Abstract: Medical waste is all waste generated by healthcare institutions, which is related to the performance of medical-technical actions in the field of diagnostics, therapy or research activities. The adequate disposal of medical waste is an issue for virtually all Southeastern European countries primarily because these countries lack the necessary capacities for the removal of medical waste. The aim of the paper is to review the results and experiences in the treatment of medical waste, as well as the potential risks to patients, medical and non-medical personnel. The implementation of a safe medical waste management system could significantly improve the quality of healthcare services, the health of patients and preserve the environment. The use of steam sterilization has been suggested in order to reduce the content of biological agents in the waste, to an acceptable level, by thermal treatment, that is, to achieve biological inactivation.

Key words: medical waste, storage, procedures, sterilization.

INTRODUCTION

Medical waste includes four types of waste: infectious waste, biohazard waste, pharmaceutical waste and radioactive isotopes. Infectious waste includes all items that have been in contact with patients’ blood (needles, syringes, bandages, gauze, scalpels, etc.), while biohazard waste includes organs, tissues and amputated body parts, which are stored in cold storage and buried in city cemeteries under the supervision of sanitary inspection. Medicinal products returned from health institutions, as well as those that have expired, are classified as pharmaceutical waste. Radioactive isotopes are the remains of substances that are used in diagnostics and therapy and which, although unusable, contain a smaller or larger quantity of radioactivity (1).

The increase in the number of inhabitants in the European Union (EU) has been accompanied by an increasing amount of waste. EU countries discarded 1.3 billion tons of waste annually, of which 40 million tons belong to the category of hazardous waste, while more than 700 million tons of waste originate from agriculture. This is a big challenge faced by EU countries, with a clear task to ensure the treatment and disposal of waste without any negative effects on human health and the environment (2).

The overall opinion is that waste generated in healthcare institutions is a mixture of municipal waste and hazardous medical waste resulting from the provision of healthcare services. Hazardous waste has the following characteristics that distinguish it from municipal waste: harmfulness, toxicity, carcinogenicity and infectivity.

Harmfulness is reflected in a substance or waste that, when swallowed or inhaled, or when it penetrates the skin, can cause danger to human health.

Toxicity means a substance or product that may contain toxic ingredients, which in case of inhalation, ingestion or skin penetration can cause serious, acute and chronic health risks, even death.

Carcinogenicity encompasses substances or products that, if inhaled, swallowed or when they penetrate the skin, can cause cancer or increase its spread.

Infectivity means substances or waste containing living microorganisms and their spores, or their toxins, that we know or suspect cause disease in humans and other living organisms (3).

Ugrinov & Stojanov (4) indicate that medical waste includes all types of waste, in solid and liquid form, from hospitals, clinics, research institutions and laboratories working within a health system. However, it should be noted that between 70 and 90 percent of medical waste is actually municipal waste.

The projection of the creation of medical waste in the Republic of Serbia depends on many factors, but the expected amount by 2030 is around 5,000 tons (5).

In most healthcare institutions, infectious waste, used needles, tampons, gauze, infusion systems, etc., are not separated from conventional garbage, but are thrown together into plastic baskets and/or stronger polyethylene bags. Veterinary stations and clinics generate a certain quantity of biohazardous waste, which is disposed of in pits or burned in an uncontrolled manner (6).

It is necessary for the personnel who are in charge of medical waste management in healthcare institutions to acquire new knowledge and skills, on a continous basis, in order to influence a reduction in medical waste, its classification, collection, storage, transport, processing and temporary or final disposal. This means that, among other things, they must be provided with professional instructions and recommendations regarding the application of adequate methods and techniques for waste management. An important segment of their work is risk assessment and the provision of preventive measures.

Appropriate management of medical waste can reduce total generated waste, as well as hazardous waste generated during the performance of healthcare activities. Therefore, medical waste is generated during diagnosis, treatment or provision of medical care, but also during research conducted at health institutions. In this respect, we mean all waste generated both in healthcare institutions and outside them, for example during home care, in institutions for the accommodation of the elderly, or in institutions that provide any form of medical care.

Contamination of the environment by radioactive substances implies the presence of radionuclides in the environment in concentrations that exceed certain values. The level of radioactive contamination in imported food, medicines, medical aids, items in general use and other goods must not be higher than that permitted for similar household items (7).

