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  (Source: The Aquatic Room)

  (Source: Wordpress)
Antidepressants could ruin the ecosystem

While antidepressants are made to improve people's mental health, the opposite reaction seems to be occurring in shrimp, which become five times more likely to commit suicide when exposed to the drug fluoxetine. 

Shrimp who show normal signs of behavior typically swim away from the light due to the fact that birds and fisherman are usually waiting to catch them in well-lit open areas. But when shrimp come in contact with fluoxetine in the water, they begin to swim toward the light putting themselves in harms way

Fluoxetine is released into the water by human excrement in waste water that is carried out to sea. What biologists are worried about is if enough shrimp come in contact with the antidepressant, it could cause a decline in the population, which could ultimately detriment the entire ecosystem.  

"Crustaceans are crucial to the food chain and if shrimp's natural behaviour is being changed because of antidepressant levels in the sea, this could seriously upset the natural balance of the ecosystem," said Alex Ford, a marine biologist at the UK's University of Portsmouth. "Much of what humans consume you can detect in the water in some concentrations. 

"We're a nation of coffee drinkers and there is a huge amount of caffeine found in waste water, for example. It's no surprise that what we get from the pharmacy will also be contaminating the country's waterways."

Ford began experimenting with this antidepressant problem when he found that a certain parasite could cause behavioral changes in shrimp by altering their serotonin levels. He started exposing shrimp to a small amount of fluoxetine to see if human antidepressants would affect them the same way and also wanted to know how much of this drug it would take to make them change their behavior. He found that this small amount was enough to make the shrimp harm themselves. 

"Effluent [outflowing waste water] is concentrated in river estuaries and coastal areas, which is where shrimps and other marine life live," said Ford. "This means that the shrimps are taking on the excreted drugs of whole towns."

But shellfish, like shrimp, seem to be returning the favor by exposing humans to unsafe levels of toxins as well, according to the U.S. Environmental Protection Agency (EPA).

The EPA held public hearings yesterday to review "a proposed safe exposure limit for dioxin," which is a common pollutant and waste product from smelting, chlorine bleaching, pesticides manufacturing and incineration. Adults obtain dioxin by eating shellfish, meat and dairy, and then pass it on to fetuses in the womb. According to the Environmental Working Group, adults are exposed to 1,200 times more dioxin than what they consider is safe. Furthermore, through nursing, infants consume 77 times more dioxin than what is considered safe for babies. High levels of ongoing exposure can lead to diabetes, heart disease, cancer, early menopause, reduced testosterone and endometriosis. 

Between the increase in antidepressant prescriptions in recent years and the new studies surrounding dioxin levels and their effects on humans, the exchange of toxins between people and shrimp have become hazardous to each one's health, and in some cases, fatal. 

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Where do we begin....?
By tmouse on 7/15/2010 1:09:15 PM , Rating: 3
Let's start with the title:
Pollutant in Water Making Shrimp Suicidal, Putting Babies at Risk

Did anyone else think that shrimp were becoming suicide bombers and targeting children?

Now let's go to Dr. Fords work, he finds " this small amount was enough to make the shrimp harm themselves. " Is that metric or US? Was he implying the shrimp were trying to commit suicide (is he a shrimp whisperer?). He then goes on to assume that the water ways where the shrimp are is at; or will be at this small amount before the compound breaks down. He points out how much caffeine we ingest and excrete, are the shrimp getting jumpy from all of that caffeine? I am assuming the UK drinks more caffeinated drinks than uses antidepressants. I know the weather can get pretty glum there but is he actually suggesting people will be excreting enough antidepressants to raise ocean levels up to pharmacologically active levels? fluoxetine breaks down to alpha-[2-(methylamino)ethyl]benzene methanol. While its reasonably stable in concentrated form and actually inhibits its own breakdown by P450 enzymes in the body it still needs to be kept from light and below room temperature to remain stable and active. I highly doubt the diluted somewhat metabolized waste products will be excreted in high enough amounts on a daily basis to bring waterways up to effective doses. It's a HUGH leap from showing the active, pure compound has an effect in shrimp, and the observation that we do excrete some active compound to assuming the diluted material, which is exposed to numerous other reactive substances, different pH and light will remain stable and active and accumulate enough to effect the environment.

RE: Where do we begin....?
By geddarkstorm on 7/15/2010 2:42:25 PM , Rating: 2
Here's the actual study, which you should read before saying such things

They tested 10ng/L to 10ug/L and found 100ng/L (100 parts per billion) had the biggest effect on making the shrimp suicidal. At the same time, they cite:
"Several studies have detected environmentally relevant concentrations of fluoxetine ranging between 0.012 and 0.54 µg/L ([Chen et al., 2006], [Gagne et al., 2006], [Glassmeyer et al., 2005], [Kolpin et al., 2002], [Metcalfe et al., 2003] and [Weston et al., 2001])"

So then, the levels of active fluoxetine secreted into water systems are biologically relevant and high enough to impact crustaceans in a negative way.

RE: Where do we begin....?
By tmouse on 7/16/2010 9:12:00 AM , Rating: 2
Ok did you read the part where they mentioned that the behavioral alterations responded in a non-monotonic concentration response curve? The majority of the references you sited showed levels well below that dose. The problem I have is this is being played up as the next environmental disaster when the doses are minimal at best. There are an equal number of studies finding less than 10 ng/L levels. Is the inclusion of active pharmacological substances into the waste water a problem, yes, we abuse antibiotics and antidepressants and other compounds. But the DT article is pure crap in the way this is being presented.

RE: Where do we begin....?
By geddarkstorm on 7/16/2010 12:45:14 PM , Rating: 2
But, notice where even 10 ng/L had a significant effect in one of their trials, and that all values were higher (though we are constrained to talk about significance statistically, rightly so!, so that only 100 ng/L can we be conclusive about) at any amount of the drug being present verses baseline. 100 ng/L was most potent, but most biologically active compounds have such a response curve where pharmacological effects trail off at higher or lower values (usually a new "side effect" starts up at the higher values).

Also, those weren't cited by me, but the authors of this study; I quoted it straight from their paper. Not all places will have concentrations that high, -but some do-, and the real point is that it shows that this drug taken by us can enter the environment and survive at high enough concentrations to effect other organisms. This is contrary on principal to your earlier statements. Again, it simply shows it happens, and can happen, if we are careless.

Yes, you are completely right that the DT article is terribly over sensationalized, like almost all news generally is, so I'm not surprised. I also think the authors of the study, if the quotes are accurate, were over sensationalizing things. None the less, this is an important study in this growing field of observing our own drug uses passing into the environment at pharmacological relevant levels. It's also interesting on a purely biological level, that our drugs can effect other wild organisms in a totally contrary way to their effects in us; and then how this ties in to parasites and what they do to alter the shrimp.

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