Virtually all Americans are exposed to phthalates daily. Pregnant women and young children are the most vulnerable group. Some workers, communities of color, and low-income people may face disproportionate exposure to phthalates, raising justice concerns.
Many experts believe that there’s no safe level of exposure to phthalates. Federal scientists reported this year that up to 725,000 American women of childbearing age may be exposed daily to phthalates at levels that threaten the healthy development of their babies, should they become pregnant.
Physicians and health scientists have raised serious concerns about the harm that elevated phthalate exposure poses to the developing brain and male reproductive organs during pregnancy.
About one in six American children have a developmental disability, and that rate increased by 17% from 1997 to 2008, say federal health scientists. There’s “now substantial scientific evidence linking toxic environmental chemicals to neurodevelopmental disorders such as autism spectrum disorder, attention deficits, hyperactivity, intellectual disability, and learning disorders,” according a scientific consensus statement.
For phthalates, several studies in children have linked prenatal exposure with neurodevelopmental problems including attention deficit hyperactivity disorder (ADHD)-like behavior, antisocial behavior (e.g. aggression and depression), and poor learning and memory. Similar outcomes are also associated with phthalate exposure during early childhood.
Genital Birth Defects
Some phthalates are associated with birth defects of male reproductive organs, which may increase the risk of prostate and testicular cancer and reduced fertility later in life.
Several studies have associated higher phthalate exposure during pregnancy with a genital birth defect in baby boys known as shorter anogenital distance (AGD). In men, shorter AGD has been linked to poor sperm quality, lower fertility, and an increased risk of prostate cancer.
In studies on lab rats, exposure to phthalates also causes shorter AGD, as well as several other male reproductive organ birth defects listed below, which are known collectively as “phthalates syndrome.” In humans, a shorter AGD co-occurs in boys that also have some of these same reproductive health problems, which include:
- Hypospadias, a birth defect marked by the abnormal positioning of the urethral opening on the penis, which requires invasive surgery to correct;
- Chryptorchidism (or undescended testes), in which one or both testes fail to drop into the scrotum from the abdomen, which increases the risk of testicular cancer later in life;
- Smaller penis size, which can persist throughout life.
Exposure of pregnant rats to phthalates also causes other malformed male reproductive tract structures in their offspring, including the prostate, seminal vesicles, vas deferens and epididymis, and retention of nipples and areolae that are normally absent in male rats.
Phthalates are Hormone Disrupting Chemicals
According to the Endocrine Society: “Hormones are substances secreted by glands throughout your body. They regulate everything from hunger to reproduction and influence nearly every cell, organ, and metabolic function. Together hormones and glands make up the endocrine system. … “hormone signaling” is a delicate process. For people to stay healthy, hormones must be released in the right amounts, and glands must be able to adjust the release of hormones in response to a changing environment.”
Chemicals that interfere with the normal functioning of hormones are known as endocrine-disrupting chemicals (EDCs) or hormone disruptors.
Many phthalates are known to be anti-androgenic, meaning that they interfere with androgens or male sex hormones. Some phthalates reduce production of testosterone, the androgen most critical to the healthy development of male reproductive organs.
Some phthalates also affect thyroid function, which is essential to healthy brain development. Testosterone may also play a role in normal brain development.
Hormone disruption is the mechanism by which phthalates are thought to affect brain development and male reproductive health.