OCCUPATIONAL HEALTH AND SAEFTY 15CV564

MODULE – 5
1.1 Water Treatment Plant (WTP)
Treatment of water poses many risks to the health of Water Treatment Plant WTP
operators. Following are the hazards related to the WTP
Accident hazards
1. Falls, slips, and trips on the level on floors made wet and slippery during the
handling of water.
2. Falls due to working with a defective ladder and/or falls from heights while
climbing and staying on an elevated industrial installation.
3. Falls inside an industrial installation and/or into water well while inspecting them
and/or taking water samples for analysis.
4. Injuries caused by capture of work-clothes and/or various parts of body,
in/between moving/ rotating unprotected parts of machinery. Electric shock
caused by contact with “live” wires or defective electrical installations (the danger
is especially high because the work is done in a wet and humid environment).
5. Exposure to hazardous substances due to the sudden release of toxic
materials as a result of an accident or human error, such as addition of
chemicals to an unsuitable installation (e.g. release of chlorine gas due to an
insertion of disinfectants such as hypochlorite into installation with aluminium
sulphate).
6. Fire hazard due to contact of a very strong oxidizer (disinfectant) with a
flammable substance, as a result of improper storage of chemicals, human
error, sudden release from process piping, etc.
7. Explosion hazard, in the event of contact between ozone (very strong oxidizer)
and organic chemical and strong reduction agents. Hazard of drowning when
working inside reservoirs, or immersed in watercourses with a strong current.
8. Suffocation hazard while carrying-out maintenance or installation works, such as
working in a confined place (tank, boiler) or when doing excavation work
Physical hazards
1. Exposure to high noise levels, from electro-mechanical equipment and a noisy
environment.
2. Exposure to adverse weather conditions: risk of catching a cold as a result of
working in windy weather, at low temperatures and while raining; or as a result of
over-sweating in the summer; and suffering heat and/or cold strokes.

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3. Exposure to UV radiation during water disinfection may be damaging for eyes

and skin.
Chemical hazards
1. Exposure to various disinfectants used for water disinfection
 Chlorine (gas): a very strong oxidizer and disinfectant. It is a toxic and
corrosive gas that causes irritation of the eyes and the respiratory tract
even at low concentrations
 Hydrofluoric acid: a very strong acid that is used in water fluoridation
 Sodium hypochlorite: it is used as a solution. The substance is toxic
and corrosive, in particular of the respiratory tract; causes burns and
irritation to eyes and skin
 Calcium hypochlorite: the substance is corrosive and very destructive
of mucous tissues; may cause chemical pneumonia and lung oedema
 Ozone is an oxidizing and an irritant gas; when inhaled, it may cause
breathing difficulties, headaches, fatigue, eye irritation, tears and
conjunctivitis
 Chlorine dioxide is a very corrosive gas that causes strong irritation of
the respiratory tract and the eyes.
2. Exposure to coagulants (such as aluminum sulfate): these substances assist
precipitation of suspended matter in the water.
Biological hazards
1. No biological hazards have been identified, except possible exposure to
insects and rodents that may transmit diseases.
2. Hazard of exposure to pathogenic micro-organisms due to accidental contact
between drinking water and wastewater.
Ergonomic, psychosocial and organizational factors
1. Musculoskeletal injuries caused by awkward working postures during the
cleaning/inspection of the pipe system and/or of installation.
2. Overexertion while moving or handling heavy and bulky equipment or big
packages of chemicals may affect various systems of the body
3. Psychological stress and pressure due to environmental factors: annoying
noise, water splashing, odors, high humidity, etc.
4. Psychosocial problems due to increased workload, requirements of improving
work output, constant need of high skill levels, lack of privacy due to the

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increased possibility of superiors to locate and reach the worker (by means of
cellular phone or beeper, even after normal working hours), and due to the
commitment to answer unexpected calls during emergency situations;
requirement of doing shift work overtime.
5. Psychological problems of adaptation to computer-based jobs (especially for
elderly workers).
Preventive measures
1. Wear safety shoes with non-skid soles.
2. Use ladders in good repair; make sure that ladder is in required position
without the possibility of displacement and/or collapse; inspect ladder before
climbing.
3. All cavities, hollow spaces, elevated working surfaces, and other locations
where there is hazard of falling should be "securely fenced" by appropriate
railing guards.
4. During work with these machines, ensure that work clothes are attached to
the body; use appropriate head gear; guard all moving parts of equipment that
may injure the worker.
5. Check electrical equipment for safety before beginning to work; call a qualified
electrician for testing of suspect equipment.
6. All chemical supply connection points must be checked and post appropriate
signs must be posted at these points.
7. Apply chemical safety rules when handling or working with hazardous
chemicals; read MSDS and consult a safety supervisor regarding specific
chemicals.
8. Apply safety rules while working in a confined space: check air quality and, if
necessary, exhaust ventilation before entering into a confined space; use
harnesses that are held by your co-workers; use respirators and gas masks;
etc.
9. Use appropriate ear protection; consult a safety supervisor or a supplier.
10. Work clothes should fit the climatic conditions of the work place.
11. Learn and use safe lifting and moving techniques for heavy or bulky loads; if
necessary, use lifting aids.

