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Someday your new iPhone could contain metals mined from poo

There's gold in them thar dookies! Researchers says there's millions worth of gold, silver, platinum and other precious metals in our sewage and they've got a plan to retrieve it.

Eric Mack Contributing Editor
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Eric Mack
2 min read

In the years to come, some of the metals that go into making our phones and computers could be mined, not just from the Earth, but also from our poop.

Sorry to ruin your lunch, but that's not a typo. This isn't a satirical article and CNET has not been hacked. Researchers at the U.S. Geological Survey are looking at ways to recover the surprising abundance of valuable metals that can be found in wastewater and sewage.

We've been flushing fortunes down our drains for decades... Oh, NOW you tell us, science! Video screenshot by Eric Mack/CNET

"There are metals everywhere," Kathleen Smith of the USGS says in a release. "In your hair care products, detergents, even nanoparticles that are put in socks to prevent bad odors."

Valuable metals including gold, silver and platinum wind up in wastewater treatment plants, where they're treated and end up in biosolids that are typically either sent to landfills, incinerated or used in fertilizers. The presence of some of the metals can actually restrict how the biosolids can be used, according to Smith.

""If you can get rid of some of the nuisance metals that currently limit how much of these biosolids we can use on fields and forests, and at the same time recover valuable metals and other elements, that's a win-win."

A talk about the work done by Smith and her team on how to mine our number twos was presented this week at the American Chemical Society's national meeting in Denver.

To get at the precious metals in our poo and whatever other terrible things troll our municipal wastewater, the USGS team has proposed using some of the same chemicals -- nasty stuff called leachates -- that industrial mining operations use to separate metals from rock. The advantage is that using the chemicals on biosolids can be done in a more controlled environment without endangering the environment.

While the particles Smith's group has found in biosolids sampled from some Rocky Mountain towns are microscopic, collectively there's still enough that the total amount would justify a commercial mining operation if it were found in rock. In fact, previous published research calculated that hidden treasure trapped in the refuse from 1 million Americans might amount to up to $13 million in precious metals.

And that's an amount that seems sure to go up once people start showering with their shiny new gold Apple Watches.

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Tiny gold or lead particles found in city waste. Heather Lowers, USGS Denver Microbeam Laboratory