Pharmaceuticals in leachate from worldwide municipal waste landfills: a review

Pharmaceuticals are emerging contaminants that are commonly found in the environment. They can also be found in leachate from landfills, which enters due to improper handling of pharmaceutical waste (throwing it into the trash). This paper aims to review pharmaceutical's occurrence in leachates from municipal landfills with a particular focus on pharmaceuticals planned for monitoring in surface waters in EU countries, as well as to prioritize the environmental risks associated with individual compounds. The data on the occurrence of individual pharmaceuticals in leachates were grouped into anti-inflammatory and analgesic drugs, hormonal drugs, anticonvulsants and antidepressants, and others. A total of 268 study results were identified, containing determinations of 110 pharmaceuticals, drug components and their metabolites. The largest number of studies concerned diclofenac, carbamazepine, ibuprofen and gemfibrozil, where diclofenac and ibuprofen had the highest concentrations in their group. Three of them (diclofenac, carbamazepine and ibuprofen) will be added to the list of priority substances in surface water, according to a proposed amendment to Directive 2008/105/EC on environmental quality standards for water policy. Risk assessment based on a prioritization index revealed that ten pharmaceutical compounds present in landfill leachates pose a very high environmental risk. These include ibuprofen, 17-beta-estradiol, estrone, and diclofenac. Even treated landfill leachates can be a source of pharmaceuticals in surface waters. Therefore, the need to define standards or guidelines regarding limit values ​​for selected pharmaceuticals contained in treated leachates should be considered, with emphasis on substances presenting the highest ecological risk.