La Presse in Rouyn-Noranda | impatience in the air

(Rouyn-Noranda) “In Quebec, it’s three nanograms, so why in Abitibi-Témiscamingue, in Rouyn-Noranda, wouldn’t it be three nanograms? “says Gabrielle Bruneau of the group Mères au front to the crowd, who responds with loud applause.

The reduction of arsenic emissions from the Horne Foundry was on everyone’s lips, Wednesday evening, in the small performance hall Le QG, in downtown Rouyn-Noranda, where nearly 200 people had crowded for an assembly citizen.

The same morning, the national director of public health of Quebec, Luc Boileau, did not want to decide on a reduction target that would be acceptable, during his visit to the city, deplored the group Mothers at the front, the committee Stop toxic discharges and emissions (ARET) and MNA for Rouyn-Noranda–Témiscamingue Émilise Lessard-Therrien.

Environment Minister Benoit Charette is aiming for a target of 30 nanograms of arsenic per cubic meter of air (ng/m^⁠3), confides the latter to her constituents.

“Is it acceptable, 10 times the Quebec standard? asks the deputy, arousing general disapproval.

“That’s three nanos, no! exclaims a woman in the crowd.

Many take the microphone to tell of their discouragement, their concern, their health problems or their indignation at the Legault government’s stated desire to pay public funds to “an Anglo-Swiss multinational” so that it pollutes less.

More cancers even when respecting the standard

The high concentrations of arsenic and cadmium in the air of Rouyn-Noranda do indeed lead to a surplus of cases of lung cancer, but the mystery still hangs over the impact of this contamination on other health problems. and on the consequences of all the heavy metals present in the air of the city.

This is what emerges from the “assessment of the carcinogenic risk attributable to the concentrations of arsenic and cadmium in the air of the city of Rouyn-Noranda”, made public on Wednesday by the National Institute of Public Health of Quebec ( INSPQ).

The document concludes that there would be a higher rate of lung cancer cases in Rouyn-Noranda even if the Horne Foundry were subject to the Quebec standard for arsenic concentrations of 3 nanograms per cubic meter of air (ng /m^⁠3), due to past exposure.

Under this scenario, there would be 6.7 to 288 additional cases of lung cancer per million inhabitants, which is higher “than the value of risk considered negligible” in Quebec, which is 1 case out of 1 million inhabitants.

Reduced to the scale of the population of the center of Rouyn-Noranda, which is 23,000 people, this represents 1 to 7 more cases than in a population not exposed to these contaminants.

“These are numbers that may seem small, but we greatly exceed the acceptable risks,” said Quebec’s national director of public health, Luc Boileau, present at the unveiling of the study.

Such a reduction in emissions would nevertheless reduce the carcinogenic risk by 48% compared to maintaining the foundry’s emissions at their 2018 level, i.e. 165 ng/m^⁠3 and would be beneficial for new generations.

The INSPQ has also studied other scenarios, such as maintaining emissions from the smelter at their 2018 level, which would cause 13 to 554 additional cases per million inhabitants, therefore 1 to 14 cases in the center of Rouyn-Noranda.

These calculations, made from more than 10,000 measurements of arsenic and cadmium levels in the air of Rouyn-Noranda between 1991 and 2018, assess the risk over a period of 70 years, taking into account exposure to contaminants 24 hours a day, seven days a week.

Shadow areas

The INSPQ assessment, however, only looks at the combined effect of arsenic and cadmium, which leaves large gray areas on the impact of heavy metals other than cadmium whose presence in the air of Rouyn-Noranda has been documented.

This is particularly the case of nickel, “which is also a carcinogen of the pulmonary tract in humans”, indicates the INSPQ report, which specifies that “the risks estimated here could theoretically be underestimated if interactions between the substances had to take place”.

These different substances can have a combined “multiplicative” rather than “additive” effect, explained an INSPQ expert during a technical presentation of the study for the media.

However, there is not sufficient data on the concentrations of other heavy metals than cadmium to make “scientifically sound” calculations, she explained.

The INSPQ’s assessment may therefore “let us believe that the causes [des cas de cancers du poumon] are elsewhere than in the discharges from the Foundry,” lamented the Rouyn-Noranda Toxic Discharges and Emissions Stop Committee (ARET), adding that the data used “are incomplete, because they do not include fine particles which have not never been measured.

Other health issues

Lung cancers are far from the only health problem linked to the concentrations of heavy metals and arsenic in the air of Rouyn-Noranda, where there is also a higher than normal proportion of babies of small weight, intrauterine growth retardation and chronic obstructive pulmonary disease (COPD), showed data published in May by Public Health.

“Today, we are reporting on the impact of two contaminants in lung cancer, but we want to do it on the other aspects [de santé] “said the D.^r Boileau.

It will not be an assessment like that of the INSPQ, which would require several months of work, he specified, but rather to collect the opinion “of the best experts from current data to characterize the risk “.

“Several actions are necessary, they will be presented concretely in the coming weeks,” said Caroline Roy, President and CEO of the Integrated Health and Social Services Center (CISSS) of Abitibi-Témiscamingue.

In particular, it will be necessary to determine what is the “consensus on the thresholds” of contamination acceptable for the community, specified the acting director of the Regional Directorate of Public Health of Abitibi-Témiscamingue, the D^r Stéphane Trépanier, indicating that he expects this to be done by September at the latest.

Until then, the D^r Boileau says there is “no data that would justify closing the business.”