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1.2 Wastewater Treatment Plant (WWTP)

Workers in the wastewater treatment sector are responsible for the day-to-day
operation, maintenance, trouble-shooting and handling of special problems of
municipal, industrial, and other wastewater treatment plants. Occupations can
include Level 1 WWR (Wastewater) Plant Operator, Level 2 WWR Plant Operator,
Senior Operator, Water Resources Specialist, Maintenance Operator, etc. in both
municipal and private facilities. This sector includes workers involved with sewer
inspection, maintenance work and sewage treatment plants operation.
Hazards
Workers in this sector are exposed to a variety of hazardous chemical and biological
materials contained within the effluents and the reagents used in the wastewater
processing or generated during the wastewater treatment. Chemical agents may
cause acute poisoning, chemical accidents (e.g., skin burns, injury to the eyes, etc.)
damage to the respiratory system, allergies, dermatitis, chronic diseases, etc.
Biological agents include pathogens such as bacteria, protozoa, viruses, helminths
and fungi. There may be injuries by slips, trips and falls on wet floors; by falls into
treatment ponds, pits, clarifiers or vats and by splashes of hazardous liquids; they
may suffer cuts and pricks from sharp tools, contusions, etc. There is also exposure
to hazards related to work in confined spaces. Strains and sprains are the most
common types of injuries.
The three primary types of exposure risks are:
1. Biological
There is a high potential for illnesses arising from contact with viruses, bacteria and
other microorganisms in sewage. The most serious viral risk is hepatitis. The most
serious bacterial risk is tetanus. The main routes of exposure are hand-to-mouth
contact. Breathing in a suspension of particles (aerosols) is a less common means of
exposure but may occur whenever sewage is agitated or aerosolized. This occurs
most commonly near incoming wastewater inlets and sludge treatment areas.
2. Chemical
Confined spaces containing sewage can sometimes be deficient in oxygen due to
organic oxidation and displacement by carbon dioxide. They can also contain
flammable gases such as methane and toxic gases such as carbon monoxide and
hydrogen sulphide. Carbon monoxide, carbon dioxide, and other exhaust gases may
sometimes be present due to a poorly located gasoline engine or generator

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exhausting into the confined space. Chloroform is a common by-product of

disinfection.
3. Metals
Metals are generally not air-stripped into the air in sufficient quantities to be
significant (with the exception of mercury). Therefore, they accumulate either in
sludge or pass through into the receiving water. Other possible hazards include
asbestos and radioactive materials from medical facilities.
The five main categories of pathogens are:
 Bacteria
 Viruses
 Protozoa
 Helminths (parasitic worms)
 Fungi
Treatment processes do not eliminate the risk of exposure. The primary treatment
process may remove 80 - 90% of Salmonella; 50% of Mycobacterium; and coliform
removal varies from 27 - 96%. The secondary treatment process removes from 50 -
90% of these pathogens. Activated sludge has a low removal rate of 85 - 99% for
pathogenic bacteria. Waste solids do contain surviving pathogens. Anaerobic
digestion appears to reduce pathogens by 74% to 97%. Tuberculosis, roundworms
and certain enteric viruses appear highly resistant to treatment processes.
The two primary routes of pathogen and chemical contact are:
1. Inhalation
This is the most common route for chemicals or pathogens to enter the body, usually
via:
 Air-stripping from wastewater
 Bubble aeration
 Workers near weirs, outfall and aerated tanks
 Dewatering process
 Dying, compacting, incineration
 Exposure to chemicals while removing debris from treatment plant equipment
The affected areas of the body initially include the nose, throat and upper respiratory
tract. Secondary areas are the eyes and lower respiratory tract.

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2. Skin contact
This is a route of entry for both chemicals and pathogens. This includes being
splashed in the mouth or on the skin. Chemicals can be absorbed through the skin
from contact with wastewater or sludge. Disease organisms can enter the body
through cuts, abrasions or needle sticks such as when removing screenings from a
bar screen. Preventive Measures are as in water treatment plant.

