Reducing the environmental impact of gastrointestinal endoscopy: a prospective study on waste management through waste segregation and staff education

Abstract

Background

Gastrointestinal endoscopy is a major contributor of medical waste and greenhouse gas (GHG) emissions. Sustainable waste management practices could help reduce its environmental footprint.

Methods

A prospective exploratory study was conducted at IRCCS Humanitas Research Hospital from April to June 2023. The intervention included installing recycling bins for paper and plastic in five endoscopy suites, alongside existing regulated medical waste (RMW) and non-regulated medical waste bins. Comprehensive staff training on waste segregation was provided, and a “Green Endoscopy” nurse monitored compliance during the intervention. Data on RMW, its emissions (in kg carbon dioxide equivalents [CO2e] per procedure), and costs were collected and compared with pre-intervention values.

Results

RMW production decreased by 24.1%, from 1.91 kg per procedure (95%CI 1.54–2.28) to 1.45 kg per procedure (95%CI 1.16–1.73; P = 0.02), with sustained reductions during follow-up (1.48 kg per procedure; 95%CI 0.84–2.12). The intervention led to a 33.3% reduction in GHG emissions (with a net difference of 1.23 kg CO2e per procedure; P = 0.02), and cost savings of approximately €3542 (±384) were achieved. This effect was consistent across different procedure types.

Conclusions

Targeted interventions such as staff education and structured waste segregation protocols substantially reduced RMW and associated GHG emissions in a high-volume endoscopy unit. These results suggest that simple, low-cost changes may improve environmental sustainability in clinical practice.

Introduction

Human activities, particularly the production of greenhouse gases (GHGs), are the primary drivers of global warming, climate change, and pollution. The health care sector continues to be an important contributor to waste generation [1] [2]. As the demand for health care services grows globally, the volume of waste generated by the sector is expected to increase, raising environmental concerns and highlighting the critical need for sustainable waste management practices tailored to health care settings. Around the globe, the health care sector contributes to environmental degradation, accounting for around 4% of global GHG emissions and equivalent to the emissions of the fifth largest polluting country [3] [4]. Within the health care sector, some specialties contribute disproportionately to environmental harm, with digestive endoscopy ranking as the third largest contributor to hazardous waste production in the hospital setting [5].

Notably, only 9% of the solid waste produced is currently recycled, while the majority is sent to landfill, highlighting a substantial opportunity for improvement in waste management practices [6]. Furthermore, up to 8.6 kg of waste generated daily within an endoscopy center could potentially be recycled, underscoring the importance of implementing more sustainable and efficient recycling strategies [7].

In Italy, hospital waste is classified under D.Lgs. 152/2006 and DPR 254/2003, which regulate its classification, segregation, and disposal. Regulated medical waste (RMW) includes hazardous and infectious materials such as sharps, biopsy specimens, and contaminated fluids, requiring incineration or sterilization. Non-regulated medical waste (NRMW) consists of non-hazardous materials, such as non-contaminated packaging and disposable equipment, which can be disposed of as municipal waste. Recyclable waste includes uncontaminated materials such as paper and glass. Italian waste management combines incineration, landfill disposal, and recycling. D.Lgs. 116/2020 allows some hospital waste to be treated as urban waste, enabling alternative disposal and recycling. At IRCCS Humanitas Research Hospital, PR.PCI.05 governs waste handling, using a color-coded segregation system to ensure safe disposal.

Small single-use endoscopy accessories are segregated by contamination risk. Critical items that penetrate sterile tissue (e.g. hemostatic clips, polypectomy snares/loops, sphincterotomes, injection needles) always enter the RMW stream for high-temperature incineration, whereas visibly clean, non-critical plastics, such as mouthguards or protective sheaths, may be discarded with municipal solid waste; any sign of contamination immediately reclassifies them as RMW. For the purposes of this study, “disposable equipment” denotes any single-patient accessory that cannot be reprocessed (biopsy forceps, retrieval nets, dilation balloons, etc.). Further details are available in the online-only Supplementary material.

The endoscopy suite, as a hub for minimally invasive diagnostic and therapeutic procedures, generates substantial amounts of waste, some of which is avoidable. Studies indicate that operational and behavioral changes in waste management can yield meaningful reductions. For example, one study reported a 12.9% reduction in mean total waste and a 41.4% decrease in contaminated waste after implementing targeted strategies, all without compromising procedural load or efficiency [8]. Similarly, another endoscopy center demonstrated that comparable waste management protocols led to reductions in environmental impact, highlighting the potential scalability of such interventions across diverse health care settings [9].

