Health and Environmental Impact of Hospital Wastes: Systematic Review

The hospital is a high-risk workplace. In addition to the risks specific to any organizational structure, there are those linked to the very essence of its activity: presence of pathogens, use of sensitive technologies or devices, dealing with stress, suffering, and death [1]. Healthcare activities generate waste with varying degrees of risk for the patient, staff, and the environment [2, 3]. The production of healthcare wastes (HCWs) is increased during special situations such as during epidemics [4, 5].

Healthcare facilities have an important economic and social role. Healthcare activities generate waste with varying degrees of risk for the patient, staff, and the environment [3, 5].

During the course of the healthcare delivery process, HCWs are generated, a large part of which is assimilated to household waste (packaging, kitchen waste, green waste, etc.) and another category which may have a risk to health and the environment given its nature and typology. This category includes waste at risk of infection such as stinging, sharp waste (needles, blade, scalpel, etc.), and waste at chemical risk [6‒10]. Among the health impacts of the mismanagement of HCWs, we can cite, at the international level, 16,000 hepatitis C (HCV) infections, 66,000 hepatitis B (HBV) infections, and approximately 1,000 infections with virus of human immunodeficiency (HIV), leading to approximately 1,100 deaths and significant disability [11].

Regarding the risks to the environment, they combine both toxic and biological pollution of the air inside and outside the premises of the healthcare environment. Water pollution and soil pollution can be caused by heavy metals such as mercury, cadmium and other biomedical wastes with a risk of contamination of the food chain [12]. Thus, the hospital is a complex structure that generates very diverse risks: it is a universe of coproduction of care and risks. The goal of the medical waste management process is to establish a pathway for the management, reduction, and elimination of biological and chemical problems due to the nature of this waste.

To prevent the risks that may be generated by these different types of waste inside and outside healthcare facilities in Tunisia, a national strategy for the optimization of waste management from healthcare activities, the main objective of which is to improve the current capacities of healthcare establishments in terms of waste management, has been put in place. In this context, there was the promulgation of decree n° 2008-2745 of July 28, 2008, setting the conditions and modalities for the management of waste from healthcare activities, and this in harmony with the framework law 41–96 of June 10, 1996, on waste and the control of its management and disposal [10]. In this regard, in 2009, a project for the establishment of a national management strategy sustainable use of HCWs was launched as part of the “Project to demonstrate and promote good techniques and practices to manage Waste from Sanitary Activities and polychlorinated biphenyls (PCB) in Tunisia,” under the aegis of the National Waste Management Agency (ANGED), cofinanced by the Tunisian government and the Global Environment Fund, and managed by the World Bank [5].

According to the recommendations, six stages of HCW management must be implemented in healthcare facilities [13]. This successful management process includes segregation, collection, storage, transportation, treatment, and ends with final disposal.

In addition, poor management of hospital waste is a problem in most developing countries [14]. This is mainly due to economic problems, which prevent governments from instituting adequate measures for the management of HCWs [15].

HCW is broadly categorized as general and hazardous waste. According to the World Health Organization estimation, the general and hazardous waste types constituted about 85% and 15%, respectively [7, 16]. So the segregation, disposal, and control of these wastes are of the utmost importance. Therefore, and in order to focus on the health and environmental impact of HCW, it is essential to identify the typology of these impacts.

The general objective of this review was to synthesize all the recent publications studying the health and/or environmental impact of the management of HCW. To meet this objective, we will first identify the different types of HCWs generated from the healthcare facilities and describe the different treatment and elimination practices of HCWs.

We carried out a systematic review of the French and English literature over 3 months (April–June 2020), in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). For this research, we used scientific search engines, namely, MEDLINE/PUBMED and Embase databases.

Studies were only eligible if they were published in the English or French language in peer-reviewed journals, during the last 10 years (from May 12, 2010, to May 08, 2020), accessed in the full-text format, and reported one of the following information: health or environmental impact or both of HCWs; HCW management practices. Studies focused on the knowledge, attitudes, and practices of healthcare workers in the management of HCWs; short communication; and unpublished student thesis were not included. The search strategy was employed using a combination of keywords and Boolean functions: “ environment and public health/epidemiology” AND “hospitals” OR “medical waste disposal” AND “environment” AND “health”; “environment” AND “health” OR “environment/epidemiology” AND “hospitals” AND “waste disposal facilities” OR “medical waste disposal”; “health” AND “health impact assessment” AND “hospitals” AND “medical waste” OR “waste disposal facilities.”