1.3 Cement Plant

Cement manufacturing is one of these industries. Cement is one of the most widely
used construction material on earth. Because cement has been used commonly, its
health effects have become an important issue both for employees and the
environment. In addition to the various health hazards, cement workers are
especially exposed to dust which causes lung function impairment, chronic
obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of
the lungs, stomach and colon at various production process such as quarrying,
crushing, raw material grinding, blending, kiln burning, cement grinding and
packaging in cement industry. Therefore, ensuring healthy and safe working
conditions for employees and contractors is a fundamental key to corporate social
responsibility, and is one of the most important issues for the cement industry.
In addition, with the increasing complexity of industrial tissue and with the rapidity
that the techniques develop in the big factories, risks assessment becomes a crucial
and strategic answer to preserve workers health and safety on the one hand and to
maintaining a qualified labour on the other hand.
Cement Manufacturing Process
Cement is a fine powder that consists of a mixture of hydraulic cement materials
comprising primarily calcium silicates, aluminates and aluminoferrites. More than 30
raw materials, which are divided into four basic categories (calcium, silica, alumina,
iron), are known to be used in the manufacture of portland cement. Cement
manufacturing process comprises of crushing, grinding, raw meal preparation, kiln
burning and cement production basically. The following figure shows the process
flow of a typical cement factory.
Quarrying of limestone and is performed by using explosives and all of the raw
materials (limestone, marn, clay…etc.) are transported to the plant. These raw
materials are crushed, finely ground, and blended to the correct chemical

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composition. The fine raw material is fed into a large rotary kiln (cylindrical 4 furnace)
which rotates while the contents are heated to extremely high. The most commonly
used kiln fuels are coal, natural gas, and occasionally oil. Rotary kiln is heated by a
2000°C flame inside of it. The kiln is slightly inclined to allow for the materials to
slowly reach the other end, where it is quickly cooled to 100-200°C. Following re-
cooling, the clinker is stored in silos, and then transformed into cement by using
gypsum and other additives according to the production requirements. Finally, the
cement is stored in silos and loaded on a truck or packaged into bags

Classification and Definition of hazards in cement manufacturing

Cement manufacturing processes including health and safety risks were classified as
follows:
 Quarrying
 Crushing
 Clinker production
 Milling processes at raw mill, cement milling and coal milling
 Material transport
 Filtering
 Storage
 Loading and delivery of final products

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 Fuel storage activities

 Use of hazardous material
 Generating units
In Table 5.1, main hazard factors associated with cement manufacturing processes
are presented. As shown from Table 5.2, main hazardous factors in quarrying of raw
materials can be defined as dust and noise. Noise emits during blasting, crushing
and operation of conveyors in quarrying operations. Noise sources in cement
manufacturing plant mainly include milling machines, crushers, electric motors.
Table 5.1 Main hazard factors associated with cement manufacturing processes
Cement Manufacturing Process Main Hazard Factor
Quarrying Dust, Noise
Raw material preparation Dust, toxic gas (CO, CO2, NOx, SO2), noise,
heat radiation
Clinker burning Dust, toxic gas, high heat radiation, high
workload
Clinker cooling and cement milling Auxiliary materials and additives, dust, heat,
noise
Packaging, storage and delivery Dust, high workload
Dust emissions are one of the most significant impacts of cement manufacturing and
associated with handling and storage of raw materials (including crushing and
grinding of raw materials), solid fuels, transportation of materials (e.g. by trucks or
conveyor belts), kiln systems, clinker coolers, and mills, including clinker and
limestone burning and packaging/bagging activities. Packaging is the most polluting
process (in terms of dust) in cement production.
Nitrogen oxide (NOx) emissions are emitted from the high temperature combustion
process of the cement kiln. Carbon dioxide defined as greenhouse gas is mainly
associated with fuel combustion and with the decarbonation of limestone.
In addition to specific hazards, there are also general hazards in all of the cement
manufacturing process such as safe behaviour, work equipment, safety labelling,
personal protective equipment (PPE), manual load handling.
Typical injury causes in cement plants are defined as slips, trips and falls (29%);
falling or moving objects (19%) and lifting, overload and exertion (18%) as shown
from Figure 5._. Fatalities are the most serious tragedy that can happen in the
cement Industry. 79% of all fatalities arise from 3 main causes: Traffic & Mobile Plant
(43%), Falls from Heights & Items falling (21%) and Caught in Moving/Starting

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Equipment (15%). It was reported that contractors and young/temporary employees

are high risk categories in cement manufacturing plants. An example of potential
hazards and preventive actions in a cement manufacturing plant was presented in
Table below.
Table 5.2. Potential hazards preventive actions in cement manufacturing plant
Potential Hazard Preventive Action
Slip, Trips & Falls Good housekeeping
Sufficient lighting
Tidy work place
Identify and fix fall hazards, such as slippery
surfaces, damaged ladders and walkways
Confined areas (Lack of oxygen, Must be avoided entry to confined spaces
Poisonous gas, fumes or vapour, Fire and Remote cameras can be used
explosions, dust, hot conditions) Permit-to-work
Cleaning before entry
Provision of ventilation
Testing the air
Provision of lightings
Electric Each panel should be labelled
Safe electrical equipment should be purchased and used
Appropriate PPE
Training of personnel
Falling/Moving Objects Tidy workplace
Avoid working beneath cuber elevators,
conveyor belts
PPE (Personal protective equipment) usage
Fire (conveyor belts, electrical cables, Proper waste disposal
fuels, waste combustible materials…) good housekeeping
Heat detectors usage
Fire extinguisher
Firefighting procedures must be
Working at height Usage of appropriate ladder and scaffolder
Usage of Fall protection system
Usage of appropriate PPE

