Types of Biomedical Waste Management and Its Sources
In Biomedical
waste management health care waste is divided into two main categories
hazardous and non-hazardous. If the waste is not segregated correctly,
hazardous waste can contaminate non-hazardous waste. This can make the
collection, transportation, treatment and disposal of waste difficult and
dangerous. Furthermore, treating non-hazardous waste as if it results in wasted
resources and effort is dangerous.
Categories and Sources of Waste
Category-1 Hazardous Waste
Examples of infectious waste
Used sharp waste
or unused sharp items examples are tools (such as scalpels and blades),
needles, syringes, and broken glass or ampoules. Pathological waste (bodily
waste) for example human tissue or fluid (such as blood and body fluids),
organs (body parts), plaques and fetuses and unused blood products. Other
infectious waste examples are dirty gloves, gauze or bandages that are
contaminated with blood, body fluids, viruses, or parasites.
Examples of toxic waste
Pharmaceutical
waste is used, expired or no longer
required pharmaceutical products (such as vaccines and drugs)
Chemical waste examples are chemical substances (such
as laboratory reagents or film developers), disinfectants, solvents, and wastes
with high heavy metal content (such as batteries, broken thermometers, and
blood pressure gauges).
Genotoxic (harmful to human genes) and cytotoxic
(harmful to human cells) example are medicines used in cancer treatment,
exposure to patients' body fluids chemotherapy or cytotoxic drugs and other
materials contaminated by these agents.
Radioactive
waste examples are
radioactive materials (such as unused fluids from radiotherapy or laboratory
research), glassware, packages, or radioactive materials, paper contaminated
with urine and feces that contain radio nuclides and seal sources (containers
that contain radioactive materials). Contaminated with or tested are stored and
sealed).
Category-2 Non Hazardous Waste
Non-hazardous waste can be disposed of as
municipal waste. Municipal waste is general waste generated primarily by
households and commercial activities, and is collected by municipalities,
ideally for disposal. Municipal waste should not contain untreated medical
waste. Examples are paper, boxes, bottles, plastic containers, and
personal protective equipment (PPE) that have not been contaminated with bodily
fluids or used in an isolation area.
Waste
Processing and Minimizing
Non-hazardous waste can be disposed of as
municipal waste. Municipal waste is general waste generated primarily by
households and commercial activities, and is collected by municipalities,
ideally for disposal. Municipal waste should not contain untreated medical
waste. Examples are paper, boxes, bottles, plastic containers, and
personal protective equipment (PPE) that have not been contaminated with bodily
fluids or used in an isolation area.
Waste Processing and Minimizing
Steps of the process:
Minimizing waste
Where possible, reducing
the amount of waste produced by a health care facility is a good waste
management practice. Waste minimization is most commonly applied at the
generation point, but it can also occur before the entry of items into a
healthcare facility.
Some examples of good waste
reduction practice include: Select the material with minimum packaging.
Choosing devices that can be reprocessed locally that is, properly cleaned,
disinfected and / or sterilized for reuse. Replacing (or replacing)
products For example, using steam sterilization in place of a toxic chemical
disinfectant (ie, glutaraldehyde).
Segregating Waste
Waste segregation can
substantially reduce the amount of healthcare waste that needs special
treatment. Health cares facilities must separate waste when and where it is
generated, such as before going to a patient's room, examination room,
operating theater, or laboratory. Depending on the potential danger
of waste and methods of treatment and eventual disposal, employees should
discard the waste in appropriate containers. Separate the waste by working on a
three-bin system. Use clearly labeled waste containers.
Recommended separation plan of WHO
General waste
Put general health care waste, such as food scraps and office waste, in a container lined with a plain plastic bag. Do not store such waste in containers or bags with biohazard symbols.
