Estimating environmental exposure to analgesic drugs : A cross-sectional study of drug utilization patterns in the area surrounding Sweden's largest drinking water source

Use of pharmaceuticals is continuously increasing globally and their residues are recognized as a risk for theenvironment. The aim of this study was to investigate drug utilization patterns of analgesics in relation toenvironmental hazard in the region surrounding Sweden’s largest drinking water source, Lake Mälaren. This wasexamined using sales data on pharmaceuticals from the Swedish E-health Agency. The total sales of analgesics(non-steroidal anti-inflammatory drugs, paracetamol, other non-opioid analgesics, and opioids) for both humanand veterinary use in the region were analyzed for the years 2016 to 2020, in relation to the inherent environmental hazard for each active pharmaceutical ingredient (API). We found that a total of 454 tons of analgesicswere sold in the region during these 5 years. Classifications of environmental hazard were available for 16 out ofthe 45 studied APIs, accounting for 98.8% of the total mass in kilograms. Paracetamol, ibuprofen, and acetylsalicylic acid, which are all classified as low-hazard compounds, were the most commonly sold APIs. Diclofenac, the only pharmaceutical classified as high-hazard, was the fifth most commonly sold API, with a total soldmass of 2321 kg. The majority of the total sold mass of analgesics originated from dispensed prescriptions forhuman use in urban areas. Visualization of drug sales for humans and animals in different settings can be used toidentify the environmental burden of pharmaceuticals. Based on our study, we suggest that additional measuresto reduce the impacts of pharmaceuticals on the environment should primarily be directed to prescribing physicians in urban areas and campaigns targeted at the high over-the-counter sales of diclofenac. Moreover, it isimportant to address the fact that many pharmaceuticals currently have limited data on environmental hazard.