Solid waste disposal and hospital waste management

SOLID WASTE DISPOSAL
AND HOSPITAL WASTE
MANAGEMENT
Dr. Sakshi kaur Chhabra
2nd year post graduate
Department of Public health dentistry

 SOLID WASTE DISPOSAL
1. Introduction
2. Sources of refuse
3. Methods of disposal
4. Public education and international cooperation
 HOSPITAL WASTE MANAGEMENT
1. Introduction
2. Definition
3. Classification of health care waste
4. Sources of health care waste
5. Health hazards of health care waste
6. Treatment and disposal technologies
7. Biomedical waste in india

SOLID WASTE DISPOSAL
Disposal of wastes is now largely the domain of sanitarians and public health engineers.
However, health professionals need to have a basic knowledge of the subject since improper
disposal of wastes constitutes a health hazard.
 The term "solid wastes" includes garbage (food wastes) rubbish (paper, plastics, wood,
metal, throw-away containers, glass), demolition products (bricks, masonry, pipes), sewage
treatment residue (sludge and solids from the coarse screening of domestic sewage), dead
animals, manure and other discarded material. Strictly speaking it should not contain
nightsoil.
 The per capita daily solid waste produced ranges between 0.25 to 2.5 kg in different
countries.

Solid waste, if allowed to accumulate, is a health hazard because:-
 a. it decomposes and favours fly breeding.
 b. it attracts rodents and vermin.
 c. the pathogens which may be present in the solid waste may be conveyed back to man's food
through flies and dust.
 d. there is a possibility of water and soil pollution.
There is a correlation between improper disposal of solid wastes and incidence of vector-borne
diseases. Therefore, in all civilized countries, there is an efficient system for its periodic
collection, removal and final disposal without risk to health.

Sources of refuse
1. Street refuse
2. Market refuse
3. Stable utter refuse
4. Industrial refuse
5. Domestic refuse

The principal methods of refuse disposal are :-
(a) Dumping
(b) Controlled tipping or sanitary land-fill
(c) Incineration
(d) Composting
(e) Manure pits
(f) Burial
METHODS OF DISPOSAL

 Refuse is dumped in low lying areas partly as a method of reclamation of land but mainly as
an easy method of disposal of dry refuse. As a result of bacterial action, refuse decreases
considerably in volume and is converted gradually into humus. Kolkata disposes of its
refuse by dumping and the reclaimed land is leased out for cultivation.
[a] DUMPING

The drawbacks of open dumping are :
(1) The refuse is exposed to flies and rodents.
(2) It is a source of nuisance from the smell and unsightly appearance.
(3) The loose refuse is dispersed by the action of the wind.
(4) Drainage from dumps contributes to the pollution of surface and ground water.
A WHO Expert Committee (1967) condemned dumping as "a most insanitary method that
creates public health hazards, a nuisance, and severe pollution of the environment". Dumping
should be outlawed and replaced by sound procedures

 Controlled tipping or sanitary landfill is the most satisfactory method of refuse disposal
where suitable land is available. It differs from ordinary dumping in that the material is
placed in a trench or other prepared area, adequately compacted, and covered with earth at
the end of the working day. The term "modified sanitary landfill"' has been applied to those
operations where compaction and covering are accomplished once or twice a week.
 Three methods are used in this operation :
1. The trench method
2. The ramp method
3. The area method
[b] CONTROLLED TIPPING AND SANITARY
LANDFILL

 [1] TRENCH METHOD -
 Where level ground is available, the trench method is usually chosen. A long trench is dug out
- 2 to 3 m (6-10 ft.) deep and 4 to 12 m, (12-36 ft.) wide, depending upon local conditions.
The refuse is compacted and covered with excavated earth. Where compacted refuse is placed
in the fill to a depth of 2 m (6 ft.), it is estimated that one acre of land per year will be
required for 10,000 population.

 [2] RAMP METHOD -
This method is well suited where the terrain is moderately sloping. Some excavation is done to
secure the covering material.

