The Healthcare Industry: Plastics, Emissions, Surgery and Sustainability 

By Nathan D. Wood, Dr. Robert Moorcroft, and Dr. Torill Bigg of Tunley Engineering

Abstract

Key unaddressed issues of sustainability within healthcare include high volumes of waste plastic, and the use of anesthetic gases with a high greenhouse gas potential.  This white paper explores the role of plastic in healthcare, offering alternative materials. Analyzing waste management allows identification of recyclable plastics to reduce the open loop plastic waste.  The energy and waste intensive field of surgery is discussed, highlighting the contribution of anesthetic gases to the carbon footprint of surgery, alongside the identification of low carbon alternatives. 

Introduction

NHS England estimates that it is responsible for 4-5% of England’s carbon footprint. With current global consensus moving towards net-zero emissions, it is imperative that healthcare plays a significant role [1]. Reducing the carbon footprint of healthcare could play a vital role in meeting climate targets, with NHS England pledging to become one of the first net-zero healthcare providers by 2040 [2].

The versatile class of materials, plastics, have become an integral component of modern medicine. Plastics, in various forms, find extensive use within medical consumables [3]. Many plastic items used within a medical context are “single-use”, with estimations showing that only 5% of plastic waste used within the healthcare system of the United Kingdom is recycled[4]. In contrast, only 15% of medical waste is classed as being biohazardous, which requires incineration due to biosecurity concerns[4]. 

It is projected that while plastic use and waste disposal plays a substantial role within the carbon footprint of healthcare (< 30%) [2], one of the main contributors to healthcare emissions is the use of anesthetic gases. Global estimates place the use of anaesthetic gases as being equivalent to one million cars being on the road [5]. Anesthetic gases such as nitrous oxide and desflurane are the single biggest contributor to NHS England’s carbon footprint, accounting for ~40% of the total emissions [6]. These anesthetic gases have a much higher CO2e, for example desflurane has a CHG potential 2,540 times greater than carbon dioxide. However, finding alternatives or changing working practices   of anesthetic gases is more complicated than reducing the use of plastics due to the regulatory framework around anesthesia.

Medicine is made up of many divisions (Paediatrics, Neurology, etc.).  The field of surgery is one of the most energy, waste, and plastic intensive aspects of healthcare [6]. It is estimated that operating theatres consume 3-6 times more energy than other parts of a hospital [6]. E.g., the number of single-use plastic items for simple surgeries such as a tonsillectomy can require over 100 items of single-use plastics [7]. These include items such as gowns, hats, instruments, packaging, and drapes, all of which could be substituted for more sustainable, multi-use alternatives [7]. Furthermore, there is an increasing trend towards more sustainable practices within surgery, with the four surgical colleges of the UK publishing pledges outlining strategies to improve the environmental impact of surgery [6]. This paper discusses the common plastics used throughout surgery and healthcare, alongside their environmental impact with regards to their usage and possible solutions in-terms of alternatives and waste handling including a discussion focussing on surgery.

We will discuss the common types of plastics used within healthcare and possible alternatives including waste management. We will then consider the carbon footprint of surgery. 

Discussion 

The use of single-use plastics within healthcare has increased since the middle of the nineteenth century due to a myriad of factors. One of the key factors being patient safety [3]. Sterile single-use equipment offers a higher degree of safety compared to multi-use alternatives, with a much lower risk of cross-contamination (e.g., Hepatitis B/C and HIV) and a decreased probability of post-surgical illnesses such as Creutzfeldt-Jakob disease [3]. Another key factor is cost. Many surgical and healthcare items are comprised of cheap commodity plastics, often composited with other materials [3], [4]. The low-cost of equipment made from commodity plastics and their high biosafety makes single-use plastics a logical choice. However, single use plastics presents a serious environmental challenge, which while not completely mitigable, can be managed. 

Table 1. Commodity plastics used commonly in healthcare and their common usage within healthcare, alongside a proposed alternative and their respective emission factor (cradle-to-gate). PP = polypropylene, PE = polyethylene, PVC = polyvinyl chloride, PC = polycarbonate and PS = polystyrene.

