Pharmaceutical Wastes as Emerging Groundwater Contaminants: A Review of Their Sources, Fate, Health Impacts, and Techniques for Analytical Detection and Treatment

Pharmaceutical wastes are emerging as significant groundwater contaminants, raising concerns over their long-term impacts on public health and ecosystems. This review examines the major sources of contamination—such as wastewater treatment plants (WWTPs), septic systems, industrial discharges, and agricultural runoff—and explores how physicochemical properties and subsurface interactions influence their environmental fate. Although advanced analytical tools, such as liquid chromatography–tandem mass spectrometry (LC-MS/MS), have improved detection at trace levels, challenges in effective removal persist. Frequently detected contaminants include non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, antidepressants, and hormone-disrupting compounds, often present in concentrations ranging from nanograms to micrograms per litre. Promising treatment technologies, including advanced oxidation processes and activated carbon adsorption, are discussed alongside their limitations. This review highlights the urgent need for comprehensive monitoring programmes, cost-effective remediation methods, and further investigation into the chronic effects of low-dose pharmaceutical exposure.