Environmental impact of COVID-19 Vaccine waste: A perspective on potential role of natural and biodegradable materials.

The mass immunization is the prioritised post-pandemic phase offering preventive countermeasure for COVID-19 pandemic. However, it is crucial to tackle the environmental impact of COVID-19 vaccine waste for sustainable vaccination management because a prolonged immunisation campaign is expected. As the pace of vaccine production, distribution and mass vaccination has been expedited, there is a simultaneous rise in plastic derived vaccine waste including syringes, needles, used/unused vaccine vials, vaccine packaging, and protective gear (surgical facemasks, gloves, face shields, etc). Henceforth, in view of the repercussions of heaping plastic waste in the environment, this article provides a perspective on the usage of synthetic and natural materials as potential substituents for vaccination tools. The biodegradable polymeric gums such as cellulose, gellan, pectin, etc. have been successfully applied for the fabrication of surgical facemasks. The highly suggestive practice is replacement of conventional polypropylene based plastics with bioplastics or paper for vaccine packaging. The usage of biodegradable bio-plastics as packaging material along with environmentally friendly face masks can help to achieve the zero waste approach. The discussion in the article significantly highlights the necessity of opting sustainable solutions of disinfecting and substituting vaccination tools for an environment friendly ongoing vaccination campaign.

Introduction

The humankind is drenched into devastating health implications due to the outbreak of COVID-19 viral disease caused by a novel virus named ‘Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2)’ [1]. In post-pandemic era, scientific community have successfully promoted the counter measures to the contagion COVID-19 through repurposed antiviral drugs for treatment of the infected patients and prevention via attenuated vaccine administration [2]. After uplifting the lockdowns, the major focus was on production, deployment, and injection of COVID-19 vaccines. The WHO in collaboration with medical personnel is currently orchestrating equitable global vaccination campaigns for mass immunization against COVID-19 [3]. As per the “Our World in Data” statistics on May, 1st 2022, 11.59 billion vaccination doses has been globally administered which means 65.4% of the world population has been vaccinated with at least one dose. Also, 10.09 million people are getting vaccinated each day globally and only 15.7% of population in low-income countries have administered single dose of vaccine [4]. Reportedly, different types of waste such as non-biodegradable plastics (disinfectant bottles, single use plastic (SUP) equipment, and packaging material), consumable waste (syringes, needles, and empty vials), and dry ice are the major polluter generated via mass vaccination camps [5], [6].

The inevitable bulk manufacture of vaccines and massive vaccination programs are tempered with the challenge of biohazardous vaccine waste generation. Due to the poor and unready management systems, biohazardous vaccine waste may end up the environment, disrupting the ecosystem at an escalating pace. Since, the key components of vaccination programs are reliant on plastic-based equipment including syringes, needles, vaccine glass vials, alcohol swab and vaccine packaging which have significantly spiked the plastic accumulation worldwide [7]. Additionally, vaccine administration includes the use of personal protective equipment (PPE), such as face masks, protective medical suits, face shields, etc composed of SUPs [8]. Overall, the substantial impact of increasing plastic waste on environment during the real-time vaccination race or due to the general safety measures to prevent COVID-19 cannot be underestimated. Therefore, the possible alternative of developing biodegradable materials like bio-plastics can be potentially utilized for elimination of hazardous plastic waste [6]. In consideration to the backfiring effects on the environment due to COVID-19 vaccine waste, we herein provide a perspective for the development of sustainable vaccination equipment substituents with recyclable, natural and biodegradable materials as an immediate societal need.

Current investigation on coronavirus vaccine waste

It is unknown the level in which vaccination consequences are impacting the environment due to the subsequent waste generation. The countries offering mass immunization campaigns are littered with hazardous biomedical waste [ Fig. 1] including syringes, needles, and waste glass vial, as a threat to increase the rate of SARS-CoV-2 transmission [9], [10]. The consumption of preventive tools i.e. PPE kits and surgical face masks during the vaccination drive have added to the microplastics fibre accumulation in the aqueous and terrestrial environment [11], [12]. In addition, the usage of safety gears is still necessary for healthcare workers in order to prevent the transmission of COVID-19 which is responsible for generating additional waste other than vaccination camps. To provide context, Omran et al., reviewed the amount of solid waste generated from the various COVID-19 related activities in the Kingdom of Bahrain, wherein the calculated amount of vaccine waste generated during the 1st dose of vaccine was 6 million g and above 9 million g after the 2nd vaccine dose against 813,728 and 602,390 vaccinated individuals, respectively until May 11, 2021 [13].

Fig. 1

The possible preventive materials used during mass immunization campaigns.

