Medications pass through our bodies, break down and get flushed away, but a new study found that microbes used in wastewater treatment might be putting them back together.

Microbes clean wastewater by eating bacteria and organic matter, but they’re not good at breaking down drugs. Apparently, sometimes they do just the opposite.

Researchers from the University of Wisconsin Milwaukee tested treatment plants to see what happens to medications after they’re flushed, either by passing through peoples’ systems or dumping of unwanted pills. They found that two drugs — anti-epileptic carbamazepine and antibiotic ofloxacin — came out at higher concentrations than they went in.

Canadian researchers in Peterborough, Ontario had previously found similar increases in carbamazepine post treatment, but were unsure why.

“Microbes seem to be making pharmaceuticals out of what used to be pharmaceuticals,” said lead author Benjamin Blair, to Environmental Health News. 

Blair is now a postdoctoral fellow at the University of Colorado Denver.

When these recombined drugs make their way into streams and rivers they damage wildlife. Studies have shown that carbamazepine can be harmful to aquatic insects and fish including the common carp, zebrafish and Japanese rice fish. According to the World Health Organization, the amounts of drugs escaping treatment plants don’t pose a threat to humans.

Tanja Raunch-Williams, wastewater researcher with Carollo Engineers, told Environment Health News that treatment plants are getting better at removing pharmaceuticals using techniques like UV disinfection and chemical cleansers. 

But Blair added that upgrading plants with new techniques is expensive and isn’t a priority because the U.S. doesn’t regulate pharmaceuticals in wastewater effluent.

— Mollie Putzig


Concerned that inbreeding has made plants vulnerable to pests and drought, scientists think reintroducing genes from their wild ancestors could give domesticated crops the strength to survive without the pesticides, herbicides and fertilizers that organic farmers shun.

Scientists at the University of Copenhagen proposed the idea of “rewilding” plants using genetic engineering, in the journal Trends in Plant Science, May 28.

“The corn we eat does not live in nature anymore,” said Michael Palmgren, senior author of the paper, in a press release. “It’s like how we turned a wolf into a poodle. During breeding you select for specific characteristics, but then you risk losing others because you’re not selecting for them. If you wanted to strengthen a dog, you would breed it with a wolf.”

Natural breeding could accomplish rewilding, but it would take much longer.

The researchers’ hope rewilding could be considered organic. In the U.S., organic plants cannot have foreign genes. Whether a plant’s ancestral genes are foreign is up for debate.

Controversy surrounding GMOs presents a significant obstacle for rewilding. U.S. regulations say GMOs are foods with genes that couldn’t have occurred in nature, but the European Union is stricter. So rewilding would fly in the U.S., no GMO label required, but not in Europe.

While Palmgren thinks rewilding could solve problems introduced by genetically engineered monocultures, anti- GMO groups maintain that a GMO by any other name is just as sour.

— Mollie Putzig