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Hot/cold surfaces (hot surface burns…) Usage of appropriate PPE

Noise and Vibration Technologies of noise attenuation, absorption and
insulation
Appropriate hearing protection
Excavation sites All excavations in the plant should be
surrounded with a handrail
Vehicles Avoid overloading
Make sure back-up alarms on all vehicles are functioning
Be sure that trucks and other vehicles are in good working
order, including audible back-up warning signals, before
operating them
Safety guards of machines Those parts must be provided with safety
guards or devices
Usage of appropriate guards (interlocking, automatic, self-
adjusting, two hand control device, etc.)
Maintaining of conveyor belt systems
Manuel handling Must be looked out for sharp edges, splinters
and nails
When lifting heavy objects, legs should be
used as much as possible to save back muscles
Tag Out - Lock Out (Electrical or Process Electrical isolating switches must be turned off
isolation)
Dust Usage of automated packing machines
Usage of enclosed conveyors
Storage of crushed raw materials in closed bays
Appropriate respiratory protection should be
worn
Cement dust Usage of respirator to minimize inhalation of
cement dust
Usage of soap and water avoid skin damage
Avoid exposure to cement dust to prevent
bronchitis and silicosis
The cement manufacturing industry is labour intensive and uses large scale and
potentially hazardous manufacturing processes. Therefore, health and safety is the

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number one priority in for the cement industry for its employees, contractors, end-
users and those who are neighbours to its operations. Exposure to dust and high
temperatures, contact with allergic substances, and noise exposure can be defined
as hazards associated with health; while falling/impact with objects; hot surface
burns; and transportation, working at height, slip/trips/falls can be defined as hazards
associated with safety.
It is the most critical issue that ensuring a health and safety culture in workplaces.
For this purpose, health and safety policy should be adapted with other policies of
the company. Additionally, risk management policy of company should be
developed, and risk assessment should be performed regularly and efficiently.

1.4 RMC Plants

Ready Mixed Concrete (RMC) industry, which is one of the most essential sub-
sectors of modern construction, is responsible for producing a construction material
crucial for constructing engineering structures, such as roads and bridges, homes
and high-rises. Combining of fie and coarse aggregates, cement and water is
creating this important building material. Statistics show that usage and demand of
Most developed countries prefer to use RMC instead of conventional concrete
production because of the advantages of RMC such as: speedy construction through
programmed delivery at site, consistency in quality through accurate & computerized
control of sand aggregates and water as per mix designs, mechanized operation with
consequent economy, minimizing cement wastage due to bulk handling, reducing
the labor cost and site supervising cost, proper control and economy in use of raw
material resulting in saving of natural resources and reducing project time resulting in
savings in all aspects. RMC have been increasing along with the number of
producers and workers.
Ready mix concrete plants have many more components to it. In other words, it is
the assembly of tools and machines such as mixers, cement batchers, aggregate
batchers, conveyors, radial stackers, aggregate bins, cement bins, heaters, chillers
and cement silos as shown in Figure 5. So, operations partially take place in the
production area, where RMC is produced and loaded into mixer
trucks. The second part of the operations continues outside the production area,
where truck mixer transports the materials to a construction site and truck operator
assists with the casting process.

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Ready mixed concrete (RMC) industry, one of the barebones of construction sector,
has its distinctive occupational safety and health (OSH) risks. Employees experience
risks that emerge during the fabrication of concrete, as well as its delivery to the
construction site. Potential hazards for workers in concrete manufacturing can be
listed as: Eye, skin and respiratory tract irritation from exposure to cement dust,
overexertion and awkward postures (ergonomics), slips, trips and falls, chemical
burns from wet concrete, loss of stability, cutting and severing, hazards generated by
vibration and radiation. The source of these hazards are usually derived from system
failure, inadequate safety guards on equipment, inadequate lockout/tag out systems
on machinery (mechanical and electrical hazards), ejection of parts or material,
shearing hazards generated by noise, stabbing or puncture, friction or abrasion, high
pressure fluid injection, combined hazards.

