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insider
10-28-2001, 03:19 PM
I understand that there are atomic particles that constantly pass through the earth and the its inhabitants. Would it be possible for one or several of these particles to strike atoms of DNA in our bodies causing mutations and leading to possible tumors or other mutagenics that may affect offsprings?

MMMason
10-28-2001, 03:31 PM
Not having a degree in biology but just remembering the days back in high school, yes cosmic radiation passes through us and could cause mutation in your cells. It normally wouldn't matter because if the mutation is harmful the cell wouldn't live and just die. The atmosphere blocks most of the harmful radiation so thank you ozone layer but mutations happen more than we think.

Where it could hurt is if the mutation occurs in our reproductive cells and does not impair the cell. Then this mutation would not just happen in a single cell but rather would be copied into the entire offspring.

Mutations can be good. For example if an algae lives in a cool pond of 60F, and a new industrial plant moves next door and dumps warmer water into the pond raising the temperature to 80F. if a mutation allows the cell to live in the warmer water that would normally die in the cooler, it will be fruitful and multiply to allow the algae to live.

ftg
10-28-2001, 04:29 PM
insider is probably asking about neutrinos. They're kinda like photons but a lot stranger. They move at or near the speed of light and have little or no rest mass (they two issues are tied together). But they are not electro-magnetic related and they have very tiny wavelengths. This means they basically have to hit a neutron directly and at just the right time to interact with matter. They were postulated to make "the math come out right" years before they were detected. They are produced in large quantities by nuclear reactions, with the Sun being a Big Time Source of that.

Billions of these can pass right through you without hitting anything. Once in an extremely great very long while one might hit the nucleus of an atom in your DNA causing a little glitch there. But you are suffering a lot more glitches all of the time from cosmic rays, local natural radiation, sunlight(!) and so on. Neutrinos are pretty much the least worrisome radiation out there.

Given their lack of interaction with matter, they travel the universe relatively unimpeded. But catching these requires very special detectors located in deep mines. These detectors will only detect a few neutrinos a month. But when a "nearby" star goes supernova, the rate goes way up.

Napier
10-28-2001, 05:00 PM
To say just a bit more, I guess along with ftg that Neutrinos inspired the question - but subatomic particles that easily pass all the way through you are not the ones to worry about. If they interacted with you in some way, such as by causing mutations, they also would not make it through you. So the ones that go all the way through you are not the problem.
Neither are subatomic particles that stop immediately, such as visible light photons that make it only a ways into the skin.
The particles that cause us the most trouble internally are energetic enough to go through us, or through much of us, but interactive enough that they often hit something inside us. I think (not sure) that more interactions occur down inside of us due to energetic photons than any other kind of particle. Note that X-rays and Gamma rays are both energetic photons, and that the definitive diference between them is where they originated, not anything intrinsic about them. X-rays come from X-ray tubes with electron beams hitting targets, whereas Gamma rays come from atoms undergoing internal changes. As a practical matter many would say that somewhere around 100,000 or 1,000,000 electron volts of energy per particle divides X-rays from more energetic Gamma rays, but there are X-rays above and Gamma rays below that energy range.
We get constant bombardment from radioactive substances including the earth and many minerals, as well as things made from them such as masonry and metals. We also get X-rays for a variety of intentional reasons. All of these things are interacting with us more or less and messing up DNA just like they mess up whatever other molecules they hit. And this situation generally has been the case for the entire duration of life on Earth; though many of the sources are historically new, for at least 50 years people have understood the hazards well enough to keep our exposures in about the same range they always were.
Of course there have been exceptions, like Radon and watch face painters and people in Hiroshima or near Chernobyl.