Ocean Pollution: Antidepressants' Fingerprints

Antidepressants are among the many pharmaceutical drugs polluting oceans and other natural bodies of water. This is due to wastewater treatment facilities not being equipped to remove drugs from sewage, as well as the improper disposal of unused drugs, which are often flushed down the toilet. The presence of antidepressants in the water has been shown to affect the behaviour of sea creatures, such as shore crabs, and can also impact the reproductive cycles of aquatic organisms. With the ocean being a potential source of new antidepressant drugs, the pollution of marine ecosystems by antidepressants is particularly ironic and concerning.

Unused medication disposal

Proper disposal of unused medication is critical to prevent it from falling into the wrong hands and to reduce pollution of natural bodies of water. According to a report by Jessica Firger, a staff writer at Newsweek, at least half of the medications we bring into our homes go unused and are simply thrown out or flushed, leading to pharmaceutical pollution in oceans, lakes, rivers, and streams.

To address this issue, several drug disposal options are available to the public. Drug take-back programs, offered by the U.S. Drug Enforcement Administration (DEA) and pharmacies like CVS and Walgreens, provide secure kiosks or drop-off boxes where people can bring their unused or expired medications for safe disposal. These programs help keep drugs out of the water and prevent drug diversion for recreational or illegal purposes. Additionally, some pharmacies offer drug mail-back envelopes that can be filled, sealed, and mailed back for proper disposal.

For at-home disposal, it is recommended to follow the instructions provided with the prescription or consult a healthcare professional. While flushing medications is generally discouraged, certain medications on the U.S. Food and Drug Administration's (FDA) "flush list" should be flushed if no other disposal options are available. Most other medications can be thrown into the household trash after being removed from their original containers and mixed with undesirable substances like coffee grounds or cat litter. Personal information on prescription labels should be scratched out before disposal.

Another at-home option is to use drug deactivation products like DisposeRx®, which turns medications into a biodegradable gel that can be safely discarded. These packets are available at select CVS and Walgreens pharmacies and are provided for free at Walgreens locations without safe medication disposal kiosks.

By utilizing proper disposal methods, we can help protect our environment and ensure the safe and responsible disposal of unused medications.

Antidepressants in wastewater

Antidepressants are a widely prescribed group of pharmaceuticals that can be biotransformed in humans into biologically active metabolites. These metabolites are then excreted and can enter sewage treatment plants, where they are only removed at low rates. This means that they are released into the environment, including oceans, and can be detected in municipal wastewater and in surface waters downstream of wastewater discharges.

A study by Metcalfe et al. in 2010 analysed the distribution of six antidepressants (venlafaxine, bupropion, fluoxetine, sertraline, citalopram, and paroxetine) and five of their metabolites in a municipal wastewater treatment plant (WWTP) and at sites downstream of two WWTPs in the Grand River watershed in southern Ontario, Canada. The antidepressant compounds present in the highest concentrations (>0.5 µg/L) were venlafaxine and its two demethylation products, O- and N-desmethyl venlafaxine. These compounds persisted in river water samples collected at sites up to several kilometres downstream of WWTP discharges.

Another study by Castillo-Zacarías et al. in 2021 investigated the occurrence of antidepressants in urban and non-urban waters and their impact on aquatic species. They found that antidepressants and their metabolites have been detected in municipal wastewater and in fish tissue, with several effects reported on exposed aquatic species, including impacts on gene transcription, reproduction cycles, predator defence, and motility.

The COVID-19 pandemic has also contributed to an increase in antidepressant consumption, leading to higher levels of these pharmaceuticals in wastewater.

The presence of antidepressants and other pharmaceuticals in the ocean is a growing concern. While there is currently no evidence of harm to humans, studies have shown adverse effects on aquatic life, including changes in behaviour. Additionally, water treatment facilities are not equipped to filter pharmaceutical waste from the water supply.

Effects on aquatic life

Antidepressants are one of the most commonly prescribed pharmaceutical classes for the treatment of psychiatric conditions. They act by modulating brain monoaminergic signalling systems (serotonin, norepinephrine, and dopamine), which are highly conserved across diverse animal phyla. This means that aquatic organisms, such as fish, are likely to be affected by these chemicals in the water.

Indeed, studies have detected the presence of antidepressants in various water sources, including lakes, rivers, streams, and oceans. These drugs enter the water through various pathways, including human excretion, improper disposal of unused medications, and agricultural runoff. For example, a U.S. Geological Survey study found contamination levels downstream from drug manufacturing plants in New York State that far exceeded those at comparable facilities.

The presence of antidepressants in the aquatic environment has been shown to have detrimental effects on fish and other aquatic organisms. Research has found that environmental levels of antidepressants can alter fish behaviour, which is significant as their ability to acquire food, seek shelter, and breed relies on nuanced movements. Antidepressants can also influence the hormones that guide the development and function of reproductive tissues, potentially impacting the quality and abundance of fish eggs and sperm.

