Phthalates, man-made chemicals used in a variety of products, may have endocrine-disruptive effects in reproductive-age women, increasing or decreasing their risk of endometriosis, according to a new study by the University of Washington School of Public Health. Researchers found that a majority of the 287 women they studied through an integrated healthcare delivery system in Washington state had detectable concentrations of phthalate metabolites in their urine. Phthalates are used to soften and add flexibility to plastics or as solvents or fixatives.