COVID-19 Precautions Imperils Ecosystems

Introduction

A huge magnitude of medical waste is generated due to the coronavirus disease 19 (COVID-19) pandemic. For instance, hospitals in Wuhan generated six-fold more hospital wastes during the pandemic.¹ India, alone generates about 608 tonnes of healthcare waste per day.² Healthcare waste can be defined as “all the waste generated by healthcare facilities, medical laboratories, and biomedical research facilities, as well as waste from minor or scattered sources, such as home health care.”³ Healthcare wastes is also defined as “any waste, hazardous or not, generated during the diagnosis, treatment, or immunization of humans or animals; or waste generated in research related to the aforementioned activities; or waste generated in the production or testing of biologicals.”⁴ Healthcare waste can be categorized according to the following general classifications:⁵

• Sharps waste
• Pathological waste
• Other infectious waste
• Pharmaceutical waste, including cytotoxic waste
• Hazardous chemical waste • Radioactive waste
• General (non-risk) waste⁵

Discussion

Personal protective equipment (PPE), such as face masks, gloves, goggles, gowns, and aprons have become indispensable items to help protect healthcare professionals from exposure to contaminants and pathogens. Traditionally, the use of PPE was intended for hospital environment for protection against harmful microorganisms. The COVID-19 pandemic has entailed the need to use PPE even in domestic scenario.⁶ This has led to insufficiency in the supply chain, and a rapid aggregation of potentially infectious PPE in domestic solid waste streams.

The production of plastic-based PPE equipment has seen a rapid surge since the COVID-19 outbreak. Between 2016 and 2020, the compound rate of rise in the global market per annum for PPE was 6.5%, ie, from approximately $40-$58 billion.⁷ On the contrary, the World Health Organization (WHO) projected that the supply of PPE must increase by 40% per month to deal the COVID-19 pandemic efficiently. The essential PPE encompasses an estimation of 89 million medical masks, 76 million pairs of medical gloves, and 1.6 million pairs of goggles and face shields. The demand for PPE is expected to increase further substantially even after the post-pandemic era, with an estimated compound annual growth of 20% in facial and surgical masks supply from 2020-2025.⁸

COVID and its impact on dental practice

The generation of non-woven material has drastically increased in the dental set up as most of the dental treatment procedures are aerosol generating and carries a risk of transmission of the novel COVID.⁹ Apart from this, the other consumables used by dentists as PPE, such as gloves, head caps, foot covers, chair covers, X-ray sleeves, patient protective equipment, such as plastic drapes, polyethylene gloves, foot covers, and tray sheets that hold the instruments, cling films, tissues, disposable paper cups, and autoclavable pouches also see a surge in consumption as dental personnel prefer the utilization of disposable products over the reusable ones owing to the stringent precautions required while handling the reusable PPEs and other auxiliary dental products. There is also a demand for more manpower and equipment to disinfect and sterilize the reusable PPEs. Thus, the gravity of the pandemic has increased the gap between eco-friendly dentistry and dental practice. Ecofriendly dentistry, synonymously known as green dentistry is an approach to dentistry that implements sustainable practices by keeping resource consumption in line with nature’s economy, safeguarding the external environment, virtue of eliminating or reducing outgoing wastes, and promoting the wellbeing of all those in the clinical environment by conscious reduction of the chemicals in the breathable air.¹⁰ This review focuses on how the ongoing pandemic has changed the very face of dental waste generation and methods to overcome these to redeem green dentistry.