 [3] AREA METHOD -
This method is used for filling land depressions, disused quarries and clay pits. The refuse is
deposited, packed and consolidated in uniform layers up to 2 to 2.5 m (6-8 ft.) deep. Each layer
is sealed on its exposed surface with a mud cover at least 30 cm (12 inches) thick. Such sealing
prevents infestation by flies and rodents and suppresses the nuisance of smell and dust. This
method often has the disadvantage of requiring supplemental earth from outside sources.

 Refuse can be disposed of hygienically by burning or incineration. It is the method of choice
where suitable land is not available. Hospital refuse which is particularly dangerous is best
disposed of by incineration. Incineration is practised in several of the industrialized
countries, particularly in large cities due to lack of suitable land. Incineration is not a
popular method in India because the refuse contains a fair proportion of fine ash which
makes the burning difficult.
 A preliminary separation of dust or ash is needed. All this involves heavy outlay and
expenditure, besides manipulative difficulties in the incinerator. Further, disposal of refuse
by burning is a loss to the community in terms of the much needed manure. Burning,
therefore, has a limited application in refuse disposal in India.
[C] INCINERATION

 Composting is a method of combined disposal of refuse and nightsoil or sludge. It is a
process of nature whereby organic matter breaks down under bacterial action resulting in the
formation of relatively stable humus-like material, called the compost which has
considerable manurial value for the soil.
 The principal by-products are carbon dioxide, water and heat. The heat produced during
composting – 60 degree C or higher, over a period of several days- destroys eggs and larvae
of flies, weed seeds and pathogenic agents. The end-product -compost - contains few or no
disease producing organisms, and is a good soil builder containing small amounts of the
major plant nutrients such as nitrates and phosphates.
[D] COMPOSTING

 The following methods of composting are now used :
(1) Bangalore method (Anaerobic method)
(2) Mechanical composting (Aerobic method)

 [1] Bangalore method or hot fermentation process - As a result of investigations carried out
under the auspices of the Indian Council of Agricultural Research at the Indian Institute of
Science, Bangalore, a system of anaerobic composting, known as Bangalore method (hot
fermentation process) has been developed. It has been recommended as a satisfactory method
of disposal of town wastes and nightsoil.
Trenches are dug 90 cm (3 ft.) deep, 1.5 to 2.5 m (5-8 ft.) broad and 4.5 to 10 m (15-30 ft.) long,
depending upon the amount of refuse and nightsoil to be disposed of. Depths greater than 90 cm
(3 ft.) are not recommended because of slow decomposition. The pits should be located not less
than 800 m (1/2 mile) from city limits

 The composting procedure is as follows :
1. First a layer of refuse about 15 cm (6 in) thick is spread at the bottom of the trench. Over this,
nightsoil is added corresponding to a thickness of 5 cm (2 in).
2. Then alternate layers of refuse and nightsoil are added in the proportion of 15 cm (6 in) and 5
cm (2 in) respectively, till the heap rises to 30 cm (1 ft.) above the ground level. The top layer
should be of refuse, at least 25 cm (9 in) thickness. Then the heap is covered with excavated
earth. If properly laid, a man's legs will not sink when walking over the compost mass .
Within 7 days as a result of bacterial action considerable heat (over 60 deg.C) is generated in the
compost mass. This intense heat which persists over 2 or 3 weeks, serves to decompose the refuse
and nightsoil and to destroy all pathogenic and parasitic organisms. At the end of 4 to 6 months,
decomposition is complete and the resulting manure is a well decomposed, odourless, innocuous
material of high manurial value ready for application to the land.

[2] MECHANICAL COMPOSTING –
 Another method of composting known as 'Mechanical composting' is becoming popular.
 In this, compost is literally manufactured on a large scale by processing raw materials and
Turning out a finished product. The refuse is first cleared of salvageable materials such as rags,
bones, metal, glass and items which are likely to interfere with the grinding operation.
 It is then pulverised in a pulverising equipment in order to reduce the size of particles to less
than 2 inches. The pulverised refuse is then mixed with sewage, sludge or nightsoil in a rotating
machine and incubated. The factors which are controlled in the operation are a certain carbon-
nitrogen ratio, temperature, moisture. pH and aeration.

