A new analysis of waters around the United States has found that the country is dumping a stunning 8 trillion bits of plastic into oceans and lakes every day. But we're not talking about irresponsible waste management here. Even eco-friendly citizens could be contributing to this invisible pollution, and just by brushing their teeth!

"We're facing a plastic crisis and don't even know it," Stephanie Green, a David H. Smith Conservation Research Fellow at the College of Science at Oregon State University, said in a statement.

"Part of this problem can now start with brushing your teeth in the morning," she explained, pointing out that many toothpaste varieties now include tiny supposedly-harmless polyethylene microbeads designed for scrubbing those pearly whites clean. Unfortunately, it seems that no one is considering what happens after you spit those beads into your sink.

"Contaminants like these microbeads are not something our wastewater treatment plants were built to handle," Green added, "and the overall amount of contamination is huge. The microbeads are very durable."

In an analysis using what Green calls "extremely conservative methodology," she and her colleagues determined that the daily dump of microbeads from US housholds alone could cover more than 300 tennis courts. And that, Green notes, is just what is directly reaching local waters. (Scroll to read on...)

Another 800 trillion, the unaccounted-for remaining beads used daily, are ending up in sludge from sewage plants, which is often spread over areas of land. Groundwater and runoff can then deliver these beads to our oceans as well, but are far more difficult to track and measure.

So what's so bad about nearly-microscopic pellets of plastic floating around in our water? The FDA and American Dental Association both maintain that the beads are perfectly safe. Even when ingested, as so often happens, the beads run straight through the human body.

But according to Chelsea Rochman, who contributed to the analysis, it's less-so about what the beads are and more-so about what they can do.

"We've demonstrated in previous studies that microplastic of the same type, size and shape as many microbeads can transfer contaminants to animals and cause toxic effects," she explained.

In other words, microbeads act like sponges for toxins already found in local waters and sewage plants. While the beads themselves pose little harm to birds and fish (unlike larger microplastics) they can serve as delivery systems for the other foul pollutants that wind up in our waters, turning from exfoliaters to poison pills the longer they freely float.

"We argue that the scientific evidence regarding microplastic supports legislation calling for a removal of plastic microbeads from personal care products," Rochman concluded. (Scroll to read on...)

The good news is that anti-microbead rhetoric has already been on the lips of environment protection advocates  for a long time, and some law-makers are listening. Last year, for instance, New York Attorney General Eric T. Schneiderman released a new report detailing the damages that microbeads cause to local ecosystems. The report was part of a bid to have the "Microbead-Free Waters Act" enacted. The bill would make New York State one of the first in the nation to ban the sale of any-and-all products containing microbeads.

Green's team points out, however, that previously successful bans wound up being rife with loopholes.

"New wording should ensure that a material that is persistent, bioaccumulative, or toxic is not added to products designed to go down the drain," the researchers wrote in their report, which can be found in the latest issue of Environmental Science and Technology."

"The probability of risk from microbead pollution is high," they wrote, "while the solution to this problem is simple."

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