Evaluation of human pharmaceutical emissions and concentrations in Swedish river basins

- An emissions inventory of 54 human pharmaceuticals was done for Sweden.
- The top ten emitted pharmaceuticals are emitted in loads > 0.5 ton/y.
- Metformin, Gabapentin and Atenolol had the highest emissions to both water and soil.
- Concentrations in water of the most consumed pharmaceuticals were predicted.
- Predicted water concentrations were > 100 ng/L for 4 substances in Stockholm area.

An emissions inventory for top consumed human pharmaceuticals in Sweden was done based on national consumption data, human metabolic rates and wastewater treatment removal rates. Concentrations of pharmaceuticals in surface waters in Swedish river basins were predicted using estimated emissions from the inventory and river discharges. Our findings indicate that the top ten emitted pharmaceuticals in our study set of 54 substances are all emitted in amounts above 0.5 ton/y to both surface waters and soils. The highest emissions to water were in decreasing order for Metformin, Furosemide, Gabapentin, Atenolol and Tramadol. Predicted emissions to soils calculated with the knowledge that in Sweden sludge is mostly disposed to soil, point to the highest emissions among the studied drugs coming from, in decreasing order, Metformin, Paracetamol, Ibuprofen, Gabapentin and Atenolol. Surface water concentrations in Sweden's largest rivers, all located in low density population zones, were found to be below 10 ng/L for all substances studied. In contrast, concentrations in surface waters in Stockholm's metropolitan area, the most populous in Sweden, surpassed 100 ng/L for four substances: Atenolol, Metformin, Furosemide and Gabapentin.

151