Hospital waste management before and during COVID-19 pandemic: An analysis of the environmental impact of CO2 emissions in four Italian facilities

The COVID-19 pandemic caused a surge in hospital waste (HW), posing an urgent public and environmental health challenge. Although a safe HW disposal method, high temperature incineration of fossil-derived materials contributes to air pollution. We analysed the monthly and yearly HW production of four Italian hospitals between 2016 and 2021, including COVID-19-related waste, to quantify the volume of activity related to COVID-19 patients, and estimate the environmental impact of HW through carbon emissions and social cost of carbon (SCC). A Mann-Kendall trend test and an Interrupted Time Series Analysis to detect trends and level changes in HW production after the COVID-19 outbreak were performed. ISMETT had the highest HW production (average annual variation (AAV) 0.89 kg/bed/day) and a positive correlation between HW generated per patient-day and the proportion of COVID-19-related bed-days. IFO (AAV 0.23 kg/bed/day) and IEO (AAV 0.19 kg/bed/day) both showed an overall increasing trend in HW production; CRH behaved similarly, although reporting the lowest HW production. ISMETT and IFO had the highest SCCs; CRH's SCC slightly decreased in the pandemic biennium, IEO's SCC peaked in 2019 and declined in 2020-2021. Optimizing waste management is vital, as disposal emissions pose significant risks to environmental sustainability and human health.