relationship between the level of exposure to mycobacteria and the presence of specific antibodies in workers.