A plastic pollution survey in Bangladesh aquaculture systems have analysed 11 million metric tonnes of microplastics including, surgical gloves, face masks, polyethylene gloves, hand sanitizer bottles [14]. A life cycle assessment analysis was carried out to estimate the effects of face mask in UK, wherein if each individual used one disposable surgical mask every day for a year, it would cause 66,000 tons of contaminated waste [15]. In addition to the environment challenges induced by extensive use of protective face masks, the discarded vials (fully or partially used) containing thimerosal-mercury based preservative is poisoning the marine animals [16]. The ecological imbalance due to the load of packaging, transportation, and deep-freezing of vaccines have increased CO2 greenhouse gas emission. For instance, in Germany 1100 kg CO2 has been emitted upon injection of one million doses of two mRNA vaccines [17]. The unsustainable vaccine waste mismanagement is also posing serious challenges such as an anticipated implication is the release of noxious gases like furans and dioxins in the environment during the open burning of microplastic waste in the landfills [18]. Appropriate healthcare waste management can facilitate the recyclable waste for instance; autoclaving may assist to lessen the volume of landfill waste [10], [19]. Autoclave treatment involves the direct steam sterilization of virus and bacteria at required temperature and pressure for a particular period of time. As a result, autoclaving of waste from healthcare can improve the recycling efficiency of waste by disinfecting them from deadly virus and bacteria. Additionally, use of disinfectants and 9-day storage approach of healthcare waste in a proper containment zone can substantially reduce the spread of virus among waste management workers [10]. Moreover, waste management for energy production is another alternative tool that can generate value added products by combustion and pyrolysis of healthcare waste [20]. However, subsequent generation of hazardous gases such as CO2, carbon monoxide, nitrogen oxides, sulphur oxide, dioxins, and other volatile organic compounds (VOCs) not only pollutes the air, but also enters into water and soil [21], [22]. Among all other toxic gases, dioxins are more poisonous and reportedly their concentration in flue gases form medical waste incineration is extremely higher than domestic waste combustion [23]. Thus, there is a commensurate need to research for alternatives of healthcare equipment, vaccination tools and protective gear to abate the negative impact on the environment.

Potential substitutes: natural and biodegradable materials

The unprecedented surge in hazardous biomedical waste and SUPs has fostered the requirement to develop natural and biodegradable substitutes of vaccine tools. The reuse of bio-hazardous syringes and needles is not advisable undoubtedly because it could put patients in danger of getting infected with Hepatitis B, Hepatitis C, and possibly HIV and SARS-CoV-2, however the regulation of recyclability and biodegradability should be implemented [24]. Also, the syringes are composed of polypropylene and polyethylene plastics which if not recycled, their disposal may contribute substantially to the hazardous release of dioxins, vinyl chloride and toxic lead and cadmium metals into the soil that stunts the plant growth [25]. From the perception of investment and operation cost, the recyclability of needles and syringes is much higher than production. Henceforth, recyclability is not economical and only a few companies have taken the initiative to recycle needles. In response to the relieving bottlenecks of non-biodegradable needles and syringes, it is suggestive to replace the polypropylene and polyethylene microplastics by bio-plastics.

The bio-plastics partly or wholly composed of oil-based equivalents, sugar cane, pines, and other biological materials are future green innovative approaches to mitigate effects of conventional plastics [26]. With the current success on 3D printing technology the development of ultra-thin polylactic acid needles is fast-evolving and can be an encouraging resort for renewable, biodegradable thermoplastic-based needles. Also, the natural polymers including sodium alginate, cellulose, chitosan, gellan, pectin are potential substituents with high biodegradability for designing of facemasks, anti-viral coatings, protective kits, etc [27]. Meneguzzo et al., extracted the flavonoids of citrus and lemon peels which exhibited high binding affinity to SARS-CoV-2 receptors for disinfection [28]. The next step towards redefining the vaccination programs towards sustainability is to redefine the vaccine packaging process. The repurposing of discarded surgical face masks by thermal blending it with concrete aggregate for pavement base application resulted in co-benefits of waste management and high tensile strength of concrete due to polypropylene [29]. A zero waste approach as the co-benefit of waste management, that promotes the minimising, recovering, and treatment of waste, rather than directly disposing it in landfill or incinerators can also be opted to get rid of burgeoning plastic waste globally. Thus, it is inevitable that the manufacturing industries should emphasis more on the usage of biodegradable or compostable materials (bags etc.) like bio-plastics with considerable degradability and recycling efficiency [30], [31]. Nevertheless, the efforts of short time window availability of multiple anti COVID-19 vaccines are undeniable yet, the use of eco-friendly sustainable substituents for vaccine tools as detailed in [ Fig. 2] should be the imminent subject of research.

Fig. 2

The natural and biodegradable materials used as substituents of vaccine tools.

Conclusions

The advent of COVID-19 mass vaccination programmes has stretched the already existing waste management system beyond capacity. It is imperative to address the issue of massive COVID-19 vaccine waste generation including needles, syringes, vaccine vials, vaccine packaging, single-use-plastic personal (surgical facemasks, gloves, etc.) and protective equipment. Plastic waste pollution was already an enormous challenge, however pandemic and post-pandemic era has alleviated this issue. To nullify the backfiring effects on the environment, the waste management system is practicing disinfection and disposal strategies for instance, incineration, pyrolysis, gasification, dumping in landfills, etc. However, currently there are no 100% effective waste-management technologies for tackling the burgeoning COVID-19 vaccine waste. Consequently, the present research seeks for substitution of the plastic derived surgical face masks, personal protective equipment, and vaccine tools to avoid the further transmission of COVID-19 through vaccine waste. Also, the existing waste management plants and infrastructures must be equipped with artificial intelligence, machine learning, and internet of things in order to improve the segregation and recycling of plastic waste. The recycling of waste via mechanical methods followed by sterilization should be encouraged with appropriate policy design for better circular economy. Moreover, chemical conversion of mixed plastic waste into value-added fuels and chemical products is another potential alternative for circularity. Additionally, considerable focus on natural and synthetic polymers such as gums, cellulose, chitosan and bioplastics which are biodegradable and environmental friendly are important substitute to replace the conventional plastic-based products. The discussion delves into the current practices and future possible sustainable solutions for ongoing COVID-19 vaccination programmes with minimal environment impact.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.