You might have seen ads on TV about black balloons encouraging people to save electricity:
Now the Los Angeles Department of Water and Power have put 400,000 black balls in a lake (read more here). It seems that the water needs to be shaded because when sunlight mixes with some chemicals in the water, a carcinogen (cancer causing chemical) forms. Stopping the sunlight stops the carcinogen forming – and that’s good for everybody! Check it out (sorry about the ad which comes up first):
Tags: Chemistry, Environment, Science, Video
