Climate change is driving the increased rates of skin cancer- here’s how
As global rates of skin cancer increase, research confirms that climate change is a contributing factor.
Climate change is real, we see it all around us.
Here in New Mexico, we’re in an extreme drought and see the impacts through dry rivers, stressed wildlife, and poor air quality due to fires raging across the West. But what about the changes you can’t see?
Global skin cancer rates are increasing 4–5% every year, is climate change to blame? Since becoming a skin cancer statistic I’ve taken time to do some research, this is what I found.
Skin cancer is on the rise.
The United States has more than 5 million cases of skin cancer annually. The World Health Organization predicts this number will increase 10% by 2050.
Over the past decade, invasive melanoma diagnoses (the most serious form of skin cancer) increased 44%; the trend continues with an estimated increase in melanoma incidence of 5.8% in 2021. Why is this happening?
UV rays from the sun cause skin cancer.
Sunlight is the primary source of UV radiation. UV [ultraviolet] is a complete carcinogen meaning it can cause cancer by itself.
In 1985, scientists discovered large holes in the stratospheric ozone layer. These holes in the ozone allowed more UV radiation to reach the southern hemisphere.
There are two types of UV rays that reach the earth’s surface:
- UVA rays make up 90–95% of the sun’s rays that hit the Earth’s surface. UVA rays penetrate deeper into the skin and can cause skin cells to age and can cause some indirect damage to cells’ DNA. UVA rays are mainly linked to long-term skin damage such as wrinkles, but they are also thought to play a role in some skin cancers. They cause an immediate tanning effect, and sometimes a sunburn. UVA rays can penetrate windows and clouds.
- UVB rays are partially absorbed by the ozone layer and are approximately 5%-10% of the sun’s rays that reach the Earth’s surface. UVB rays makes contact with the outer layer of the skin, can damage the DNA in skin cells directly and are the main rays that cause sunburns. UVB rays cause most skin cancers.
Ozone layers in the upper atmosphere filter some UV radiation. Damage or loss to the ozone allows more UV radiation to reach the earth’s surface increasing skin cancer rates.
Climate change and skin cancer
Climate change contributes to rising skin cancer rates in three ways:
· Stratospheric ozone depletion — in 2017 studies conducted by Harvard University atmospheric chemist James Anderson and his colleagues discovered that as the planet heats up, summer storms are becoming more frequent and powerful enough that they are sending moisture into the stratosphere. Once there the moisture triggers an ozone-depleting chemical reaction like that referenced above. This chemical reaction is reducing ozone density at the mid-latitudes. Global warming feeds warmth and moisture into the atmosphere, and that fuels instability in the stratospheric ozone.
· Heat due to global warming — Heat impacts people’s behavior. When temperatures rise people spend more time outdoors, they wear fewer clothes and are exposed to more UV radiation. Heat also has an impact on carcinogenesis. Research shows that not only is UV radiation more effective at creating tumors at higher temperatures, but that nonmelanoma skin cancer risk increases for every Celsius degree of temperature increase.
· Air pollution — Known to cause respiratory issues, air pollution also has implications for skin cancer as some particulate matter, an important indicator of air quality, not only penetrates the lungs but also enters systemic circulation, crosses the blood-brain barrier, and can even penetrate the epidermis directly.
What can you do?
With a greater percentage of UVB rays hitting the Earth’s surface it’s more important than ever to adopt an aggressive sun care strategy. The American Cancer Society recommends flat-out avoiding the sun (especially between 10am — 4pm). But for those of us who love being outdoors, integrating these tips will help to protect you from the suns dangerous rays:
· Cover up with protective clothes (SPD when possible) including hats and sunglasses
· Integrate a broad spectrum (UVA/UVB) mineral sunscreen with an SPF of 15 or higher into your daily skincare routine.
· For extended outdoor activity, use broad spectrum mineral sunscreen with an SPF of 30 or higher. Reapply every two hours or after swimming or sweating.
· Stay in the shade whenever possible.
More ultraviolet radiation is reaching the earth’s surface due to the damaging impact climate change is having on the fragile ozone. While this is bad news for outdoor enthusiasts, you can protect yourself by being more strategic when it comes to sun exposure.
Interested in helping us make the best sunscreen ever? Take our survey here and join our adventure.
Want to make a difference? Check out these 10 things you can do about Climate Change from our friends at the David Suzuki Foundation.