Despite these promising results, the successful implementation of environmentally conscious practices requires more than policy changes; it depends on the accurate and consistent execution by health care staff. Surveys reveal a concerning gap in waste management practices: in one survey, 58% of endoscopy staff members and 65% of gastroenterologists incorrectly disposed of simple endoscopic accessories as RMW, inadvertently increasing both waste volume and associated disposal costs [10]. This mismanagement underscores the need for comprehensive staff education on proper waste segregation protocols, supported by regular training and clear guidelines.

We hypothesized that implementing targeted interventions, including waste segregation protocols and comprehensive staff education, would reduce RMW, thus decreasing the environmental impact, all without compromising the quality of clinical care.

The primary aim of this study was to evaluate the effectiveness of a waste segregation protocol, combined with comprehensive staff education, in reducing RMW, GHG emissions, and costs in a high-volume endoscopy unit.

Methods

Study design

This was a prospective, interventional, single-center study aimed at reducing RMW by implementing a structured waste management protocol. The functional unit of analysis was the total volume of RMW. The boundary of analysis included the clinical care pathway, which encompassed endoscopy procedures requiring equipment (disposable endoscopes were not included in the analysis), and the temporospatial boundaries, defined as the intervention period from April 1 to June 30, 2023, at the IRCCS Humanitas Research Hospital, with follow-up data collected from July 1 to September 30, 2023. Key study parameters included an ambulatory endoscopy suite setting, five endoscopy suites equipped for endoscopic procedures, and a six-month timeline in Milan, Italy. The multidisciplinary study team comprised gastroenterologists, nursing staff, waste management experts, and environmental scientists. The methodological approach was guided by the European Society of Gastrointestinal Endoscopy (ESGE) sustainability guidelines and focused on implementing a simple protocol to improve waste sorting and recycling [11].

Interventions

The intervention aimed to reduce RMW through better waste segregation. Key actions included:

• installation of two additional 60-L recycling bins for paper and plastic in each suite, alongside the existing RMW and NRMW bins

• comprehensive staff training on waste separation protocols

• appointment of a “Green Endoscopy” nurse. Before the intervention, the nurse was responsible for training nursing and medical staff on waste segregation using setting-specific examples and visual aids provided by the waste management office. During the intervention, the nurse conducted daily compliance checks (30–60 minutes across five endoscopy suites) and supported the nursing staff, who were primarily responsible for waste sorting.

Variables and outcomes

The primary environmental impact metric was the reduction in RMW (measured in kg). Secondary outcomes included GHG emissions (measured in kg carbon dioxide equivalents [CO₂e] per procedure) and cost savings from reduced RMW production.

Key assumptions:

• proper segregation leads to a net reduction in environmental impact by minimizing unnecessary incineration

• definitions of RMW and NRMW align with Italian waste management regulations.

The study followed the Endoscopic Sustainability PrimAry Reporting Essentials (E-SPARE) checklist.

Data sources and management

Data collection was managed by the hospital’s Waste Management Department using an automated system. Each RMW bin was labeled with a unique Quick Response (QR) code on the lid, enabling the system to track and record the total weight of waste generated from each department. The weight was automatically calculated by subtracting the bin’s tare weight from the total weight. A monthly retrospective report was provided for each hospital department and updated regularly.

To evaluate the effectiveness of the intervention, data from the intervention period (April–June 2023) were compared with the same period in 2022, focusing on the reduction in the generation of RMW.

The environmental impact reduction was assessed based on the decrease in RMW, as this waste category largely contributes to GHG emissions.

Regarding carbon emission factors for waste, we applied the International Energy Agency [12] database for generic waste-emission factors (latest update 2020); however, for RMW destined for high-temperature incineration, we applied the more recent, activity-specific 2024 UK Government conversion factor of 1833 kg CO₂e t^-1 (1.9 kg CO₂e kg^-1).

Sample size

The sample size comprised waste data from five endoscopy suites over 3 months (intervention period) and 3 additional months (follow-up).

