Toxic Traces Of New Freons Were Found In Arctic Ice
Canadian scientists have found that toxic compounds of fluorine and organic acids, which are used as a substitute for freons, have been accumulating in Arctic ice deposits for several decades. The results of their research were published in the scientific journal Geophysical Research Letters.
"In recent decades, the share of these chemicals in ecosystems has increased dramatically. This is the first time we've seen them spread in a long time. Our data suggest that the ban on "old " freons has led to the accumulation of their substitutes in the Arctic. This is an excellent illustration of what unpredictable consequences such measures can have," said Cora young, one of the authors of the study, an associate professor at York University in Toronto (Canada).
Freons are compounds of hydrocarbons, fluorine, and other Halogens that scientists discovered almost a hundred years ago. Until the mid-1980s, freons were almost universally used as refrigerants and building materials components. However, after scientists found out that freons destroy the ozone layer and have already created an ozone hole over Antarctica, the public sounded the alarm.
After lengthy international negotiations, the production and use of the most dangerous types of freons at the global level were banned under the Vienna Convention of 1985 and its Montreal Protocol of 1987. Four years ago, climate scientists for the first time recorded signs that due to this, the changes in the ozone hole have decreased, and the state of the ozone layer has improved.
These agreements forced Industrialists to develop new types of freons and switch to them. They do not destroy ozone, but at the same time, as climate scientists have recently found out, they remain the strongest greenhouse gases. It turned out that they act on the atmosphere tens of thousands of times more strongly than carbon dioxide.
Young and her colleagues learned of another unexpected consequence of the Montreal Protocol. Researchers studied ice samples that were formed over four decades in two different corners of the Canadian Arctic. Scientists were interested in the toxic and dangerous substances in these deposits and how their concentration changed over time.
Analyzing the composition of different layers of ice, ecologists have noticed that in the last three decades, the share of toxic molecules that consist of fluorine and various organic compounds has begun to grow in them. At first, scientists could not understand what these substances were and how they got into the ice.
Young and her colleagues found out this by noting that the concentration of these compounds in ice began to rise sharply in the 1990s when classical freons began to be replaced by other types of fluorine compounds. The Arctic ice contained a large amount of one of the subclasses of such substances, the so-called perfluorinated carboxylic acids.
These substances, as young noted, are practically non-degradable in nature. Because of this, they must quickly accumulate not only in the Arctic glaciers but also in drinking water and food in other parts of the world. Given their toxicity, this could become no less dangerous for humanity than the formation of an ozone hole, scientists conclude.