Since plastic became known as the “miracle material that has made modern life possible” in 1950, humanity has produced 9.2 billion tons of plastic. [1] Plastics are produced using a large variety of materials which are often harmful to the environment and have been commonly found in human tissue. [2] PROTECT studies Endocrine Disrupting Chemicals (EDCs), which are chemicals often found in plastics that impact the endocrine system and can result in infertility and reproductive problems, heart disease, and hormone related cancers.[3]

In a recently published study on the “Associations of Phthalates and Phthalate Replacements With CRH and Other Hormones Among Pregnant Women in Puerto Rico,” PROTECT researchers focused on a group of EDCs called Phthalates and particularly how they impact reproductive health. According to the CDC, phthalates (also known as plasticizers) are a group of synthetic, endocrine-active compounds “used to make plastics more flexible and harder to break” and are utilized in the manufacturing of a myriad of consumer and personal care products including beverage containers, perfume, lotions, medical tubing, soaps, shampoos, nail polish just to name a few. Once a person has been exposed, usually by either ingestion or absorption through the skin, their body will metabolize the parent compound into one or more metabolites, which then circulate throughout the body and interfere with hormone synthesis and action.

To find out more about the impacts of phthalate exposure on hormones, PROTECT researchers took urine and blood samples from women participating in the study at two times during pregnancy to measure concentrations of phthalate metabolites (in urine) and hormones (in blood). Since phthalates have a relatively short biological half-life, meaning that the metabolites are often excreted in the urine within 36 hours of the initial exposure, a single urinary phthalate measurement is likely indicative of an exposure that occurred in the very recent past, and not necessarily indicative of long-term exposure. This makes it necessary to measure phthalate concentrations more than once to ensure we can assess what each person’s general phthalate exposure looks like.

PROTECT researchers found that many phthalate metabolites were widely associated with different hormone concentrations in healthy pregnant women. Furthermore, significantly altered hormone levels were found to be associated with elevated phthalate metabolite concentrations. This means that once phthalates appear in the body, they can cause hormone levels to change when they’re not supposed to change, potentially leading to negative health outcomes. Because the scientific community continues to uncover negative health effects associated with phthalate exposure, other synthetic chemicals have been developed which were intended to be safer alternatives, but this study demonstrates that even these chemicals may interfere with normal hormone activity.

This study adds to an existing body of literature which implicates phthalate exposures in a variety of adverse health effects, including birth outcomes. Further, this research sets the groundwork for future studies which will assess the possible roles that hormones play in the mechanism between phthalate exposure and preterm birth. In the meantime, a couple of simple ways to reduce your phthalate exposure level include switching from plastic food storage containers to glass containers, buying personal care products like shampoo and lotions that are labeled as phthalate-free, and using a glass or stainless-steel water bottle instead of a plastic one. More information on reducing your exposures to phthalates and other chemicals can be found in the PROTECT Resource Center.