Introduction to Occupational Health Hazards
Subtopic:
Waste Management
Waste is any discarded material, whether solid, liquid, or gaseous, that is considered unwanted, valueless, or has been released by its owner.
Healthcare Waste, also known as biomedical waste, infectious waste, or medical waste, encompasses all waste generated from healthcare-related activities. This includes waste produced by healthcare facilities, research institutions, and laboratories.
If not properly managed, the significant volume of healthcare waste presents a worldwide danger. Improper handling can lead to the spread of highly communicable diseases, and the hazardous chemical byproducts from medical items can cause substantial harm to both ecosystems and the general environment.
Classification of Wastes
Wastes can be categorized in several ways:
Classification based on Physical State (Properties)
Solid Waste: This category includes everyday refuse from households (like kitchen and garden waste), commercial and industrial operations, treated sewage sludge, construction and demolition debris, waste from agricultural practices and food processing, and tailings from mining and quarrying activities.
Liquid Waste: This includes wastewater from domestic sources (such as liquid waste from kitchens, laundry rooms, and bathrooms), rainwater runoff, used lubricating oils, and effluent from industrial processes.
Gaseous Waste: This category comprises gases and fine particles released from sources like open fires, incinerators, and vehicle exhausts, as well as those generated by agricultural and industrial activities.
General Classification based on Degradability
Biodegradable Waste: These are materials that can be broken down or decomposed through natural physical or biological processes. Examples include paper, wood, fruits, and other organic materials.
Non-biodegradable Waste: These materials resist breakdown by natural physical or biological processes. Examples include plastics, glass bottles, discarded machinery, metal cans, and polystyrene (Styrofoam) containers.
Classification based on Effects on Human Health and the Environment
Hazardous Waste: These are substances that are considered unsafe for commercial, industrial, agricultural, or economic applications. They require special handling and disposal, especially when transported across international borders for dumping or disposal.
Non-hazardous Waste: These substances are considered safe for commercial, industrial, agricultural, or economic applications and do not pose the same level of risk during transportation, dumping, or disposal.
Typical Composition of Healthcare Waste
| Type of Waste | Percentage |
| Non-infectious Waste | 80% |
| Pathological and Infectious Waste | 15% |
| Sharps Waste | 1% |
| Chemical or Pharmaceutical Waste | 3% |
| Pressurized Cylinders, Thermometers | Less than 1% |
SOURCES OF HEALTHCARE WASTE
Healthcare waste originates from a variety of sources, broadly categorized as major and minor contributors:
Major Sources
Hospitals
Clinics
Laboratories
Research Centers
Animal Research Facilities
Blood Banks
Nursing Homes
Mortuaries
Autopsy Centers
Minor Sources
Dental Clinics
Physician’s Offices
Home Healthcare Services
Nursing Homes (also a major source)
Acupuncturists’ Practices
Psychiatric Clinics
Cosmetic Piercing and Tattooing Studios
Funeral Services
Paramedic Services
Institutions for Persons with Disabilities
WASTE MANAGEMENT HIERARCHY
The Waste Management Hierarchy is a prioritized framework for managing waste effectively to minimize its negative impact on the environment. It outlines a series of steps, arranged from most to least preferred actions.
The primary goal of the waste hierarchy is to maximize the practical value derived from products and to minimize the volume of waste generated. The hierarchy prioritizes waste management options from most desirable to least desirable, based on environmental impact.
Prevention/Avoidance: This top-priority strategy focuses on preventing waste creation in the first place. It involves implementing measures to avoid generating any type of waste initially. For example, in a healthcare setting, this could include strategies like avoiding disposable food containers by encouraging staff and patients to use reusable options or minimizing single-use product consumption wherever feasible. This proactive approach is the most effective element in any waste management program.
Reduction/Minimization of Waste: This strategy emphasizes decreasing the quantity or reducing the hazardous nature of waste generated. In healthcare, this could involve reducing the unnecessary use of disposable gloves by adhering to evidence-based guidelines on when glove use is truly required. From a manufacturing perspective, companies can innovate by using less toxic materials in product design to minimize the hazardousness of byproducts. The aim is to lessen the environmental and health impacts of waste.
Reuse: Reuse is a highly effective waste management strategy that prevents materials from entering the waste disposal stream. It involves utilizing items multiple times for their original purpose or for a different purpose. A prime example in healthcare is the practice of autoclaving reusable metal surgical instruments or sterilizing other medical equipment so they can be safely used again. This extends the lifespan of items and reduces waste generation.
Recycling: Recycling involves processing waste materials into new products. This process entails collecting various types of waste materials and subjecting them to specific treatments. After processing, these recycled materials become raw materials that are reintegrated into production lines to create new goods. Recycling offers dual benefits: it reduces pollution by diverting waste from landfills and conserves energy by reducing the need for virgin materials.