 

1. CLASSIFICATION OF MEDICAL WASTE

 

There are several criteria for sorting waste, but the most commonly used division is into non-risky and hazardous waste. Sorted medical waste is packed in accordance with the space that regulates the storage, packaging and labeling of hazardous waste. For certain types of medical waste, packaging is done in the following manner (8):

• communal waste – in black bags;
• sharp objects – in yellow containers (the bag is filled up to ¾, after which it is closed);
• pathoanatomical waste – in brown bags;
• infectious waste – in yellow bags or containers (the bag is filled up to ¾, after which it is closed);
• waste contaminated with blood and bodily fluids – in double bags or yellow containers.

 

• Non-hazardous waste

 

A characteristic of non-hazardous waste is its similarity to waste generated in households. These include, for example, paper, glass, plastic, food, wood (recyclable materials).

 

• Hazardous waste

 

Hazardous waste is all waste having one of the above characteristics: explosiveness, flammability, corrodibility, toxicity, which represents an additional risk to health and the environment. This also includes waste from radiology.

 

The World Health Organization divides medical waste into several groups (9):

1. Waste contaminated with blood and other bodily fluids, cultures and supplies of infectious agents from laboratory work or waste from patients with infections;
2. Sharp objects. Any object that is used to pierce the skin and comes into contact with biologically hazardous substances such as scalpels, needles, wires, lancets, blades, ;
3. This group refers to samples taken from patients for laboratory analysis such as human tissues, organs or fluids, body parts and contaminated animal carcasses;
4. Includes products contaminated with radionuclides, including radioactive diagnostic material or radiotherapeutic materials;
5. Healthcare facilities use a variety of chemicals to ensure adequate sanitation. Chemical waste such as solvents and reagents used for laboratory preparations, disinfectants, sterilization agents and heavy metals contained in medical devices and batteries;
6. Pharmaceutical products. This category of waste includes used and unused medicines, vaccines, injections, as well as expired medicines and contaminated medicines;
7. Cytotoxic/genotoxic properties. This category represents one of the most dangerous forms of medical waste: it contains substances with genotoxic properties meaning that they are mutagenic, teratogenic or carcinogenic;
8. Non-hazardous general waste. Is waste that does not pose a risk to human health, e., waste that does not pose a particular biological, chemical, radioactive or physical hazard.

 

According to data from the World Health Organization, due to inadequate disposal of needles and syringes, 21 million people in the world were infected with the Hepatitis B virus, of which 32% were newly discovered cases, while two million were diagnosed with Hepatitis C, of which 40% were newly discovered, and 250,000 with a confirmed HIV infection, which is 5% of all newly diagnosed cases (10).

The amount of hazardous medical waste increases every year and threatens to seriously endanger the environment. This is one of the most important reasons that ever more attention is being paid to the disposal of medical waste. Thanks to scientific and technological discoveries, as well as raising environmental awareness to a higher level, significant progress has been made with three objectives in mind:

 

• To avoid, e., reduce medical waste;
• To be used, e., recycled and
• To be processed and finally disposed of in a safe manner.

 

The World Health Organization recommends incineration as a method of medical waste disposal. This method is promoted because it reduces its volume by 90%, destroys microorganisms. Savings are achieved due to a reduction in transport costs while the energy obtained in this way can be used for heating (space, water, etc.). In addition to the above, a significant benefit is reflected in the efficiency of the method as incineration safely neutralizes the potential danger of infection.

However, it should be noted that incineration as a method also carries certain dangers, which are reflected in the emission of harmful and dangerous gases, while in some cases, improper disposal of ashes is a danger considering that ashes can have the properties of hazardous waste.

With the support of the European Union, a project was implemented at the Clinical Center of Kragujevac that marked a turning point in the treatment of medical waste, i.e., the application of steam sterilization in a vacuum under pressure. This method transforms medical waste into harmless waste to human health and the environment, and it is achieved by the process of heat treatment up to the level of acceptable reduction of biological agents in the waste (inactivation of spores defined by the test at 4 log¹⁰ or at a higher level of reduction). Only after that process, medical waste is acceptable for sanitary disposal provided that its origin cannot be recognized (11).

