What do your phone, the sun, the stove, far-off
black-holes and the palm of your hands all
have in common?
Radiation, baby.
It's everywhere.
Up and atom friends, Trace here emitting and
absorbing radiation at your eyeballs for DNews!
When I say radiation, most people do this,
but to be honest, radiation on it's own isn't
necessarily harmful!
The term radiation is super broad, gamma rays
shooting out of stars is radiation, heat coming
off the pavement on a hot day is radiation,
and the radio waves picked up and emitted
by cell phones, radio stations and WiFi networks
are radiation too -- even the light you're
seeing on this screen is radiation.
The thing is, even though radio, microwave,
visible and infrared, are technically radiation
-- when we SAY radiation, most people think
of dangerous high-energy particles called
IONIZING radiation.
That includes Ultraviolet, X-Rays, or Gamma
Rays.
Which makes sense, but what can that stuff
DO to you when it hits your body?
In 1927, in the journal Science, Hermann Muller
published a paper showing the ionizing radiation
of x-rays damaged the genes of fruit flies.
He later won a Nobel prize!
Ionizing radiation is high-energy radiation…
it's got a lot of energy.
When this high-energy particle or wave hits
an atom, the atom absorbs the energy; causing
the weakest electron to pop off!
This creates a charged atom called an ion!
Do that enough and all that high-energy can
cause chemical changes in our tissue.
If ionizing radiation affects too many cells
at once, or we absorb a bunch over time -- that's
when we risk sickness, radiation poisoning,
or eventually cancer.
That happens when the radiation changes how
things fit together.
It might knock off bits of our DNA, mess with
its structure, or (at worst) break one or
both strands of the DNA double helix!
That alone isn't damaging, but sometimes,
the body makes mistakes when repairing that
damage -- causing wide-spread issues.
But chances are, you'll never have to worry
too much about how much radiation you're being
exposed to.
Radiation dosage is measured in sieverts.
One sievert in a short time can cause radiation
sickness and 10 can kill.
But because we'd never really encounter a
full sievert, scientists usually talk in millisieverts.
Every year, just living on Earth exposes us
to 2.4 mSv in natural background radiation,
and its fine.
A chest x-ray, for example, is 6.8 mSv, so
while ONE X-Ray won't hurt you, a bunch throughout
your life (or all at once) can damage your
tissues enough to cause health problems.
If that weren't complicated enough, there
are different types of ionizing radiation!
Alpha, Beta, Gamma and X-Rays; listed in increasing
energy levels.
Alpha radiation is the slow big fella, it
can't really penetrate your body, but it's
essentially a handful of protons and neutrons.
Beta is basically a tiny fast-moving electron;
it can penetrate your body, but not some denser
materials, like aluminum.
Then there's gamma radiation, which is just
fast-moving pure energy!
It's so small it can pass between your cells,
but if it hits your DNA it'll mess you up
-- though it won't make you green and invulnerable.
In fact gamma so high energy, it can pass
though you, aluminum and even concrete walls
-- though not lead it's too dense.
X-Rays are like gamma rays, but lower energy.
In the end, you probably don't have to worry
a LOT about ionizing radiation.
UV rays can damage DNA over time, so wear
sunscreen.
X-Rays are highly regulated, and hopefully
you haven't spent too much time near unbridled
nuclear reactions, or exposed yourself to
cosmic rays.
Most radiation is just regular non-ionizing
stuff.
Heck, even humans emit infrared radiation
in the form of heat and some ionizing radiation
that we absorb from food, like bananas.
It's everywhere!
And though some of it can damage you, it's
not all bad.
