A recent study released by NASA claims that Gamma-rays (high energy particles which are known to cause cancer) are emitted within thunderstorms every day. This type of harmful radiation is especially prevalent in storms occurring within developing tropical systems.
So, do thunderstorms cause cancer? While research has not been conducted on this aspect of how Gamma-rays might affect the surrounding biological environment, we can use basic scientific understanding to help determine risk in the short term and the answer is: probably not. BUT, it's an important question because The American Cancer Society says affirmatively that even small doses of gamma radiation increase risk of cancer.
NASA revealed that since the launch of their orbiting, "Fermi" Gamma-ray Space Telescope, 9 years ago, the instrument has detected 4,000 gamma bursts from thunderstorms. They say that number is actually too low to represent what's really happening, because it can't detect each one. For a Gamma-ray to register aboard Fermi, it would have to pass thru the satellite. The problem is that Gamma-rays can travel in any which direction and the likelihood of one striking a small target like the Fermi satellite becomes rather remote. NASA estimates that due to this measuring problem and based on their approximations, it's likely 1,000 Gamma-ray bursts happen each day on our planet.
Scientists have dubbed these, "terrestrial gamma-ray flashes", or TGFs. The reality that thousands of TGF's are emitted every day from our atmosphere does raise an eyebrow.
Considering the health effects of Gamma-rays, the bigger question is, "what direction" do these TGF's travel within a storm? Do they go toward space harmlessly, or do some shoot down toward us, here on Terra firma?
The answer may be found when examining how these Gamma-rays form. NASA says when electrons are expelled vertically (toward space) from the top of a thunderstorm, they sometimes strike air molecules head-on. That can break molecules apart, releasing Gamma-rays. But, do these collisions react like a pool cue ball might when it strikes the triangle of pool balls during a break, to start the game? Does momentum carry them away in the same general direction? Or, do Gamma-rays act differently because they have no mass and may be subject to particle scattering on a quantum level?
Like you, I'm not a fan of articles with more questions than answers, but it's an important example of exciting research yet to be done in the field of weather!
Here's a nice video by NASA: