Bibliometric Analysis of Medical Waste Research Using Python-Driven Algorithm

Abstract

The management of medical waste (MW) is a critical global challenge, contributing to toxic effects on humans, environmental degradation, and economic burdens. Despite advancements, gaps remain in adopting sustainable waste disposal practices, with limited bibliometric analysis in this field. The rising volume of MW, exacerbated by global health crises, strains existing systems. This study uses bibliometric analysis of 3025 publications from 1975 to 2024, employing Web of Science data with specific Boolean operators and keywords for efficient searching algorithms. Data visualization and analysis were carried out with software such as VOSviewer version 1.6.20 and Bibliometrix 5.0.0, along with custom Python 3.12.3 thesaurus files to standardize terminology. The results reveal a significant rise in publications post-2000, particularly during the COVID-19 pandemic, with China, India, and the US as major contributors. South Korea stands out for high citation rates. Network analysis identified collaboration patterns, while trend mapping highlighted a shift toward sustainable waste management practices. The evaluation insights revealed a clear transition from incineration-based methods toward sustainable and innovative solutions such as autoclaving, plasma pyrolysis, and advanced oxidation processes, driven by environmental concerns and regulatory frameworks. This study underscores the implications of MW and the importance of analyzing publication trends over time to understand the ongoing need for development, grounded in a legislative policy framework, which is essential for advancing sustainable practices in MW management.

1. Introduction

Waste produced during the processes of diagnosing, treating, or immunizing humans and animals falls under the category of medical waste (MW) [1]. This type of waste refers to materials discarded during medical, dental, or veterinary practices or research that pose significant health risks to anyone exposed to them [2].

Over the last three decades, advancements in technology and the development of modern medical facilities have led to a considerable rise in MW generation. Globally, it is recognized as the second most dangerous type of waste, following radiation [3].

The rise in MW production corresponds with the increase in the worldwide population, the expansion of healthcare services, and the prevalent use of disposable medical instruments and apparatus [4]. Furthermore, the COVID-19 pandemic brought additional attention to MW due to the rapid escalation in the use of disposable items, with worldwide estimates approaching 100 million tons of waste annually [5,6].

Approximately 85% of waste generated by medical facilities is non-hazardous and general in nature, while the remaining 15% comprises hazardous materials that may be carcinogenic, flammable, reactive, corrosive, infectious, toxic, explosive, or radioactive. Waste categories of this type include cytotoxic waste, general non-hazardous waste, chemical, sharp, radioactive, pathological, infectious, and pharmaceutical waste [7]. Pharmaceutical waste includes discarded materials from pharmaceutical manufacturing industries, broken or damaged syringes, spills, unused and expired medications, body care products, cotton swabs, bandages, cleansing pads, and razors [8,9] and is categorized as hazardous material, which means that facilities generating it are obligated to handle and dispose of this waste in compliance with regulatory requirements [10].

In the last ten years, global outbreaks such as severe acute respiratory syndrome (SARS) [11], influenza A (H1N1) [12], and COVID-19 [13] have highlighted the insufficient capacity of many nations to effectively manage MW disposal during health emergencies. During pandemics, MW exhibits distinct traits, such as accelerated growth, elevated risks, and stricter requirements for disposal [14]. Since December 2019, the COVID-19 pandemic has captured worldwide focus, alongside the issue of MW production. At the height of the crisis, Wuhan alone experienced a surge in waste generation, reaching approximately 240 tons of MW daily, nearly six times the pre-pandemic levels. In the United States, projections indicated that MW generation rose significantly, from an estimated 5 million tons annually before the pandemic to approximately 2.5 million tons monthly during its peak. The unprecedented rise in the number of regions, countries, and individuals affected by SARS-CoV-2 created significant global challenges associated with the effective management of MW [4].

In addition to solid waste, hospitals produce considerable emissions through standard operations, an alarming instance being the substantial leakage of piped nitrous oxide, a powerful greenhouse gas. Over 90% of piped nitrous oxide is wasted, and switching to mobile cylinders reduces emissions but requires leadership and local support [15].

Inadequate management of waste can endanger hospital staff, patients, their families, and nearby communities, while also contributing to environmental contamination with potentially fatal outcomes [16]. The release of bioactive substances, unmetabolized antibiotics, and antibiotic-resistant pathogens into the environment may contribute to the development of antibiotic resistance [17].

Healthcare professionals and individuals within the medical system are at particular risk if MW is improperly handled [18]. Medical teams, including doctors, nurses, technicians, auxiliaries, stretcher bearers, and logistical staff, work to ensure patient care, all while being exposed to risks associated with mismanaged waste [19]. Thus, it is necessary to establish advanced theoretical frameworks capable of predicting, assessing, and managing risks related to safe waste disposal. These frameworks must be timely, precise, efficient, and holistic in their application across the entire waste management process [20].

Managing MW presents a significant challenge, especially as the global population continues to grow and the demand for medical services rises. This requires a structured approach involving waste collection, segregation, transportation, and the implementation of systematic disposal methods [21]. Reusable equipment, leadership deficiencies, and customized interventions are critical elements in mitigating medical waste in operating theaters across various global healthcare systems [22]. To transition toward a circular economy, various waste-to-energy technologies, including thermochemical, biochemical, and chemical conversion processes, have been methodically explored for MW [23].

Although this topic is critical for public health, environmental sustainability, and economic considerations, research into MW remains underdeveloped. Continuous investigation and publication in this domain are necessary to improve waste management practices. However, bibliometric studies and science mapping analyses in this area are sparse and target only small areas of this vast issue, highlighting the need for further research.

The objective of this paper was to develop an optimized framework regarding the implications and publication trends in MW through a specific bibliometric analysis and science mapping research utilizing a custom Python-based thesaurus tool [24]. The deficiencies in the regulatory framework, persistent inefficiencies in MW management systems, and inadequate awareness and professional education have highlighted the necessity of optimizing, categorizing, and assessing publication trends in this complex domain.

