A combination of everyday chemicals found in people’s bodies may be associated with a worldwide plunge in male fertility, a new study has found.
Sperm counts have dropped by more than a half in the past 40 years — a circumstance that the study’s authors attributed to “daily exposure to a mix of hormone-disrupting chemicals,” meaning those that increase or decrease the body’s hormonal activity.
This blend of common chemicals — found in items such as milk cartons, canned tuna, receipts and acetaminophen — have a “cocktail effect way more dangerous than any single substances,” according to the scientists, who published their findings in Environment International on Friday.
The toxicologists involved in the study, based at British and Danish institutions, analyzed levels of mixtures of chemicals such as bisphenols, dioxins, phthalates and paracetamol in the urine of 98 Danish men ages 18 to 30, according to the study.
They found that every single man tested had concentrations that were higher than those considered safe, with some up to 100 times higher than safe levels.
And because important steps in male sexual development begins during the mother’s pregnancy, the authors warned in a statement that “developing babies are most at risk.”
Studies exploring the connection between male infertility and chemical exposures have up until now focused predominantly on phthalates — compounds added to plastics to increase their flexibility.
But the authors behind this latest research concluded that bisphenols, polychlorinated dioxins and acetaminophen have a greater impact on infertility.
Bisphenols are compounds also used in the manufacturing of plastics, with bisphenol A (BPA) the most common in the group.
“Most of the chemicals we considered together reach us via food,” Andreas Kortenkamp, a professor at Brunel University London, said in a statement.
“A lot of bisphenol A intake is via milk,” he added. “The linings of milk cartons and canned food, for example the tomato tins, leach BPA into the product.”
Polychlorinated dioxins, often referred to simply as dioxins, can occur naturally but are predominantly found in waste incineration, metal smelting and other industrial processes.
Acetaminophen, called paracetamol in Europe, is an over-the-counter analgesic used to treat pain and fever, known by common brand names such as Tylenol and Panadol.
“Some of the chemicals we looked at only stay in the body for a few hours, but because exposure is continuous, the internal concentrations are always topped up,” Kortenkamp said.
This process, he explained, applies to several different bisphenols, phthalates and acetaminophen.
“When they meet in the body, they each exert their toxicity, so the effect adds up,” Kortenkamp added.
While France specifically bans BPA from coming into contact with food, the researchers stressed the importance of extending this ban to apply to all bisphenols in all countries.
Aside from government action and individual efforts to be “careful with paracetamol,” Kortemkamp warned that “people can do relatively little to reduce exposures.”
“The problem can only be tackled through better policy,” he added.
