For several decades, the existence of a hole in the ozone layer has been known, in the Arctic region, to the north of our planet. Efforts to make it “close” have been extensive, and the hole is constantly monitored; in fact, during the pandemic, it recovered somewhat. However, a new concern has arisen because it is no longer a single hole but two.
A new hole was recently detected in the tropical zone of the Earth.
It is 7 times larger than the Arctic and remains open all year round, which researchers call a “major global concern.” The tropical hole is believed to have been available since the 1980s.
A hole in the ozone layer is an area where the loss of O3 (trioxygen, an inorganic molecule) is 25% greater than the rest of the surrounding atmosphere. In these, the levels of ultraviolet radiation are higher, so the Earth’s surface is more exposed, which represents a threat to human health since it increases the risk of developing skin cancer and other diseases.
The hole in the tropics was detected thanks to a combination of data and cosmic rays. Using cosmic ray-driven electron reaction models and an observational data set, it was found that there were physical mechanisms over the tropics very similar to conditions in the polar ozone hole.
According to the article published in the journal AIP Advances, the tropical hole has a depth comparable to that of the polar hole; however, it is seven times larger. The size of the fix added to its location are factors that make the scientific community really concerned since the consequences on the population’s health could be very serious.
“The tropics cover half of the planet’s area and are home to about half of the world’s inhabitants,” explained Qing-Bin Lu, a scientist at the University of Waterloo and author of the paper.
The tropical hole was also found to be persistent all year round. In comparison, the polar hole has a seasonal cycle and loses more O3 in September and October but recovers it before the process starts again. On the other hand, the tropical spot persists through the seasons. This means that the population mentioned below are subjected to high levels of UV radiation throughout the year.
« Increased UV radiation at ground level can result from ozone layer depletion. This is connected to a higher risk of skin cancer and cataracts in humans, a weakening immune system, a drop in agricultural output, and a negative impact on aquatic species and sensitive ecosystems.” Lu commented.
Since the 1970s, scientists have warned about the role of certain industrial chemicals in depleting the ozone layer. Chlorofluorocarbons (CFCs) were banned as they were considered the biggest culprits. However, the effects of these products seem to still be present.
” The current finding calls for more careful studies on ozone layer depletion, UV radiation shift, increased cancer risks, as well as other detrimental consequences on ecosystems and human health, tropical regions,”