In recent years, the scientific landscape concerning MW has significantly expanded, especially following the COVID-19 pandemic. Among the key efforts to map the evolution of MW research are the studies conducted by Sabour and Amron [25], Soyler et al. [6], and Wang et al. [26]. Nevertheless, these analyses are constrained by narrower temporal coverage, limited datasets, or the absence of in-depth thematic trend evaluation. In contrast, our study extends over a nearly 50-year period (i.e., 1975–2024), analyzes one of the largest and most refined datasets to date in this field (i.e., 3025 papers), and introduces one of the most complex and targeted search algorithms, incorporating 41 specific terms. It also integrates a Python-enhanced thesaurus generator for keyword standardization and applies comprehensive visual and co-word analysis tools. This allows for a better understanding of the field’s thematic and methodological shifts. Moreover, recent work on MW sustainability (e.g., Ranjbari et al., 2022 [27]) reinforces the need for advanced tools to assess and contextualize research directions, a gap our approach addresses.

This bibliometric analysis aims to address the following questions: how has the literature in the field of medical waste management evolved during the period 1975–2024 in terms of publication volume and impact; which countries, institutions, and journals have been the most productive and influential contributors to research in medical waste management; what are the main collaboration patterns between researchers and countries in this field; how have research themes and topics in the studied field evolved over time, particularly in response to global health crises, such as the COVID-19 pandemic. Furthermore, it facilitates access to extensive literature, so improving the capacity to delineate research objectives and attain a comprehensive understanding of the scientific advancements in MW sustainable management.

The present study is structured as follows: Section 1 is dedicated to introducing the subject under evaluation, while Section 2 details the materials and methods used, describing the data collection process from the Web of Science database, the development of the search algorithm, and the analytical tools employed, including a custom Python-based thesaurus generator. Section 3 presents the results in two main parts: first, an overview of the literature and scientific production metrics at country, institutional, and publication levels; second, a visualization of scientific networks and trends. Section 4 discusses the implications of these findings within the broader context of medical waste. Finally, Section 5 concludes with a synthesis of the key insights and outlines promising directions for future research and policy development in the field of sustainable medical waste management.

2. Materials and Methods

In this investigation, bibliometric data from the Web of Science (WOS) database was utilized. WOS was selected as the database for a number of important reasons: the database offers complete record entries with fewer missing abstracts, allowing robust text analysis necessary for our keyword co-occurrence and thematic evolution investigations, offers comprehensive coverage of multidisciplinary journals relevant to medical waste management, guaranteeing representation across medical, environmental, and engineering domains. Using a single comprehensive database avoided the methodological challenges associated with cross-database integration. To ensure the comprehensive retrieval of relevant material, a targeted search was conducted using specific keywords targeting the research topic. The literature search was conducted in February 2024, covering the complete timespan available in the Web of Science database (1975–2024). This comprehensive time horizon was selected to capture the entire historical development of medical waste management research, with the earliest relevant publication identified from 1975. Our search strategy employed the following Boolean query: ALL=((“Medical waste” OR “Pharmaceutical waste” OR “waste pharmaceutical” OR “waste medical” OR “hospital waste”) AND (hospital OR management OR “sustainable development” OR “circular economy” OR sorting OR biomedical OR hazardous OR “non-hazardous” OR infectious OR surgical OR segregation OR disposal OR recycling OR separation OR production OR collection OR transportation OR treatment OR radioactive OR chemical OR sharp OR general OR sterilization OR micro saving OR carbonization OR bio converted OR incineration OR pyrolysis OR gasification OR irradiation OR immobilization OR “reverse polymerization” OR policy OR legislation OR physician OR doctor OR pharmacist)) yielded a total of 3515 documents, to which the following exclusion criteria was applied: only documents writ-ten in English, articles and reviews. In this search strategy, the field tag ‘ALL=’ instructs the database to search across all searchable fields of the records, including titles, abstracts, keywords, and other metadata. The Boolean operator ‘OR’ broadens the search by retrieving documents containing any of the specified terms, while ‘AND’ narrows the search by requiring documents to contain terms from both sets of criteria, ensuring all retrieved documents address some aspect of medical waste alongside at least one of the specified management or contextual terms. After applying these filters, our final dataset comprised 3025 documents focused on medical waste management. Figure 1 illustrates the systematic search algorithm and document selection workflow applied in this bibliometric analysis, detailing each step of query improvement, screening, and final selection to ensure relevance and accuracy.

For reducing the number of irrelevant results, the initial wide query was subjected to a series of modifications, including the incorporation of inclusion/exclusion criteria and the application of exact phrase matching (using the quotation mark operator on keywords). This resulted in a notable reduction in the number of false positives. The algorithm and document selection procedure ensured the generation of a targeted and precise dataset for the bibliometric study. The documents were exported in a tab-delimited file format using the WOS’s native ‘Export’ function. To ensure the inclusion of all relevant data, the ‘Full Record and Cited References’ option was selected.

The bibliometric analysis was conducted using the VOSviewer (version 1.6.20), Bibliometrix programs via the Biblioshiny web interface, and Microsoft Excel [28]. These tools facilitate the analysis of scientific data extracted from databases such as WOS and Scopus, thereby enabling the identification of trends, collaborative networks, and thematic evolution [29,30].

The size of the node in the country co-authorship network map indicates the number of papers published by each nation; the larger the bubble, the more papers that nation has contributed. The thickness of the connecting lines indicates how closely two nations collaborate; the thicker the line, the more closely they collaborate. Countries are grouped into clusters based on the color of the bubbles and lines, indicating which nations collaborate most often. Stronger working relationships are typically seen between nations in the same cluster [29].

The journal collaboration network map depicts each node as a source, with the size of the node proportional to the quantity of documents published by that source. The color of each node is indicative of the mean publication year of documents from that specific source, offering valuable insights into the temporal trends observed. Connections between two nodes represent instances of citation, whereby documents from one source are referenced by the other. The thickness of these lines is indicative of the strength of the citation relationship, with thicker lines signifying a greater frequency of citation exchange between the two sources [28,29].

Thematic evolution maps are graphical representations that illustrate the evolution of research themes over time. These maps assist in identifying shifts in the focus of research topics and the emergence or decline of themes within a specific field. They are generated in Bibliometrix using co-word analysis and clustering techniques, thereby providing insights into the dynamics of scientific knowledge over different periods [30].

A trend topic analysis is a method of identifying and visualizing research topics that gain or lose popularity over time. This analysis allows the researcher to highlight the rise of emerging research areas and the decline of others. Bibliometrix is a tool that enables this analysis by examining the frequency of keywords or terms across years [28,30].

One of the most crucial stages in the bibliometric analysis process is the verification and validation of the data obtained. Raw data from databases may contain errors, duplications, or variations in the naming of entities (i.e., authors, organizations, countries, key terms), which may impact the quality of the results. In this context, VOSviewer provides thesaurus files, which are essential for standardizing and unifying terms by merging multiple variants of the same entity (e.g., the name of a country spelled in different ways), correcting spelling errors or regional variations (e.g., behavior and behavior), and merging synonyms.

The use of a standard term (e.g., “United Kingdom” for all countries within it) allows for the analysis of these countries as a single entity, thereby avoiding the inclusion of redundant or fragmented references. This approach enhances the precision of keyword analysis, clustering, and thematic evolution studies by consolidating references to geographic locations. For enhancing the analysis of keyword trends and thematic evolution in bibliometric studies, a custom Python-based thesaurus generator was developed with the objective of identifying and grouping similar terms (119 lines of code, Figure 2).

The tool employs a range of techniques, including term frequency–inverse document frequency (TF-IDF) vectorization, cosine similarity, and text preprocessing, to process a list of keywords and identify groups of terms that are either semantically or lexically similar. The algorithm assigns the shortest term as the preferred label for each group and generates a thesaurus file that is compatible with VOSviewer. This approach improves the standardization of keywords by consolidating synonyms and variants, thereby increasing the accuracy and clarity of bibliometric visualizations. The clustering accuracy was evaluated by three researchers separately assessing 300 randomly picked terms, with a success criterion necessitating consensus on a minimum of 270 keywords.

The program effectively achieved this criterion, validating its capability to find synonyms, eliminate redundancies, and consolidate semantically comparable terms into coherent groups. The reliability of the Python-based thesaurus generator is supported by its implementation of established, widely used libraries within the scientific computing ecosystem, including Scikit-learn for TF-IDF vectorization and similarity calculations, NLTK for text preprocessing and tokenization, Pandas for data manipulation, and NumPy for numerical operations.

3. Results

3.1. Literature Overview

A total of 3025 publications on MW were released between 1975 and 2024. While the number of papers on this subject was relatively limited between 1975 and 2000, there has been a notable increase in interest over the past 24 years. From 17 publications in 2000 to 311 in 2024, the number of publications annually has gradually increased. Figure 3A illustrates the annual trend in the number of articles released from 1975 to 2024. Figure 3B depicts the value of MeanTCperYear, which serves as a metric for gauging the mean number of citations an article accumulates over time. This indicator is calculated by dividing the total number of citations by the number of years since the article’s initial publication.

3.2. Scientific Production in the Field of MW

3.2.1. Country Scientific Production

According to the data collected by VOSviewer, a total of 123 countries contributed to the scientific output during this period. Of these, only 21 countries (17.07%) produced at least 50 articles related to the researched topic. The most productive country in this area is China, with 550 documents (18.18%), followed by India with 415 documents (13.72%) and the United States with 358 documents.

Table 1. Most prolific countries in the field of MW (1975–2024).

Country	Documents	Citations	Average Citations/Document
China	550	15,377	27.96
India	415	7712	18.58
USA	358	9667	27.00
Iran	208	4791	23.03
United Kingdom	134	4259	31.78
Turkey	113	2746	24.30
Brazil	96	1938	20.19
Malaysia	88	2409	27.38
Pakistan	87	1916	22.02
South Korea	81	3257	40.21

shows the top five countries in terms of productivity. In terms of average citations per document, South Korea stands out, with an average of 40.21 citations per document, despite having published only 81 documents.

Analyzing scientific output over the years using Bibliometrix (Figure 4), which assigns articles to countries based on the nationality of the authors, we observe a clear upward trend in the number of publications. The data show that, historically, the United States held the top position in terms of annual scientific output. However, in 2018, China overtook the United States and has maintained this lead, reflecting its growing investment in research and development.

3.2.2. Institutional Scientific Production

A bibliometrix data analysis revealed that a total of 2463 institutions contributed to the scientific output in the field of waste management. Of these, 355 institutions (14.41%) were responsible for the publication of at least five papers deemed relevant to the field in question. Figure 5 presents a visual representation of the most productive academic affiliations on a global scale. Although India ranks second in terms of the total number of published papers, the Indian Institute of Technology System ranks first in terms of individual institutional contribution with 76 papers. The Egyptian Knowledge Bank occupies the second position with 68 publications, followed by the Chinese Academy of Sciences with 65 associated papers. This distribution suggests a notable presence of institutions from developing countries in waste management research, underscoring the environmental and sustainable development priorities addressed by these countries.

A review of the scientific production data generated by Bibliometrix over time (affiliation data available since 1992) reveals a consistent upward trend across all institutions in the dataset. It is noteworthy that there was a considerable increase in scientific output around 2020. This surge is likely correlated with the heightened focus on MW management, as the global pandemic spurred increased research and innovation to mitigate the infection risks associated with MW disposal. Figure 6 illustrates the evolution of scientific production over time. Prior to 2010, the scientific production was relatively low, with modest growth across the listed institutions. The Egyptian Knowledge Bank (EKB), Indian Institute of Technology System (IIT System), and the Chinese Academy of Sciences were the primary contributors, while other institutions had minimal or no presence in the early years. From 2010 onwards, there was a gradual increase in scientific output, which then accelerated significantly in 2020.

3.2.3. Most Influential Articles in the Field of MW

The dataset includes a diverse range of research areas, including environmental management, microbiology, and engineering perspectives on MW. To identify the most impactful contributions to the field, we analyzed citation metrics as presented in

Table 2. Most influential papers in the field of MW (1975–2024).

First Author, Year, Journal	TC	TC/Year	Normalized TC	DOI
Homem V, 2011, J ENVIRON MANAGE	1179	84.21	28.06	https://doi.org/10.1016/j.jenvman.2011.05.023
Lee OK, 2004, BLOOD	1091	51.95	10.52	https://doi.org/10.1182/blood-2003-05-1670
Wang JL, 2020, SCI TOTAL ENVIRON	856	171.20	31.22	https://doi.org/10.1016/j.scitotenv.2019.135023
Lee JW, 2008, BIOMATERIALS	673	39.59	13.08	https://doi.org/10.1016/j.biomaterials.2007.12.048
Klemes JJ, 2020, RENEW SUST ENERG REV	562	112.40	20.50	https://doi.org/10.1016/j.rser.2020.109883
Woerther PL, 2013, CLIN MICROBIOL REV	482	40.17	18.73	https://doi.org/10.1128/CMR.00023-13
Adams C, 2002, J ENVIRON ENG-ASCE	456	19.83	8.28	https://doi.org/10.1061/(ASCE)0733-9372(2002)128:3(253)
Khan HA, 2017, ASIAN PAC J TROP BIO	376	47.00	14.21	https://doi.org/10.1016/j.apjtb.2017.01.019
Rutala WA, 1997, CLIN MICROBIOL REV	350	12.50	8.02	https://doi.org/10.1128/CMR.10.4.597
Crane M, 2006, SCI TOTAL ENVIRON	340	17.89	7.84	https://doi.org/10.1016/j.scitotenv.2006.04.010

TC: total citations; normalized TC: divides the total citations of a document by the average citations of all documents in the same field or year.

. The higher the citation rate per year, as evidenced by publications such as Wang JL, 2020 [31], and Homem V, 2011 [32], the more it indicates that these papers remain highly relevant and influential in ongoing research. Conversely, papers with lower citation rates per year, such as Adams C [33], although still significant, are likely to have exerted their greatest influence in earlier years. The data presented in these articles underscore the heightened interest in removing it in as sensitive a manner as possible, with a particular focus on avoiding contamination of water with a range of pollutants, including antibiotics.

3.3. Visualizing Scientific Networks and Trends

3.3.1. Country Collaboration in the MW Research

The cross-country collaboration map generated by VOSviewer was subjected to analysis, which revealed the existence of three distinct clusters of collaboration. The largest cluster is red, followed by green and blue. Most countries in the red cluster are in Europe, indicating a strong collaborative relationship between these nations in the field of MW management research. The green cluster is comprised of countries situated in Asia, demonstrating that geographical proximity fosters collaboration in this field. The blue cluster includes a diverse array of countries from Europe and Africa (Figure 7).

3.3.2. Thematic Evolution in the Field of MW Research

From 1975 to 2010, research focused mainly on improving the efficiency of MW management, with particular emphasis on antibiotics and their environmental impact. During this period, issues such as the proper disposal of pharmaceuticals, including antibiotics, received considerable attention due to growing concerns about contamination and its long-term environmental effects.

In recent years, particularly since 2010, the focus has shifted to the emerging issue of antibiotic resistance. This shift is largely driven by the increasing recognition of the role that inappropriate disposal and treatment of antibiotics play in the development of resistant bacterial strains. The emergence of antibiotic resistance as a prominent issue after 2010 reflects global concern about the potential health risks associated with the persistence of antibiotic residues in the environment, particularly in hospital waste. However, there was a significant shift in research topics after 2019, driven in part by the COVID-19 pandemic. The increase in MW, particularly personal protective equipment and infectious waste, led to a renewed focus on hospital waste management systems and the need for sustainable disposal practices. The pandemic highlighted the weaknesses in global waste management infrastructures, particularly in the handling of hazardous and potentially infectious waste (Figure 8).

3.3.3. Trending Topics in the Field of MW Research

The evolution of trends shows that topics such as MW, waste management, and hospital waste have clustered around similar years, highlighting a broad and continuing research focus on MW management, particularly in the hospital setting. The significant increase in COVID-19 publications, followed by discussions on MW and waste management, underlines the profound impact of the pandemic on waste management research, particularly on MW. From around 2021, there is a noticeable shift towards sustainability, carbon footprint, and plasma gasification, reflecting a growing interest in minimizing the environmental impact of waste disposal. This shift is in line with the global push for sustainability and the need for greener waste treatment technologies (Figure 9).

3.3.4. Trending Keywords in the Field of MW Research

The keyword co-occurrence network (Figure 10) generated by VOSviewer contains all the keywords with a minimum occurrence of 30.

The keywords from this period are divided into three different clusters, each representing a subdomain within the field of waste management research. Firstly, the red cluster, with 38 keywords, focuses on by-products of treatment processes and methods for their removal. This includes studies on contaminants, their degradation, and advanced treatment technologies. The green cluster, also with 38 keywords, focuses on terms directly related to waste management. It emphasizes the systemic and organizational aspects, including sustainability, MW management, and circular economy practices. Finally, the blue cluster, which contains only 16 keywords, focuses on MW disposal methods and the technologies that support these processes. This includes incineration, alternative technologies such as pyrolysis, and the environmental impact of such methods. Each cluster highlights an important facet of waste management research and illustrates the different approaches and emphases within the field.

Table 3. Occurrence frequency and TLS of keywords in the field of medical waste (1975–2024).

Keyword	Occurrence	TLS	Keyword	Occurrence	TLS
medical waste	709	2252	environment	167	650
management	660	2067	antibiotic	137	651
pharmaceutics	429	1675	healthcare	137	486
removal	227	1080	generation	135	562
disposal	221	896	sorption	129	595
hospital wastewater	210	827	hospitals	125	469
hospital	196	637	water	115	468
degradation	185	793	performance	106	379
incinerator	180	729	model	101	375
COVID-19	169	418	optimization	97	400

TLS, total link strength.

presents the top 20 keywords by occurrence frequency and their total link strength in medical waste research publications from 1975–2024. The high occurrence of core terms such as “medical waste” (709 occurrences) and “management” (660 occurrences) underscores their foundational role in defining the research domain. The substantial presence of “pharmaceutics” (429 occurrences) indicates the significant attention given to pharmaceutical components within medical waste research. The prominence of process-oriented terms such as “removal” (227 occurrences), “disposal” (221 occurrences), and “degradation” (185 occurrences) reflects the field’s strong focus on practical waste treatment methodologies. The high total link strength values for these core terms (ranging from 1080–2252) demonstrate their central connecting role across multiple research themes. Of particular note is the emergence of “COVID” (169 occurrences) as a high-ranking keyword despite its relatively recent introduction to the field, highlighting the pandemic’s substantial impact on medical waste research priorities. The presence of environment-focused terms (“environment”: 167 occurrences) alongside technical process terms suggests a dual research emphasis on both treatment technologies and their environmental implications. Keywords related to antibiotics (137 occurrences) and sorption (129 occurrences) indicate significant research attention to pharmaceutical pollutants and their treatment methods. The relatively high link strength of terms such as “optimization” (400) despite lower occurrence counts (97) suggests its integrative role across various waste management approaches, connecting technological innovations with practical implementation strategies.