Commodity Plastic	Usage	Alternative material	Emission Factors (kg CO2e kg-1)
PP	Syringes, Containers, Waste Bins	Bio-PP	PP = 4.98 [8] Bio-PP = 0.63[9]
PE	Tubing, PCR/Test tubes, Aprons, Gowns	Polylactic acid (PLA)	PE = 2.54 [8] PLA = 1.83[10]
PVC	Catheters, Blood bags, Tubing, Oxygen masks	High-Density PE (HDPE) Bio-PP	PVC = 3.10 [8] HDPE = 2.52 [8]
PC	Test tubes, Visors, Suction pump jars	Bio-PC e.g., DURABIO™	PC = 7.62 [8]
PS	Containers, Vials, Cuvettes, Test tubes	Cardboard Polylactic acid (PLA)	PS = 3.43 [8] Cardboard = 1.29 [8]

The most common types of plastic used with healthcare are broadly categorized as “commodity plastics”, including polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polycarbonate (PC) and polystyrene (PS). It is estimated that PE, PVC, PP and PS usage accounts for 70% of the total plastic usage of medical items [4]. Half of the personal protective equipment (PPE) is made from PC, PP or PVC [4]. Whilst it may be very difficult to replace plastics for certain applications,  Table 1 highlights common plastic usage within healthcare and proposed alternative materials, with similar material properties, alongside their respective emission factors. 

Several commodity plastics have the potential to be replaced with biologically sourced alternatives (Table 1). For example, PP can be produced from non-petroleum feedstocks such as cooking oils, offering a much-reduced emission factor (0.63 kg CO₂e kg^-1 vs 4.98 kg CO₂e kg^-1, equating to an 87.4% reduction) [9]. The biodegradable plastic PLA, can be produced from a wide array of organic matter such as food waste and wastewater sludge [11]. We have proposed alternative plastics where relevant, for example, PVC shares many material properties with the lower emission factor plastic HDPE (Table 1). 

Replacing the plastics used within medical items with alternate materials may not be initially feasible for certain applications e.g., where biological/patient safety is a concern. However, as only 15% of medical waste is classed as being biohazardous and currently only 5% of plastic waste used within the healthcare system of the United Kingdom is recycled, working on waste management and recycling could be an area of focus [4]. Indeed, there have been numerous publications in recent years discussing this topic [12]–[15]. A copious number of reasons are reported for the lack of recycling within healthcare such as; the lack of adequate waste disposal systems, poor training in proper waste management, lack of economic/human resources and meager attention towards the matter [15]. Several suggestions for improving waste management were proposed by Lattanzio, et al.[15]:

• Promotion of practices to reduce the volume of waste and proper segregation of waste streams e.g. sorted recycling boxes 
• Implementation of policies to incrementally improve waste management strategies, aiming to improve segregation, disposal, and destruction practices  
• Reducing the number of waste streams which are incinerated by the adoption of safe and greener treatment of hazardous waste by autoclaving, microwaving, chemical treatment, etc. 
• Implementation of a comprehensive waste management system, involving the delegation of duties and resourcing around waste disposal. 
• Implementation of strategies and policies to raise awareness of the risk-level of healthcare waste and ensure protections are put in place for those collecting, handling, transporting, storing, treating, or disposing of healthcare waste. 

Several key items used within healthcare can be recycled with relative ease when strategies are implemented to ensure correct waste management. Examples include visors, drapes, observation folders and plastic packaging for medicines/equipment [3].

The more energy and waste intensive areas of healthcare, such as surgery, play a key role in meeting climate targets. It is estimated that a typical operation emits in the range of 46–232 kg CO₂e [16], whilst generating over 100 items of single-use plastics [7]. With over 1.6 million major surgeries performed each year in NHS, this has a significant carbon footprint [17]. The implementation of serialized metal containers to hold surgical tools instead of plastic packaging could be one route to reducing the number of single-use plastics in surgery [3]. The use of plastic surgical hats, aprons or gowns can also be minimized by replacing them with fabric, or multi-use plastic alternatives which can undergo sterilization [3]. However, the energy used sterilizing equipment is usually substantial through the use of autoclaves, or irradiation, and hence should be factored into decisions [6]. The environmental impact of the increased energy usage could be mitigated through electricity supplied via green tariffs, or investment in on-site renewable sources (wind, solar, etc,).  Figure 1 highlights the carbon footprint of surgery, per hour, excluding anesthesia use (Figure 1A) and per year of surgical activities (Figure 1B)

Figure 1. Pie charts illustrating carbon Emissions (CO₂e) of surgical activity in NHS England, UK. (A) Carbon footprint (kg CO₂e h^-1) produced per hour for each activity category excluding anesthesia. (B) Annual carbon footprint (kt CO₂e) of NHS England surgical activities, per reporting year 2017. Data is adapted from Whiting, et al. [1]

Whiting, et al. [1]provides an emissions figure of 24.11 kg CO₂e per hour of surgery (Figure 1A). However, this disregards the use of anesthetic gases which would lead to a much larger overall carbon footprint. Nevertheless, Figure 1A provides granularity into the emission factors per surgery activity category. It is apparent that energy usage is the largest source of emissions (14kg CO2e h-1, 58.07%), followed by the use of medical consumables (7.7kg CO2e h-1, 31.94%), which include single-use plastics. Therefore, one key area of focus should be towards minimizing the energy usage e.g. through use of LED lighting instead of incandescent, or investing in energy smart equipment. Another, is aiming to minimize the use of single-use plastic consumables, by utilizing multi-use plastics or alternative materials. 

