Los Angeles' 96 million shade balls are bizarre to say the least—which is partly why the media pounced on the story of their role in conserving water, as officials had hoped, Grist included. Now, the website does a careful walk-through of just why these balls aren't so hot. Based on an LA Weekly report, Grist finds the city has been using the balls since 2008, before California's drought, because their main purpose is to prevent the formation of bromate, a carcinogen that develops when sunlight mixes with bromide and chlorine in water. Why do we care about the balls now? Apparently, LA mayor Eric Garcetti correctly thought tying the balls to the drought would help sell them to the public and emphasized they'll save 300 million gallons of water a year. However, that much water is worth $2 million or $20 million over a decade; LA's shade balls cost $34.5 million, according to LA Weekly.
In comparison, the Washington Post reported California could save 500 billion gallons if the agriculture industry cut its water use by 5%. Grist notes that marine pollution researcher Max Liboiron has additional concerns. At Discard Studies, he argues "most plastics leach endocrine disrupting chemicals that interfere with animal and human hormone systems." Some of these disruptors break down in water in weeks or months and most water treatment systems don't remove them. Then there's the fact that plastics break down into microplastics and are consumed by humans and marine animals. The "poison pills" also soak up chemicals that then enter animal tissue and food chains, Liboiron says. Apparently the risk is worth the reward for Garcetti, who told the Huffington Post, "It takes bold ingenuity to maximize my goals for water conservation."