The database search was performed by one author who screened titles and abstracts to identify studies eligible for full-text review with reference to another author. Two authors reviewed the full text of potentially eligible studies for criteria and checked for relevance. Any discrepancies between the reviewers were resolved by discussion. The articles were sorted according to the general characteristics of the publications: first author, journal where the study was published, year of publication, setting, and type of study.

After data extraction, the findings were grouped together into three thematic areas: “definition and classification of HCWs,” “waste treatment and disposal practices,” and “health and environmental impact of HCWs.” Finally, data were presented using texts. We used Zotero software to manage the citation.

This systematic review was conducted on studies published over the past 10 years reporting the health and environmental impacts of HCWs and their management practices. An online electronic search was performed using the MEDLINE/PUBMED database and Embase, from which we identified 412 articles. Then these articles were refined by title and abstract and 374 studies were excluded due to short communication, unpublished thesis, and KAP-type studies because they did not meet our objective. Thirty-eight full-text articles were reviewed and 19 of them were excluded due to lack of relevant information for this systematic review. Finally, we included 19 articles (Fig. 1). General characteristics of the studies were summarized in Table 1.

There are several terms used to represent wastes generated from healthcare facilities such as “Healthcare Waste,” which was used by Yazie et al. [13]. In the review carried out by Hossain et al. [14], the authors used the term “Clinical Solid Waste” and presented the different definitions in a summary table: “Healthcare waste,” “Hospital waste,” “Medical waste.” In this same review, these different terms denote either general and medical waste, or general, medical, and sharp waste, or hazardous and nonhazardous waste. Another classification has been reported to distinguish between infectious and noninfectious waste [14].

Sharma et al. [16] used the term “Health-care wastes” to refer to all wastes produced by different healthcare units during the course of the healthcare delivery process, including infectious and noninfectious wastes, chemical wastes, hazardous waste, and other nonhazardous waste. The same term was used by Kuchibanda and Mayo [17] to refer to general waste (food and paper products) and clinical waste (sharps, infectious, pharmaceutical, and radioactive wastes). On the other hand, Gautam et al. [18], in their study evaluating the impact of incinerators on the environment, used the term “Biomedical waste” to refer to any waste which is generated during the diagnosis, treatment, or immunization of human beings or animals or in research activities pertaining there to or in the production or testing of biological.

In the meta-analysis performed by Mol et al. [19], the term “Solid waste” has been used to designate both HCW and household waste. Kasuku et al. [20] used the term “Hospital waste” corresponding to a mixture of waste similar to household waste and HCWs with infectious risks. Udofia et al. [21] used the term “Solid medical waste” to refer to any solid material generated by activities involving health promotion, medical diagnosis, treatment, scientific research, as well as dental and veterinary services.

Overall, the main terms used were “Medical waste” or “Clinical waste” [22‒24], “Solid hospital waste” [25], “Healthcare waste” [26, 27]. Other publications have studied a specific typology of waste, such as “Solid dental waste” [28, 29] and “Regulated medical waste/Red bag waste” [30].

Numerous studies have been carried out in many countries to identify the best methods of managing HCWs, in order to reduce the risks to health and the associated environmental pollution [14]. As a result, several developed countries have developed practical manuals and recommendations for the treatment and disposal of these wastes [15, 31, 32]. The management of HCWs, particularly in developing countries, is often deficient. In these countries, HCW is often treated and disposed of with household waste, which creates inevitable risks for healthcare workers, the general population, and the environment [11, 12]. According to Hossain et al. [14], in 2002, the results of a WHO study conducted in 22 developing countries showed that the proportion of healthcare facilities that did not properly dispose of their HCW was 18–64% [33]. Different methods for eliminating HCWs identified by Hossain et al. [14] were open landfill, incineration, open combustion, autoclaving, thermal disinfection, recycling-reuse, sanitary landfills, and pyrolytic combustion.

