PhthalatesTrusted Source are chemicals, sometimes known as plasticizers, that are used to make plastics more hardwearing. They are used in hundreds of products, including plastic packaging and personal care products, such as shampoos, soaps, and hair sprays.

People are exposed to phthalates all the time, by eating and drinking foods from packaging that contains phthalates, and from breathing in phthalate particles from the air.

They are known to be endocrine disruptersTrusted Source and are harmful to human health. There are some restrictions on phthalate use in the United Kingdom, and in the United States, the Food and Drug Administration (FDA) has restrictedTrusted Source some uses of some phthalates. However, their use has not been banned.

Corresponding author on the current study, Dr. Serdar E. Bulun, a reproductive endocrinologist and department chair of Obstetrics and Gynecology at Northwestern University Feinberg.

‘Phthalates make the tumor bigger’

Epidemiological studiesTrusted Source have strongly indicated a link between environmental phthalates and uterine fibroids.

In this new study, the researchers investigated whether phthalates, particularly di-(2-ethylhexyl) phthalate (DEHP), increased the growth of uterine fibroids. The larger a fibroid grows, the more likely it is to cause symptoms.

DEHPTrusted Source is commonly used in many medical products, furniture materials, cosmetics, and personal care products.

Dr. G. Thomas Ruiz, obstetrics and gynecology lead at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, not involved in this study, commented that the researchers have “been able to demonstrate the presence of a chemical compound in the environment, as well as its breakdown product in urine to show a correlation between increased levels of the breakdown product in the urine and increased risk of leiomyomas.”

People metabolize DEHP into mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). MEHHP is then excreted in urine. For their in vitro study, the researchers used concentrations of MEHHP equivalent to those found in urine.

The researchers took uterine cells taken from women undergoing hysterectomy or myomectomyTrusted Source, a surgical procedure through which doctors remove the fibroids while keeping the uterus intact.