as far as water parks are concerned, they're fine, there is so much chlorine in that water nothing survives. i asked my dr about swimming in lakes and rivers and he said as long as you don't get it up your nose, you're probably ok, especially if the water is flowing like in a river or creek. In lakes and ponds, you should be more careful, especially with ponds, lakes aren't so bad because the corp of engineers control those and keep track of what's in the water and the water goes in and out more and doesn't just sit getting stagnant like a pond. I swim in creeks, lakes, the ocean on occasion (which you don't have to worry about because of the salt water in most cases) in fact i was at the lake just a couple of weeks ago and i'm going to be swimming in a spring fed creek this weekend. The best thing would be to just ask your doctor