Several shortcomings have been noted when treating HCWs in Ethiopia according to Yazie et al. [13]. Indeed, some studies have indicated that no practice of waste segregation was carried out. In others, segregation was very limited. There was no use of appropriate color-coded bins for waste separation. General and infectious wastes were mixed together. Plastic buckets were used to temporarily store the HCW. Disinfection of waste storage and/or transport of utilities were rare. In a few studies analyzed in this review [13], a low-combustion incinerator was used to treat all types of HCWs. In other studies, incineration and open combustion were the hazardous and general waste treatment methods, respectively. Regarding the disposal of treated waste by-products, some studies have reported the use of burial pit, while in others the disposal is unsanitary in open dumps. Several studies are interested in studying incinerators as a means of eliminating HCWs [16, 18].

According to the study conducted by Khan et al. in Pakistan [23], the waste management practice among the 135 clinics studied was deplorable. None of the clinics fully followed good hospital waste management practices. They demonstrated poor segregation of HCWs, improper storage, transport, and disposal.

According to Gao et al. [24], the majority (71%) of healthcare centers reported having packed their hazardous medical waste in containers. However, only 37% of these containers were sealed, and only 49% were labeled with biohazard markings. In half of the center cases studied, combustion was the method of disposal of hazardous medical waste. Just over 10% of centers reported dumping medical waste in sanitary landfills. In some rural centers, hazardous medical waste was disposed of with household waste (11%) or sold to recycling providers.

The study carried out in Tanzania [17] showed that the three healthcare facilities did not separate HCWs from general waste at the point of production. It was also revealed that the separation into infectious and noninfectious waste was not carried out in accordance with regulations and standards. The results revealed that HCWs were neither quantified nor separated in the three hospitals [17]. At the regional referral hospital in Shinyanga, they are disposed of by incineration and combustion on-site, and some wastes are disposed of offsite. At the Kolandoto District Designated Hospital, only on-site combustion and sanitary landfill were practiced, while in Kambarage, the urban sanitary center, HCWs are cremated, dumped in sanitary landfills, and burned.

Finally, according to the results of the study by Udofia et al. [21], unused drugs and sharps were mostly thrown in household trash cans. The disposal of sharps followed a similar pattern using containers (53.5%) and household bins (35%). Soiled items were often wrapped and thrown in the trash (68.2%) or burned/buried (19.6%). Items soaked in blood, including sanitary napkins, were thrown in the trash in 40.6% of cases and also burned/buried in 33.8% of cases.

Four of the 19 articles analyzed presented new management practices of HCWs. Thus, the objective of the project carried out by Debois et al. [30] was to reduce the disposal volume and costs and minimize the negative impact of the treatment and disposal of biohazardous waste on the environment. This was accomplished by diverting the infusion circuit to municipal solid waste. Indeed, before disposal, biohazardous waste must be decontaminated by various processes. Autoclaving contributes to the emissions of dioxins and mercury. Another treatment process, which is incineration, is a major source of dioxin, mercury, and lead. These common disposal methods emit hazardous air pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or adverse environmental effects. Clear bag waste can now be disposed of in waste-to-energy facilities, a process that not only releases significantly less amount of carbon dioxide into the environment but also helps generate renewable energy [30].

The work carried out by Motta et al. [25] described a novel technique for waste management in healthcare settings with a view to facilitating infection prevention and control. This strategy is to explore the innovative use of sodium dichloroisocyanurate (NaDCC) by investigating the microbicidal activity of chlorine, which derives from the hydrolysis of NaDCC mediated by humidity, and by testing its effect on inhibition of microorganism growth. The results of this strategy have demonstrated the effectiveness of NaDCC in controlling and/or inhibiting the proliferation of microbes and supporting its possible use in the treatment of hospital waste to control the spread of contamination.

In October 2013 [29], a new international treaty called the Minamata Convention on Mercury was opened for signature in Minamata City, Japan, which represented the most catastrophic site in terms of public and environmental health due to the heavy contamination of mercury. The treaty aimed to reduce the impacts of mercury pollution on health and the environment and included provisions dealing with the extraction, export and import, storage, and waste management of products containing mercury. The Minamata Convention specifically addressed dental care using amalgam, aiming to gradually reduce the use of dental amalgam [34].

