As a result of Canada's icy winters, salt is needed in order to deice slippery roads. The primary ingredient of road salt is sodium chloride. Road salt, while helping cars and people to gain traction in the winter, can have serious consequences for soil. As National Geographic found, "Road salt can pollute soil at every stage in the deicing process." This pollution is a result of numerous factors such as runoff, application and spray from vehicles. In Canada, there has been research that shows that "salt run-off from roads can increase local chloride levels to between 100 and 4,000 times normal levels." Salt can have adverse effects on soil and soil composition. Significant levels of chloride (one of the main components in salt) can "alter the soil 's pH chemistry and elevate levels of heavy metal pollutants, while at the same time causing a loss of soil structure and killing off micro-organisms". These effects can have dire consequences for plants rendering them unable to grow or stunting their growth.
