Hazard Exposure of Wood Carvers
INTRODUCTION
1.1 ERGONOMY
Ergonomics
is derived from two Greek words: ergon and nomos: ergon meaning work, and nomos
means rules, rules, or principles. Ergonomics is the science which studies
human or rules as a component of a working system includes physical and
non-physical characteristics, human limitations and capabilities in order to
design a system that is effective, safe, healthy, comfortable, and efficient
(Sutalaksana, 1979).
International
Ergonomics Association (n.d.) said that , ergonomics (or human factors) is the
scientific discipline concerned with understanding of the interactions among
humans and other elements of a system, and the profession that applies theory,
principles, data and method to design in order to optimize human well-being and
overall system performance. Ergonomics is also called human factors. The goal
of ergonomics is to provide a safe, healthy, comfortable and productive work
environment. So, ergonomics approach is to make the workplace or environment to
fit people, not the other way around (Dul Jan & Weerdmeester Bernhard,
2008).
Ergonomics
has three domains of specialization, which are physical ergonomics, cognitive
ergonomics, and organizational ergonomics. Physical ergonomics is concerned
with anatomical, anthropometric, physiological and biomechanical
characteristics of human in related to their physical activities. Cognitive
ergonomics is concerned about mental processes as they affect interactions
between humans and other elements of a system. Organizational ergonomics is
concerned about how to optimize the sociotechnical systems, including the
organizational structures, policies and processes (International Ergonomics
Association, n.d).
1.2
TASK ASPECT
In our
daily life, we need to carry out many tasks. Our body will react according to
the given task. Specific postures and movements are needed to those tasks.
Therefore, postures and movements are important in ergonomics which to help us
optimise our work and prevent from getting musculoskeletal disorders, injury
and stress.Types of postures are sitting, standing and walking whereas types of
movements are bending, twisting, awkward and backward. When we are carrying out
a movement or postures, force will be applied and our body’s muscles, ligaments
and joints will react according to it.
The
ergonomics of postures and movements are derived from three aspects which are
anthropometrics, physiology and biomechanical. Anthropometry is the subject
which deals with the measurements of the human external body dimensions in
static and dynamic conditions. Anthropometric data is used for product and
workplace design. In other words, the tools and products are designed to fit to
human. In physiological aspect, it is the science of mechanical, physical and
biochemical functions of humans in good health and how to apply that
information in the evaluation and design of work. Our musculoskeletal system
and energy expenditure are involved while doing the tasks. For biomechanical
aspect, it is the study of the structure and function of biological systems by
means of the methods of mechanics. It is the application of mechanical
principles to biological systems of human being. Three factors are considered
in this aspects which are force, joint and range of motion.
1.3 ORGANIZATION ASPECT
1.4 ENVIRONMENT ASPECT
DISCUSSION
2.1 OBSERVATION
On 15th July 2015, we did an observation to a
woodcarving workshops which is located at Jalan
Nangka 52, Denpasar. Our purpose is to evaluate the
woodcarving workshops based on their ergonomics. We did an observation
and also took a survey based on the attached questionnaire.
In our observation, we looking for some materials which
could cause an injury. For example, injured feet from fallen heavy
objects (woodcarving tools), electrocuted by tools,
cuts and punctures caused by sharp edges of tools or woods.
We also observed about the work-time, the enviroment, and
the noise level of the machinesin the woodcarving workshops.
Beside that, we observed is there some chemicals
which are toxic and also observed the affect psychology of workers in the
woodcarving workshops.
Other than interview and observation, we have also
conducted a reserach on journals that have been written about this topics. We
did our research using mostly PubMed and also Google Scholar.
2.2 RESULTS AND DISCUSSION
Task Aspect
Movement
Movement
means a change in place or position. In ergonomic, there are 4 types of
movement including bending, twisting, awkward, and backward.
- Bending
Wood
carvers usually do a body bending or neck bending.Prolonged bending have a bad
impact to the body. It can be lower back pain, neck pain or limb pain if it is
done in the wrong body position. But the wood carver that we observed doesn’t
feel any discomfort after doing his job.