Finally, in order to control the spread of an epidemic, efficient management of rapidly increasing medical waste is of vital importance through the establishment of a temporary reverse logistics system. The work carried out by Yu et al. [22] proposed a novel, multi-objective, multi-period, mixed-integer program for reverse logistics network design in epidemic outbreaks, which aimed at determining the best locations for temporary facilities and the transportation strategies for effective management of the exponentially increased medical waste within a very short period [22]. The application of the model was illustrated by a case study based on the 2019 coronavirus (COVID-19) outbreak in Wuhan, China. The results suggested that installing temporary incinerators could be an effective solution to dealing with the huge increase in HCWs during the COVID-19 outbreak in Wuhan.

The extent of the problem linked to HCWs, in particular hospitals, is determined not only by the extent of the production of waste but also by the health risk they represent for human health and for human life. Unless HCWs are properly treated and disposed of, they can pose risks to healthcare workers, the general population, and the environment [35, 36].

HCW can be the source of different risks at each stage of its disposal. The main risks are infectious or biological, traumatic or physical, chemical or toxic, or psycho-emotional. According to the review carried out by Hossain et al. [14], people involved in the treatment of HCWs are exposed to infectious agents by several routes, in particular by skin penetration, direct skin contact, or by air. A study conducted in South Korea to investigate the types of microorganisms in various HCWs as well as to characterize the survival of microorganisms in these wastes [37] showed that a number of microorganisms, including Pseudomonas spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp., Kocuria spp., Brevibacillus spp., Microbacterium oxydans, and Propionibacterium acnes, were present in various HCWs. In the same context, another microbiological analysis was carried out by Alagoz and Kocasoy [38], also listed in this systematic review [14], to determine the quantity of infectious microorganisms in the HCWs. Coliform bacteria, Escherichia coli, Enterobacter, Pseudomonas spp., Staphylococcus aureus, Bacillus cereus, Salmonella spp., Legionella, yeasts, and molds have been detected in HCWs.

The study of Kasuku et al. [20] investigated the impact of HCWs on the workplaces. Thus, out of 20 people chosen, more than 70% suffered from the sensation of chest tightness, organic dust syndrome, dry throat and nose, molds, and actinomycetes. About 40% suffered from gastrointestinal disorders while handling HCW (from collection to treatment/disposal). The major health impacts of incinerators according to Sharma et al. [16] were the high incidence of cancer and respiratory symptoms. Other problems have also been identified, namely, birth defects, hormonal abnormalities, and increased sex ratio. Indeed, several studies have indicated a decrease in the proportion of male births in the general population of Denmark, The Netherlands, the USA, and Canada who have been exposed to trichlorophenate contaminated with dioxin [39].

In the cross-sectional study conducted by Udofia et al. [21], 29 respondents (4.8%) reported harms associated with solid medical waste in the household, while for 16 respondents (2.7%), reported harms were associated with solid medical waste in the community where they resided. The damage reported was mainly related to used razor blades (1.8%). In the community, the damage reported was mainly attributed to broken glass vials of medicine (1.5%).

With regard to illnesses associated with HCWs, the top three illnesses listed were tetanus (48%), HIV (45%), and tuberculosis/chronic cough (23%). In the study carried out in Pakistan [26] and in order to determine the impact of the lack of personal protective equipment, they examined 132 out of a total population of 206 employees of all the hospitals included in the survey for the screening of HCV and HCB. Rapid test kits were purchased and provided to laboratory staff in each hospital for testing. In many cases, hospitals have rechecked the results using their own kits or methods such as ELISA. In the end, 18 (13.63%) of the subjects came back positive for HCV, and accidental needle sticking was revealed as a significant risk factor after regression analysis [40]. Mol et al. [19] also demonstrated in their meta-analysis that there was a statistically significant association between exposure to HCW and the positivity of markers of HCB infection. Indeed, a significant association was noted between exposure to HCW and a positive serology for the surface antigen of the virus of hepatitis B (HBsAg) (OR: 1.89; 95 CI%: 1.27–2.86; p = 0.0019). The prevalence rates of HBsAg and anti-HBc seropositivity were 0.04 (95 CI%: 0.03–0.05) and 0.21 (95 CI%: 0.14–0.28), respectively (p < 0.0001).