Fig 5.2 Ready Mix concrete production

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Table 5.3 Hazard and Safety measure for corresponding Operation

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Table 5.4 Hazard and Safety measure for corresponding Operation

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1.5 Construction Sites

The importance of the construction industry should not just be distinguished by its
final products, as it involves various organizations (consisting of large numbers of
personnel) both directly and indirectly, as well as due to its contribution to the
economy of a nation. Therefore, the occupational safety and health (OSH) aspect
should not be disregarded in the process of pursuing project completion or improving
the economy. The safety and health of individuals that are associated in the
construction process should be considered as a major concern.
The construction industry can be considered as a unique, complex and hazardous
workplace. The unique nature of the construction industry in terms of transient
workforce, the need to be working at high elevations, variable hazards and very
demanding physical as well as mental requirements for the working process,
contribute to accidents in the industry.
OSH problems in the construction industry is a global issue which is not unique to
any single country within the context of the global market, and more importantly, the
continual injuries and fatalities that occur has made it one of the most high-risk
industries in terms of safety. An effective OSH management system at construction
sites is essential to address the high rate of fatalities, which is higher than other
industries. An efficient safety management program could be beneficial in providing
a safer working environment. By reducing the number of accidents, productivity level
could be enhanced and expenditure of an organization could be reduced.
Potential hazards for workers in construction include:
 Falls (from heights)
 Trench collapse
 Scaffold collapse
 Electric shock and arc flash/arc blast
 Failure to use proper protective equipment; and
 Repetitive motion injuries
Hazards and solution
1. Scaffolding
Hazard: When scaffolds are not erected or used properly, fall hazards can occur.
Solutions:
 Scaffold must be sound, rigid and sufficient to carry its own weight plus four times
the maximum intended load without settling or displacement.

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 It must be erected in solid footing.

 Unstable objects, such as barrels, boxes, loose bricks or concrete blocks must
not be used to support scaffolds or planks.
 Scaffold must not be erected, moved, dismantled or alerted except under the
supervision of a competent person.
 Scaffold must be equipped with guardrails, mid-rails and toe boards.
 Scaffold accessories such as braces, brackets, trusses, screw legs or ladders
that are damaged or weakened from any cause must be immediately repaired or
replaced.
 Scaffold platforms must be tightly planked with scaffold plank grade material or
equivalent.
 A “competent person” must inspect the scaffolding and at designated intervals,
re-inspect it.
 Rigging on suspension scaffolds must be inspected by a competent person
before each shift and after any occurrence that could affect structural integrity to
ensure that all connections are tight and that no damage to the rigging has
occurred since its last use.
 Synthetic and natural rope used in suspension scaffolding must be protected
from heat-producing sources.
 Employees must be instructed about the hazards of using diagonal braces as fall
protection.
 Scaffold can be accessed by using ladders and stairwells.
 Scaffolds must be at least 10 feet from electric power lines at all times.
2. Fall Protection
Hazard: A number of factors are often involved in falls, including unstable working
surfaces, misuse or failure to use fall protection equipment and human error. Studies
have shown that using guardrails fall arrest systems, safety nets, covers and
restraint systems can prevent many deaths and injuries from falls.
Solutions
 Consider using aerial lifts or elevated platforms to provide safer elevated working
surfaces.
 Erect guardrail systems with toe-boards and warning lines or install control line
systems to protect workers near the edges of floors and roofs.
 Cover floor holes; and/or

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 Use safety net systems or personal fall arrest systems (body harness).
3. Ladders
Hazard: Ladders and stairways are another source of injuries and fatalities among
construction workers. Nearly half of these injuries are serious enough to require time
off the job.
Solutions:
 Use the correct ladder for the task.
 Have a competent person visually inspect a ladder before use for any defects
such as:
 Structural damage, split/bent side rails, broken or missing rungs/steps/cleats
and missing or damaged safety devices.
 Grease, dirt or other contaminants that could cause slips or falls;
 Paint or stickers that could hide possible defects.
 Make sure that ladders are long enough to safely reach the work area.
 Mark or tag (“Do Not Use”) damaged or defective ladders for repair or
replacement or destroy them immediately.
 Never load ladders beyond the maximum intended load or beyond the
manufacturer’s related capacity.
 Be sure the load rating can support the weight of the user, including materials
and tools.
 Avoid using ladders with metallic components near electrical work and overhead
power lines.
4. Stairways
Hazard: Slips, trips and falls on stairways are a major source of injuries and fatalities
among construction workers.
Solutions
 Stairway treads and walkways must be free of dangerous objects, debris and
materials.
 Slippery conditions on stairways and walkways must be corrected immediately.
 Make sure that treads cover the entire step and landing.
 Stairways having four or more risers or rising more than 30 inches must have at
least one handrail.

