Are you sure you quoted Mark J. Nieuwenhuijsen accurately in this article? To wit: “. . . he was surprised to find that [the factors most influencing trihalomethane production in pools] include water temperature, large numbers of swimmers, and high concentrations of organic compounds.” Elevated temperature generally accelerates chemical reactions. More swimmers mean more grunge. And high concentrations of organic compounds–well, what’s to find?

Mark E. Kahn
Darnestown, Md.