Two of our studies [27, 41] investigated the spread of multi-resistant bacteria through HCWs. In the study carried out by Nascimento et al. [27], among 73 bacterial strains isolated from the percolated leachate of HCW, seven different species were identified by 16S rDNA sequencing: Staphylococcus felis (64.4%; n = 47), Staphylococcus sciuri (26.0%; n = 19), Staphylococcus epidermidis (2.7%; n = 2), Staphylococcus warneri (2.7%; n = 2), Staphylococcus lentus (1.4%; n = 1), Staphylococcus saprophyticus (1.4%; n = 1), and Staphylococcus haemolyticus (1.4%; n = 1). Penicillin was the least effective antimicrobial (60.3% resistance; n = 44) followed by erythromycin (39.8%; n = 29), azithromycin (28.8%; n = 21), and oxacillin (16.5%; n = 12). The most effective antibiotic was vancomycin, for which no resistance was observed, followed by gentamicin and levofloxacin, for which only intermediate resistance was observed (22%, n = 16 and 1.4%, n = 1, respectively). Among strains resistant to oxacillin, the mecA gene was detected in two isolates.

Thus, given the high antimicrobial resistance observed, these results raised concerns about the survival of pathogens carrying important markers of resistance in HCW and their spread in the environment through untreated discarded residues in sanitary landfills. In the study conducted by Moges et al. [41], among 60 samples of wastewater analyzed for the presence of pathogens resistant to antibiotics, 113 bacterial isolates were identified, of which 65 (57.5%) came from the hospital environment and 48 (42.5%) were from a nonhospital environment. The most frequently identified bacterium was Klebsiella spp. 30 (26.6%) followed by Pseudomonas spp. 19 (16.8%), E. coli (11.5%), Citrobacter spp. (11.5%), and Staphylococcus aureus (8.2%). The overall prevalence of multi-resistance to antibiotics in this study was 79/113 (69.9%). This prevalence was 53/68 (81.5%) in the hospital environment, while it was 26/48 (54.2%) in the nonhospital environment. The consequence is that contamination of wastewater with antibiotics will lead to increased resistance due to selection pressure.

Vieira et al. [28] were able to demonstrate the possibility of cross-contamination between dental waste and the handlers of this waste, by highlighting strains of yeast recovered from dental waste treatment sites, including professional clothing, and in dental waste. Finally, a major but not yet resolved concern about the use of dental amalgam is its potential impact on the health of the population given its widespread use in dentistry. It is largely undisputed that intraoral amalgams lead to continued exposure to elemental/inorganic mercury vapor, an element recognized for its toxicity and associated with a number of adverse health effects (including neurological and renal adverse health effects) mainly observed in the workplace [29].

The environmental risk associated with HCWs is aggravated during their disposal of household waste in uncontrolled landfills on public roads, vacant lots, forests, rocks along the coast, etc., and also during their defective incineration. This results in degradation of aesthetics; gas emission and fire risk; the proliferation of rodents and insects; soil degradation; water pollution; atmospheric pollution.

Hossain et al. [14] identified in their review the environmental impacts of the various means of treating HCWs. This analysis is summarized in Table 2.

Most of our studies have analyzed the environmental impacts of incinerators. Thus, in the study carried out by Gautam et al. [18], it was clarified that the incinerators emit toxic air pollutants and toxic ash residues which were the main sources of dioxins in the environment.

According to Sharma et al. [16], the pollutants emitted into the atmosphere by the incinerators will be deposited on the ground near the incinerator and thus contaminate the local environment. Research on environmental contamination near incinerators has shown that soil and vegetation near incinerators are contaminated with dioxins and metals at levels above normal background concentrations, leading to contamination of agricultural products.

In the study by Kasuku et al. [20], the potential environmental impacts were assessed by the physicochemical analysis of leachate from internal landfills where waste is deposited in an uncontrolled manner. The physicochemical parameters analyzed were considered as indicators of pollution. These parameters were temperature; electrical conductivity; pH; concentration of Cl-, SO4--, PO4---, Mg++, Na+, K+, NH4+ ions; chemical oxygen demand; biochemical oxygen demand (BOD5); content of certain heavy metals (zinc, copper, and cadmium). The physicochemical characterization of the runoff from the littering deposits of the four selected hospitals showed high concentrations for most of the parameters studied.