Quantitative variables

Quantitative variables included the weight of RMW, which was measured as a continuous variable in kg. The study also assessed percentage reductions or increases in RMW generation, associated GHG emissions, and costs relative to the baseline data from April to June 2022. Additionally, monthly trends were analyzed during both the intervention and follow-up periods to evaluate changes over time.

Statistical methods

Descriptive statistics were first used to summarize the data, including mean values and 95%CIs for RMW per procedure, P value of the mean difference, GHG emissions per procedure, and associated disposal costs. Given that the primary outcome was the reduction in RMW production per procedure, we compared the pre-intervention period (2022) with the intervention period (April–June 2023) and the subsequent follow-up (July–September 2023).

Comparative analyses were performed using paired t tests to assess differences in the mean RMW per procedure between the periods. This approach was chosen under the assumption of a normal distribution of the continuous variables, which was verified through preliminary data checks. A statistical significance level of P < 0.05 was set for all statistical tests. Additionally, monthly trends in procedure numbers were analyzed to ensure that variations in clinical activity did not confound the observed changes in waste production.

Results

No statistical difference was observed in procedure numbers during the intervention and pre-intervention periods ([Fig. 1]), representing consistency. In 2022, before the intervention, the endoscopy units generated 21 445 kg of RMW, and in 2023, after the intervention, 13 714 kg. [Fig. 2] shows the 2022 and 2023 trends in total RMW production per month.

Fig. 1 Endoscopy procedures per month during 2022 and 2023.

Fig. 2 Total regulated medical waste production per month, in 2022 and 2023.

During the pre-intervention period (April–June 2022), the average RMW production was 1.91 kg per procedure (95%CI 1.54–2.23). This decreased to 1.45 kg during the intervention (95%CI 1.16–1.73; P value pre-intervention vs. intervention = 0.02), corresponding to a reduction of 24.1%. During the follow-up period, the rate was 1.48 kg per procedure (95%CI 0.84–2.12; P = 0.26) without the daily presence of the Green Endoscopy nurse.

In 2022, before the intervention, the unit spent €32 166 on RMW disposal. During the first 9 months of 2023, after the intervention, this figure was reduced by approximately €3542 (±€384), corresponding to a 9.1% reduction, attributed to the decrease in RMW requiring costly disposal methods.

The reduction of RMW was associated with a reduction of GHG emissions; the GHG pre-intervention value in 2023 was 3.69 kg CO₂e per procedure, whereas during the intervention it dropped to 2.46 kg CO₂e per procedure, with a net difference of 1.23 kg CO₂e per procedure (a reduction of 33.3%; bootstrap one-tailed P = 0.02).

To calculate per-procedure waste, the weighted average waste was divided by the number of procedures, according to different procedure types. Both esophagogastroduodenoscopies and colonoscopies averaged 1.63 kg per procedure, whereas endoscopic retrograde cholangiopancreatographies generated 5.42 kg per procedure, making it the most consumptive procedure. Overall, a reduction of nearly a third was achieved across all types of procedures, in line with the previous finding of 24.1%.

Discussion

The intervention successfully reduced RMW – the most resource-intensive waste stream – by likely shifting a portion toward NRMW, paper, and plastics. While the total waste volume may have remained stable, its composition changed, favoring less environmentally demanding disposal methods. This shift did not affect clinical performance, as procedural volumes remained stable (see Table 1s and Table 2s).

The mean difference in the reduction of RMW between the intervention and follow-up periods was statistically significant, indicating that the magnitude of waste decrease – and the related economic and environmental benefits – are operationally meaningful.

A recent study assessing the carbon footprint of ambulatory gastrointestinal endoscopy provided a detailed breakdown of emissions sources, revealing that waste and consumables account for 3% and 7% of total emissions, respectively [13]. While these categories represent a relatively small fraction of the overall carbon footprint compared with patient and staff travel (45%) and medical equipment (32%), they remain critical – and actionable – areas for intervention [2] [13].

Our 24.1% cut in RMW parallels the ~40% decrease achieved by a staff education and bin-relocation program [8] and meets the 1.5 kg target identified in a French life-cycle audit of endoscopy [13]. Compared with a tertiary center assessment that generated 1.8 kg per procedure with only 17.8% correct recycling [14], our approach yielded an additional 19% waste reduction. Crucially, it also delivered ~€3500 in disposal cost savings, adding an economic incentive to its environmental gains.

