I just finished taking anti-biotics for my cough. It started as a viral infection but it continued for more than two weeks prompting my doctor to prescribe anti-biotics for five days.
While the medicine helped my body fight bad bacteria, portion of it will be discharged to the environment. How’s that? According to studies, it is estimated that 30–90% of antibiotics are excreted from the body in the form of parent compounds or main metabolites, along with feces or urine. Our septic tanks or wastewater treatment plants cannot totally remove these pharmaceutical product residues.
According to a McGill University-led study, millions of kilometres of rivers around the world are carrying antibiotic pollution at levels high enough to promote drug resistance and harm aquatic life. Published in PNAS Nexus, the study is the first to estimate the scale of global river contamination from human antibiotics use.
Researchers calculated that about 8,500 tonnes of antibiotics, around one-third of what people consume annually, end up in river systems around the world each year even after in many cases passing through wastewater systems. The research team used a global model validated by field data from nearly 900 river locations.
The study found that amoxicillin, the world's most-used antibiotic, is the most likely to be present at risky levels, especially in Southeast Asia, where rising use and limited wastewater treatment amplify the problem.
I found a study done here in the Philippines about this subject. The title of the study is “Emerging pharmaceutical contaminants in key aquatic environments of the Philippines” authored by Shyrill Mae F. Mariano, Luisa F. Angeles, Diana S. Aga, Cesar L. Villanoy, and Caroline Marie B. Jaraula.
Areas studied were two watershed continuums (Davao Gulf, Davao City; Macajalar Bay, Cagayan de Oro City), two tourist areas (Boracay Island, Aklan; Mabini, Batangas) and one pristine atoll (Tubbataha Reefs, Palawan).
The results show that caffeine and acetaminophen (also called paracetamol) were the most detected pharmaceuticals and personal care products (PPCPs) in the study. Caffeine is considered a drug, specifically a stimulant. Caffeine was even detected in the pristine atoll, Tubbataha Reef.
Sulfamethazine, a commonly used veterinary antibiotic, was detected at 764.91 ppb in a river site in Cagayan de Oro. Untreated hospital wastewater contained metformin, iopamidol, sulfamethoxazole, acetylsulfamethoxazole, ciprofloxacin, and azithromycin, but these pharmaceuticals were not detected in other river and coastal waters. The study can be read in full at https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2023.1124313/full.
These studies show pollution not seen by the naked eye is present in the environment and may contaminate even our drinking water. Aside from potential health impacts, pharmaceutical pollution can also cause ecosystem disruption and antimicrobial resistance.
To address this type of pollution, there must be proper disposal of unused medication, improved wastewater treatment, strict regulation and manufacture of eco-friendly drugs.