f industrial chemicals over the same period. Iguchi and Katsu maintain that it is "plausible and provocative" to associate the obesity epidemic to chemical triggers present in the modern environment. Several other ubiquitous pollutants with strong biological effects, including environmental estrogens such as bisphenol A and nonylphenol, have been shown to stimulate the growth of fat storage cells in mice. The role that tributyltin and similar persistent pollutants may play in the obesity epidemic is now under scrutiny.