Research links common plastic additives to declining sperm counts, with scientists urging action to curb their use as environmental factors emerge as the “most significant role” of the global decline.
Dr. Shanna Swan, professor of environmental medicine and public health at the Icahn School of Medicine at Mount Sinai, US, has looked into human exposure and health impacts of harmful chemicals and examined hundreds of scientific studies on sperm decline and conducted her own.
Previous studies have indicated that sperm count has been declining globally over the past 50 years at a rate of 1%, with the rate accelerating to over 2.6% when observing studies after the year 2000. This decline can be identified even when controlling for all variables, such as genetic and lifestyle factors.
This year, Swan has spoken at an event from the Health and Environment Alliance (HEAL) in Brussels, Belgium, addressing the need for extensive chemical regulations: “We are in a fertility crisis because of the amount of synthetic chemicals in the environment.”
“The science we already have is alarming, and it is only the tip of the iceberg. People should not have to worry about exposure to harmful chemicals in their daily life — and for that, we need stronger regulation.”
Researchers grouped countries into Western and non-Western for analytic purposes, and found significant sperm declines in both.Sandra Jen, the Health and Chemicals Programme lead at HEAL, says: “This is a critical moment to protect both current and future generations from harmful chemicals. As the European Commission (EC) prepares to revise the EU’s Registration, Evaluation, Authorisation, and Restriction of Chemicals regulation, it must prioritize human health over mere economic competitiveness. An unhealthy, declining population is not an advantage.”
Chemical toxicity
Sperm decline coincides with the increased use of industrial chemicals, suggests Swan.
Phthalates, which are man-made chemical compounds used to make plastics more flexible and to make cosmetics and scents last longer, have an impact on consumers’ health.
These chemicals have an anti-androgenic effect that lowers testosterone. Swan noted that when exposure occurs in utero, phthalates can disrupt testosterone surges, influencing male genital development, such as smaller size or smaller ano-genital distance, and undescended testicles. Shorter ano-genital distance has been associated with lower sperm count later in life.
Swan explains that anytime people pick up “a soft water bottle or tubing, like medical tubing, or a food container that’s soft,” they are going to be touching phthalates.
Bisphenols are employed to harden plastics and make them more rigid in production. Swan says that the exposure to bisphenols is linked with the increase of oestrogen. This year, the EC banned the use of Bisphenol A in food-contact materials due to its potentially harmful health impact.
She also reminds us that exposure to chemicals has a transgenerational effect as germ cells present in the egg and fetus will be passed on to children and grandchildren.