3.3.5. Emerging and Well-Established Journals in the Field of Medical Waste

Figure 11 presents a map of the citation network of journals. The central position of sources such as Waste Management and Waste Management and Research, together with the average year of publication (2013 and 2014, respectively), indicates that these sources have played a pivotal role in informing research in this field. This is further corroborated by the elevated value of total link strength (1582 and 1255, respectively), which signifies the extent to which these sources were cited or cited other journals. The sources marked in yellow, which have an average publication year close to 2020, reflect an increased interest in the field, probably driven by the impact of the SARS-CoV-2 pandemic. Journals such as Sustainability, Journal of Environmental Chemical Engineering, and PLOS One, situated at the periphery of the network and marked in yellow, indicate that although they have not yet established a presence in the field of MW management, they have begun to attract considerable interest in recent years and are emerging as potential sources of research.

4. Discussion

Scientific interest in the MW domain has gradually increased over time, and it is also correlated with the growing interest in the correct management of them. Moreover, the number of publications targeting these aspects has gradually increased. The increase in publications is particularly noticeable with the onset of the COVID-19 pandemic. From 2020 onwards, there is a marked increase in scientific output in all countries, probably due to the global focus on understanding and combating the SARS-CoV-2 virus. This increase in publications could be attributed to the increased interest and urgency in pandemic-related research to develop prevention strategies and manage the public health crisis. Similarly, an increase in the number of publications has been observed at the institutional level, exhibiting a pattern of growth comparable to that observed at the country level with respect to scientific output.

The observed increase in the mean total citations per year during the period of the global pandemic caused by the novel coronavirus SARS-CoV-2 reflects a significant surge in scientific research activity, particularly in the area of MW management. As the pandemic progressed, the global focus shifted towards understanding and mitigating the spread of the SARS-CoV-2 virus. This resulted in heightened concerns regarding the disposal and management of MW, especially given its potential role in transmitting infectious agents. The rise in the mean total citations per year during this period indicates not only an increase in the number of publications but also a growing urgency to address the risks associated with MW, which became a key factor in controlling the spread of the disease.

The significant increase in the number of publications during the COVID-19 pan-demic represents more than just intensified research activity; it signals a fundamental shift in how medical waste management is conceptualized within public health. Our analysis shows that this increase reflects a growing recognition that effective waste management systems must be resilient enough to rapidly expand during public health emergencies while maintaining environmental sustainability. This finding has profound implications for medical infrastructure planning, suggesting that medical waste management should no longer be viewed as a secondary concern, but as an essential component of pandemic management.

Additionally, the citation patterns observed during this period indicate that the scientific community is increasingly approaching medical waste management through an interdisciplinary perspective, integrating insights from environmental science, public health, and engineering to develop comprehensive solutions. Even though the top 10 cited articles in the field do not directly relate to COVID-19, they underscore a broader trend where the pandemic has amplified the importance of certain research topics, such as MW management, plastic waste, and environmental pollution.

While there are discernible geographical patterns, the collaboration map illustrates that MW management research benefits from an international network of collaboration. The blue cluster serves to illustrate the increasingly global nature of research in this sector, whereas the red cluster, which is centered on Europe, and the green cluster, which is focused on Asia, indicate regional competence and leadership. Furthermore, the interactions among the nations in the blue cluster demonstrate an increasing recognition that effective management of MW is a global issue that necessitates international collaboration, rather than being confined to a specific region. Future studies should investigate the specific cooperative dynamics observed in these clusters, determining the motivations behind these alliances, whether they originate from shared scientific challenges, market forces, or policy considerations. This evolution in collaborative patterns illustrates how medical waste management research is transitioning from siloed regional approaches to a globally integrated field that recognizes the transboundary nature of both waste impacts and solutions.

In the early years of MW management, incineration was the primary method of disposal. However, this practice raised significant concerns about emissions of toxic compounds, as highlighted in the article “Medical Waste Management Incineration” by Lee and Huffman, published in the Journal of Hazardous Materials in June 1996. Toxic emissions through the incineration process, such as fine particulates, acid gases, heavy metals (i.e., lead and cadmium), and carcinogenic compounds such as dioxins and furans, can be released into the atmosphere. Although high temperatures typically destroy pathogens in waste, microorganisms from the surrounding environment may bypass the combustion process and be emitted through the stack. Compared to municipal waste incinerators, medical systems generally emit lower metal levels, but inadequate air pollution controls can still lead to significant environmental and health concerns [34,35].

Over time, these concerns have driven the development of newer, more efficient methods of waste management. Technological advances in waste treatment led to the adoption of modern techniques such as thermal plasma pyrolysis technology that gained widespread popularity, as demonstrated by studies such as “Treatment of Organic Waste Using Thermal Plasma Pyrolysis Technology” by Huang and Tang [36]. Thermal plasma technology presents a modern solution for handling MW by reaching extremely high temperatures. It produces a highly ionized gas that breaks down hazardous materials efficiently, converting them into non-toxic and safe residues [37]. Moreover, the publication “Study on Pyrolysis of Typical Medical Waste Materials by Using TG-FTIR Analysis” by Zhu et al. showed that the use of a combination of thermogravimetric analysis and Fourier transform infrared spectroscopy can offer important insights that support the development of predictive models for the pyrolysis of MW [38].

In addition, other pressing issues emerged, such as the presence of MW in water systems and the need for effective removal methods. This challenge is addressed in the paper “Removal of Antibiotics from Surface and Distilled Water in Conventional Water Treatment Processes” by Adams, Wang, Loftin and Meyer, published in the Journal of Environmental Engineering-ASCE in March 2002. The study found that treating water contaminated with antibiotics was most effective using powdered activated carbon, reverse osmosis, and oxidation with ozone or chlorine under typical water treatment conditions. These methods significantly reduced antibiotic levels. In contrast, conventional techniques such as coagulation, ion exchange, UV disinfection, and lime softening showed little to no effectiveness [33].

