Human Journey

BPA Linked to Higher Testosterone Levels

BPA’s in almost everything, it seems. The chemical is great for making transparent, nearly shatter-proof plastic, called polycarbonate, so it shows up everywhere–in CDs, water bottles, even eyeglasses.

Now it’s in your urine, too. And if you’re a guy, it’s messing with your hormones.

Researchers at the School of Biosciences at the University of Exeter in the UK have found an association between BPA (Bisphenol A) and higher levels of testosterone, proving a link that up until now has only been decisively shown in lab animals.

The new study, published this month in Environmental Health Perspectives, looked at hundreds of men in Italy who had volunteered to donate blood and urine samples.

Out of all these men of all ages, 98 percent had some level of BPA in their urine.

“And as soon as you see something in 98 percent of the population, you think, ‘That could be a health risk,'” said Tamara Galloway, the lead author of the study.

plastic.jpg Photograph by Ana Meza/MyShot

Galloway’s group’s previous work with BPA has established links between exposure to the chemical and cardiovascular diseases, and diabetes. But the chemical had long been suspected to also act as an endocrine disruptor; that is, something that mimics or blocks hormones in the body.

The men who excreted the most BPA through their urine also had the highest amount of testosterone in their blood.

BPA passes through the body “rapidly and completely,” according to the study. But because BPA is so ubiquitous, the damage is through a low level of constant exposure, so even as “old” BPA is flushed out, we’re ingesting more of it. “everything we’ve seen suggests that there’s a low level of consistent exposure,” Galloway said.

Getting Rid of BPA

In an unrelated study, researchers have been working on ways to degrade BPA-containing plastic without releasing BPA into the environment.

Mukesh Doble, a professor in the Indian Institute of Technology‘s biotech department, and his colleagues exposed sheets of polycarbonate to UV light and then inoculated them with white-rot fungus. The researchers were able to partially decompose the plastic with no release of harmful BPA. The fungus isn’t exactly feeding on the BPA, Doble said, but “this fungi breaks it into pieces, so whatever is coming out is not exactly a BPA molecule.” Left alone without the white-rot fungus, the plastic will be attacked by bacteria that eventually do break it down, but release BPA into the environment during the process, Doble explained.

Instead, using Doble’s technique, the UV light “pretreats” the plastic, making it easier for the mold, used commercially for bioremediation all over the world, to grow. Combined, they made for the best and fastest plastic killer.

The solution isn’t a quick fix: after a year, the plastic was only about 6 percent degraded. Doble estimates it would take about 20 years to break down the entire thing. And until a plastic treatment plant based on the scientists’ findings opens up near you, your only option to get rid of your bottle is to dump it in the trash. Most municipalities don’t accept #7 plastics for recycling.

Many companies, prompted by health concerns, have been phasing out polycarbonate in favor of other plastics. But BPA is still found in some food storage containers, baby bottles, the linings of metal cans, and in all sorts of non-food related uses, so it’ll be with us for a long time. Even if we do let it rot.

–Rachel Kaufman

Forty years in U.S., UK, and South African media gives David Braun global perspective and experience across multiple storytelling platforms. His coverage of science, nature, politics, and technology has been published/broadcast by the BBC, CNN, NPR, AP, UPI, National Geographic, TechWeb, De Telegraaf, Travel World, and Argus South African Newspapers. He has published two books and won several journalism awards. He has 120,000 followers on social media. David Braun edits the National Geographic Society blog, hosting a global discussion on issues resonating with the Society's mission and initiatives. He also directs the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship, awarded to Americans seeking the opportunity to spend nine months abroad, engaging local communities and sharing stories from the field with a global audience. Follow David on Facebook  Twitter  LinkedIn

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