Spaulding’s classification [15] – albeit developed decades ago – still anchors infection-risk–based reprocessing in gastrointestinal endoscopy: critical accessories (biopsy forceps, snares, injection needles) breach sterile tissue and therefore must be sterilized or used only once; semi-critical devices such as flexible endoscopes require high-level disinfection; non-critical equipment receives low-level disinfection. Understanding these categories is crucial for developing sustainable solutions that remain compliant with infection control standards.

Reprocessing small endoscopic accessories could further reduce waste, but in Italy, biopsy forceps, snares, and retrieval nets are classified as single-use due to infection control regulations. While flexible endoscopes undergo high-level disinfection, critical accessories penetrating sterile tissue require sterilization, making reuse impractical. European initiatives are exploring controlled reprocessing of some accessories, and future research should evaluate the sustainability of single-use versus reusable alternatives.

A key strength of this intervention is its lasting impact. Even after the intervention period, hazardous waste reduction was maintained, suggesting that once protocols are implemented, they require minimal oversight. However, the slight increase from 1.45 kg to 1.48 kg per procedure post-intervention highlights the need for periodic reinforcement to ensure compliance.

To further improve sustainability, appointing a “Green Endoscopy Manager” could promote environmental initiatives across health care settings. By advocating for sustainably produced medical equipment and disposal methods with lower emissions, health care providers could influence industry practices. For instance, tracking the carbon footprint of medical products could drive innovation and sustainable procurement.

Several limitations of the study need to be addressed. First, emissions data for NRMW and recycled waste were not included as these waste streams were not separately tracked; therefore, the study could not assess their contribution to overall waste reduction or emissions. While this may underestimate the intervention’s full impact, the reduction of RMW – a waste category with the highest environmental burden – remains a meaningful and measurable outcome. Second, selection bias is possible as the study was conducted in a single, high-resource, high-volume hospital with existing sustainability initiatives, which may not reflect conditions in other settings, limiting generalizability. Measurement bias may also be present, as waste tracking relied on automated QR-coded bins, which might not have consistently recorded all waste. Additionally, while the study highlights reductions in RMW and costs, it does not fully account for possible downsides, such as staff training efforts or the environmental cost of producing extra recycling bins. However, the intervention itself is simple, cost-effective, and does not require advanced resources, making it adaptable to other health care settings, especially in high-volume endoscopy units with similar waste management practices. Future studies should incorporate life-cycle assessments of all waste types to provide a more comprehensive environmental evaluation, and test interventions in different hospital environments to strengthen external validity. Third, the short study duration may not fully capture long-term sustainability outcomes. Nevertheless, the continued reduction in RMW during the follow-up period suggests that improvements can persist even with minimal oversight. Periodic reinforcement of waste segregation protocols may further enhance long-term effectiveness. Fourth, the success of the intervention depended on staff compliance, which may fluctuate over time or between institutions. Even so, the results indicate that proper training and a structured waste segregation system can lead to lasting changes in disposal practices. Implementing periodic refresher training could help sustain these improvements across various health care teams. Additionally, as an observational study, this research does not establish a direct causal relationship between the intervention and the observed outcomes. Unmeasured factors, such as procedural complexity or changes in patient demographics, could have influenced the results. However, the substantial and consistent reduction in RMW across different months strengthens the plausibility that the intervention played a key role. Future research should incorporate randomized controlled trials to confirm causality.

While this study did not assess the broader environmental impact, such as the energy costs of recycling or trade-offs in waste processing, its findings offer a practical, evidence-based approach to reducing high-impact medical waste.

Finally, while our intervention focuses on improving waste disposal rather than reducing waste generation itself, a more comprehensive approach should also consider limiting unnecessary procedures. The Environmental Protection Agency’s waste management hierarchy prioritizes waste reduction at its source, which in endoscopy means ensuring procedures are performed based on appropriate clinical indications rather than as routine or precautionary measures. Integrating both waste segregation strategies and responsible procedural planning could further enhance sustainability efforts in gastrointestinal endoscopy [16].

Our findings demonstrate that structured waste segregation and staff education can optimize waste management in endoscopy, particularly by reducing the proportion of waste classified as RMW, the most resource-intensive disposal category. This aligns with the ESGE’s goal for gastrointestinal endoscopy to reach net zero emissions by 2050, emphasizing the role of more sustainable waste handling in reducing the environmental impact of endoscopic procedures [11]. Future multicenter, longer-term studies (e.g. life cycle assessment and cost–benefit analyses) are warranted to confirm and extend these promising findings.