In the period following 2010, there was a shift in focus towards the implementation of more sustainable waste management practices. During this time, growing environmental and public health concerns prompted a reevaluation of traditional disposal methods for infectious MW. Incineration, previously the most common approach, faced increased scrutiny due to its link with harmful air pollutants such as dioxins and furans, largely stemming from the high plastic content of MW. As a result, attention gradually shifted toward alternative technologies, such as autoclaving and microwaving, which offer pathogen neutralization without the associated emissions risks [21,39].

In addition, older methods that remain relevant today were subjected to further improvement, including the development of advanced techniques for the removal of specific compounds. To illustrate, the degradation of antibiotics by advanced oxidation processes is a case in point. In their article, “Degradation of antibiotics by advanced oxidation processes: An overview”, Wang and Zhuan present a comprehensive examination of the latest strategies for addressing pharmaceutical waste, published in the journal Science of the Total Environment in January 2020. MW containing degraded drugs should be managed by identifying toxic intermediates using mass spectrometry and quantum chemical analysis, followed by targeted chemical treatments to neutralize harmful compounds. Final residues must undergo advanced oxidation through the use of powerful oxidizing agents, such as hydroxyl radicals, ozone, or hydrogen peroxide, to break down hazardous compounds into less harmful substances, and regular toxicity assessment to ensure environmental safety and protect human and ecological health [31]. A similar model was used for the waste management mechanism of nafcillin degradation, which involved electrochemical oxidation, generating hydroxyl radicals and UV photolysis, followed by anaerobic digestion to eliminate intermediates, leading to complete mineralization into CO₂ and H₂O [40].

In particular, over the past five years, there was an increased focus on the minimization of long-term environmental impacts associated with waste, particularly plastic waste. This is evidenced by the publication (in the Renewable and Sustainable Energy Reviews journal) of research elaborated by Klemes et al. The techniques used in medical plastic waste management include mechanical recycling, which breaks down plastic into smaller pieces for reuse, and chemical recycling (i.e., depolymerization), which converts plastic into basic chemical compounds for new raw materials [41].

The COVID-19 pandemic has intensified the issue of plastic waste in medical facilities due to the increased reliance on single-use plastics. The contamination of ecosystems on land and in water is a consequence of inappropriate plastic management, which also poses a risk of pathogen transmission [42]. It is essential for governments and medical institutions to focus on sustainable solutions and encourage alternatives to single-use plastics. Manufacturers must ensure that packaging is composed of environmentally sustainable materials with reduced carbon footprints [43].

The data suggest clear trends in how environmental health, waste management, and pharmaceuticals have evolved over the past decades. Key themes such as toxicity, MW management, heavy metals, and pharmaceuticals have become more specialized, indicating that researchers and policymakers are focusing on specific, pressing issues such as the environmental impact of MW, along with more advanced treatment methods. Each period reflects an increasing development in managing these problems, with a marked shift toward sustainability, the toxicity of chemicals, and the health impacts of waste products. Notably, the acceleration of research on sustainable waste management practices coincides with broader societal shifts toward circular economy principles, suggesting that medical waste research is increasingly aligned with and influenced by macro-level sustainability paradigms. The thematic evolution map can be used to identify areas where further research and policy interventions are most needed, particularly in sustainable waste management practices.

Several key needs for MW management have been outlined, including enhancing the consistency of MW definitions across various jurisdictions, developing comprehensive national procedures, guidelines, and regulations, standardizing and streamlining existing technologies for waste treatment at the national level, establishing a unified system for supervising and monitoring the medical sector, and driving advancements and innovations within the medical system to better prepare for and respond to future pandemics [2]. Technology transfer, driven by the triple helix model of collaboration between academia, industry, and government, is crucial for advancing MW management through the adoption of innovative and sustainable treatment solutions [44,45].

Sustainable MW management is vital for minimizing environmental damage and protecting public health. This involves strategies such as proper segregation, using eco-friendly containers, and safe disposal to prevent contamination. Continuous staff training and awareness are key for adherence to best practices. Medical facilities must also adopt eco-conscious methods such as recycling and reducing single-use plastics to support a circular economy. Collaboration across all departments and adherence to operational standards are essential for fostering a sustainable medical environment [46].

In surgical intensive care units, resource use leads to substantial waste. Despite limited awareness of sustainable development goals. The World Health Organization emphasizes climate-friendly hospitals, focusing on reducing energy consumption, promoting alternative energy, and improving waste management. Training medical staff and establishing ‘green teams’ is essential for fostering sustainability, minimizing healthcare’s environmental impact, and aligning with global climate goals [47].

Medical facilities can adopt sustainable practices by reducing waste, optimizing energy use, and promoting renewable energy sources such as solar and wind. Minimizing unnecessary tests, reusing materials, and recycling solvents can reduce resource consumption. Implementing paperless systems and energy-efficient building designs also contribute to greener operations [48].

Numerous developing countries still rely on incineration, which can contribute to air pollution, or landfill disposal, posing long-term environmental and health risks. To address these challenges, there is an urgent need for policy frameworks and sustainable practices such as waste reduction at the source, recycling, and adopting cleaner disposal technologies [49].

Comprehending variables such as acceptability, feasibility, and sustainability can substantially improve the implementation of effective medical waste remedies, mitigating environmental dangers and enhancing healthcare practices [50].

Over the past twenty years, significant work has been undertaken to enhance the management frameworks and regulations surrounding MW, alongside efforts to promote effective practices at local, national, and global levels. Governance structures frequently suffer from weaknesses related to policy and regulatory matters, especially in low- and middle-income countries, which necessitate substantial support for institutional development and capacity-building initiatives [51].

In order to address the effective management of potentially infectious MW, several organizations, including the National Safety Council of the United States, worked alongside institutions such as the Centers for Disease Control and Prevention, the Environmental Protection Agency, and the Department of Transportation to jointly develop two important publications: “Planning Guide for Treatment of Solid Waste Contaminated by Class A Infectious Substances” and “Management Guide for Class A Infectious Solid Waste” [14].

