Many women are unaware that rayon and rayon-cotton blends are widely used in the manufacture of tampons. Rayon is commonly chlorine-bleached, and is a highly absorbent fibre. Dioxin, a toxic carcinogen, is a by-product of all chlorine bleaching methods and is also found throughout the environment in varying levels as a by-product of pesticide spraying and pollution from incinerators. Dioxin has been found to collect in the fatty tissues of animals, including humans and should, therefore, be a real concern for women. Published scientific reports have shown that evidence is growing that even low levels of dioxins may be linked to cancer, endometriosis, low sperm counts and immune system suppression. Considering a woman may use as many as 11,000 tampons in her lifetime, she may be subjecting herself to additional dioxin exposure.