A 20-year follow-up study from Taiwan found that:
This prospective epidemiologic study in an East Asian cohort demonstrates that women with both high di-(2-ethylhexyl) phthalate (DEHP) exposure and a high percentage of mono-2-ethylhexyl phthalate (MEHP%) have a significantly increased risk of breast cancer, establishing clear temporal causality.
DEHP (which stands for Di(2-ethylhexyl) phthalate) is a chemical additive known as a plasticizer. Its primary job is to take a plastic that is naturally hard and brittle and turn it into something soft and flexible. It is most commonly used with a specific type of plastic called PVC (polyvinyl chloride).