 The entire process of composting is complete in 4 to 6 weeks. This method of composting is in
vogue in some of the developed countries, e.g., Holland, Germany, Switzerland, Israel. The
Government of India is considering the installation of mechanical composting plants in selected
cities. Cities such as Delhi, Nagpur, Mumbai, Chennai, Pune, Allahabad, Hyderabad, Lucknow
and Kanpur have offered to join the Government for setting up pilot plants for mechanical
composting.

 In rural areas in India, there is no system for collection and disposal of refuse.
 Refuse is thrown around the houses indiscriminately resulting in gross pollution of the soil.
The problem of refuse disposal in rural areas can be solved by digging 'manure pits' by the
individual householders. The garbage, cattle dung, straw, and leaves should be dumped into
the manure pits and covered with earth after each day's dumping. Two such pits will be
needed, when one is closed, the other will be in use. In 5 to 6 month's time, the refuse is
converted into manure which can be returned to the field. This method of refuse disposal is
effective and relatively simple in rural communities.
[E] MANURE PITS

 This method is suitable for small camps.
 A trench 1.5 m wide and 2 m deep is excavated, and at the end of each day the refuse is
covered with 20 to 30 cm of earth. When the level in the trench is 40 cm from ground level,
the trench is filled with earth and compacted, and a new trench is dug out. The contents may
be taken out after 4 to 6 months and used on the fields. If the trench is 1 m in length for
every 200 persons, it will be filled in about one week
[F] BURIAL

 Refuse disposal cannot be solved without public education. People have very little interest
in cleanliness outside their homes.
 Many municipalities and corporations usually look for the cheapest solution, especially in
regard to refuse disposal. What is needed is public education on these matters, by all known
methods of health education, viz., pamphlets, newspapers, broadcasting, films etc. Police
enforcement of the laws may also be needed at times.
PUBLIC EDUCATION

 An organization was formed - the International Solid Wastes and Public Cleansing
Association (ISWA) in 1970. to assist countries in the general endeavour to improve
sanitary services. A WHO International Reference Centre has also been set up in
Switzerland to collect, evaluate and disseminate information z n wastes-disposal practices
and to foster research
INTERNATIONAL COOPERATION

HOSPITAL WASTE MANAGEMENT
 INTRODUCTION
The waste produced in the course of health-care activities carries a higher potential for infection
and injury than any other type of waste. Therefore, it is essential to have safe and reliable
method for its handling. Inadequate and inappropriate handling of health-care waste may have
serious public health consequences and a significant impact on the environment. Appropriate
management of health-care waste is thus a crucial component of environmental health
protection, and it should become an integral feature of health-care services.

DEFINITION
 According to Bio-Medical Waste (Management and Handling) Rules, 1998 of India, "Bio-
medical waste" means any waste, which is generated during the diagnosis, treatment or
immunization of human beings or animals or in research activities pertaining thereto or in the
production or testing of biologicals.

SOURCES OF HEALTH CARE WASTE
 The institutions involved in generation of bio-medical waste are :
 - Government hospitals - Laboratories
 - Private hospitals - Research organizations
 - Nursing homes - Vaccinating centres
 - Physician's office/clinics - Biotechnologies institutions
 - Dentist's office/clinics - Blood banks
 - Dispensaries
 - Primary health centres
 - Medical research and training establishments
 - Animal houses
 - Slaughter houses
All these health-care establishments
generate waste and are therefore
covered under Bio-Medical Waste
(BMW) Rules.

HEALTH HAZARDS OF HEALTH CARE WASTE
 Exposure to hazardous health-care waste can result in disease or injury due to one or more of
the following characteristics :
(a) it contains infectious agents
(b) it contains toxic or hazardous chemicals
(c) it contains sharps
(d) it is genotoxic
(e) it is radio-active.
 All individuals exposed to such hazardous health-care waste are potentially at risk, including
those who generate the waste or those who either handle such waste or are exposed to it as a
consequence of careless management.
 The main groups at risk are : medical doctors, nurses, health-care auxiliaries, and hospital
maintenance personnel etc.

[1] HAZARDS FROM INFECTIOUS WASTE AND SHARPS
 Pathogens in infectious waste may enter the human body through a puncture, abrasion or cut
in the skin, through mucous membranes by Inhalation or by Ingestion. There is particular
concern about infection with HIV and hepatitis virus B and C, for which there is a strong
evidence of transmission via health-care waste. Bacterias resistant to antibiotics and
chemical disinfectants, may also contribute to the hazards created by poorly managed waste.