In other studies [20, 29, 41], the environmental impact has been approached in another way. Based on the knowledge of the harmful effects of poor management of HCW on the environment, the authors proposed new procedures for managing HCWs. Thus, according to Mustafa Ali [26], in order to reduce the environmental cost of disposing of HCW, the best option was to implement an integrated waste disposal system consisting of incineration, composting, and recycling of materials [42]. Methylmercury has been globally recognized as an environmental toxin by organizations including the United Nations Environment Program, the World Health Organization, the International Labor Organization, and the United States Environmental Protection Agency. Specifically, mercury-related medical wastes from the extraction, disposal, and incineration of dental amalgam fillings and human cremation are sources of contamination of the atmosphere, land, water sources, and wastewater [43, 44]. This is why Mackey et al. [29], through the Minamata Convention on Mercury, aimed to reduce the impacts of environmental pollution by mercury by basing it on provisions dealing with extraction, export and import, storage, and waste management of mercury-containing products.

Debois et al. [30] tried to replace bypass circuits from the traditional regulated medical waste to clear bag waste or municipal solid waste. The objective was to reduce the volume of waste disposal, to minimize the negative impact that the treatment of these regulated wastes and their disposal have on the environment. Indeed, before disposal, regulated waste should be decontaminated by various processes. Autoclaving contributes to emissions of dioxins and mercury. As for incineration, it is a main source of dioxin, mercury, and lead. These common disposal methods emit hazardous air pollutants which are known to have negative environmental effects.

Our study is the first systematic review carried out in Tunisia to synthesize recent scientific data relating to the management and treatment procedures of HCW in the world, as well as their health and environmental impacts. Our bibliographic research did not identify any Tunisian published works. It is that either this subject was not addressed in our context or it was presented in the gray literature (theses and dissertations). Our review was based on publications indexed on PubMed, testifying the reliability of the information listed. However, we did not consult publications by other search engines, thus limiting the articles analyzed in our journal (publications not indexed in Medline).

The multiplicity of definition and classification of HCWs could constitute a problem because there are considerations for differentiating waste in general from HCW, and this is in relation to choosing the right method of disposal that comes from a clear understanding [45, 46]. In the literature, the terms “Clinical waste,” “Health care waste,” “Infectious waste,” and “Medical/hospital waste” are the most commonly used; they can have similar meanings or be subsets of one another, which limited the comparison of data from different countries [45‒47].

The term “infectious waste” could not be used. In fact, only 10–25% of all HCWs are infectious [45, 48]. However, to overcome this problem, HCW could be classified as nonclinical waste (unregulated HCW can also be defined as general waste) and clinical waste (special waste, regulated waste) [32, 49]. Nonclinical waste is defined as any waste presenting no risk to human health or the environment. Examples of nonclinical waste include packaging materials like cardboard, office paper, food scraps, cans, etc. Clinical waste is defined by the Controlled Waste Regulation (1992) [50] as follows.

• Any waste composed entirely or partially of human or animal tissues, blood or other body fluids, excretions, drugs or other pharmaceutical products, swabs or dressings or syringes, needles or other sharp instruments, being waste which unless being put to safety could prove to be dangerous for those in contact.

• Any other waste resulting from medical, nursing, dental, veterinary, pharmaceutical or similar practice, investigation, treatment, care, teaching or research or collection of transfusion blood, being waste liable to cause infection to any person entering in contact with it.

• Between 75 and 90% of the HCW is general waste, which would be comparable to household waste, while only about 25% are considered hazardous and could create health and environmental risks [51].

Currently, the management of HCW is a concern for both public health and the environment worldwide and in particular in developing countries [52]. Hazardous wastes must be properly separated at their source of general waste [6]. However, in this systematic review, the studies mentioned the absence of good waste management practices. This could probably be due to the lack of proper means of sorting waste, lack of awareness, or lack of compliance with laws and regulations. A systematic review carried out in Africa indicated that 47% of the studies analyzed mentioned the absence of waste sorting [53].

