The results showed that Covid-19 pandemic has increased the waste generation rate in the studied hospitals. As can be seen in Table 3, the waste generation rate in studied hospitals were not the same; on average, 102.2 % increases were observed for daily waste generation rate in five studied hospitals. The detailed information on waste generation rate in new established ward, Covid-19 ward is summarized in Table 4.
The increased waste generation rate in healthcare centers during Covid-19 pandemic were reported in similar studies . Evidence shows that during an epidemic, as the experience of Covid-19 pandemic emphasize in this period, the municipal solid waste production will change in the future. However, the changes in waste generation have not been same in the different communities . However, increased medical and hospital waste generation rates in all communities is predictable for some reasons including the increase in the number of patients admitted to hospitals. The results of this study showed that although an increase in waste generation was seen in all hospitals, however, the ratio of increase ranged from 0.82 to 3.5 kg/bed/day. In addition, the results showed the average waste generation rates per patient bed in the time before the epidemic and during the epidemic, were found to be 1.77 and 3.46 kg waste per day per bed, respectively.
Another noteworthy point about the results of this study is the increases in the amount of infectious waste in all studied hospitals during the epidemic Covid-19. Given to the increases in total waste production during the epidemic, the ratio of infectious waste in the waste mass has increased in most hospitals; this ratio increased by an average of 9.7 % for the studied hospitals (See Fig. 1).
However, the increases in the use of personal protective equipment by citizens during the epidemic causes the production of waste with the potential infections from the municipal waste [12, 14]; the continuous use of this equipment by the employees and clients, as well as an increase in patients in hospitals leads to increased ratio of infectious wastes in the Covid-19 pandemic. In this condition, hospital waste management will be of particular importance because there is a concern about the possibility of transmitting the disease agent from the waste mass to staff and the community [11, 15].
Considering the increases in waste generation in the studied hospitals and also the increase in the ratio of infectious waste compared to before the Covid-19 pandemic, a change in the hospital waste management activities based the new conditions is necessary to reduce the possibility of disease transmission from the waste mass . The results showed that the management of medical waste in the studied hospitals in the Covid-19 pandemic has a satisfying status, which is due to the proper management of hospital waste as a serious risk to health and the environment in recent decades in Iran . However, in some countries there is concern about the spread of the virus due to poor management of infectious waste . As shown in Table 5, the management of medical waste in the studied hospitals in the stages of segregation, storage, disinfection and transportation shows that the increase in the quantity and infectious potential of waste in Covid-19 pandemic was on range of storage and disinfection equipment in hospitals. The use of autoclave as a common method of waste disinfection in hospitals as well as on-site use of this equipment provides a good model for medical waste management in epidemic. This method of disinfection will reduce the possibility of transmitting the disease agent during the transportation of waste to the final disposal centers. However, an important point in the management of infectious waste due to concerns about the possibility of virus transmission is the reduction of storage time, as reported in South Korea reducing this period from 7 days to less than one day . In all hospitals, due to the appropriate capacity of disinfection equipment, the time of waste storage before disinfection was less than one day, while the collection period of disinfected waste in some hospitals was done after 2–3 days.
An important point in medical waste management is the segregation of infectious waste from the other waste, especially during the pandemic period . In the studied hospitals, by separating Covid-19 ward from other wards, the waste produced in this ward was generally considered as infectious waste and entered the disinfection stages. However, according to the previous procedure in other words, infectious, sharp and pathological wastes were stored and managed separately. Although these conditions can be effective in reducing the risk of transmission of the virus to medical waste mass and finally to the environment, there are some reports that in Covid-19 pandemic all generated waste in the hospital is considered as infectious waste . However, such precautionary plan will depend on the financial situation and available equipment. However, due to the contamination potential of face masks and gloves used by staff, patients and clients , it is necessary to consider special containers to dispose of them separately from the common waste in the hospital. However, this procedure was not observed in the studied hospitals. Based on the classification presented in Fig. 2, taking into account the results of this study and also the use of personal protective equipment by all staff related to hospital waste management and the use of special trucks for waste transport, the status of medical waste management in studied hospitals were evaluated to be in low risk and save status.