Furthermore, early-life exposure to antidepressants can leave long-lasting impressions on fish development. For example, Prozac (fluoxetine) has been shown to influence how fish produce cortisol, a crucial stress hormone. Antidepressants have also been found to influence how fish grow, which could reduce the ability of smaller fish to survive in the wild. While the specific mechanisms are still being studied, there is growing concern about the potential impact of antidepressant pollution on aquatic ecosystems and the biodiversity within them.

To address this issue, some initiatives have been implemented, such as drug take-back programs that allow people to dispose of unused medications properly, and guidelines discouraging hospitals and nursing homes from flushing unused drugs. However, more comprehensive solutions are needed to mitigate the pollution of oceans and other water bodies by antidepressants and other pharmaceutical waste.

Pharmaceuticals in drinking water

Antidepressants and other pharmaceuticals are increasingly being found in drinking water, raising concerns about their potential impact on human health and the environment. While the levels of pharmaceuticals in drinking water are generally very low, in the parts per trillion, there is a lack of understanding about the effects of chronic exposure to these drugs over time.

Pharmaceuticals are chemical compounds found in prescription medications, over-the-counter drugs, and veterinary medicines. These chemicals can enter the water supply when they are excreted by people taking these medications or when unused drugs are flushed down the drain or toilet. Conventional wastewater and water treatment methods often fail to completely remove these pharmaceuticals from the water, leading to their presence in drinking water supplies.

A study by Chris Metcalfe, a professor of environmental and resource studies at Trent University in Peterborough, Ontario, found traces of six antidepressants downstream from wastewater treatment plants on the Grand River in southern Ontario. This study adds to the growing body of evidence that pharmaceuticals are indeed present in our water supplies.

In addition to antidepressants, other pharmaceuticals such as antibiotics, contraceptives, ibuprofen, caffeine, and hormones have also been detected in drinking water. The sources of these pharmaceuticals in the water include drug manufacturing, agriculture, and healthcare institutions, particularly nursing homes, where medications are often flushed down the toilet after a patient's death or transfer.

The presence of pharmaceuticals in drinking water has sparked concerns among experts about the potential risks to human health and the environment. While there is no definitive evidence of harm to humans, studies have shown adverse effects on aquatic life. Advanced water treatment methods such as ozonation, granular activated carbon (GAC), reverse osmosis, and nano-filtration (NF) have been found to effectively remove more than 99% of targeted pharmaceuticals from water. Proper disposal of unused medications is also crucial in reducing pharmaceutical concentrations in water resources.

Pollution solutions

While the focus is on pollution solutions, it is important to first understand the sources of pharmaceutical pollution. The ocean, a common target of pollution, is polluted by medication in a variety of ways. Many unused and discarded medications are thrown out in the trash or flushed down the toilet, with the chemicals from these drugs eventually making their way into the ocean. Additionally, medication that is excreted through human urine and stool can also contribute to pharmaceutical pollution in the ocean. The manufacturing of drugs and agricultural practices, such as the use of hormones and antibiotics in livestock, are other sources of medication pollution.

Now, let's discuss some solutions to address this issue:

• Medication Disposal Programs: Implementing and promoting drug take-back programs can provide a safe and environmentally friendly way to dispose of unused medications. These programs allow individuals to drop off their unused drugs at central locations, preventing them from being flushed or ending up in landfills, which can lead to ocean pollution.
• Guidelines and Regulations for Institutions: Federal guidelines should be established and enforced to prevent healthcare institutions, such as hospitals and nursing homes, from improperly disposing of unused medications. This includes flushing drugs down the drain or toilet. Regulations should also address the disposal practices of drug manufacturing plants to reduce contamination levels in nearby water bodies.
• Improved Wastewater Treatment: While not currently equipped to handle pharmaceutical waste, investing in and developing advanced wastewater treatment technologies can help remove medication chemicals from water before it enters natural water bodies, including the ocean.
• Reduced Medication Usage: Encouraging individuals to use medication only when necessary and to properly dispose of any unused portions can help reduce the overall amount of medication entering the waste stream. This can be achieved through educational campaigns and initiatives promoting responsible medication usage and disposal.
• Alternative Disposal Methods: Educating the public about proper medication disposal methods can help redirect medications from landfills and sewage systems. This includes providing clear instructions on how to dispose of different types of medications safely, such as through hazardous waste programs or specific pharmaceutical waste streams.
• Agricultural Reforms: Implementing stricter regulations on the use of hormones and antibiotics in agriculture can reduce the amount of medication entering the groundwater and waterways. Encouraging sustainable farming practices and alternative methods to promote animal health can help reduce the environmental impact of medication runoff from agricultural sources.

These solutions require a combination of individual action, improved regulations, and technological advancements to effectively address the issue of medication polluting the ocean. By working together and prioritizing the protection of our oceans, we can make a significant difference in reducing the impact of pharmaceutical pollution on marine ecosystems.

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