Background

There have been media reports about the research findings of a geography professor in Victoria, British Columbia that suggested a correlation between road salt and cancer. Following is the Canadian Cancer Society perspective/viewpoint about this issue.

Research into the link between road salt and cancer

From discussions with Health Canada, the Canadian Cancer Society has learned the following:

The evidence of a link between road salt and cancer is inconclusive. A single study has identified a statistical association between road salt and cancer rates in the United States. However, other factors in addition to road salt use should have been taken into account (for example: greater pollution in urban areas, diet and smoking patterns among members of the community). Any one of a number of factors could be more plausible than road salt as the responsible agent.

The study was weak in design and no further investigations have been carried out since its publication six years ago; therefore there is no supporting data and the evidence of a link between road salt and cancer is inconclusive.

People are exposed to road salt principally through the contamination of roadside wells, where sodium and chloride levels can be relatively high. Sodium and chloride may affect the taste of well water, thereby decreasing its potability. However, levels are usually not high enough to cause any concern for human toxicity. Other substances in road salt, such as ferrocyanide and certain metals, are only present at trace levels.

Health Canada’s Guidelines for canadian drinking water quality have established guidelines for sodium and chloride in drinking water.

Environment Canada is currently conducting an assessment of the environmental impacts of road salt. Health Canada is not conducting an assessment of this link, but will continue to monitor the scientific literature for any supportive data on health effects.

Canadian Cancer Society Perspective

At this point in time, there is no "body of evidence" that shows a link between road salt and cancer. If more research is done about this subject the Canadian Cancer Society will assess the research and the results to ascertain if there is enough evidence to support a link.