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5. Trenching
Hazard: trench collapses cause dozens of fatalities and hundreds of injuries each
year.
Solutions:
 Never enter an unprotected trench.
 Always use a protective system for trenches feet deep or greater
 Employ a registered professional engineer to design a protective system for
trenches 20 feet deep or greater.
 Protective systems:
 Sloping to protect workers by cutting back the trench wall at an angle inclined
away from the excavation not steeper than a height/depth ratio of 11 2:1,
according to the sloping requirements for the type of soil.
 Shoring to protect workers by installing supports to prevent soil movement for
trenches that do not exceed 20 feet in depth.
 Shielding to protect workers by using trench boxes or other types of supports
to prevent soil cave-ins.
 Always provide a way to exit a trench--such as a ladder, stairway or ramp--no
more than 25 feet of lateral travel for employees in the trench.
 Keep spoils at least two feet back from the edge of a trench.
 Make sure that trenches are inspected by a competent person prior to entry and
after any hazard-increasing event such as a rainstorm, vibrations or excessive
surcharge loads.
6. Cranes
Hazard: Significant and serious injuries may occur if cranes are not inspected before
use and if they are not used properly. Often these injuries occur when a worker is
struck by an overhead load or caught within the crane's swing radius. Many crane
fatalities occur when the boom of a crane or its load line contact an overhead power
line.
Solutions:
 Check all crane controls to insure proper operation before use.
 Inspect wire rope, chains and hook for any damage.
 Know the weight of the load that the crane is to lift.
 Ensure that the load does not exceed the crane's rated capacity.

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 Raise the load a few inches to verify balance and the effectiveness of the brake
system.
 Check all rigging prior to use; do not wrap hoist ropes or chains around the load.
 Fully extend outriggers.
 Do not move a load over workers.
 Barricade accessible areas within the crane's swing radius.
 Watch for overhead electrical distribution and transmission lines and maintain a
safe working clearance of at least 10 feet from energized electrical lines.
7. Head protection
Hazard: Serious head injuries can result from blows to the head.
Solution:
 Be sure that workers wear hard hats where there is a potential for objects falling
from above, bumps to their heads from fixed objects, or accidental head contact
with electrical hazards.

1.6 Municipal Solid waste Management

The United States Environmental Protection Agency (EPA) defines solid waste as
Any garbage, or refuse, sludge from a wastewater treatment plant, water supply
treatment plant, or air pollution control facility, and other discarded material,
including solid, liquid, semi-solid, or contained gaseous material resulting from
industrial, commercial, mining, and agricultural operations, and from community
activities.
Thus, MSW includes durable goods (e.g. appliances), non-durable goods (e.g.
newspapers), containers and packaging, food wastes, yard trimmings, and
miscellaneous inorganic wastes, resulting from residential, commercial, institutional
and industrial activity. The following table gives a brief summary of these possible
exposures and health hazards related to solid waste industry workers. Similar to their
hazardous waste colleagues, MSW workers are exposed to physical and
chemical/biological hazards from their work. The physical hazards are associated
with the waste itself (i.e. Heavy loads, sharp objects, inappropriately disposed of
hazardous wastes) and the machinery; these physical hazards cause significant
ergonomic health effects (particularly back injury), trauma (lacerations, amputations
and burns), and even death.

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Again similar to hazardous waste, the chemical/biological hazards are predominantly

associated with the solid waste itself (i.e. Biological aerosols, inappropriately
disposed of hazardous wastes, heavy metals, and VOCs). These exposures have
been associated with acute and chronic health effects of multiple organ systems,
including dermatological (skin rashes), respiratory (asthma), cardiovascular
(myocardial infarctions), gastrointestinal (gastroenteritis), and neurologic (noise
induced hearing loss).
Table 5.5 Reported Exposures and Related Health Effects for Waste Collectors
Reported Exposures Reported Health Effects
Heavy lifting Disorders of the neck, shoulder and back,
tendon diseases, extreme pain, lumbar disc
prolapse, increased pulmonary ventilation.
Machinery Crushed body parts, broken bones,
amputations, musculoskeletal aches, twisted
muscles, sprains, permanent disability, noise-
induced hearing loss.
Traffic Pedestrian accidents, broken bones, bruising,
death
Chemicals improperly disposed of Burns, fires, explosions, eye and skin irritation
Sharp and broken objects Lacerations, punctures, abrasions
Diesel Exhaust Eye irritation, asthma, decreased lung function,
upper respiratory tract irritation, lung cancer
Carbon monoxide No documented health effects; potential
cardiovascular, neurologic, asphyxiation
Polycyclic Aromatic Hydrocarbons No documented health effects; potential
carcinogenic
Dust Eye irritation, organic dust toxic syndrome
(ODTS), non-allergic pulmonary disorders,
impaired lung function
Microorganisms Dry cough, exercise induced dyspnea, asthma,
chronic bronchitis, ODTS, chest tightness,
fever, chills, flu symptoms
Endotoxin Fever, chest tightness, airway irritation,