- Twisting
Twisting
means to rotate or turn in another direction. When people do twisting in a
wrong position or technique, it can cause lower back pain, wrist pain, waist
pain, or sprain. (Davis et al, 2005)
- Awkward
Awkward
posture is the condition when joints are not in neutral positionslike
squatting, kneeling, raising elbow above the shoulder, and so on. The wood
carver that we observed usually does this awkward position. He usually does
squatting while doing his job. Activities that requiring prolonged awkward
postures as we mentioned before can be particularly stressful.
- Backward
Backward
means facing toward the back or rear. Wood carvers sometimes to do this
movement, but should be considered, that backward should be avoided because if
little wrong technique will be a problem in the back.
Posture
·
Sitting
Sitting
is a rest position supported in humans by the buttocks or thighs where the
torso is more or less upright. Some research said that the amount of daily
sitting time was positively associated with mortality rates from all causes, cardiovascular
disease, and other causes but not from cancer in the combined sample of men and
women. The results of this study suggest that greater daily time spent sitting
in major activities is associated with elevated risks of mortality from all
causes and from cardiovascular disease. These results remain significant after
adjustment for potential confounders, including age, sex, smoking status,
alcohol consumption, leisure time physical activitylevels,andthePAR-Q.
(Katzmarzyk PT,2009)
In
woodcarvers are also in risk of getting hazard from their position, sitting.
Workers have sitting position in along time for more than 45 minutes. He can’t
avoid and prolonged in sitting position. From the interview, the woodcarvers
told us that he felt unccomfortable with his work position which make him sit
for a long time. He admited experiencing low back pain because of their sitting
position. In order to prevent prolonged sitting disadvantage we can give him
education that sitting for long time is not good for his health
·
Standing
Standing
is a human position in which the body is held in an upright and supported only
by the feet. Some research said that there was a relationship between blood
pressure regulation and standing balance. The associations between intermittent
blood pressure measures and the ability to maintain standing balance adjusted
for age and sex. And there were 2 position for standing with eyes open,
intermittent blood pressure measures were not associated with the ability to
maintain balance. In standing positions with eyes closed, intermittent blood
pressure measures.( Pasma JH,2014)
In
woodcarvers are also a risk of getting hazard from his position, standing. But
on the woodcarvers standing is not prologed, and from the interview he is
standing just for relax for the sitting that he was doing and there is no
lementation.
·
Squatting
Squatting
is a position where the weight of the body is on the feer (as with standing)
but the knees are bent either fully (full of deep squat) or partially
(partiaal, standing, half, semi, parallel or monkey squat). There is a research
said that prolonged squatting for more than 30 minutes per hour can be the risk
factors of ostheoarthritis (OR :1,51 95%CL 1,12-2,04)( Pasma JH,2014). And can
causing low back pain.
We
have to reduce long term of squatting in woodcarvers, for the interview the
woodcarvers said that he do squatting for a long time to polish and sometimes
shaping the detail of the carves. And from the interview he admitted that
sometimes he got a back pain because of squatting that did’t realize he did
that for long time cause he too serious of his work. And to prevent the hazard
from squatting we can give them small chair or cushion for him.
Material
·
Paint
Paint countain much anorganic material such us
formaldehide and lead. The paint and coating can be used in spray application.
