It’s been shown conclusively: protect the ozone layer to decrease skin cancer cases.
Montreal Protocol
An international agreement to protect the ozone layer is expected to prevent 443 million skin cancer cases and 63 million cataract cases for people born in the US by the end of this century. The new research is by scientists at the National Center for Atmospheric Research (NCAR), ICF Consulting and U.S. Environmental Protection Agency (EPA). They focused on the far-reaching impacts of a landmark 1987 treaty, the Montreal Protocol. The agreement phased out the use of chemicals such as chlorofluorocarbons (CFCs) that destroy ozone in the stratosphere.
Stratospheric ozone shields the planet from harmful levels of the sun’s ultraviolet radiation, protecting life on earth.
Computer modelling
The scientists developed computer modelling that enabled them to look to both the past and the future by simulating the treaty’s impact on Americans born between 1890 and 2100. Finally, the modelling revealed the treaty’s effect on stratospheric ozone, the associated reductions in UV radiation and the resulting health benefits.
In addition to avoiding a large number of skin cancer and cataract cases, the study also showed that the amended treaty will prevent approximately 2.3 million skin cancer deaths in the U.S.
NCAR
scientist Julia Lee-Taylor said, “It shows that, given the will, the
nations of the world can come together to solve global environmental
problems.”
Mounting concerns
over the ozone layer
In the 1970s, scientists began highlighting the threat to the ozone layer when they found that CFCs release chlorine atoms in the stratosphere. These set off chemical reactions that destroy ozone. Consequently, concerns mounted the following decade with the discovery of an Antarctic ozone hole.
The loss of stratospheric ozone would be catastrophic, as high levels of UV radiation are linked to certain types of skin cancer, cataracts and immunological disorders. The ozone layer also protects terrestrial and aquatic ecosystems, as well as agriculture.
Under the amended treaty, the modelling results showed UV radiation levels returning to 1980 levels by the mid-2040s. In contrast, UV levels would have continued to increase throughout this century if the treaty had not been amended. And they certainly would have soared far higher without any treaty at all.
Increased skin cancer cases
Even with the amendments, the simulations show excess cases of cataracts and various types of skin cancer occurring with the onset of ozone depletion and peaking decades later as the population exposed to the highest UV levels ages. Thus, those born between 1900 and 2040 experience heightened cases of skin cancer and cataracts. But the worst health outcomes affect those born between 1950 and 2000.
However, the health impacts would have been far more severe without the treaty. Without protecting the ozone layer, cases of skin cancer and cataracts would have risen at a rapid rate through the century.
Naturally, the researchers focused on the US because of ready access to health data and population projections. According to Lee-Taylor, the health outcomes in other countries may vary, but the overall trends would be similar.
The message is clear: protect the ozone layer to decrease skin cancer cases.
Story Source: Materials provided by National Center for Atmospheric Research/University Corporation for Atmospheric Research. Original written by David Hosansky.
– sciencedaily.com