[2] HAZARDS FROM CHEMICAL AND PHARMACEUTICAL
WASTE
 Many of the chemicals and pharmaceuticals used in health-care establishments are toxic,
genotoxic, corrosive, flammable, reactive, explosive or shock-sensitive. Although present in
small quantity they may cause intoxication, either by acute or chronic exposure, and injuries,
including burns. Disinfectants are particularly important members of this group. They are
used in large quantities and are often corrosive, reactive chemicals may form highly toxic
secondary compounds.

[3] HAZARD FROM GENOTOXIC WASTE
 The severity of the hazards for health-care worker responsible for handling or disposal of
genotoxic waste is governed by a combination of the substance toxicity itself and the extent
and duration of exposure. Exposure may also occur during the preparation of or treatment
with particular drug or chemical. The main pathway of exposure is inhalation of dust or
aerosols, absorption through the skin, ingestion of food accidentally contaminated with
cytotoxic drugs, chemicals or wastes etc.

[4] HAZARD FROM RADIOACTIVE WASTE
 The type of disease caused by radioactive waste is determined by the type and extent of
exposure. It can range from headache, dizziness and vomiting to much more serious
problems. Because it is genotoxic, it may also affect genetic material.

[5] PUBLIC SENSITIVITY
 Apart from health hazards, the general public is very sensitive to visual impact of health-care
waste particularly anatomical waste.

TREATMENT AND DISPOSAL TECHNOLOGIES FOR HEALTH
CARE WASTE
 Incineration, used to be the method of choice for most hazardous health-care wastes, and is
still widely used. However, recently developed alternative treatment methods are becoming
increasingly popular.
1. INCINERATION
2. CHEMICAL DISINFECTION
3. WET AND DRY THERMAL TREATMENT
4. MICROWAVE IRRADIATION
5. LAND DISPOSAL
6. INERTIZATION

[1] INCINERATION
 Incineration is a high temperature dry oxidation process, that reduces organic and
combustible waste to inorganic incombustible matter and results in a very significant
reduction of waste-volume and weight. The process is usually selected to treat wastes that
cannot be recycled, reused or disposed off in a land fill site.

Characteristics of the waste suitable for incineration are :
(a) low heating volume - above 2000 kcal/kg for single - chamber incinerators, and above 3500
kcal/kg for pryolytic double-chamber incinerators.
(b) content of combustible matter above 60 per cent.
(c) content of noncombustible solids below 5 per cent.

TYPES OF INCINERATORS
Incinerators can range from very basic combustion unit that operates at much lower temperature
to extremely sophisticated, high temperature operating plants. It should be carefully chosen on the
basis of the available resources, the local situation, and the risk- benefit consideration.
 Three basic kinds of incineration technology are of interest for treating health-care waste :
 (a) Double-chamber pyrolytic incinerators which may be especially designed to burn infectious
health-care waste;
 (b) Single-chamber furnaces with static grate, which should be used only if pyrolytic
incinerators are not affordable; and
 (c) Rotary kilns operating at high temperatures, capable of causing decomposition of genotoxic
substances and heat-resistant chemicals.

[2] CHEMICAL DISINFECTION
 Chemicals are added to waste to kill or inactivate the pathogens it contains, this treatment
usually results in disinfection rather than sterilization. Chemical disinfection is most suitable
for treating liquid waste such as blood, urine, stools or hospital sewage. However, solid
wastes including microbiological cultures, sharps etc. may also be disinfected chemically
with certain limitations.

[3] WET AND DRY THERMAL TREATMENT
 WET THERMAL TREATMENT
Wet thermal treatment or steam disinfection is based on exposure of shredded infectious waste
to high temperature, high pressure steam, and is similar to the autoclave sterilization process.
The process is inappropriate for the treatment of anatomical waste and animal carcassess, and
will not efficiently treat chemical and pharmaceutical waste.