The woodwoker said he never have health problem caused by exposure of paint
.The woodworks use double surgerical mask when he work to minimize inhaling by
paint. Paint is cheamical material, double surgerical mask not good enough for
woodwokers when he use paint. The wood warker also use tools for protect his
eyes.but its not a standar safety for this occupation. The possible health
effects of overexposure to these products can vary depending on the chemicals
they contain (1. National Cancer
Institute. Formaldehyde and Cancer Risk . 2015) Formaldehyde is a colorless,
strong-smelling gas. It is used to make building materials and household
products. Exposure occurs primarily by inhaling formaldehyde gas or vapor from the air
or by absorbing liquids containing formaldehyde through the skin. Some
individuals may experience adverse effects such as watery eyes, burning
sensations in the eyes, nose, and throat, coughing,
wheezing, nausea, and skin irritation. Some people are very sensitive to
formaldehyde, whereas others have no reaction to the same level of exposure. The long term effect is cancer as stated by The International Agency for Research on Cancer
(IARC) that classifies formaldehyde as a human carcinogen(CDC,2014)
LEAD is a naturally occurring metal found deep
within the ground. It occurs in small amounts in ore, along with other elements
such as silver, zinc or copper. Chronic lead
exposure in adults can decrease kidney function, increased blood pressure,
decreased fertility, cataracts, nerve disorders for example increased incidence of essential tremor, muscle
and joint pain, memory or concentration problems(Niehs.nih.gov.Lead.2015)
·
Lacquer
Lacquer is
a clear or colored coating (called varnish) that is often used to give wooden
surfaces a glossy look. Same with paint, the woodworkers use double mask to
prevent the bad inhaling causeing by lacquer, Also the woodworker said never
have health problem when using tehe lacquer. Most
of the health effect caused by lacquers is from the solvents. Some of the
common solvents are toluene, xylene, ketones, esters and alcohols. The bad
effects in workers that use unregulary and repeated exposure is breathing
difficulty (from inhalation), dizziness, nausea, severe pain or burning in
nose, eyes, lips, skin accompanied with irritation, vision loss, chronic
respiratory disease, kidney failure and brain demage(Jacob L,2014)
·
Thinner
Thinner is
a chemical mixtures used as industrial solvents. The woodworker use thinner
too. The woodworker never have health problem with thinner, even He poured
thinner on his hand and feel his hand is cool. Humans can come into contact
with thinner by occupational exposure or by intentional inhalation . Toluene and acetone are the most
abundant compounds in commercial thinner. Thinner inhalation induces oxidative
stress and activation of free radical
processes. Free radicals induce the
cross linking between, DNA and proteins,damage between deoxyribose and the
phosphate skeleton, and specific modifications between the purine and
pyrimidine bases resulting in mutation of DNA(Martinez, 2011). The
process can also give bad effects on
organs like brain, lung, kidney and blood ( Konuk, 2014)
·
Wood
The place
the woodworker work is very dusty. The woodworker use single surgerical mask to
prevent the effect and he claimed that he doesnt have health problem with the
dust(no effect irritation and bad effect of inhaling the dust) . In the working
place there’s no one ventilation and that can make bad air circulation when he
work.The effects of wood consist by two , Organic and Anorganic
a. Organic dust
Organic
dust consists of particulate matter from microbial, plant or animal origin. Its specific agents include viruses,
bacteria, fungi and etc. The main effect is irritation that can be caused
by skin contact with wood, it sap and it dust. Symptoms usually only persist as
long as the affected skin site remains in contact with the source of irritation
such as the wood dust or sap etc (HSE,2014)
b.