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headache, joint and muscle

pain, nausea, fatigue, non-allergic pulmonary
disorders, impaired lung function, acute
gastrointestinal symptoms
Gram-negative bacteria Inflammation of airways, diarrhea, nausea
Fungal spores Allergic alveolitis, asthma
Aerosols from waste Eye and nose irritation, nausea, vomiting
Unknown exposure Coronary heart disease, myocardial infarction,
angina, insufficiency

Sharp objects:
Opportunities to contact sharp objects are greatest at points where solid waste is
manually separated, sorted, or otherwise handled. Any break in the skin caused by
sharp objects can become the site of infection following exposure to bacteria,
viruses, fungi, or parasites. Contact with sharp objects can be minimised through the
use of personal protective equipment such as gloves, hard hats, boots, safety
glasses, and over clothes.
Ergonomic and lifting injuries:
Worker injuries that occur during collection resulting from lifting and dumping heavy
bins, twisting and reaching during curb side sorting and repeatedly climbing in and
out of vehicles. Falls and other miscellaneous ergonomic injuries may occur
throughout solid waste management. Elevated platforms, floor mounted conveyor
belts, and sunken bins or dumpsters increase the opportunity for falls. The potential
for ergonomic injuries is a significant occupational concern for numerous activities.
Poorly designed work stations and improper manual materials handling and lifting
practices can result in various injuries or disorders. These problems are not
generally associated with repeated, low-level insults to localised body region. The
back and upper extremities are the most commonly affected areas. Poorly designed
collection vehicles and other equipment that require workers to make repeated
awkward motions during collection and sorting increase the possibility of ergonomic
injuries. In many cases, these hazards can be successfully eliminated through
design improvements.

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Fire and Explosions

The sorting and storage of combustible paper, plastic products and the presence of
flammable chemical residues pose the primary fire and explosion hazards.
Explosions may occur in shredder chambers, slicers, crushers and balers when
residues of flammable or explosive substances are ignited. Explosions are more
likely when an unsorted mixture of MSW is shredded. Hazards associated with the
fire or explosions are primarily occupational and environmental. Burns are the
greatest hazard posed by a fire or an explosion and can vary in severity from minor
superficial burns to deep tissue damage. Explosions can result in damaging noise
exposure. Environmental impacts include fire-related air emissions. Frequent
collection and processing reduces combustible paper stockpiles at home and
material recovery facility. Shredder explosions can be avoided by visually inspecting
and using magnetic detectors and separators to identify potentially dangerous metal
containers within the recycle stream so that they can be removed before shredding.
Flying and Falling Debris
Debris can fly or fall during most stages of processing. Flying materials can result at
drop-off centers where the public is often required to sort recyclables by throwing or
dropping them into uncovered bins or dumpsters. Recyclables may fall on workers
during operations when the recyclables are being loaded into collection vehicles,
sorted in overhead booths or conveyed through an MRF by belts or cranes.
Flying and falling objects may lead to a variety of occupational injuries to unprotected
workers. Items accidentally dropped from overhead may cause head, neck and
shoulder injuries, such as fractures concussions, and lacerations. Objects also can
be dropped during material handling (lifting or carrying) and cause injuries to feet
and toes such as crushing injuries, fractures and concussions. Flying objects can
cause cuts and lacerations or strike unprotected eyes and result in eye injuries,
including blindness.
Personal protective equipment such as hardhats and safety glasses helps prevent
injuries from both flying and falling debris. In addition, establishing and maintaining
safety zones beneath elevated equipment and in dumping areas are an effective
means of limiting worker exposure to falling objects. Objects hurled from processing
equipment can be contained by proper guards and housing on shredders and other
equipment.

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Temperature and Pressure extremes

Managing SW potentially expose workers to temperature extremes during outdoor
collection processing at facilities with inadequate climate controls. A variety of waste
reprocessing techniques may expose workers to temperature and pressure
extremes. The primary concerns are heated liquids generated during container
washing, plastic separation or pulping operations and hot machine parts such as
extruder blades or aluminium and steel furnaces. Plastic extruders and some paper
pulping equipment also operate at high pressures.
Exposure to high or low ambient temperatures and contact with hot materials are
primarily occupational hazards. Processes that involve heating of materials or wash
water can result in burns. Exposures to indoor temperature extremes can be
controlled through the installation of adequate climate control systems.
A popular solution to the challenge or heating or cooling a large open air building is
to isolate workers within small enclosed booths. Collection workers can be
encouraged to wear appropriate clothing and provided with training on the symptoms
and prevention of thermal stress.
Movement equipment and heavy machinery
Stationary as well as mobile equipment present hazards to workers in SW
management facility. Moving mechanical parts even under normal operating
conditions present potential hazards. Moving equipment and heavy machinery pose
primarily occupational safety hazards, although accidents can occur when
consumers handle recyclables at drop-off centers. Injury can be caused by crushing,
squeezing, or pinching of a body part between a moving object and a stationary
object or between two moving objects.
Another hazard related to recycling equipment includes accidents an emissions
associated with forklift and loader operations. Injuries associated with material
processing and handling equipment can be avoided through the appropriate
placement of guards and shields. Training regimens stressing safety practises for the
use of specialized equipment help prevent injuries resulting from equipment misuse.
Safety zones and warning signs alerting employees to hazardous areas and
equipment also help prevent accidents. Proper ventilation and vehicle emission
controls can help reduce workers exposures to vehicle emissions during loading and
unloading operations.

