Discharges of nuclear medicine radioisotopes in Spanish hospitals

► The hospital of Granada with nuclear medicine transfer radionuclides to the sewerage. ► 99mTc, 131I, 67Ga, and 111In have been detected in the control point of the hospitals. ► The 78.51% of radioactivity discharged that day is due to 99mTc. ► This study shows the differences between direct discharges and after-storage. ► Storage tanks in hospitals with nuclear medicine department must be obligatory.