Green stamp explained

Waste disposal in endoscopy is often inappropriate with large volumes of regular waste sometimes being disposed of as hazardous waste, which requires special processing (e.g. incineration) thereby incurring environmental and economic cost. This single-center study showed that education about waste disposal and setting up appropriate bins and labeling (including recycling) can lead to a lasting reduction in hazardous waste (almost 25%), carbon footprint (33%), and cost, providing a model for other endoscopy units to optimize waste disposal using simple and effective sustainable practice.

Conflict of Interest

C. Hassan is a consultant for Fujifilm Co. and Medtronic Co. A. Repici is a consultant for Fujifilm Co., Olympus Corp., and Medtronic Co. M. Menini, C. Crisciotti, T. Rizkala, L. Di Stefano, M. Spadaccini, A. Fumagalli, A. Fugazza, E. Vanni, P. Oliva, R. Iacovino, and S. Giordano declare that they have no conflict of interest.

• References

• 1 Watts N, Adger WN, Ayeb-Karlsson S. et al. The Lancet Countdown: tracking progress on health and climate change. Lancet 2017; 389: 1151-1164
• 2 Arup and Health Care Without Harm. Healthcare’s climate footprint. Accessed January 26, 2022 at: https://www.arup.com/en/perspectives/publications/research/section/healthcares-climate-footprint
• 3 Pichler PP, Jaccard IS, Weisz U. et al. International comparison of health care carbon footprints. Environ Res Lett 2019; 14: 064004
• 4 Lenzen M, Malik A, Li M. et al. The environmental footprint of health care: a global assessment. Lancet Planet Health 2020; 4: e271-279
• 5 Park SB, Cha JM. Gastrointestinal endoscopy’s carbon footprint. Clin Endosc 2023; 56: 263-267
• 6 Namburar S, von Renteln D, Damianos J. et al. Estimating the environmental impact of disposable endoscopic equipment and endoscopes. Gut 2022; 71: 1326-1331
• 7 Desai M, Campbell C, Perisetti A. et al. The environmental impact of gastrointestinal procedures: a prospective study of waste generation, energy consumption, and auditing in an endoscopy unit. Gastroenterology 2024; 166: 496-502.e3
• 8 Cunha Neves JA, Roseira J, Queirós P. et al. Targeted intervention to achieve waste reduction in gastrointestinal endoscopy. Gut 2023; 72: 306-313
• 9 Jain M, Agrawal V. Making endoscopy practice environmentally sustainable – early experience from Central India. Indian J Gastroenterol 2023; 42: 860-862
• 10 Agrawal D, Shoup V, Montgomery A. et al. Disposal of endoscopic accessories after use. Gastroenterology Nursing 2017; 40: 13-18
• 11 Rodríguez de Santiago E, Dinis-Ribeiro M, Pohl H. et al. Reducing the environmental footprint of gastrointestinal endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) Position Statement. Endoscopy 2022; 54: 797-826
• 12 International Energy Agency. Global energy and CO2 emissions in 2020. 2025 https://www.iea.org/reports/global-energy-review-2020/global-energy-and-co2-emissions-in-2020
• 13 Lacroute J, Marcantoni J, Petitot S. et al. The carbon footprint of ambulatory gastrointestinal endoscopy. Endoscopy 2023; 55: 918-926
• 14 Ribeiro T, Morais R, Monteiro C. et al. Estimating the environmental impact of endoscopic activity at a tertiary center: a pilot study. Eur J Gastroenterol Hepatol 2024; 36: 39-44
• 15 Rowan NJ, Kremer T, McDonnell G. A review of Spaulding’s classification system for effective cleaning, disinfection and sterilization of reusable medical devices: viewed through a modern-day lens that will inform and enable future sustainability. Sci Total Environ 2023; 878: 162976
• 16 United States Environmental Protection Agency. Sustainable materials management: non-hazardous materials and waste management hierarchy. 2025 https://www.epa.gov/smm/sustainable-materials-management-non-hazardous-materials-and-waste-management-hierarchy

Publication History

Received: 03 December 2024

Accepted after revision: 06 July 2025

Article published online:
19 August 2025