LECTURE II – OCCUPATIONAL MEDICINE
Dr. SIJAL FADHIL FARHOOD- M.Sc.(community medicine)-M.B.Ch.B.
Identifying Safety and Health Hazards
Hazards, risks, outcomes
The terminology used in general:
• A hazard is something that can cause harm if not controlled.
• The outcome is the harm that results from an uncontrolled hazard.
• A risk is a combination of the probability that a particular outcome will occur and the severity of the harm involved.
“Hazard”, “risk”, and “outcome” are used in other fields to describe
e.g. environmental damage, or damage to equipment. However,
“harm” generally describes the direct or indirect degradation,
temporary or permanent, of the physical, mental, or social well-being
of workers. For example, repetitively carrying out manual handling
of heavy objects is a hazard. The outcome could be a musculoskeletal disorder (MSD) or an acute back or joint injury. The risk can be
expressed numerically (e.g. a 0.5 or 50/50 chance of the outcome
occurring during a year), in relative terms (e.g. "high/medium/low"),
or with a multi-dimensional classification scheme (e.g. situation-
specific risks).
Hazard Assessment
Hazard analysis or hazard assessment is a process in which
individual hazards of the workplace are identified, assessed and
controlled/eliminated as close to source (location of the hazard) as
reasonable and possible. As technology, resources, social expectation
or regulatory requirements change, hazard analysis focuses controls
more closely toward the source of the hazard. Thus hazard control is
a dynamic program of prevention. Hazard-based programs also have
the advantage of not assigning or implying there are "acceptable
risks" in the workplace. A hazard-based program may not be able to
eliminate all risks, but neither does it accept "satisfactory" -- but still
risky—outcomes. And as those who calculate and manage the risk
are usually managers while those exposed to the risks are a different
group, workers, a hazard-based approach can by-pass conflict
inherent in a risk-based approach.
Risk Assessment
Modern occupational safety and health legislation usually demands
that a risk assessment be carried out prior to making an intervention.
It should be kept in mind that risk management requires risk to be
managed to a level which is as low as is reasonably practical.
This assessment should:
• Identify the hazards
• Identify all affected by the hazard and how
• Evaluate the risk
• Identify and prioritize appropriate control measures
The calculation of risk is based on the likelihood or probability of the
harm being realized and the severity of the consequences. This can be
expressed mathematically as a quantitative assessment (by assigning
low, medium and high likelihood and severity with integers and
multiplying them to obtain a risk factor, or qualitatively as a
description of the circumstances by which the harm could arise.
The assessment should be recorded and reviewed periodically and
whenever there is a significant change to work practices. The
assessment should include practical recommendations to control the
risk. Once recommended controls are implemented, the risk should
be re-calculated to determine of it has been lowered to an acceptable
level. Generally speaking, newly introduced controls should lower
risk by one level, i.e., from high to medium or from medium to low.
Common workplace hazard groups
• Mechanical hazards include:
By type of agent:
•
o Impact force
? Collisions
? Falls from height
o Struck by objects
o Confined space
o Slips and trips
o Falling on a pointed object
o Compressed air/high pressure fluids (such as cutting fluid)
o Entanglement
o Equipment-related injury
By type of damage:
•
o Crushing
o Cutting
o Friction and abrasion
o Shearing
o Stabbing and puncture
• other physical hazards:
o Noise
o Vibration
o Lighting
o Barotrauma (hypobaric/hyperbaric pressure)
o Ionizing radiation
o Electricity
o Asphyxiation
o Cold stress (hypothermia)
o Heat stress (hyperthermia)
? Dehydration (due to sweating)
• Biological hazards include:
o Bacteria
o Virus
o Fungi
? Mold
o Blood-borne pathogens
o Tuberculosis
• Chemical hazards include:
o Acids
o Bases
o Heavy metals
? Lead
o Solvents
? Petroleum
o Particulates
? Asbestos and other fine dust/fibrous materials
? Silica
o Fumes (noxious gases/vapors)
o Highly-reactive chemicals
o Fire, conflagration and explosion hazards:
? Explosion
? Deflagration
? Detonation
? Conflagration
• Psychosocial issues include:
o Work-related stress, whose causal factors include excessive working time and overwork
o Violence from outside the organization
o Bullying, which may include emotional and verbal abuse
o Sexual harassment
o Mobbing
o Burnout
o Exposure to unhealthy elements during meetings with business associates, e.g. tobacco, uncontrolled alcohol
• Musculoskeletal disorders, avoided by the employment of good ergonomic design
Fire prevention (fire protection/fire safety) often comes within the
remit of health and safety professionals as well.
OCCUPATIONAL SKIN DISEASES
An occupational skin disease is one in which workplace exposure to some physical , chemical or biologic hazard has been a causal or a major & necessary contributing factor in the development of the disease.
Contact Dermatitis accounts for at least 60% of occupational dermatoses.
The industries most likely to result in occupational dermatitis are:
FOOD HANDLERS
HAIRDRESSERS
MEDICS/DENTISTS/NURSES/VETS
GARDENERS
CLEANING/LAUNDRY
PAINTING
CONSTRUCTION/ENGINEERS
Contact Irritant Dermatitis
• An irritant is a substance which will induce dermatitis in anyone if applied to the skin
• In high enough concentrations
• Over sufficient time
• Or with sufficient frequency
Irritant contact dermatitis is therefore concentration dependent
Management of contact irritant dermatitis
Treat with steroids, emollients , antibiotics.
Reduce exposure by:
1-REDUCE FREQUENCY OF EXPOSURE
2-SUBSTITUTE LESS IRRITATING CHEMICALS
3-AVOID OCCLUSION
4-AVOID SKIN TRAUMA
5-AVOID EXCESSIVE HEAT & HUMIDITY
Occupational Infections:
• Human papilloma virus type 7 warts occur in butchers, fishmongers and poultry processors.
• Some infections may be transmitted from animals to man in those who work with animals eg. Orf and milkers’ nodules.
Physical Agents:
Friction blisters
Raynaud’s phenomenon
Miliaria( sweat duct occlusion)
Chilblains
Miscellaneous Occupational Dermatoses
• Folliculitis ( eg. Auto mechanics)
• Chloracne
• Viteligo ( rubber industry)
• Acrosclerosis due to silicosis
Contact Allergic Dermatitis
• Involves Type IV (cell mediated) immune reaction.
Allergic reactions are NOT concentration dependent
Some
causes:
Seafood
Various fruits
Various vegetables
Meat/ blood
Animal secretions
Rubber latex
• The time interval between the first contact with a chemical and development of sensitization depend on:
THE CHEMICAL
THE CONDITION OF EXPOSURE
CONSTIUTIONAL FACTORS
Management of contact urticaria
Treat the underlying dermatitis
Avoid the chemical which induces contact urticaria
Change of work may be required