When considering the carbon footprint of all surgical activity in NHS England (Figure 1B), surgical inpatient days produce the largest emissions (138 kt CO₂e, 29.18%). This could be minimized by the implementation of less invasive surgery (e.g., laparoscopy) where appropriate. This is followed by the surgical procedure itself, to which the discussion in the previous paragraph is relevant. The third largest source of emissions is the use of anesthetic gases (105 kt CO2e, 22.20%) which account for 42.3% of all emissions when nitrous oxide is also considered. Anesthetic gases are potent forms of greenhouse gases, an example being sevoflurane which has a global warming potential (GWP) of 130 [18]. They are often employed as a mixture of gases (e.g., with nitrous oxide). The use of the gas mixture   desflurane/sevoflurane/nitrous oxide emits ~45kg CO2e per hour [19]. However, if sevoflurane is only mixed with air the emissions become substantially lower at ~1 kg CO2e per hour [19]. The NHS published a long-term plan in 2019, which emphasised anesthesia usage as an area of action in order to meet its climate goals, committing to achieve a 2% reduction in the overall NHS carbon footprint through better anesthetic practices [20]. Another alternative is the Total Intravenous Anaesthesia (TIVA) in place of anesthetic gases where appropriate, with an emissions factor 10,000 times less than current anesthetic gases [21].

Conclusion

Sustainability in healthcare is a complex and nuanced topic. We have highlighted some key areas of the carbon footprint of healthcare. It is apparent that the role of single-use plastics plays an important role within patient safety. However, single-use plastics are used extensively throughout healthcare in a variety of scenarios where replacement with multi-use plastics or alternative materials is possible. The management of waste in healthcare settings could be one major route to reducing the carbon footprint, with the implementation of management policies a promising route forward. The field of surgery presents several challenges towards the overall footprint of surgery, accounting for the largest source of emissions for NHS, England. The implementation of metal boxes for surgical equipment, and multi-use sterilizable plastics can reduce the burden of plastic waste. Whilst optimizing the way anesthesia is employed can reduce emissions substantially. 

Nathan Wood, Carbon Reduction Scientist, Tunley Engineering

Nathan is a Carbon Reduction Scientist at Tunley Engineering and is responsible for processing, analyzing, and presenting carbon assessment data.  He combines this with finishing his PhD in “Modelling the Thermoelectric Properties of SrTiO3 and its (Nano-)composites” at the University of Huddersfield. Nathan has an undergraduate background in Chemistry, with his PhD focusing on computational materials science. Thus far, he has published one paper investigating defect chemistry in SrTiO3, with several more planned. 

Dr. Robert Moorcroft, Carbon Reduction Scientist, Tunley Engineering

As a Carbon Reduction Scientist, Rob applies his multidisciplinary scientific background spanning biology, chemistry and materials science to the carbon assessments and realistic reduction plans for the customers’ often complex needs.  Rob completed his PhD at the University of Manchester on microbiologically influenced corrosion, where he co-authored the publication “Gemini surfactant as multifunctional corrosion and biocorrosion inhibitors for mild steel” in Bioelectrochemistry (Pakiet et al, 2019).  Prior to working at Tunley Engineering, he has carried out fundamental research on second generation biofuels, high efficiency shipping coatings and novel biosensing technologies.

Dr. Torill Bigg, Chief Carbon Reduction Engineer, Tunley Engineering

Torill is the Chief Carbon Reduction Engineer of Tunley Engineering and leads the carbon reduction team.  Torill is passionate about environmental protection and decarbonization; she delights in mentoring the carbon reduction team and takes pride in their outstanding achievements and the quality of their work. With much experience in engineering design, innovation, operational and asset management, and an academic background in biochemistry, chemical engineering, and business management, Torill continues to apply creative problem solving and leadership skills to her role as the Chief Carbon Reduction Engineer of Tunley Engineering.

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