 SCREW-FEED TECHNOLOGY
Screw-feed technology is the basis of a non-burn, dry thermal disinfection process in which
waste is shredded and heated in a rotating auger. The waste is reduced by 80 per cent in volume
and by 20-35 per cent in weight. This process is suitable for treating infectious waste and sharps,
but it should not be used to process pathological, cytotoxic or radioactive waste.

[4]MICROWAVE IRRADIATION
 Most microorganisms are destroyed by the action of microwave of a frequency of about 2450
MHz and a wave length of 12.24 nm. The water contained within the waste is rapidly heated
by the microwaves and the infectious components are destroyed by heat conduction. The
efficiency of the microwave disinfection should be checked routinely through bacteriological
and virological tests.

[5] LAND DISPOSAL
 MUNICIPAL DISPOSAL SITES
If a municipality or medical authority genuinely lacks the means to treat waste b-efore disposal,
the use of a land fill has to be regarded as an acceptable disposal route. There are two types of
disposal land-open dumps and sanitary landfills. Health-care waste should not be deposited on
or around open dumps. The risk of either people or animals coming into contact with infectious
pathogens is obvious.

 Sanitary landfills are designed to have at least four advantages over open dumps : geological
isolation of waste from the environment, appropriate engineering preparation before the site is
ready to accept waste, staff present on site to control operations, and organized deposit and
daily coverage of waste.

[6] INERTIZATION
 The process of "inertization" involves mixing waste with cement and other substances before
disposal, in order to minimize the risk of toxic substances contained in the wastes migrating
into the surface water or ground water. A typical proportion of the mixture is: 65 per cent
pharmaceutical waste, 15 per cent lime, 15 per cent cement and 5 per cent water. A
homogeneous mass is formed and cubes or pellets are produced on site and then transported
to suitable storage sites.
 The United Nations Conference on the Environment and Development (UNCED) in
1992 recommended the following measures :
(a) Prevent and minimize waste production
(b) Reuse or recycle the waste to the extent possible
(c) Treat waste by safe and environmentally sound methods, and
(d) Dispose off the final residue by landfill in confined and carefully designed sites.

TREATMENT/DISPOSAL
METHOD
ADVANTAGES DISADVANTAGES
[1] ROTARY KILN Adequate for all infectious waste, most
chemical waste and pharmaceutical waste.
High investment and operating costs.
[2] PYROLYTIC
INCINERATION
Very high disinfection efficiency. Adequate for
all infectious ' waste and most pharmaceutical
and chemical waste.
Incomplete destruction of cytotoxics.
Relatively high investment and
operating costs.
[3] SINGLE CHAMBER
INCINERATION
Good disinfection efficiency. Drastic reduction
of weight and volume of waste. The residues
may be disposed off in landfills. No need for
highly trained operators. Relatively low
investment and operating costs.
Inefficiency in destroying thermally
resistant chemicals and drugs such as
cytotoxics.
[4] DRUM OR BRICK
INCINERATION
Drastic reduction of weight and volume of the
waste. Very low investment and operating
costs.
Destroys only 99% of
microorganisms.

[5] CHEMICAL
DISINFECTION
1. Highly efficient disinfection under good
operating conditions.
2. Some chemical disinfectants are
relatively inexpensive.
1. Requires highly qualified technicians for
operation of the process.
2. Uses hazardous substances that require
comprehensive safety measures.
3. Inadequate for pharmaceutical, chemical
and some types of infectious waste.
[6] WET
THERMAL
TREATMENT
1. Environmentally sound.
2. Relatively low investment and operating
costs.
1. Shredders are subject to frequent
breakdowns and poor functioning.
2. Operation requires qualified technicians.
3. Inadequate for anatomical,
pharmaceutical, chemical waste and
waste that is not readily steam-permeable.
[7] MICROWAVE
IRRADIATION
Good disinfection efficiency under
appropriate operating conditions.
Relatively high investment and operating
costs
[8]INERTIZATION Relatively inexpensive. Not applicable to infectious waste.

BIO – MEDICAL WASTE IN INDIA
 Bio-Medical Waste (Management and Handling) Rule 1998, prescribed by the Ministry of
Environment and Forests, Government of India, came into force on 28th July 1998. This rule
applies to those who generate, collect, receive, store, dispose, treat or handle bio-medical
waste in any manner. Table 4 shows the categories of bio-medical waste, types of waste and
treatment and disposal options under Rule 1998. The bio-medical waste should be segregated
into containers/bags at the point of generation of the waste.