Hazardous Sharp West
Disposal of hazardous sharp waste such as syringes, scalpels, suture needles, and glass in a puncture resistant sharp container to prevent needlesticks, cuts and puncture injury. Sharp containers must be labeled with a biohazard symbol and designated "sharp". The sharp container must be located within arm's reach where the sharp is used. Avoid overfilling sharp containers and discard them when three quarters are full to prevent excessive injury. Sharp containers must be single-use
Hazardous Non-Sharp Waste
Other hazardous wastes, such as pathological and infectious wastes, should go in a separate container which is: Leak proof and puncture resistant, Covered with a lid, properly labeled with a bio hazard symbol and color coded, Lined and closed with a plastic bag and three quarters of the bag is closed and loaded to enable safe transport
Other hazardous waste
Other hazardous wastes such
as chemical, pharmaceutical and radioactive wastes should be packed and labeled
with the appropriate hazard symbol. Ensure that packaging materials do not
react with hazardous components of waste.
Waste Collection, Transportation, and Storage
After separating waste,
designate staff to collect and transport each ward or unit for disposal or
transport to a dedicated storage area for disposal.
Collection
To deal with hazardous or
infectious waste, always wear PPE which should include: Utility gloves
(not nitrile gloves), a heavy duty apron and the shoes
Transport
The equipment in the healthcare facility that holds and transports waste should not be used for any other purpose. If available, use separate equipment, such as a cart or wheelbarrow, to transport hazardous and non-hazardous waste separately. The dedicated team should be:
- Easy to load and unload
- It has no sharp edges that can tear bags or damage containers.
- Easy to clean
- Clearly labeled
Storage
Store waste until it can be
treated or transported offsite. Health care facilities should have an
operational plan for waste so that the need to store waste is minimized. When making
an operating plan, consider the amount of waste produced daily, the needs of
waste management staff, the size of storage areas, and the final disposal
method. Waste storage areas may be located within a health care facility or in
a designated area in the field.
Whether kept indoors or
outdoors, waste must be protected from people and animals, and protected from
rain. Ensure that the waste storage area is easily accessible by the staff in
charge of handling waste. If waste is moved offsite, consider placing a storage
area where waste-collection vehicles have easy access the waste storage area
should be of appropriate size for the amount of waste generated by the health
care facility.
Infectious waste should not
exceed the following periods: Temperature: 72 hours in winter / 48 hours in
summer and 48 hours in cold weather / 24 hours during hot weather. If
a refrigerated storage room is available, the infectious waste can be cooled to
temperatures from 3 ° C to 8 ° C for more than a week.
Waste Treatment and Disposal
After collection, health
care waste is treated and / or disposed according to its type. The WHO
recommends the treatment of hazardous waste prior to disposal to reduce risk
and hazard. The disposal method depends on how it has been treated, as
well as the type and quantity of waste, the space available on site, and access
to disposal options.
Thermal methods
Heat methods, which destroy
microorganisms in the waste through heat, include low- and high-temperature
technologies. Non-combustion (low-heat) processes, like autoclave and steam
based treatment systems, operate at 100–180 ° C (212–356 ° F). Combustion
(high-temperature) processes range from about 200 ° C (392 ° F) to over 1,000 °
C (1,800 ° F).
Chemical methods
With chemical methods, the
waste is exposed to a chemical agent that kills microorganisms such as chlorine
dioxide, sodium hypochlorite, lime solution or calcium oxide
powder. Chemical disinfection is best suited for the treatment of
liquid waste such as blood, urine, feces, or hospital sewage. Manual
chemical disinfection of solid wastes is not recommended.
Radiation method
Radiation methods use
ultraviolet radiation or microwaves to destroy microorganisms. They
complement other settlement methods and are not easily accessible in low and
middle income countries.
Biological methods
Biological methods,
including manure and burial, depend on the natural decomposition of organic
materials. These procedures are recommended for the placenta.
Mechanical methods
Mechanical methods include shredding, grinding, mixing, and compacting techniques that reduce waste volumes but do not destroy microorganisms. They usually complement other treatment methods. These procedures can be used to destroy needles and syringes. Use them after dissolution of waste, or as part of a closed system.
Infectious Waste Treatment and Disposal
Pathological / Anatomical Wastes
Waste in these categories
is traditionally buried or cremated in incinerators. Treatment and disposal of
pathological and anatomical wastes may be bound by social and religious norms.
For example, placenta waste can be buried in pits or taken home.
