## 3 Results
### Global Efficiency Indices
#### 3.1.2 Environmental Efficiency Index per Category  
The results obtained with the CML-IA methodology for the environmental efficiency indices in 2019 and 2020 are presented in detail in Table 3, for each of the eleven impact categories studied. The results obtained show an increase in the environmental impact of the hospital under study as all indices have increased in 2020 compared to 2019, by an average of 9.42%. For the index associated with global warming potential, \(\mathrm{EEI}_{\mathrm{GWP100a}}\), a value of \(6.80\times 10^{2}\) was obtained in 2020, which represents an increase of 9.25% compared to 2019. Amongst all the aspects analysed, the hospital waste production during 2020 represents the greatest increase in impact, with respect to the indices obtained in 2019. That is particularly valid for the \(\mathrm{EEI}_{\mathrm{AD}}\), \(\mathrm{EEI}_{\mathrm{ADF}}\), \(\mathrm{EEI}_{\mathrm{GOP}}\), \(\mathrm{EEI}_{\mathrm{GOP}}\) and the \(\mathrm{EEI}_{\mathrm{AP}}\) indices, in which the contribution of waste production has increased by more than 100%, with respect to 2019. COVID-19 resulted in a doubled production of waste in the hospital in 2020. This translates into a significant change for both the internal hospital waste management and for waste management in the treatment plants. The environmental impact of healthcare waste during COVID-19 makes it clear that better, safer and more environmentally sustainable waste management practices are needed and, above all, good preparation for future pandemics is necessary. [PERSON] et al. (2020) studied the impact of the pandemic on hospital wastewater and concluded that the increase in antimicrobial drug compounds had significantly changed the structure and dynamics of the microbial population in wastewater. In light of the pressing urgency to address environmental sustainability, some good practices to ponder are the use of environmentally friendly packaging, as well as the procurement of safe and reusable PPE (e.g., surgical gloves and masks) and recyclable or biodegradable materials. [PERSON] et al. (2020) analysed the environmental impact of different types of hospital gowns and implemented a pilot circular economy model using non-sterile surgical gowns as the core element of the project. Likewise, one could add the investment in non-burn waste-treatment technologies, such as autoclaves and reverse logistics, to ensure that materials such as plastics can have a second life. The consumption of medical gases has also been a contributing factor to the overall increase in all indices, increasing by 28.26% in 2020 compared to 2019. Medical gases, particularly oxygen, have been essential in the treatment of complications in people hospitalised with coronavirus. Oxygen is manufactured by an industry characterised by a high electricity consumption, as the main element in its production, which increases its environmental impact. Faced with this situation, the best solution would be to produce energy in a more sustainable way. Patient transport was the only aspect that--in 2020--saw a reduced impact on all the indices studied. During the pandemic, the hospital's normal activities were reduced, relegating face-to-face activities and patient monitoring to a minimum due to the high demand for care of patients with possible COVID-19. As a result, most consultations and tests were cancelled in order to minimise patient travel and avoid contact with the hospital environment. In Spain, specific telephone numbers were made available to the public for consultation on COVID-19, in addition to the international emergency number 112. This possibility of virtual health contact became a very significant opportunity for patient relations. The possibility of non-face-to-face care reduces travel and sometimes represents an added advantage related to avoiding the need for family members or companions to request permission to leave their jobs for a few hours, which is a social or work-related advantage.