Energy Recovery: Energy recovery, also known as waste-to-energy conversion, involves converting non-recyclable waste into usable forms of energy. This includes generating heat, light, or electricity. Processes like incineration (combustion), anaerobic digestion, landfill gas capture, pyrolysis, and gasification are employed to convert waste into energy. This approach aids in conserving natural resources and reduces reliance on fossil fuels.
Treatment and Disposal: Disposal is the least preferred option in the waste management hierarchy and represents the final step for waste that cannot be prevented, reduced, reused, recycled, or used for energy recovery. Landfilling remains the most common method of waste disposal, although it is the least desirable due to environmental concerns. Proper treatment of waste before disposal, such as incineration or chemical treatment for hazardous waste, can reduce its harmfulness before it is landfilled.
Waste Management Steps / Waste Stream
The waste stream refers to the systematic sequence of steps involved in managing healthcare solid waste, from its point of origin to its ultimate disposal.
Generation:
Non-Hazardous/General Waste: This category originates from areas not directly involved in patient treatment and carries no significant health risk. Sources include offices, kitchens, administrative areas, general public spaces, hostels, storage facilities, and restrooms.
Hazardous Waste (Infectious & Toxic): This category arises from patient care areas and poses a risk of infection or chemical exposure. Sources include patient wards, treatment rooms, dressing rooms, operating theaters (OT), intensive care units (ICU), labor and delivery rooms, laboratories, dialysis units, CT scan and radiology departments.
WHO Classification of Healthcare Waste:
WHO Category Description of Waste Examples 1. General Waste No identifiable biological, chemical, radioactive, or physical risk. Office paper, food wrappers, kitchen scraps, general sweepings. 2. Pathological Waste Human tissues, organs, or body fluids. Body parts, tissues, organs, blood, and other bodily fluids. 3. Sharps Waste Items capable of puncturing or cutting skin. Needles, scalpels, lancets, broken glass slides and vials. 4. Infectious Waste Potentially contaminated with pathogens. Cultures and stocks of infectious agents, swabs, dressings, bandages. 5. Chemical Waste Contains hazardous chemicals. Laboratory reagents, disinfectants, fixatives, developer solutions. 6. Radioactive Waste Contains radioactive materials. Unused radiotherapy liquids, research isotopes, contaminated glassware. 7. Pharmaceutical Waste Expired, unused, or contaminated medications. Expired or discarded drugs, vaccines, and pharmaceuticals. 8. Pressurized Containers Waste from pressurized items. Gas cylinders, aerosol cans, and pressurized containers. Segregation:
Waste segregation is the essential practice of separating different waste types at the point of generation. This crucial step ensures that each waste stream is handled and disposed of appropriately, according to its specific risks and requirements.
Segregation is implemented right where waste is produced.
Waste is placed into designated containers, typically colored bags or bins, to facilitate easy identification and proper handling. It is important to note that color-coding systems for waste segregation can differ based on national regulations or specific hospital protocols. Therefore, adherence to local guidelines is crucial.
3. Waste Collection and Handling
Waste collection is the methodical process of gathering different categories of healthcare waste within a facility. Handling encompasses the procedures for collecting, weighing, and ensuring appropriate storage conditions for the collected waste.
Trained Personnel: Waste collection and handling are typically managed by trained sanitation staff. Nursing personnel and sanitation supervisors often oversee these operations.
Segregation Verification: Sanitation personnel are responsible for ensuring that waste is correctly segregated at the point of generation. This involves verifying that waste is placed into the appropriately color-coded containers according to waste type.
Documentation: Proper record-keeping is essential. Waste handlers maintain a register to accurately track the quantity and type of waste collected from various areas.
Hygiene Maintenance: Regular cleaning and disinfection of garbage bins and waste containers are critical components of the handling process to maintain hygiene and prevent odor and pest issues.
Safety Compliance: The entire waste collection and handling process must adhere to strict safety regulations and established guidelines. This is paramount to protect sanitation personnel, healthcare staff, patients, and the environment from potential hazards associated with medical waste.
Time Limits for Storage: To minimize risks, waste should not be stored in patient care or waste generation areas for extended periods. A timeframe of no more than 4-6 hours is generally recommended before waste is moved to designated storage, treatment, or disposal areas.
Preparation for Transport: Once collected, waste is prepared for either on-site transport to treatment facilities or for off-site disposal, depending on the waste type and the facility’s waste management plan.
4. Transportation
Safe and efficient transportation of healthcare waste within and outside the facility is crucial to prevent cross-contamination and environmental hazards.
Dedicated Pathways: Hospitals ideally should designate separate corridors and lifts (elevators) exclusively for transporting waste materials. This segregation minimizes the risk of waste contamination in patient care and public areas.
