Are Fish and Plants on Antidepressants?

Prozac: an antidepressant with Fluoxetine. Image courtesy of Wikipedia Commons
Prozac: an antidepressant with Fluoxetine.  Image courtesy of Wikipedia Commons.

Prozac: an antidepressant with Fluoxetine. Image courtesy of Wikipedia Commons.

What happens when people take prescribed medications?  The obvious, immediate effect is helping the person with their ailment, but unfortunately, drugs are also getting into the environment through wastewater and are harming aquatic life.  When people are prescribed pharmaceuticals, the patients’ assumptions are that their bodies absorb all of the chemicals and that is what causes them to feel better.  In actuality, the body usually interacts with the medication, but the active chemical can sometimes remain undisturbed and is eventually secreted from the body as waste in the bathroom.  The water is then treated, but not on a small enough scale to filter out most pharmaceuticals.  Once the wastewater is integrated into lakes and streams, the drugs are still present in the water and wildlife is exposed to human medication.

One type of drug that is consistently found in aquatic environments is fluoxetine.  Fluoxetine is the active ingredient is Prozac, an antidepressant medication that can also be used to reduce the negative symptoms of anxiety and obsessive-compulsive disorders on patients.  Fluoxetine works by increasing the activity of serotonin in the brain, a chemical responsible for giving people a sense of happiness.

When aquatic animals are exposed to fluoxetine, serotonin activity is not the only body function altered, unlike in humans.  In a study done by Maria Gonzalez-Rey, a researcher at the Center for Marine and Environment Research in Portugal, mussels exposed to fluoxetine and other commonly found drugs in the environment had complications that resulted in DNA damage and growth problems.  Medications are tailored to alter the chemicals in the human body, but as seen with mussels in particular, the same chemicals can also affect animal differently.

Fluoxetine accumulates in fish’s livers, brains, and muscles where it not only alters their bodies physically on a small, molecular scale with DNA, as previously discussed, but also has huge effects on their mood as a side effect.  Male fish were observed to be more aggressive, seek isolation, and continuously do repetitive behaviors. Since the males were so aggressive, reproduction became limited and many of the female fish died.  Additionally, when the animals were exposed to just fluoxetine, the anxiety levels were altered.  This has the potential to be tragic because the animals will have decreased perceptions of threats and become targets in the food chain.

Are these experiments actually representative of what happens in the environment?  While it seems like these responses from animals are drastic, proper dosages that are actually observed in nature were used.  One of the major problems with fluoxetine in the environment is that it does not break down easily.  When testing many types of pharmaceuticals in water, fluoxetine had the longest attenuation rate, which means that it does not break down as fast as other pharmaceuticals found in the water.  So as more people are prescribed Prozac, fluoxetine accumulates in the environment causing concentrations to rise.

After traveling through streams and rivers, fluoxetine can then gather in soil and can be taken up by plants.  In a study used to test how fast pharmaceuticals break down in soil, fluoxetine was one of the most persistent and was still completely present after 40 days.  The plants growing in the soil then incorporate fluoxetine in their roots.

Fluoxetine in plants can have a huge effect on humans.  Since one of the main sources of nutrients for people is through plants, people can indirectly consume this medication.  Fluoxetine was notably present in roots, which people eat regularly in beets, carrots, and potatoes.  In order for a human to consume fluoxetine through food, the soil would have to be contaminated, but even then the concentrations would not be as high as an actual prescribed dosage.  In the future, as contamination increases, the concentration will increase and people will be more at risk.

Unfortunately, fluoxetine is not the only medication that is accumulating in the environment.  There are antibiotics, anti-convulsants, hormones such as estrogen, and mood stabilizers in addition to antidepressants.  This accumulation of medications in water calls for the improvement of water treatment filtration.  Since people need medication, the only viable solution is to fix the filtration systems.  Some cities are starting to reuse waste water and redistribute as drinking water, which poses a huge threat to humans when there are residues of old medication still present.  The problem of pharmaceuticals not being properly filtered out through water treatment facilities is already harming the environment and aquatic organisms, but is beginning to pose a threat to humans as well.

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