•New challenges in MSW management in Tehran after the COVID-19 pandemic was studied.•Over 5.5 millions of PPEs are being daily discarded in Tehran during COVID-19.•Hospital wastes are being disposed of without undergoing any treatment in Tehran.•Landfilling of MSW has increased by 34.7% after the outbreak of COVID-19.•Secondary contagion from improper management of MSW is probable in Tehran.