According to the review carried out by Yazie et al. [13], the proportion of dangerous HCW varied in Ethiopia between 21 and 70%. This proportion was higher than the waste threshold of 10–25% predicted by the WHO [7]. This could be due to the fact that during the sorting process, an amount of hazardous waste would be added to the category of general waste, leading to contamination of the latter with hazardous waste. According to WHO recommendations, all HCWs should be stored in specific rooms for cleaning equipment, dirty laundry, and storage of waste [7]. If these facilities were not available, the HCWs would have to be stored in other secure locations [54]. However, the studies analyzed by Yazie et al. [13] indicated that the storage of hazardous waste was done in primary waste sorting containers parked in the corridors. This practice could probably be due to the lack of sufficient and isolated waste storage space away from public access. Treatment of HCW results in a reduction in volume, weight, and the risk of infection. The WHO recommended that the choice of method for removing HCW should be cost-effective, easy to implement, and environmentally friendly [55].

Until today, special attention is devoted to methods of inactivating viable microorganisms in HCW [14]. Therefore, the waste disposal method should have the capacity to inactivate infectious microorganisms so that the waste does not present any risk of infectious disease to any exposed person [56]. Several technologies have been developed to inactivate pathogenic microorganisms. However, neither of these practices was able to do this adequately as each practice had its own weaknesses and drawbacks [46]. In developing countries, the most common disposal methods were open landfills, landfill, or incineration [7, 17, 32, 37, 46]. Other methods were used for the management of HCW: steam sterilization or autoclaving, chemical sterilization, microwaves, etc. [15, 36]. In Ethiopia [13], incineration and open burning were the most commonly used methods of treating hazardous and general wastes, respectively. However, the incinerators were often operated under suboptimal conditions, mainly with untrained personnel, which are believed to have negative effects on the environment.

These aspects of mismanagement are said to be the consequence of economic problems in developing countries which prevented the government from adequately managing HCWs [15]. Indeed, many studies have highlighted the problems of management practices of HCWs in developing countries. There was no proper waste management system in place in most developing countries [57]. In these countries, the management of HCW was assigned to the municipal waste manager without providing any training or specialized instruction to treat this waste in a different way [58]. A study in India also reported poor management of HCW [59]. Many health facilities used different methods of disposing of HCW, such as burning, dumping, burying, and reuse. Similar results have been reported in other studies conducted in different resource-limited countries such as Brazil, Jordan, Iran, and Ghana [31, 60].

Poor management of HCW caused health risks for patients, healthcare professionals, the general population, and the environment. Indeed, this mismanagement could be a source of infection and pollution of groundwater and also of destruction of flora and fauna [17]. The quality and availability of HCW disposal facilities were generally poor, and the systems for the disposal of infectious wastes, including sharps, were inadequate. The risk is particularly high when HCW is disposed of with general waste, which can be a cause of disease transmission among waste pickers, waste recycling operators, cleaners, and waste collectors [61]. Sharps were a major concern in communities and were the cause of the damage associated with HCW in and outside the household. Several diseases are the consequence of HCW, classified as infectious risk. According to several studies [62‒64], this risk is considered the highest risk to the community and the environment. The study conducted by Udofia et al. [21] showed that those who reported an adverse event were more likely to be those who felt at risk for illnesses caused by HCW. Aside from the possibility of transmission of pathogens resulting from inoculation through wounds, other significant difficulties would be related to medical and care costs, lack of concentration, anxiety and emotions prior to distress and after laboratory examinations [65].

Injuries from used needles and syringes found in community settings were of great concern. The user is usually unknown, and parents and healthcare providers were concerned that the needle might have been thrown away by a carrier of infectious diseases. Although the actual risk of infection from such an injury is very low, the parents’ perception of the risk caused a lot of anxiety [66]. The pathogens to consider in this situation are primarily HBV, HCV, and HIV [67]. In some developing countries, it is common for the poor to collect part of the waste (e.g., syringe needles, saline bags, blood bags) to sell despite deadly health risks [68]. Studies have shown that the incidence of illness is more common among waste handlers compared to that among hospital staff [68, 69]. Waste handlers were infected with other common diseases due to unsafe handling, such as cholera, typhoid fever, hepatitis, tuberculosis, bronchitis, diarrhea, skin infection [68, 69].