Liquid infectious waste
This type of waste includes
liquid culture media, blood, body fluids, human excreta, and fluids from
operating theaters. Autoclaves and incineration techniques typically
available in low-resource settings are not effective for large quantities of liquids.
Liquid infectious wastes can be disposed of directly in closed sewer systems
(such as a utility sink drain or flushable toilet) or in dispatch septic tank
systems by employees wearing PPE and taking precautions to avoid
spraying.
Other Hazardous Waste Treatment and Disposal
Chemical, pharmaceutical
and radioactive wastes should be included in the National Strategy for
Hazardous Wastes, and treated according to international and local regulations.
Ashes from ash are considered dangerous as they may contain heavy metals and
other toxins. Ash must be disposed of properly at hazardous waste sites
(such as engineered landfills), encapsulated and buried, or disposed of in
concrete-lined ash pits.
Avoid direct contact and inhalation, and wear appropriate PPE (such as utility
gloves, plastic aprons, goggles, and masks or N95 respirators).
Other Treatment and Disposal Options
If healthcare facilities do
not have the ability to treat waste or return it to the manufacturer,
encapsulation or inactivation may be used to dispose of small amounts of
sharps, chemicals, or pharmaceutical wastes. These methods can reduce the risk
of injury to people and reduce the risk of toxins migrating to the surface or
ground water.
These methods are rarely
used. Encapsulation is a process that seals waste containers with an
immobilizing material such as a container. After hardening, the
containers can be safely disposed of in a landfill. Insurization involves
mixing of waste (such as pharmaceutical and high metal-content ash) with water,
lime, and cement before disposal to reduce the risk of toxic substances in
surface and groundwater. Pharmaceuticals must be removed from their
packaging and ground before being mixed.
Disposal Sites
In the previous section, we
mentioned different types of settlement sites. Now we will learn more about
these sites.
Landfills
If done properly, disposing
of healthcare waste, both treated and untreated, in landfills can protect
staff, the community and the environment. Landfills are specifically designed
and engineered for the safe disposal of waste on land.
Properly constructed sanitary landfills:
Restrict access to prevent
sweep Prevent infiltration of water. They are lined with a low permeability
material (such as clay) Ideally, at the end of each work day, the waste should
be spread out in thin layers, compacted and covered with soil. Gases
should not be allowed to build up as they become dangerous.
Placenta pits
In many cultures, burying
placentas is an important custom. In low-resource settings, a placental
well is an effective option for safe removal. The site for a placental
well should minimize public accessibility the size will depend on the number of
daily deliveries in the facility. On average, a placenta and its
associated fluids will require 5 liters (1.5 gallons) of well capacity.
The well must be designed to prevent debris from contaminating the surrounding
groundwater. A distance of at least 1.5 meters (approximately 5 feet)
from the bottom of the well to the ground water level is recommended. Placental
wells are not recommended for sites where the water table is close to the
surface or in areas prone to flooding.
Sharp holes
Even after decontamination,
the waste from sharp objects could present physical risks. There could also be
a risk of reuse. Decontaminated sharps debris can be disposed of in concrete
lined sharps pits on the facility premises or can be encapsulated by mixing the
debris with immobilizing material, such as cement, before disposal. These
procedures are recommended only in cases where waste is handled manually and
landfill for general waste is not insured.
Ash pits
Incineration ash is
conventionally considered hazardous by virtue of its likely heavy metal content
and the dioxins and furans it may contain. It should preferably be
disposed of in sites designed for hazardous waste, eg. cells designated in
engineering fillings, encapsulated and placed in specialized monofill sites or
placed on the ground in an ash pit. The ash pit must be lined with
concrete, not accessible to the public and at least 1.5 meters above the water
table.
Small burial sites for waste disposal
In health care facilities
with limited resources, the only option available for waste disposal is the safe
short-term burial of waste in or near the facility. Safe burial at the
site is practical only for limited periods of time (1–2 years) and for
relatively small amounts of waste. Burial can be used as a method of
waste disposal only when the water table is more than 4 meters (12 feet) below
the surface. During this time, the health care center should continue to
search for better and more permanent methods of waste disposal.