I’ve been known to use Splenda (an artificial sweetener) in cooking for diabetic friends and those following an Atkins-like diet. Now, research done by a high school student in the 2009 Intel Science Talent Search shows that Splenda isn’t broken down by most water treatment methods and thus raises questions of whether this could accumulate in our lakes and rivers.
But eventually she was allowed to subject sucralose to various treatments, like bacterial digestion, typically used in wastewater treatment plants. She found that sucralose resisted most of these treatments, and was only broken down into biodegradable molecules with extensive time and concentration of titanium oxide and ultraviolet light. Since few plants use these methods, that means almost all the sucralose people eat or drink winds up in the ecosystem.
More at the Scientific American blog
P.S. It isn’t broken down in the human body either.