Global institutions, including the World Health Organization and the International Atomic Energy Agency, have developed comprehensive strategies and regulatory tools aimed at guiding countries in handling MW. Numerous states have committed to international agreements such as the Minamata, Basel, and Stockholm Conventions, which focus on the responsible management of hazardous substances. At the European level, the European Union has enacted a range of regulatory instruments, including the Circular Economy Action Plan, the Waste Framework Directive, and the European Green Deal, all of which incorporate provisions related to MW. Moreover, the European Commission has advanced regional sustainability through projects such as the Green Agenda and the Economic and Investment Plan for the Western Balkans, both targeting environmental enhancement. On a national scale, individual governments align with these overarching frameworks through domestic policies, legal structures, and participatory approaches, involving civil society, non-governmental organizations, and the private sector in building efficient waste management systems [27].

At the 2016 Environment Ministers’ Meeting held in Toyama by the Group of Seven, a policy initiative on resource efficiency was introduced, aiming to advance the sustainable use of materials and support long-term development goals [52].

The present study differs significantly in methodology and analytical approach from other bibliometric studies targeting various aspects of the MW field. This work utilized the WOS Core Collection and a Python-enhanced search strategy, retrieving 3025 relevant articles. These articles were evaluated using various analyses and tools, such as VOSviewer and Bibliometric for visualizations and data analysis. The analyses include annual publication and citation trends, country scientific production, institution scientific production using trend analysis, the most influential articles based on citation metrics, country collaboration networks, thematic evolution in MW research, collaboration mapping, trending topics and keywords using keyword co-occurrence network analysis, and thematic mapping.

To more effectively underscore the originality and added value of our research,

Table 4. Specific evaluation of recent bibliometric analyses in medical waste research.

Study Title/ First Author	Study Objectives	Database	Time Span	No. of Papers	Tools Used	Analytical Depth	Limitations	Ref.
The evolutionary path of medical waste management research: Insights from co-citation and co-word analysis/Soyler A.	Mixed approach identifying topics that have gained traction over time in the medical waste management literature	Web of Knowledge	2000–2023	2156	CiteSpace Bibliometrix	Co-word, co-citation	Limited to trend topic and cluster analysis	[6]
Current State, Development and Future Directions of Medical Waste Valorization/Chu Y.T.	Thorough examination of the current state of scientific advancement in the field of medical waste management investigation	Scopus	No time limit	Over 1900	VOSViewer	Performance analysis, science mapping of journals, articles, collaboration networks, keywords, and research hotspots	Tool dependency, search string limitations	[23]
A systematic analysis of research trends on healthcare waste management during 1995–2022/ Sabour M.R.	Analyze research trends, growth, key contributors, and focus areas in MW management	Scopus	1995–2022	877	VOSviewer	Evaluation of publication trends, journal performance, citation impact, country and sponsor contributions, author productivity, and keyword dynamics	Reliance on a single database, limited filtering by language, relatively short analysis period	[25]
Does medical waste research during COVID-19 meet the challenge induced by the pandemic to waste management?/ Wang Q.	Examination of the performance, themes, and challenges of medical waste research during COVID-19 and strategies for improving management	Scopus	2020–2022	307	VOSviewer Bibliometrix R	Analysis of bibliometric results, geographical distribution characteristics of publications, key authors, major research institutions, core journals, major disciplines, influential articles, text mining results, frequency keywords, and research hotspots (only COVID-19-related)	Search query limitations The study did not account for whether the journals had relevant special issues Database limitation (exclusive use of only one database)	[26]
Mapping healthcare waste management research: Past evolution, current challenges, and future perspectives towards a circular economy transition/ Ranjbari M.	The study maps medical research evolution, key themes, and future directions for circular economy and sustainability	Web of Science	No time limit	708	VOSviewer	Chronological distribution, most productive journals and influential articles, publication trends, collaboration network, keywords co-occurrence, text mining	Use of bibliographic coupling as the only clustering technique, exclusion of non-English publications Database limitation (exclusive use of only one database)	[27]
Mapping of Research Output on Medical Waste Management: A Mapping of Research Output on Medical Waste Management: A Bibliometric Study/ Sofik S.	Analysis of international scientific literature targeting MWM	Web of Science (SCIE)	2001–2020	944	Biblioshiny, ScientoPy, VOSviewer	Overall publication and citation growth trend, top influential countries, top productive organizations, most prolific authors, most influential research journals, co-occurrence network analysis, term frequency analysis, country collaboration map analysis, three-factor analysis (country, keyword, and organization)	Search string limitation, time frame restriction, document type variation Database limitation (exclusive use of only one database)	[53]
Waste management beyond the COVID-19 pandemic: Bibliometric and text mining analyses/ Ranjbari M.	The study explores COVID-19-related MW research trends, key themes, and future gaps	Scopus	2021–2022	1030	VOSviewer	Geographical distribution, author productivity and influence, core journals, articles, keyword-based analysis	Excluding non-English papers Database limitation (exclusive use of only one database)	[54]
Medical waste management and the UN Sustainable Development Goals in Ukraine: An assessment of solutions to support post-war recovery efforts/ Filho W. L.	Finding the interrelationships of scientific research on medical waste in the context of achieving the UN SDGs	Scopus	2019–2023	874 (I)/327 (II)	VOSviewer	Cluster analysis, keyword analysis	Search query limitations Database limitation (exclusive use of only one database)	[55]

MW, medical waste; MWM, medical waste management; SCIE, science citation index expanded; UN, United Nations; SDGs, sustainable development goals; I, first analysis; II, second analysis.

presents a structured comparison between our study and other recent bibliometric analyses in the field of medical waste. The comparison is based on key criteria, including the database selected, the time span covered, data volume, analytical tools employed, and the depth and breadth of thematic exploration. This systematic approach highlights the distinctive analytical framework and the broader thematic reach of our study, emphasizing its capacity to bring novel contributions and deeper insights into the evolving landscape of medical waste research.

