Holy Moly, Thats a Lot of Shady Balls In One Place

How bad is California’s drought? So bad that the LADWP has released around 96 million “shade” balls into various reservoirs to reduce evaporation. The balls block ultraviolet light with a special chemical coating that also stops algae growth and helps them last for almost 25 years.

So my question is; how will those coated plastic balls pollute the water?