Environmentalists warn over damage to wildlife from salt on roads

Thousands of tonnes of salt have been spread on roads in the Czech Republic and the rest of Europe during recent heavy snowfall. So much so, that stocks threaten to run out. Heavy use has sparked warnings from environmentalists about the damage to plants and animals.

Mojmír Vlašín

Gritting lorries have been out in force across the Czech Republic since heavy snowfalls started at the end of last week. The Czech Road and Motorway Directorate — responsible for the country’s main road artery — estimates that it spread around 15,000 tonnes of grit, containing 90 percent salt, and a further 3.5 million litres of saline solution during the first three days of the white out. The city of Prague says it scattered 7,000 tonnes of in the capital.

Such figures, with more gritting likely during the prolonged cold snap, have caused environmentalists to warn against the damage to wildlife caused by heavy salting. Mojmír Vlašín works with the environmental institute Veronica.

“The salt makes problems for trees because it causes diseases and, if the doses of salt are too big, trees die. It is one of the three main reasons why trees in cities die ― this big overloading by salt.”

It is perhaps significant that in a survey of its natural springs, Prague city council has itself highlighted heavy levels of sodium chloride or ordinary salt which it suggests is a result of treating the roads in winter. The use of salt for roads is banned in Czech spa towns such as Mariánské Lázně.

Photo: CTK

Birds and animals are also menaced. Salt can, for example, lodge itself into the paws of domestic and wild animals causing lesions which can easily become infected. It also represents a more direct threat in the form of a salt overdose. Mr Vlašín again.

“Salt is a poison, not in a small dose but in big doses. For example, in men, if you probably ate half a kilo of salt in one day you will probably die. So for birds, which are smaller, if they eat a certain amount — I do not know what amount exactly — it causes a problem, it is a poison, and they can die.”

In other instances, animals are tempted to eat the roadside salt and are mowed down by vehicles taking advantage of the cleared route.

And the salty solution that runs into streams and rivers disrupts natural processes cleaning the water and directly or indirectly kills fish and other water life.

But Mr Vlašín points out that there are alternatives to highly damaging salt.

Photo: CTK

“It is possible to use another type of salt: calcium chloride which is less damaging to trees and it is also better for the roads because it also works down to minus 29 degrees Celsius.”

But this less damaging salt and other options, such as so-called eco-grit, are more expensive to buy. So, the damage looks like it will continue as long as the cold weather.