As more snow starts to fall and temperatures plummet, road conditions for drivers and pedestrians become more difficult. For a long time, gritters have been used to de-ice roads and pavements but unfortunately they are a source of pollution for our ecosystems.
Currently gritters are the most commonly used method to de-ice roads, as it is also the most economical. A tonne of chloride costing about one hundred pounds is not really a financial barrier, especially if it helps to reduce road accidents and doesn’t have a massive impact on the region’s economic activities.
However gritter are being increasing used to de-ice roads. So much so, the amount of salt used to spread on roads has greatly exceeded the amount of salt used in food! For this winter season British local councils have stockpiled 1.4 million tonnes of grit to de-ice roads and pavements.
Harmful ecological impact
Although grit manages to lower the temperature at which water turns into ice, this substance also considerably damages vegetation and wildlife as well as the soil. An American study published in January 2018 reported a worrying situation in the United States. Salt levels in 37% of the cold and wet areas of the north-east of the country are directly due to grit spread on the roads.
In addition, groundwater is also at risk ( groundwater tables, lakes) as it can often have a sodium concentration that can be dangerous, especially for people with high blood pressure. Salt can “burn” vegetation along the road sides, which can impact tree growth in the spring. Moreover, the chemical – or even biological – composition of aquatic environments can be modified, which can harm the local fauna due to a lack of oxygen. As for soils, they can suffer from “physiological dryness“, as they are drained of their trace elements by soaking up salt water.
Faced with this degradation of freshwater ecosystems, scientists believe there is an urgent need to develop new strategies and test different initiatives when it comes to de-icing roads.