Summer is winding down but, around the Borderland, it's still more than warm enough to enjoy the pool. Don't pee in it though -- that's dangerous!

We've all seen the "We don't Swim In Your Toilet, Please Don't Pee In Our Pool" signs and jokingly warned kids about chemicals that change the water's color if they do but, guess what? In addition to being disgusting, it really does pose a genuine health hazard.

According to Purdue University Professor Ernest R. Blatchley, it's the same as a chemical attack. He says:

The urine itself is probably nothing to worry about, but the fact is that urine contains a lot of organic nitrogen that's gonna react with chlorine, and the products of those reactions are sometimes pretty unpleasant. They include things like cyanogen chloride, which has been used as a chemical warfare agent.

See? Your folks were right, don't pee in the pool!