Present in wastewater, endocrine disruptors disrupt the hormonal systems of aquatic animals. A team from the National Institute for Scientific Research (INRS) wants to implement a tool to better assess the toxic effects of these chemicals.
Posted at 7:00 a.m.
The method proposed by Julie Robitaille, doctoral student in water science, and Valérie Langlois, professor at INRS, has the particularity of directly measuring the combined effect of disruptors.
Omnipresent pollutants
“Endocrine disruptor” is a broad term. It refers to any contaminant that interferes with the endocrine system of humans and animals, that is, with their hormones.
“The hormonal system is generally finely regulated,” explains Julie Robitaille. By disrupting the functioning of this system, these products can create problems with reproduction, growth, fertility, etc. »
These pollutants are everywhere: in pesticides, plasticizers, drugs. “When a woman takes the contraceptive pill, for example, a certain part will end up in her urine and eventually end up in the waterways,” points out Julie Robitaille. The fish didn’t ask for birth control, but the medicine works pretty much the same on them. »
From humans, industries or agricultural land, these contaminants accumulate in wastewater. “Pretty much every disruptor we are exposed to ends up in these waters,” says Jonathan Chevrier, professor of environmental health science at McGill University.
Large quantities manage to escape water treatment. Many harmful effects on the survival of aquatic species are thus observed, such as feminization in fish and the reduction in the size of eggs.
A failing system
Part of the reason so many pollutants end up in aquatic ecosystems is how pollutant limits are set in wastewater treatment. To calculate thresholds, animals are given increasing doses of pollutants until a toxic effect is observed.
“The problem with endocrine disruptors is that they have different mechanisms of action from normal pollutants, explains Isabelle Plante, co-director of the Intersectoral Center for the Analysis of Endocrine Disruptors. Intense toxic effects will not necessarily be observed, but constant exposure to low doses can have significant consequences on reproduction and metabolic systems. »
Another major factor is neglected by these tests: the combined effect of the products. “Sometimes, each contaminant meets the criteria, but it’s when you put them together that they will have effects on hormones,” says Valérie Langlois.
Changing ways of doing things
Valérie Langlois and Julie Robitaille are working to implement a tool to overcome some flaws in the current system. The method they use directly measures the combined effect of disruptors on hormonal systems.
These INRS researchers genetically modify human cells to make them sensitive to the presence of certain hormones. Cells emit light when affected by endocrine disruptors. “It’s not going to tell us what’s in the mix,” observes Julie Robitaille. Rather, it will tell us whether or not we should worry about our wastewater, so if we should do something. »
In a recent article in the journal Environmental Research, the researchers demonstrated the effectiveness of their approach. Their goal is now to use this method to improve water treatment infrastructures in Quebec and elsewhere in the world. Already, provincial, municipal and industrial partners are responding to the call.