IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

Biological contaminants in wastewater treatment plants


Workers in wastewater treatment plants run the risk of exposure to biological contaminants such as bacteria and moulds. Several municipalities and regional health boards have expressed interest in obtaining reliable data on exposure levels to these agents at different workstations. Using proven methods, the IRSST measured contaminant levels at various workstations in the four largest wastewater treatment plants in Québec. Mean total bacteria concentrations exceeded the exposure limit at a few of the 80 sampling stations. The concentration of Gram-negative bacteria exceeded the exposure limit at only one station. The mean concentration of moulds exceeded the equivalent concentration in outdoor air at several stations. The microbiological quality of outdoor air did not appear to be affected by the operations at these plants.

Additional Information

Type: Project
Number: 0095-3110
Status: Completed
Year of completion: 1997
  • Jacques Lavoie (IRSST)