> coat them in a known carcinogen That's actually the opposite of what's going on. From wikipedia: Starting in mid-2008, the Los Angeles Department of Water

> coat them in a known carcinogen That's actually the opposite of what's going on. From wikipedia: Starting in mid-2008, the Los Angeles Department of Water and Power (LADWP) deployed around 400,000 balls in the Ivanhoe reservoir with the main objective of preventing the formation of a carcinogenic chemical, bromate, which forms when naturally occurring bromine reacts with chlorine in the presence of sunlight.