The pharmaceutical industry is one of the largest and most lucrative industries in the world, valued at over $1.2 trillion globally. With all the attention on the exciting Research and Development (R&D) process of creating new vaccines, therapies, and antibiotics, there is little speculation on what happens to medications after they are used. How are drugs disposed of? Where does pharmaceutical waste go?
Sources of Pharmaceutical Remnants
Almost 50% of Americans take prescription drugs, and that number is steadily climbing. Drug abuse, especially of synthetic drugs, is also at an all-time high. What most people are unaware of is that between 30% and 90% of the active ingredient of an ingested drug gets excreted back into the environment, meaning drugs that are meant for humans and animals end up in the ecosystem and inevitably affect various other populations.
Agricultural antibiotics, given to crops, emit runoff, further adding manmade antibiotics and compounds into the environment. The metabolites of many drugs often remain active in the environment long after they are excreted, resulting in concentrations of manufactured chemicals that are dangerous to all kinds of flora and fauna.
In 2015, metformin, a drug used to treat diabetes, was found in alarming quantities in Lake Michigan, three miles away from the sewage treatment plants. Upon examining the effect of the drug on fish in the lake, it was found that male fish were expressing a gene related to egg production, indicating that metformin was having a feminizing effect on male fish, decreasing their reproductive ability.
Unfortunately, problems like these go unnoticed unless there is a population crash in a larger or more noticeable animal. Oftentimes, affected populations, such as algae or sea lice, are not in the public eye, yet they form the crucial bases to important food chains that necessarily affect other organisms.
One Extreme: The Indian Vulture Crisis
Such a population crash occurred in India between 1996 and 2007. Diclofenac, an anti-inflammatory drug, is often given to livestock to treat the fever and pain from disease or wounds. In India, cattle are fed diclofenac, but because cows are sacred in the Hindu religion, which is practiced by around 80% of the Indian population, the carcasses of dead cattle are often left out for vultures to feast on. Vultures of the genus Gyps happen to be particularly sensitive to diclofenac, however, and somewhere between 10 million and 40 million vultures died from abdominal gout and acute kidney failure in about 10 years. Three particular species of Gyps vultures declined by over 95% in population; they are now critically endangered in Asia.
What effect did this have on the larger ecosystem? As the natural animal disposal system in India, vultures played an important role in public sanitation, and their disappearance has resulted in a number of problems. Other scavenger populations such as rats and wild dogs have grown in place of vultures, but their metabolic systems are not as efficient as vultures’ in killing pathogens. Furthermore, feral dogs attract leopards, their predator, into human spaces, leading to more conflict.
Diclofenac has been banned for veterinary use in India, Nepal, and Pakistan, but remains available by prescription in the United States. Though incidents like the Indian vulture crisis are uncommon, they serve as warning signs of the potential escalating effects of pharmaceutical residue. Often, it takes an event as drastic as the 95% decline in the Gyps vulture populations for a drug to be pulled from store shelves, but smaller, more subtle effects of antibiotics entering the environment, like the growing microbial resistance to antibiotics, are less visible and perhaps more dangerous.
From the private sector, there has been evidence of biotech companies actively stepping up to reduce antibiotic wastewater, whether by installing new wastewater treatment technology to absorb or chemically destroy antimicrobials, or by vacuum cleaning residual powder from production equipment instead of washing it down the drain.
Though these measures are undoubtedly impactful, it remains an issue that most pharmaceuticals enter the environment through the excretion of ingested drugs. Tackling the root of the problem, then, involves creating medications from more organic ingredients and leaving out manmade or unnaturally extracted elements like halogens that persist for a long time in the ecosystem.
America has become so reliant on medications -- and especially the expedient development of new medications (e.g. rapid development of a COVID-19 vaccine) -- that to prolong an already painstakingly long R&D process by asking researchers to find other, more organic ways to create medications seems unfair. However, we must keep the dangers of introducing synthetic or otherwise harmful chemicals into the environment in mind before hurtling forward in the continuous development of new pharmaceuticals that could very well be destroying our world as we know it.