As winter approaches, the discussion over natural alternatives to road salt is heating up. Joining that discussion are York University researchers, who suggest that one of those natural alternatives isn’t necessarily eco-friendlier.

Gaining a foothold in the world of alternatives to road salt is beet juice deicer — a fully biodegradable alternative to road salt that contains just 12% sodium chloride (salt) versus commonly used deicers composed almost entirely of sodium chloride.

Beet deicer is a proven alternative, reducing the temperature at which water will freeze on pavement and coating roadways for up to one week at a time, thereby preventing snow accumulation and ice formation. But graduate student Laura Ana Cuciureanu along with a team of researchers believes the beet juice deicer runoff may be dangerous for nearby aquatic species.

To test that theory, researchers observed the responses of immature mayflies when freshwater insects were introduced to the beet juice deicer.

"Mayflies can act as water pollution indicators as they are particularly sensitive to runoff contaminants such as road salts and metals," the researchers wrote.

When compared to a control group, researchers discovered that insects that were exposed to the natural deicer experienced significantly higher levels of fluid retention and elevated blood salt levels. Additionally, salt was excreted from the gills of those mayflies exposed to the beet juice — a finding that surprised researchers as the response is in direct opposition to the normal function of the gills.

Likewise, researchers were surprised that the concentration of potassium contained in the deicer would be powerful enough to elicit such a response, leading the team to consider that another ingredient in the beet juice deicer might be responsible for the response. As such, the team believes that further examination of the mixture is necessary.

"Before a new product can be deemed environmentally friendly, it is important to understand its effects on a range of organisms including aquatic species that are key to maintaining a healthy ecosystem," Cuciureanu said.

The research was presented at the American Physiological Society's (APS) Comparative Physiology: Complexity and Integration conference in New Orleans.