On the other hand, broken medicine bottles, part of the HCW, are considered problematic within the community and contributed to 2% of reports at home and in the community [21]. Broken glassware caused wounds, allowing the penetration of pathogens through non-intact skin predisposing to infections such as tetanus. It was one of the diseases listed by respondents in association with HCW [21]. Although the proportion of people affected was small, eliminating preventable hazards from HCWs should be aimed at ensuring a healthy and safe environment. When HCW is mixed with general waste in health facilities, the entire load is assumed and treated as contaminated or potentially infectious [70]. These wastes should therefore be treated to minimize risks to the environment before final disposal. The practice of disposing of unused medicines in household bins has been reported in the UK, Kuwait, and Lithuania [71]. About 25% of residual household pharmaceutical waste was disposed of with municipal solid waste in Germany and Austria [72]. The ultimate disposal of household waste containing pharmaceuticals in poorly designed landfills is a cause for concern. Low environmental exposure to some pharmaceuticals has been reported to contribute to toxic effects on aquatic and terrestrial life [73]. Finally, leachate from landfills and other dumpsites containing HCW can contaminate surface and groundwater resources that serve as sources of drinking water. Agricultural food crops can take up the active pharmaceutical ingredients, leading to unintentional, intermittent, often long-term exposure in humans [74].

In Tunisia, the deposit of waste from healthcare activities is estimated at 16,000 tons/year, of which 7,000 tons are hazardous and risky waste and 40% are generated in greater Tunis. A national HCW management program, financed by the World Bank, has been set up by ANGED [75].

Institutionally, the management of HCWs is supervised by ANGED, the Ministry of Health, and the Ministry of the Interior. The producers of HCW are public and private healthcare structures and establishments under the supervision of the Ministries of Health and the Interior. Like several developed countries, Tunisia has recently replaced in situ incineration for the treatment of HCW with infectious risk by trivialization. This involves a pretreatment by chemical disinfection followed by grinding in order to lower the microbial load. This pretreatment is followed by a 98% sterilization, making it possible to join this waste to the category of household waste [5]. In this review, HCW management practices were investigated to determine their impact on health and environment.

The main priority has been given to the treatment and disposal of the HCW, taking into account the infectious risks and the economic constraints. It is obvious that the current management of HCW is not capable of adequately preserving human health and environment from infection contamination.

The surveys analyzed have shown that if incineration is properly treated, it would be an appropriate treatment method to deal with HCWs. However, exposure to pollutants produced by the incineration of HCW is still a public health problem. If incineration is seen as a practical solution for dealing with HCW, low-temperature incinerators should be banned and replaced by modern incinerators equipped with air pollution control units.

The problems are typical for any developing country which does not have the means to purchase incinerators which are more environmentally friendly and equipped with the latest technologies. Thus, autoclaving and microwaves are considered better alternatives for HCW treatment. However, these methods are generally not adequate for the disposal of pathological, radioactive, laboratory, and chemotherapy wastes.

The specific management of HCW is a major concern due to the potentially high risks for human health and the environment. Therefore, we recommend that the general population should be educated on the handling and disposal of HCWs. Community members have the right to know the hazardous properties of waste generated by healthcare activities in the household and how to dispose of it. Communication should take place in local dialects and on electronic media. Regarding the impacts of managing HCWs, community members need to know what to do in the event of harm, how and where to report such events.

An ethics statement is not applicable because this study is based exclusively on published literature

The authors have no conflicts of interest to declare.

The authors received no financial support for the research, authorship, and/or publication of this article.

Hela Ghali – literature review, data collection, editing of the manuscript, and drafting the manuscript; Asma Ben Cheikh – data collection and editing of the manuscript; Sana Bhiri – editing of manuscript; Lamia Bouzgarrou – editing of the manuscript and drafting the manuscript; Mohamed Ben Rejeb, Imed Gargouri and Houyem Said Latiri – manuscript correction and supervision of the manuscript.

The data that support the findings of this study are available on request from the corresponding author.