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Noise
A sum of SW managing activities that generate significant levels of noise, including
collection, sorting and general material handling. Aside from the noise associated
with equipment motors and engines, significant noise is generated by contact
between aluminium, glass and steel containers when they are loaded on a collection
vehicle, dumped on the tipping floor, or transported on conveyor belts.
Excessive noise is primarily an occupational hazard but also can be a public health
concern associated with certain collection activities. The effects of noise on ear are
related to the duration of exposure and the intensity of the noise. Noise can have
direct effects on both the middle and inner ear.
A simple and inexpensive means of reducing worker noise exposure is to require the
use of earplugs or headphone style protectors. Another option is the use of
engineered controls that reduce the levels of noise generated. Selecting quieter
collection vehicles or reducing the number of vehicle trips to collect all MSW can
minimize noise effects on the public.
Traffic
Traffic hazards are attributable to trucks collecting recyclables at the curb side,
private vehicles delivering recyclables to drop-off and buy-back centers and vehicles
transporting recyclables between processing and within facilities. Traffic poses public
health, occupational and environmental hazards. Vehicular accidents, release of
materials from collection vehicles, emission and maintenance generated wastes, and
noise are all traffic related hazards. Workers collecting recyclables may be subjected
to traffic related hazards during collection and truck loading activities. Two-sided
sorting may result in a higher accident rate because it has the potential to place
workers in the path of traffic.
A thorough, safety conscious traffic flow plan can minimize potential accident
hazards at all types of recycling facilities. Traffic safety zones can be established
within no vehicles are allowed. A well-organised collection strategy that anticipates
and avoids periods and routes of high traffic will help reduce road accidents. Keeping
vehicles well maintained reduces emissions.
Process chemicals and container residues
Container residues may include insecticides, herbicides and other lawn and garden
products; paints, stains and construction products; automotive oils and cleaners;
gasoline, kerosene and other fuels, and miscellaneous household cleaning products.

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Individuals may be exposed to these residues during collection, cleaning and storage
of recyclables in their homes.
Workers are exposed primarily during collection, sorting and washing steps.
Mishandled or mismanaged process chemicals or residues can cause adverse
effects to workers and the public. Direct skin contact, inhalation and incidental
ingestion exposures are possible.
Personal Protective equipment including glasses, gloves and aprons are
recommended for reducing chemical exposures. Requiring workers to shed
dedicated work uniforms before leaving the facility will help reduce exposures to
chemical spills. In addition, showers and eyewash stations can help to minimize
contamination.
Particulate releases
Certain materials produce more particulates that are more hazardous when they are
shredded or processed. Paper, because of its fibrous nature, generates significant
dust when it is sorted or shredded. Other dusts include fine glass shards from
crushing or grinding, plastic fines from shredding and aluminium and steel bits from
shredding and demagging and detinning.
Particulate releases from recycling activities may pose potential public health,
occupational and environmental hazards. In general, the principal potential health
effects of particulate exposure include the aggravation of asthma or other respiratory
or cardiorespiratory symptoms, increased cough and chest discomfort and increased
mortality.
Ventilation and filtration systems and personal protective equipment are two
approaches to controlling dust and protecting workers from elevated levels of
airborne particulates.
Microbiologic hazards
Microorganisms such as bacteria, fungi, and viruses often grow within recyclable
containers or on paper products. Infectious agents also can be present on
hypodermic needles that contaminate the recyclable waste stream. Microbiologic
agents are of particular concern when recyclables are mixed with MSW before
sorting but separated recyclable also provide suitable for microorganisms.
Operations that increase the risk of worker exposure to microbiologic hazards
include comingled MSW and recyclable collection, the use of the same vehicles to
collect both MSW and recyclables, bag breakers and other equipment that stir up

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contaminated materials and potentially disperse microorganisms, and manual sorting

operations that require workers to handle recyclables and remove putrescible
wastes. Individuals may be exposed to microorganisms in aerosols, on dust particles
or on objects they contact.
The most common health problems associated with pathogens include respiratory
infections, diarrhoea, and skin diseases. Contact dermatitis can occur from contact
with fungi. Washing vehicles and other processing equipment regularly also
minimizes the build-up of microorganisms. Personal Protective equipment such as
water-resistant gloves have been shown to effectively protect workers. Respiratory
protection reduces occupational inhalation exposures to airborne pathogens.

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