A class of chemicals called phthalates that are often used to make plastics more flexible is exacting a toll on fertility rates and leading to genital malformation, an environmental scientist claims. 

Shanna Swan, Ph.D., professor of environmental medicine and public health at the Icahn School of Medicine at Mount Sinai, details the health consequences of pollution in her new book "Count Down," which argues more babies are being born with smaller penises, Sky News reported. 

Swan’s research began with rats, findings that rat fetuses exposed to the chemical were more likely to be born with shrunken genitals. Later, Swan found that male human fetuses exposed to phthalates resulted in a decreased anogenital distance, a measure associated with penile length, per Sky News. Other findings cited in Swan’s book include a claim that "sperm levels among men in Western countries" declined by over 50%, drawing on hundreds of studies involving nearly 45,000 healthy men.

ANNIE'S REMOVING A CHEMICAL IN MAC AND CHEESE LINKED TO FERTILITY ISSUES

The claim isn’t all too surprising; scientists have previously suggested exposure to the chemical can harm fertility, babies' health, disrupt hormones key for development, and damage the genetic material in sperm. Phthalates have already been banned in many kids' toys over health concerns. 

These chemicals can be found in manufacturing equipment and have a firm foothold in supply chains beyond just the food industry. The Centers for Disease Control and Prevention (CDC) says phthalates can be found in personal hygiene products, makeup, plastic packaging and more.