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Ever wonder what happens after you flush? You should, because your pee is causing problems! Hank talks about how, and why, human waste is having weird effects on the natural world. We're talking homicidal fish and hermaphroditic frogs...

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We live in a pharmacological wonderland. Got a sore back? Pop some anti-inflammatories. Can't shake the blues? Try antidepressants. Care to avoid pregnancy? Just take the pill.

Today we've got access to all manner of pills, many of which come with their own colorful side effects, but you probably don't think much about the side effects outside your own body. By which I mean, you are probably not considering the homicidal fish or the hermaphroditic frogs, but maybe it's time you did.

(Sci Show intro plays)

You've heard all about the host of dangerous chemicals found in pesticides and herbicides, heavy metals, and industrial waste run off the land into the earth's water systems. That kind of contamination creates major ripples throughout ecosystems and unfortunately there are some newcomers to the list: pharmaceutical drugs.

Yes, with all those pills trace amounts of drugs get peed out every day and scientists are seeing a rise of concentrations of those drugs in our water and these chemicals, particularly estrogen hormones and antidepressants, can seriously effect aquatic animals. Antidepressants are the most commonly prescribed medication in the United States. Also, the most documented pharmaceutical contaminants in our waterways.

A new study shows that when male fathead minnows were exposed to levels of Prozac found in some waste water, they became aggressive, even killing females in some cases. The researchers said that the drug seems to scramble the brains of the developing fish, disrupting how their brain genes are expressed and noticeably changing their behavior. Another study exposed perch to a common anxiety medication and watched timid fish grow bold, reckless, anti-social and ravenous. And yet another study exposed zebrafish to levels of ibuprofen similar to what is found in municipal waste water and found that males significantly lost interest in courtship behaviors. It seems in humans, the drug inhibits the production of prostaglandins which play a role in inflammation, but in these fish prostaglandins also work as pheromones, so the fish weren't in the mood for love.

Now, these are lab studies and we're not sure how they are going to translate to wild populations, but even low levels of pharmaceuticals may have big repercussions.

There is a high likelihood that  if some of the drugs, antidepressants especially, bioaccumulate in fish, or build up in their tissues, just as they do in humans. And any drug that effects animals eating prey (avoidant aggression?) and reproductive behavior may end up seriously impacting fish populations.

And we already know that something in our pee is messing with aquatic animals: excess estrogen being eliminated by women taking birth control or hormone therapy can contribute to reproductive messes including the so-called "feminization" of fish and frogs. Intersex fish like males with eggs in their testes have been found in many urban and suburban waterways like the Potomac river.

But humans aren't the only ones eliminating extra estrogen: bodies of water near large industrial livestock farms contain unusually high levels of the hormone -- in some cases, a thousand times higher than found in human sewage plants due to natural and synthetic hormones flushed out in cow waste. Some of these hormones leach into soil and groundwater and could contaminate drinking water for humans.

Exposure to excess estrogen increases women's risk of breast and ovarian cancer and can lead to smaller generals and lower sperm count in males, so that should be enough to worry you no matter what your gender.

The United States Environmental Protection Agency labels pharmaceutical contamination as an emerging concern and believes some drug chemicals may pose risks to wildlife and humans. Although compounds in waste drinking water are not federally monitored, a dozen pharmaceuticals are currently on the EPA's contaminant candidate list, which may lead to future regulation under the Safe Drinking Water Act and a call for more advanced water treatment facilities.

Either way, the evidence suggests that we may need to look more closely at the importance of the non-lethal pollutants in our own waste. Just because it leaves the body doesn't mean it leaves the planet.

 Ending Dialogue

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