 

2. CATEGORIES OF MEDICAL WASTE FROM THE EUROPEAN CATALOG

 

In 1994, the European Commission defined a comprehensive European waste catalog in order to introduce a common terminology throughout the countries of the European Community and improve waste management (Council directive No. 2000/532/EC). This document is a list of waste and is not final, but is updated and changed from time to time.

The European Waste Catalog defines medical waste as waste that is generated during the provision of health care, in medicine and veterinary medicine (humans and animals) and/or related research, and is listed under number 18 00 00 with subsets. (12)

 

Subsection No. 18 01: Waste from hospitals and/or health centers, waste generated during diagnosis, treatment or preventive health services for people (in human medicine).

 

Table 1. Waste generated in healthcare institutions (human medicine)

 

18 01 01*	Sharp objects (except 18 01 03)*)
18 01 02	Body parts and organs, including blood bags and blood products (except 18 01 03*)
18 01 03*	Infectious waste, waste whose collection and disposal is subject to special requirements to prevent the spread of infection
18 01 04	Non-infectious waste (waste whose collection is not subject to special requirements due to the prevention of infections, e.g., bandages, casts, bedding, disposable clothing, diapers)
18 01 06*	Chemical waste containing hazardous substances
18 01 07	Other chemical waste
18 01 08*	Cytotoxic drugs and cytostatics
18 01 09	Medicines except those from 18 01 08
18 01 10	Amalgam waste from dental care

 

Subsection 18 02: Waste generated during the provision of veterinary health care (waste from research, diagnostics, treatment or disease prevention in veterinary medicine)

 

Table 2. Waste generated by veterinary institutions

 

18 02 01	Sharp instruments (except 18 02 02)
18 02 02*	Waste whose collection and disposal is subject to special requirements to prevent infection
18 02 03	Waste whose collection and disposal is not subject to special requirements for the prevention of infection
18 02 05*	Chemicals consisting of or containing hazardous substances
18 02 06	Chemicals other than those mentioned in 18 02 05
18 02 07*	Cytotoxic and cytostatic drugs
18 02 08	Medicines other than those mentioned in 18 02 07

 

Source: (13)

 

According to the European Waste Catalog, each type of waste has a classification number or its own code consisting of 6 digits (example: 18 01 03). If certain categories of waste, in addition to the six-digit classification number, also have an asterisk after the number, the asterisk indicates that the waste belongs to hazardous waste (example: 18 01 03*, Infectious waste).

 

3. MEDICAL WASTE STORAGE

Before organizing the transport, treatment or handing over of hazardous medical waste, it is necessary to store that waste in a place that is pre-determined and arranged for that purpose alone.

The location for the storage of medical waste must be fenced in and must represent a separate area or facility, known to the personnel involved and intended exclusively for that purpose. The space intended for storage should meet the following conditions:

• to be of adequate size in relation to the quantity of waste produced and its frequency of collection and removal;
• to have water supply and drainage for cleaning and maintenance purposes;
• to be a clearly and visibly marked with a notification of the purpose of the space, prohibition of entry by unauthorized persons, as well as a warning about the possibility of endangering people’s health;
• to be built so as to have impermeable and resistant floor surfaces, as well as smooth wall surfaces that are easy to clean and disinfect;
• to be easily accessible to health service personnel in charge of waste management;
• to be locked, that is, to prevent access to unauthorized persons;
• to be easily accessible to carts and waste collection containers inside health service and waste transport vehicles;
• to be inaccessible to animals and other carriers of infectious agents;
• to be well lit and equipped with natural or artificial ventilation;
• to ensure protection from atmospheric influences;
• to be sufficiently removed from fresh food storage and food preparation areas, patient and visitor routes;
• to have fire protection in accordance with separate regulations.

 

The place for storing infectious waste must be disinfected at least once a week, and if necessary, more often. Pharmaceutical waste is always stored separately from other types of medical waste, and unused medicines from facilities where health care is provided should be stored in a separate area or a room in those facilities. In order to avoid unwanted chemical reactions, chemical waste of different composition should be stored separately. Cytotoxic and cytostatic waste is stored in separate rooms, spaces or facilities, separately from other types of medical waste. Spilled, contaminating drugs, as well as packages containing drug residues from facilities where health care is provided, are packed in adequate packaging, at the place of origin, before storage (14).

