Does smoke in the air intensify harmful UV rays?

Question

I heard this and I have no idea if its true. I have searched and can't find anything to back it up, so I thought I would see if anyone here knows. I am guessing its not true, but who knows.

So if there is a fire burning nearby causing the air to be hazy and a bit smokey, will the air quailty have any effect on the suns rays? Should you avoid outdoor activites such as a day at the beach?

Obviously a fire will damage air quaility, but can the smoke in the air cause the suns rays to be more damaging?

Answer 1

No smoke will not intensify UV waves.

Enough of a transparent gases like ozone (O3) can block UV rays, but ozone doesn’t intensify them.  If ozone can block some UV radiation then smoke will surly block more of them.

Some UV rays are still energetic enough to reach the surface of the Earth despite the ozone layer; more of them will reach the surface on a clearer day.  Many of them can pass right through the clouds, so you can still get UV burns (sunburn) even on a cloudy day.  UV radiation can even pass through a thin T-Shirt.

To intensify UV rays you would need a concave lensing effect and rain drops are curved outward; convex.  If the ozone layer was thinner, say at the South Pole then the ozone layer may act like a intensifying lens.  However, smoke is only opaque and it will just block more UV radiation.

Fires can create their own weather system, sparking lightning and more fires.  They are clouds and can collect water droplets as they rise and the air cools.  They won’t form rain clouds though, those would be swept away by the rising heat, but they can form clouds with lightning, just another risk of forest fires.

Answer 2

No, I don't believe so.  The particles that make up the smoke would reflect and absorb ultraviolet light, so there will be less of it making it to the surface.  During large fires around here people actually were looking at the sun when it could be seen through the smoke and it appeared very red--the shorter wavelengths were not making it through.  Some people  could even see sunspots (which meant they almost had to stare at sun) and I don't recall anyone damaging their eyes that way.  I wouldn't recommend it, though.