Composition of PPE

Majority of the PPE comprise of polymeric plastics in their composition, such as polypropylene (PP), polyethylene pteryphthalate (PET), and polyethylene (PE).¹¹ Other common plastics in healthcare waste are low-density polyethylene, high-density polyethylene, and polystyrene.¹² However, as much as 40% of plastic waste in modern hospitals is chlorinated plastics. Decreasing the percentage of halogenated plastics (such as polyvinyl chloride) reduces the amounts of hydrogen chloride and other halogenated pollutants emitted during combustion.¹¹

Unfortunately, many polyvinyl chloride products, such as intravenous bags, tubing, gloves, and enteral feeding sets, are not labelled. The frequent start-up and shut down operations of medical waste incinerators could lower incineration temperatures and cause an increased formation of persistent organic pollutants (POPs), such as dioxin-like polychlorinated biphenyls (PCBs), dioxins, furans, and polycyclic aromatic hydrocarbons (PAHS), which are proved to be carcinogenic.¹³

Strategies for sustainable practice

The various approaches towards sustainable practice can be dealt with in three different dimensions: personnel level, practice level, sterilization, and biomedical waste management (Table 1).

Current trends towards greener alternatives

• Green PET films: PET films constitute 30% of mono-ethylene glycol (MEG) usually extracted from non-renewable petro-based feedstock is now replaced by green MEG that is sourced from bio-ethanol made from renewable agro inputs. These are called green PET films and are the world’s first polyester product for sustainability.¹⁵
• Biological methods of biomedical waste disposal: The emerging system, Bioconverter (Biomedical Disposal, Inc.) uses a solution of enzyme to decontaminate medical waste. The sludge generated is processed through an extruder to remove water for sewage disposal. The remaining solid waste is sent to landfill.^16,17

Environmentally friendly BMW disposal

• Microwave energy: Microwave energy generates moist heat and steam generated, which is used for sterilizing all infectious waste, including human, laboratory, and soft wastes (gauze, bandages, and gowns); and sharps are sterilized in microwave. Microwave used for biomedical waste disposal has the advantage of minimal emissions.¹⁸
• Plasma pyrolysis: Plasma energy is generated from plasma torches. In plasma state, the ionized gas conducts electric current and produces heat energy due to its high resistance. Infectious waste, sharps, plastics, dialysis waste, hazardous waste, chemotherapeutic waste, chemotherapy waste, and lowlevel radioactive waste can be sterilized with plasma-based technology. This system has low emission rate, waste residue is inert and sterile, ie, environment friendly, and there is reduction in volume (95%) and mass (80%-90%).¹⁹
• Lynntech’s ozone technology: Ozone is a strong oxidant; it destroys microbes and converts it into molecular oxygen.¹⁹
• Ionizing radiation: This causes damage to deoxyribonucleic acid (DNA), proteins, and enzymes of microbes by producing free radicals. The waste to be treated are infectious wastes, including human waste, laboratory waste, soft waste (gauze, bandages, and gowns), and sharps. This technique does not produce toxic emission, no liquid effluent, and no ionizing radiation when the equipment is switched off.¹⁹
• Biodegradable plastics for waste management: Many biomedical implants built with biodegradable plastics undergo biological degradation with microbial extracellular enzymes. These microbes utilize these biodegradable polymers as substrate under starvation and in unavailability of suitable substrate. Further research needs to be done for largescale economic manufacture of biodegradable plastics.¹⁹

Conclusion

The quantitative data on the healthcare waste generated at hospital and domestic levels is sparse. The data on this is kept at municipal/corporation/national levels. Much of this equipment is not even properly collected and is right now almost certainly making its way into unmanaged dumpsites in the environment and being burned openly. The magnitude of the impact of COVID has been so huge in the sudden demand in manpower and personnel that the focus has been channelized on rising to this crisis and other aspects, as BMW and recycling of medical wastes have taken a back seat. Success in integrated healthcare waste management will gear our progress towards meeting many of the UN Sustainable Development Goals (SDG), especially to mention— SDG 3 - good health and wellbeing, SDG 6 - clean water and sanitation, SDG 8 - decent work and economic growth, SDG 12 - responsible consumption and production, and SDG 13 - climate action. Thus, emphasizing on the hazards of the consumables used in the dental office and efforts to effectively plan the procurement and utilization of the same is the need of the hour.

Conflict of Interest

None.