CATEGORIES OF BIO – MEDICAL WASTE IN INDIA [SCHEDULE-1]
OPTION WASTE CATE]GORY TREATMENT AND
DISPOSAL
CATEGORY
NO. 1
Human anatomical waste
(human tissues, organs, body parts).
incineration / deep
burial.
CATEGORY
NO. 2
Animal waste
(animal tissues, organs, body parts carcasses, bleeding parts,
fluids, blood and experimental animals used in research,
waste generated by veterinary hospitals colleges, discharge
from hospital, animal house).
incineration / deep
burial.
CATEGORY
NO. 3
Microbiology and biotechnology waste
(waste from laboratory cultures, stocks or specimens of
micro-organisms, live or attenuated vaccines, human and
animal cell culture used in research and infectious agents
from research and industrial laboratories, waste from
production of biologicals, toxins, dishes and devices and for
transfer of cultures).
local autoclaving /
microwaving /
incineration.

CATEGORY
NO. 4
Waste sharps
(needles, syringes, scalpels, blades, glass, etc.
that may cause puncture and cuts. This includes
both used and unused sharps).
disinfection (chemical
treatment®/ autoclaving/
microwaving and mutilation
shredding).
CATEGORY
NO. 5
Discarded medicines and cytotoxic drugs
(wastes comprising of outdated, contaminated
and discarded medicines).
incineration® destruction and
drugs disposal in secured
landfills
CATEGORY
NO. 6
CATEGORY
NO. 7
Solid waste
(Items contaminated with blood, and fluids
including cotton, dressings, soiled plaster casts,
linen, beddings, other material contaminated
with blood).
Solid waste
(wastes generated from disposable items other
than the waste sharps such as tubings, catheters,
intravenous sets etc.).
incineration® autoclaving /
microwaving.
disinfection by chemical
treatment®® autoclaving/
microwaving and mutilation /
shredding ##.

CATEGORY
NO. 8
Liquid waste
(waste generated from laboratory and washing,
cleaning, housekeeping and disinfecting
activities).
disinfection by chemical
treatment @@ and discharge
into drains.
CATEGORY
NO. 9
Incineration ash
(ash from incineration of any bio-medical
waste).
disposal in municipal landfill.
CATEGORY
NO. 10
Chemicals used in production of biologicals,
chemicals used in disinfection, as insecticides,
etc.
chemical treatment®® and
discharge into drains for liquids
and secured landfill for solids.

COLOUR
CODING
TYPE OF CONTAINER WASTE CATEGORY TREATMENT OPTIONS AS
PER SCHEDULE 1
YELLOW PLASTIC BAG CAT.1, CAT.2 AND
CAT.3, CAT.6
Incineration/deep burial
RED DISINFECTED
CONTAINER/PLASTIC
BAG
CAT.3, CAT.6, CAT.7 Autoclaving/Microwaving/
Chemical treatment
BLUE/WH
ITE
TRANSLU
CENT
PLASTIC BAG/PUNCTURE
PROOF CONTAINER
CAT.4, CAT.7 Autoclaving/Microwaving/
Chemical treatment and
Destruction/Shredding
BLACK PLASTIC BAG CAT.5 AND CAT 9
AND CAT.10
(SOLID)
Disposal in secured landfill
COLOUR CODING AND TYPE OF CONTAINER FOR DISPOSAL OF BIOMEDICAL WASTE
[SCHEDULE – 2]

REFERENCES
 Park K. Textbook of Preventive & Social Medicine, 22nd Edition. Jabalpur: Banarasidas Bhanot
Publishers; 2013.
 C.M. Marya, A Textbook of Public Health Dentistry, Jaypee Brothers Medical Pub; 1 edition, 30
March 2011.
 S.S. Hiremath, Textbook of preventive and community dentistry, Elsevier; Second edition, 1
January 2011
 www.googleimages.com
 WWW. WHO. HEALTH CARE WASTE.

Solid waste disposal and hospital waste management

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