The issue of treating household medical waste is particularly important. Namely, home care services are crucial for helping patients with difficulties in accessing conventional health services, and in this sense there is a continuous need to protect medical staff, patients and their families. The results of research carried out in Brazil during December 2020 and January 2021 warn that the main weaknesses are the lack of training of healthcare workers, and the absence of instructions that should be shared with patient caregivers regarding the treatment of medical waste. In addition to sharp waste, all other household medical waste management practices have also been shown to be inadequate and to pose a threat (15).

 

• European Union legislation in the field of medical waste management

 

The movement of waste is an important issue for the European Union, given that the EU is the world’s largest exporter and importer of non-hazardous waste, ahead of the US and China. European paper and plastic are often recycled in Asia. The Waste Shipment Regulation aims to monitor and control such shipments in order to protect human health and the environment, and applies to all international shipments of waste, regardless of purpose, both from within or from outside the EU. In essence, the European Union transposed into its legislation the Basel Convention on the Control of Transboundary Movements of Hazardous Waste and its Disposal, which is therefore binding on all EU countries, which are required to take the necessary steps to inspect, sample and monitor waste shipments (16).

The modern medical waste management system is based on the hierarchical treatment of waste, from the control of the place of origin to the place of final disposal. The complete management of a large quantity of municipal waste could require less funds for the disposal of medical waste, which is the task of the legal framework and specific practical implementation.

European Union’s foundation for waste management policy is the Resolution of the Council of Europe on waste management strategy (97/C76/01), which is based on the framework waste directive (75/442/EEC) and other regulations on waste management in the EU.

 

Five basic principles were established (17):

• Hierarchy of waste management;
• Self-sustaining disposal facilities;
• Best available technology;
• Proximity to waste disposal;
• Manufacturer’s responsibility.

The European Union has ambitions to regulate, as many activities as possible, which affect its functioning with laws and regulations. That is precisely why current EU legislation has a large number of laws and directives that regulate the state and management of waste. Legal acts are divided into five categories, and only the first category represents the General Framework, which includes strategies and measures related to the reduction and recycling of certain types of waste, disposal, types of landfills and control of disposal. Other categories are focused on the characteristics of waste and its management.

Specific waste category contains regulations and guidelines on the treatment and disposal of packaging waste, metal waste, old tires, oil, sewage water, batteries and accumulators, electrical and electronic waste, as well as PVC, which is viewed not only through the problem of a long half-life, but also because of its composition.

Hazardous waste category defines the controlled management of hazardous waste, through directions for the separation, marking, treatment and disposal of hazardous and dangerous medical waste. The segment of the Regulation on the transportation of the mentioned waste, which is known as the Basel Convention, is particularly emphasized here.

Radioactive waste and substances are specifically separated from the category of hazardous waste considering that this type of waste is subject to special legislation, from the management of nuclear fuel and radioactive waste, the transportation of such waste and rigorous control with the aim of protecting against ionizing radiation.

Incineration of waste category is considered the method of choice in the final treatment of waste, and the reason is that it ensures the most significant reduction in the volume of waste and toxic substances, and is also considered the most beneficial for human health and the environment (18).

 

CONCLUSION

 

Medical waste does not account for a large share of total environmental pollution, but it is potentially among the most dangerous types of waste. Pollution from healthcare institutions can be dangerous for the health of those who work in those institutions, the patients, as well as for the environment. Precisely due to the potential danger, a strict obligation of properly handling medical waste has been imposed.

The method of disposal and storage of medical waste represents one of the biggest challenges as it must be safe, efficient and must not endanger the environment. Concern for the safe management of medical waste should be the most important guide when collecting, storing, disposing and transporting waste.

Of crucial importance is the obligation to create rehabilitation programs that offer technologically safe and environmentally acceptable solutions for all future locations. It is necessary to further affirm the approach according to which rehabilitation is carried out at the location itself, whereby it is expected that the rehabilitation program is harmonized with the spatial and urban plans of the local community within whose territory the disposal area is located.

In addition, it is necessary to create as many opportunities as possible for the reuse of materials, as well as to establish a concept of continuous site monitoring, accompanied by regular reporting.

 

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