Glucocorticoids as emerging pollutants in surface water: A systematic review on their global occurrence and distribution.

Glucocorticoids (GCs) are synthetic drugs widely used for treating several diseases with inflammatory pathophysiology. In general, 1-20% of the concentration of GCs initially administered is eliminated unchanged in the urine while still in its active form, and therefore, fractions of GCs are constantly released in effluents. Currently, water treatment plants do not have sufficiently effective technologies to remove these substances completely, favoring the presence of these emerging pollutants in the effluents of wastewater treatment plants. In this context, we conduct a systematic review to identify studies that found GCs in surface water. The general data of the included studies, the GCs found and their concentration, the water body where the GCs were found, and the place and date of sampling were summarized. GCs have already been found in the surface water of 24 countries, mainly China, Malaysia, and the United States. Countries with the highest concentrations of GCs found in surface water were Mexico, India, and Brazil. Betamethasone, budesonide, corticosterone, cortisol, cortisone, dexamethasone, fludrocortisone, fluticasone, hydrocortisone, methylprednisolone, prednisolone, prednisone, and triamcinolone were reported at concentrations ranging from 0.00098 to 24760 ng/L, including in water for human consumption. Revised data showed that the real presence of these substances worldwide is still underestimated, requiring further studies to determine their real distribution. Furthermore, we believe that some strategies can be adopted to mitigate surface water contamination by GCs, such as the intensification of public programs about educational activities related to the rational use of medicines, and the urgent need to improve and expand the water treatment methods.