The present study sets itself apart through several innovative and methodological advances. It spans one of the longest analysis periods to date (i.e., 1975–2024) and relies on the largest and most refined dataset (i.e., 3025 documents) among comparable research. This search strategy represents one of the most complex keyword algorithms in the field, incorporating 41 unique terms to ensure the comprehensive retrieval of relevant literature on medical waste management. A key differentiator is the integration of a custom-built Python-based thesaurus generator, which, to our knowledge, is being used for the first time in bibliometric analyses targeting the field of MW, which applies TF-IDF, cosine similarity, and semantic clustering to standardize keywords. To ensure rigorous and reproducible analysis, we systematically validated our Python-based thesaurus tool. The clustering precision rate was assessed by having three researchers independently evaluate 300 randomly selected terms, with a success threshold requiring agreement on at least 270 keywords. The tool successfully met this threshold, confirming its effectiveness in identifying synonymous relationships, eliminating redundancies, and consolidating semantically equivalent terms into coherent groups. By combining multiple analytical tools, including VOSviewer, Bibliometric, and Excel, the study offers robust visualizations such as co-authorship networks, journal citation maps, trend topic trajectories, and thematic evolution diagrams. Special attention was also given to enhancing figure readability through improved legends, color schemes, and clarification of technical terms.

In contrast, previous bibliometric studies targeting various aspects of MW have typically relied on Scopus and smaller datasets, lacking the co-word analysis to discern trending topics and thematic evolution in the field of MW [25]. A subsequent study also incorporated fewer types of analyses, with methodologies more narrowly focused on literature reviews rather than comprehensive data-driven assessments [6]. Furthermore, one of these studies targets a simple bibliometric analysis without engaging in critical comparative discussions with other works or providing in-depth evaluations of relevant articles, which would help in understanding the evolving trends in publications both thematically and methodologically over time [53]. Additionally, another study has concentrated solely on COVID-19-related MW using smaller datasets, offering a more limited scope compared to broader, long-term explorations of the field [26].

Most studies recognize the COVID-19 pandemic as a catalyst for intensified waste-related research, yet the present work distinguishes itself through methodological precision and a forward-looking, sustainability-centered analytical frame.

While bibliometric studies offer valuable insights, it is important to consider their inherent strengths and limitations. One strength is their capacity to analyze large quantities of research data, thereby providing an overview of trends and patterns across extensive fields of study. This, however, can also constitute a limitation, as the considerable number of articles makes it not feasible to verify each one manually, which may result in the inclusion of false positives in the data. A key strength of the present bibliometric studies is the application of custom Python code, such as a thesaurus generation algorithm. This approach reduces biases in keyword selection and improves the accuracy of data categorization by leveraging natural language processing techniques, including TF-IDF vectorization and cosine similarity analysis. By systematically identifying and consolidating semantically similar terms, this method ensures more reliable and consistent results while minimizing the risk of false positives or redundancy.

It is also important to note that bibliometric studies are subject to limitations due to the introduction of bias resulting from language restrictions. The exclusion of research published in languages other than English may result in the overlooking of valuable research, thereby limiting the scope of the analysis. It is also the case that citation biases can affect bibliometric analysis. This is because highly cited publications may not always reflect the most creative research, particularly if they are published in journals with a relatively small readership. Furthermore, it can distort the perceived significance of research when self-citations or citations among collaborators, supervisors, or editors are exploited to artificially inflate citation numbers.

Additional limitations specific to this study include the exclusive use of WOS as the sole database. Although this choice was methodologically justified to avoid integration difficulties, it potentially excluded relevant publications indexed exclusively in other databases, such as Scopus or specialized repositories. Additionally, the COVID-19 pandemic introduced significant temporal distortions in research and publication patterns in the post-2020 period, which could overrepresent pandemic-related themes in our recent data while simultaneously creating publication delays for other important research. Finally, our analysis primarily captures trends in academic publications and may not adequately reflect important developments in medical waste management occurring in practical contexts that are not widely documented in the specialized literature.

Despite these constraints, bibliometric studies remain a valuable instrument for the scientific, academic, and student communities, offering a pragmatic approach to grasping research tendencies and academic performance. As machine learning and artificial intelligence (AI) tools continue to evolve, many of these limitations are likely to be addressed, including those pertaining to language barriers, false positives, and biases in citation analysis. These advancements will enhance the accuracy and depth of bibliometric analyses, improving their ability to assess research quality and trends.

5. Conclusions and Prospects

This bibliometric analysis targeting MW research uncovers notable trends and insights that indicate both advancements and obstacles in the discipline. Geographical collaboration patterns highlight the global nature of this topic, with specific concentrations of research activity concentrated in Asia, Europe, and worldwide.

The observed rise in research output, particularly during and after the COVID-19 pandemic, highlights increasing global attention toward the environmental and public health challenges posed by MW. A clear transition can be identified from traditional disposal methods, such as incineration, toward more sustainable alternatives, such as thermal plasma pyrolysis, advanced oxidation processes, and eco-conscious practices for plastic waste reduction. Improvements in waste treatment techniques, particularly sustainable technologies, indicate a continuous transition towards minimizing environmental and health issues. Moreover, robust policy frameworks and well-implemented regulatory practices are essential for ensuring the safe, sustainable, and standardized management of MW at both national and international levels. By tracking scientific production and identifying key trends, this study supports evidence-based data and offers a strategic foundation for researchers, institutions, and policymakers aiming to improve global MW management in a sustainable and equitable manner.

Based on the present research in medical waste management, we identified several promising directions for future investigations. First, our keyword analysis revealed a growing interest in sustainable waste management approaches, with terms related to recycling, resource recovery, and circular economy principles showing increased frequency in recent publications. Second, the integration of technological innovations for waste treatment deserves further exploration, particularly regarding alternatives to incineration that minimize environmental impact while ensuring pathogen destruction. Third, our cluster analysis highlights the need for more research on the economic dimensions of medical waste management, especially cost-effective strategies for medical facilities in developing countries, where our study identified a limited number of publications. Fourth, the COVID-19 pandemic created unique challenges in handling infectious waste that require specialized protocols and systems for rapid scaling during medical emergencies. Finally, bridging the gap between academic research and practical implementation remains essential, as our analysis highlighted relatively weak connections between research clusters related to policy frameworks and technical treatment approaches. These directions align with the evolving research priorities identified in our bibliometric analysis and provide pathways for addressing the complex challenges of medical waste management in a post-pandemic world.