Anorganic
Dust
In addition to causing several infectious
diseases, exposure to organic dust at the workplace is known to lead to an
increased frequency of cough,sneezing that can increase risk of occupational
respiratory diseases, such as chronic obstructive pulmonary disease (COPD),
asthma, hypersensitivity pneumonitis ,organic dust toxicsyndrome and lung
cancer
- Sandpaper and Electric Sandpaper
Sandpaper are generic names used
for a type of coated
abrasive that
consists of a heavy paper with abrasive material attached to
its surface. andpaper is produced in different grit sizes and is used to remove
small amounts of material from surfaces,
either to make them smoother (for example, in painting and wood
finishing), to remove a layer of material (such as oldpaint),
or sometimes to make the surface rougher. Not only produce the dust , The
electric sandpaper also produce noise. The woodworker use the tool without ear
plug or something alse that can help to reduce bad effect of noise. The tools
(electric Sandpaper) also quite heavy , so if the woodwork holding it the wrong
way ,the bad effects can happen like injoury and wound (Osha,2015)
·
Spiritus
Methanol, also known as wood alcohol, is a clear colorless liquid with a
faint alcoholic odor. As a solvent, it is present in cleaning solutions,
printing and duplicating solutions, adhesives, enamels, stains, dyes,
varnishes, and paint removers. The woodworker use cheamical material without
adequate personal protective equipment,he said doesnt have health problem with
this material. Bad effect may be happen
to the woodworkers ,exposure to methanol (by inhaling or
touching directly) will cause toxic metabolites, which present symptoms such as
manifesting a mild euphoria inebriation, and drowsiness in early stages,
whereas in long-term exposure, methanol will cause headache, vertigo, lethargy,
masked face, and mild dementia. A study about methanol in rat shows that
exposure to methanol dilution will cause hypotension with high heart rate
(Jammalamadaka,2010)
·
Saw/ Cutting Tools
In woodworking, hand saws, are used to cut pieces of wood into
different shapes. This is usually done in order to join the pieces together and carve a wooden object. They usually
operate by having a series of sharp points of some substance that is harder
than the wood being cut.The monotounes movement can effect his hand become
tired quickly . Inspect the wood stock for nails, knots, or
imperfections in the wood that could damage the hand saw.(13) The
woodworker also use the Electric
circular saw is The side drive saw is usually less expensive and is the most
common type for general work. The size of the saw is determined by the maximum
size of blade that can be used. One of the disadvantages of the side drive saw
is that the handles are offset from the blade and the saw tends to twist to the
side as it is being pushed through the cut. This makes it much harder to follow
a line and the constant torque that must be applied to the saw handles can
cause the arm and wrist to become tired quickly The common practice of resting
the weight of the saw on the guard will damage the moveable guard, but they are
more likely damaged by the saw being dropped (Portable Circular Saw, 2015)
·
Air Compressor
Air compressor appliance producers High pressure air blower used to clean dirty material and can reduce attachment of dust. The air compressor can produce noise . where the woodworker can feel unconfertable when he work and can effect of hearing system (Trocchi M,2015)
Organization Aspect
·
Working
hour and resting time
According
to the interview with wood carver worker, every day the workers will start
their work at 8 o’clock in the morning and finish their work at 5 o’clock in
the evening where the work approximately 9 hours daily. Within the 9 hours
daily of the work, the worker will rest 90 minutes daily for their lunch and
they can go home for a while if they want it. In this workshop the workers work
in daily hours and there is no shift work and also there is late night shift
emphasized in the workshop.
·
Day
off
In
this workshop, each worker has to work from Monday until Saturday, leaving
Sunday as their only day off for every week. According to the interview every
workers are given permission to take day of holiday by the owner of the
workshop, if they have religion ceremony at home or sometimes they get sick.
There is no limitation for they permission for holiday each month, because
based on interview the workers rare to take a long holiday so there is no
problem with the owner of the workshop. But sometimes when the workers take
long holiday in the workshop, the owners will replace it with another worker
until they back again.
Environment Aspect
Physical
1. Noise
Wood carver
are exposed to load noise in their daily work. The noises are come from their
equipmenst like electric saws, sanders, drills, and other
woodworking machines. Woodworking
machines are often very noisy, with noise levels ranging as high as 115 dB.This
can cause permanent hearing loss with
long-term exposure. The generally
accepted standard to minimize hearing risk is based on an exposure to 85 dBA for a maximum limit of eight hours per day, followed
by at least ten hours of recovery time at 70 dBA. (http://www.noisehelp.com/noise-dose.html). The noise is often increased with old machinery
with worn parts and poor maintenance.
From our
interview and observation, Mr. Ketut Suyatra use electric saws, drills and
compressor in doing his job. He change
the equipment every 5 years.He never wear ear protection when he use wood
working machines. He had been working as wood carver for 24 years. While now he
doesn’t complain about hearing problem, long-term exposure of noise in his job
can cause hearing loss in the future.
For prevent
the harm effect of noise the wood carver can shield noisy machines and replace
it whenever possible and use hearing protection such as ear plug or ear muffs.
