A group of microbiologists is calling on the Réseau express métropolitain (REM) and its builder to “quickly control the humidity level” in the Mont-Royal tunnel, where mold discovered last week raises fears of air quality hazards for workers.
“We want the people involved in the REM to be people who are competent in the field. There are still far too many people who proclaim themselves experts and specialists in air quality, when they are not. That could very well be the case here, so we will have to be very careful,” says Marc Hamilton, president of the Association des microbiologistes du Québec (AMQ).
Earlier last week, photos of the Mont-Royal tunnel construction site released by the Conseil provincial du Québec des métiers de la construction – International (CPQMC-I) showed what appeared to be black spots visible on pieces of wood and concrete surfaces.
Since then, “they have decided to change the panels to put in new carbon ones, so that mold does not cling to them as much,” notes the Council’s communications director, Carl Charest. However, he denounces that “the proliferation will continue the same, because the humidity is at 80%.” “We can put in different panels, but if we don’t address the humidity, we won’t address the problem,” he summarizes.
“When you go in there, you can’t breathe anymore. The humidity is so high that it hits you like your nose,” adds Mr. Charest.
Based on science
At the AMQ, Marc Hamilton agrees. “We need to quickly control the humidity level in the tunnel so that the current mold does not have enough water to grow on a surface. Putting stain removers on the contaminated pieces of wood, or replacing them thinking that it will reduce it, will not necessarily help,” he notes.
“We really have to make decisions based on science, otherwise it could make the situation worse and cause serious health problems for workers,” Hamilton insists.
The situation is reminiscent of that of the La Fontaine tunnel, whose megaproject was delayed by two weeks after the discovery of mold in the service corridor in August 2023. In the Mont-Royal tunnel, work is already being accelerated to make up for the delay caused by the discovery of century-old explosives in 2020.
NouvLR, responsible for the construction of the REM, indicates for its part that since the start of the work, its teams have been present “every day […] to contain risks and protect [les] workers “.
A “mold-specific protocol,” which was presented to workers, was established and “is subject to regular monitoring,” says the organization, which relies on additional ventilation systems, recurring measurements of air quality, in addition to cleaning and surface treatment.
“We confirm that there is no proliferation throughout the Mont-Royal tunnel. The examples raised are limited to a few very isolated and treated sectors,” they assure us in passing.
The Commission des normes, de l’équité, de la santé et de la sécurité du travail (CNESST) says it has been informed of the situation and indicates that it will ensure “appropriate monitoring of the problem on this site.”