Scientists have found that tens of thousands of tons of potentially harmful “eternal” chemicals enter the environment every year. This is the price of a decision made almost 40 years ago to protect the ozone layer. There was no need to equate the concepts of “non-toxic” and “safe.”
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More than 335,000 tons of an extremely persistent and potentially harmful substance, trifluoroacetic acid (TFA), have accumulated on the planet. Its quantity is growing by tens of thousands of tons per year, and the peak is far from passed. The main source of TFC is chemicals that have replaced freons, which are harmful to the ozone layer.
Refrigerators as a global threat
The complicated story of the ozone layer and the struggle to restore it began back in 1928, when chemists synthesized the first chlorofluorocarbon (CFCs). This class of substances is known as freons or refrigerants for a reason — it has become a real godsend for refrigerator manufacturers. Unlike previously known refrigerants, such as ammonia, freons are non-toxic and their leakage was not considered a problem.
In 1973, British chemist James Lovelock measured the freon content in the air in different parts of the World and found that it was approximately the same everywhere. Then he calculated the number of CFCs produced since 1930, compared them with his own figures and came to the conclusion that all these freons are still floating in the atmosphere. This is natural for such chemically inert substances.
However, American geochemist Frank Rowland questioned this conclusion. Every substance in the chemical cycle on the globe has not only sources, but also drains, where it is destroyed. Rowland’s graduate student Mario Molina has experimentally shown that chlorofluorocarbons decompose under the influence of ultraviolet radiation. This releases chlorine, which destroys ozone in the upper atmosphere.
Ozone depletes most strongly over the poles, especially the Southern ones. Here, low temperatures, the sun that does not set for six months, and other factors play against the ozone layer. Various scientific groups recorded depletion of the ozone layer, but dismissed these data as erroneous. Finally, the scientists climbed into the stratosphere and took air samples right in the ozone hole. As the concentration of ozone decreased, the concentration of chlorine increased.
The shape and size of the Antarctic ozone hole has varied greatly from year to year. Sometimes it covered the southern tips of Australia and South America, New Zealand and the Falkland Islands. The thinning of the ozone layer was also recorded over the Arctic, although here it did not reach the state of a hole. Ozone protects living organisms from harmful ultraviolet radiation. In humans, ultraviolet light causes eye cataracts and skin cancer.
Stages of skin disease development
Controversial replacement
Chlorofluorocarbons have been replaced by related substances: hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). They have the same advantages as freons, but they do not destroy the ozone layer. However, HFCs have proven to be effective greenhouse gases contributing to global warming. In this regard, in 2016, it was decided to phase out HFCs.
The new study focuses on another disadvantage of HCFCs and HFCs. These substances can hover in the atmosphere for decades, but sooner or later they are destroyed with the release of trifluoroacetic acid (TFA). The latter falls to the surface of the Earth within a few days, mixing with water and entering living organisms. This substance accumulates in drinking water, and traditional purification methods cannot cope with it.
The conclusions are quite alarming. The intake of TFC from these sources increased 3.5 times from 2000 to 2022, to about 20,000 tons per year, and the total amount of this chemical in the environment exceeded 335,000 tons. And this is not the limit: despite the decisions taken, the production of HCFCs and HFCs continues. Experts expect that the peak of the annual allocation of TFC is still ahead.
The authors of the research call for at least increased monitoring of the level of TFC in the environment. But it is clear that this is not enough. It is necessary to better study the biological effects of this compound and, if necessary, develop ways to purify water from it. But most importantly, it is necessary to reconsider approaches to the introduction of new chemicals into the industry.
Humanity has made the same mistake with freon substitutes: it has equated “non-toxic” and “safe.” It is necessary to evaluate not only the substance itself, but also the potential products of its processing on Earth. Of course, this will slow down technological progress and, consequently, economic growth. But this is the only way to avoid mistakes that may cost future generations dearly.
By Anatoly Glossev
