By Bae Ji-sook
Staff Reporter
In a swift measure to cope with the unprecedented snowfall that halted the nation's traffic on Monday, the government spread 4,769 tons of calcium chloride on roads to melt the snow.
However, environmentalists warned that the chemical could have a negative effect on the environment and damage cars, calling for the use of environmentally-friendly substances.
Calcium chloride is a liquid in its natural state and is converted into a solid by dehydrating it - thus creating its moisture-absorbing effect. When it is converted back into a liquid, it gives off heat. Calcium chloride melts ice at temperatures below zero degrees Celsius.
Currently, authorities have been mixing calcium chloride with sodium chloride as the method is cheap and effective.
However, concerns over the side effects of the mixture are constantly being raised. The Wisconsin Transportation Bulletin recently reported that soil, vegetation, water, highway facilities and vehicles are all affected by the chemicals.
The corrosion of vehicles is estimated to be the most serious impact. Even a relatively small amount of the chemicals can significantly accelerate this, it said.
During a National Assembly hearing in 2005, some asserted that the infamous 1994 collapse of Seongsu Bridge in Seoul, which killed some 100 people, was caused by damage due to calcium chloride. In 2004, the National Institute of Environmental Research verified the allegation that an excessive amount of calcium chloride was detected in ground water near a facility housing snow-removal supplies. The residents using the water suffered from various skin diseases and other ailments.
Prof. Yoo Jeong-chil of Kyung Hee University said the chemical could also have a negative effect on trees nearby.