Ari – Year 12 Student
Editor’s Note: Year 12 student Ari writes here for the GSAL Science Magazine, looking at the serious long-term impact of antidepressant medication on the natural environment. More effective water treatment technologies are certainly in the pipeline: is this soon to be an environmental success story? CPD
[Featured image: Antidepressants. (Wallpaper Flare: Free Download)]
The use of drugs to treat depression has brought some happy results to many, while leaving an almost irreversible side effect on our environment. The reason of my focus on antidepressants, as well as other illegal alternatives such as stimulants (i.e. methamphetamines), is because of how common their use is, especially amongst the youth, and hence their more recurrent presence in water resources.
Antidepressants, like many other drugs, are taken via oral capsules. With a common antidepressant like Prozac, its mechanism is a Selective Serotonin Reuptake Inhibitor (SSRI) that works by blocking the absorption of the neurotransmitter serotonin in the brain. By having more control of the amount of serotonin, this will result in a more stable mood, and with time it alleviates the stressful effects of depression. However, it’s very obvious that the drug effect does not last forever: once they have been used, most of them will be released by the body and should be out in 24 hours depending on the dose. Despite the water systems in the Western world being one of the most advanced, many of the chemicals cannot always be removed, and one particular compound is formed as a result of the presence of antidepressants − nitro chloroform.
A study in the US showed how treatment plants remove only about half of the prescription drugs and other contaminants, which, again, is not a very reassuring figure. This contamination seems to only be increasing with the demands of the population, and, unfortunately, the technology is not enough in order to keep up with the pace this contamination is going at. As of now, there’s two main methods used to purify water, which include ozone treatment and carbon filters.
Researchers from the University of Southern California have recently been able to trace down a possible origin for nitro chloroform in water, which links the contamination with antidepressants. Prozac, the most famous, containing an N-methylamine group; ephedrine; methamphetamine react with ozone, and then the amines react to form nitromethane, which during the process of chlorination converts into nitro chloroform. Alluding to my previous point, this use of chlorination when purifying water is so widely used it makes it inevitable for the formation of these chemicals to form.
The ingestion of this compound is carcinogen and toxic to humans, while also repressing the environment by devaluing the quality of the water. For this reasons the US government has put a limit to the exposure, this being 0.1 ppm on an eight-hour period, yet this does not provide a sustainable solution for the future.
The effects of the antidepressant contamination have been studied and is known to have effects on animals, affecting their behaviour. One of these examples includes aquatic organisms such as fish, on which the ecological and evolutionary nature cycles are disturbed, showing a correlation between the contamination and the wellness of these animals. This again highlights one of the challenges that nature fights against -contamination can through food webs. The fish that were exposed to this water with pharmaceuticals such as oxazepam (common opioid used for anxiety), such as the perch, a predator, displayed a decrease in efficiency when catching prey. Another of the effects the exposure to water contaminated with antidepressants can be seen is with birds; the chemicals are able to alter their appetite, showing a similar effect that the consumption of antidepressants can have on humans.
It is not impossible to remove some chemicals from water, but antidepressants, as I have shown, are surely difficult, perhaps irremovable, unless a new implemented treatment surges. Despite all the factors, the research that looks to treat wastewater seems to be promising. Researchers from the University of Hong Kong recently developed a new treatment able to remove pollutants efficiently.
This sparked curiosity in me as it displayed a high potential of this new water treatment, and emphasized the inefficiency of the current treatments used; the novel process is more cost effective than conventional wastewater treatment processes, and can remove more harmful chemicals. For instance, the cost of chemically enhanced primary sedimentation (CEPS) for wastewater treatment is less than a half of that of the secondary wastewater treatment. This also allowed recovering products such as organic carbon and phosphate to later be used in other additional applications, including carbon filters. On the other hand, the acidogenic fermentation of CEPS sludge can further remove other pollutants.
I consider that this is a problem that researchers should tackle more often, and have hopes that the water treatment will eventually become efficient enough to remove all the pollution. Thanks to the environmental awareness social media is creating, more people are waking up and realising the impact that their lifestyle choices might be causing on the environment. This is necessary, in order to prevent further inequalities in the world where perhaps water might become a luxury, instead of a safe refreshing drink. In the meantime, stay hydrated.
 https://doi.org/10.1021/cn400186j 30/05/20
 https://www.chemistryworld.com/news/prozac-and-methamphetamine-likely-responsible-for-toxins-in-tap-water/4011268.article 30/05/20
 https://www.scientificamerican.com/article/only-half-of-drugs-removed-by-sewage-treatment/ 31/05/20
 https://pubs.acs.org/doi/full/10.1021/acs.est.9b04742 31/05/20
 https://www.cdc.gov/niosh/npg/npgd0132.html 31/05/20
 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-151138 30/05/20
 www.sciencedaily.com/releases/2020/03/200330110355.htm 30/05/20