2. Vibration
Wood carver are also exposed to vibration. Vibrating
tools, for example chain saws, can cause "whitefingers" (Raynaud's
phenomenon) involving numbness of the finger and hands. This can lead to permanent damage. Mr. Ketut
Suyatra doesn’t have problem with the vibration from the equipment. For prevent
the harm effect of vibration the wood carver canmount the machinert with
vibration isolators (like shock absorbers).
3. Electrical shock and fire
Woodworking machinery and tools also present physical hazards from accidents. Machinery accidents are often due to missing machine guards, faulty equipment, or using the wrong type of machine for a particular operation. Tool accidents are often caused by dull tools or improper use. The accident causes by electrical equipment can present electrical shock andfire hazards from faulty or inadequate wiring. Sawdust and wood are fire hazards. In addition, fine sawdust is an explosion hazard if enclosed. Mr Ketut Suyatra often changed his equipment to make sure that they are in good condition. All wood carver must keep all electrical equipment and wiring in good condition and avoid extension cord to avoid electrical shock and fire
Chemical
Chemical
Wood
carvers have a high risk to be exposed to chemical in two forms : liquids and
dusts. The liquids form, including paint and thinner, and also the dusts can
have a bad impact for the workers.
• Liquids
The major
component of thinner is toluene, which is known as a neurotoxic agent. Acute
and chronic effects of toluene on neurons have been well documented. Thinner
inhalation induces oxidative stress in some organs, such as brain, lung,
kidney, and blood (http://www.ehow.com/info_8249573_dangers-paint-thinner.html) The other hazardous substances
contained in thinner is benzene, which is lately classified as a genotoxic.
This indicates that more thinner inhaled by the workers, the greater risk they
have to suffer from disease. Moreover, the use of this substance should always
be handled carefully. Based on the place we observed, we can assume that the
workshop hasn’t reached a good standard of safety for the workers. They don’t
use any equipment when they put the paint and the thinner. There has never been
accident connected to this, but paint and thinner have some chemical
composition that can be harmful, some effects may occur in some future time.
Too much direct contact with paint thinner can cause allergic, irritation, and
respiratory problems.
• Dusts
Wood
carvers are likely to be exposed to wood dust all the time. Numerous recent
studies have shown that exposure to wood dust can cause some health problems.
Woods contain some chemicals that is toxic which can result headaches,
giddiness, weight loss, breathlessness, cramps, and irregular heart beat.
Furthermore, wood dust can also irritate eyes, nose, and throat, cause
dermatitis condition in the skin, cause some respiratory system problems such
as decreased lung capacity and allergic reaction in the lungs, and the most
harmful effect that can appear in the future is cancer. However, we found that
the workers at the observational place have already use masks in their work.
This is a good precaution to protect themselves from dust hazards (Work Safe Alberta, 2004)
Mental psychology
CONCLUSION
3.1 CONCLUSION
There are so many exposure that
can hazard the health of wood carvers. Posture is common problem with them,
they are getting hazard from their position, especially sitting. Workers have
sitting position in along time for more than 45 minutes. He can’t avoid and
prolonged in sitting position and this
can be result as low back pain. Furthermore, wood dust as a residual in their
work can also irritate eyes, nose, and throat, cause dermatitis condition in
the skin, cause some respiratory system problems such as decreased lung
capacity and allergic reaction in the lungs, and the most harmful effect that
can appear in the future is cancer. The hazardous substances contained in
thinner is benzene, which is lately classified as a genotoxic also frequently
exposure the wood carvers. Too much direct contact with
paint thinner can cause allergic, irritation, and respiratory problems. Wood carver are also exposed to load noise in their
daily work. The noises are come from their equipment like electric saws, sanders, drills, and other
woodworking machines. Woodworking
machines are often very noisy, with noise levels ranging as high as 115 dB. This
can cause permanent hearing loss with
long-term exposure.
3.2 RECOMMENDATION
During
our interview we
realize posture from
wordcarvers which monoton and long time can affect many healt problem, frequent
short break is recommended while prolonged duty can’t avoidable. Wood carver also
have no protect device in contact with chemical substance like tinner so we
suggest to use slope so risk factor for irritation can be reduced.
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