General Waste Transport: General, non-hazardous waste is typically transported directly to municipal waste collection points or designated general waste areas within the hospital for eventual disposal in municipal landfills.
Waste for Treatment: Waste that requires specialized treatment, such as autoclaving for sterilization or incineration for hazardous materials, is transported separately to designated on-site treatment facilities or to a separate site for external transport to off-site treatment centers. Distinctively colored and labeled, sealed containers are used for this purpose.
Sealed Containers: Transportation of all types of healthcare waste, especially hazardous waste, must be conducted using sealed, leak-proof containers. This precaution is essential to prevent leaks, spills, and the accidental release of potentially infectious or hazardous materials during transit, both within the facility and during external transport.
5. Treatment & Disposal
Waste disposal represents the final critical stage in a comprehensive healthcare waste management system. It involves the safe, responsible, and environmentally sound elimination or destruction of healthcare waste, ensuring it no longer poses risks to human health or the environment.
General Waste Disposal: General, non-hazardous waste, after collection and internal transport, is typically disposed of at municipal solid waste dumping sites or landfills, following local regulations for general waste disposal.
Coordination with Municipal Authorities: The sanitation officer or waste management department within the healthcare facility is responsible for effective coordination with municipal waste management authorities. This ensures proper and compliant disposal of general waste, and often involves arrangements for regular waste collection and transport to municipal sites.
Waste Identification: To ensure proper treatment, clear labeling and standardized symbols are essential for identifying different categories of healthcare waste. Labels and symbols are used to indicate specific hazards associated with the waste, such as:
Risk of Corrosion
Danger of Infection (Biohazard symbol)
Toxic Hazards (Chemical Hazard symbol)
Glass Breakage Hazard
Radioactive Materials (Radiation symbol)
Pharmaceutical Waste
Treatment and Disposal Techniques for Healthcare Waste: A range of specialized techniques are employed to treat and dispose of different types of healthcare waste, aiming to minimize risks and environmental impact. Common methods include:
Technique Description 1. Incineration – A high-temperature dry oxidation process that typically operates at temperatures exceeding 800°C (1472°F).
– Effectively reduces organic and combustible waste materials to inorganic and non-combustible residues, significantly decreasing waste volume and weight.
– Incineration is particularly suitable for managing most types of hazardous healthcare waste and waste streams that are not amenable to recycling or other treatment methods.
– While effective in volume reduction and pathogen destruction, incineration requires careful air pollution control to manage emissions.
2. Chemical Disinfection – A treatment method that utilizes chemical agents to kill or inactivate pathogenic microorganisms present in waste, rendering it safer to handle or dispose of. <-– Primarily applicable for liquid waste streams, such as urine, blood, liquid stool specimens, and hospital sewage, where pathogens are primarily in liquid suspension.
– Chemical disinfection is often used as a pre-treatment step before discharging liquid waste into sewage systems.
3. Thermal Treatment Wet Thermal Treatment (Autoclaving):
– Utilizes pressurized steam sterilization, typically in an autoclave, to kill microorganisms.
– Steam sterilization is effective for treating a wide range of infectious healthcare waste, rendering it non-infectious.
– Commonly used for sharps, cultures, and laboratory waste contaminated with microorganisms.
Dry Thermal Treatment (Non-Burn):
– A non-combustion, dry heat-based disinfection process.
– Suitable for treating infectious waste and sharps to reduce biohazard risk.
– Generally not appropriate for pathological waste (body parts, tissues), cytotoxic waste (chemotherapy waste), or radioactive waste.
4. Microwave Irradiation – A disinfection technology that uses microwave energy at specific frequencies and wavelengths to destroy most types of microorganisms, including bacteria, viruses, and spores.
– The efficiency of microwave irradiation treatment is typically verified through bacteriological and virological testing to ensure adequate pathogen inactivation.
– Suitable for treating infectious waste and sharps.
5. Land Disposal (Burial) – Land burial, including open dumping and sanitary landfills, represents the least preferred method in the waste hierarchy and should only be considered when more sustainable treatment options are not feasible.
– Land disposal may be considered for hazardous healthcare waste only when no other viable treatment or disposal pathways exist.
– Prior to resorting to land disposal, thorough investigation and consideration of more environmentally sound treatment methods should be undertaken.
6. Inertization/Encapsulation – A pre-treatment process aimed at reducing the environmental impact of hazardous pharmaceutical waste prior to final disposal.
– Involves mixing pharmaceutical waste with inert materials like cement, lime, and water to create a solid, stable matrix.
– The inert mixture, once hardened, inhibits the leaching of hazardous components from the waste into the environment, reducing the risk of groundwater and surface water contamination.
– A typical mixture proportion for inertization may consist of 65% pharmaceutical waste, 15% lime, 15% cement, and 5% water, although proportions can vary depending on waste characteristics.