PHYSICAL

HAZARDS - I

HAS 222

OCCUPATIONAL HEALTH

AND SAFETY

Dr. Şeyda ÇOLAK

H.Ü. Engineering of Physics Department

Occupational Health

and Safety

The aim of Occupational Health is; to sustain andimprove the mental, social and physical well-beings of all

employees in all occupations.

The target of the Occupational Health and Safety is identification of health problems in working life and making efforts to protect the health of employees.

The fundamental principles in these studies are based on «preventive» approach.

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Occupational Diseases

For the purpose of the Protocol of 2002 to the

Occupational Safety and Health Convention of

International Labour Organisation (ILO), the term

‘occupational disease’ covers any disease contracted

as a result of an exposure to risk factors arising from

work activity”

1. Physical Induced Occupational Diseases

2. Chemical Induced Occupational Diseases

3. Dust Induced Occupational Diseases

4. Biological Induced Occupational Diseases

5. Occupational Infectious Diseases

Occupational Diseases Risk Groups

Physical Hazards

Working environment factors include important physical risk

factors and these physical induced diseases are frequently

observed among the other occupational diseases.

1. NOISE

2. VIBRATION

3. PRESSURE

4. THERMAL COMFORT

5. LIGHTING

6. RADIATION

Classification of Physical Risks

1. NOISE

Noise is stated as «unwelcome and unpleasant sound".

Noise is one of the most common physical risk factors in

working life (ILO).

Hearing loss problem induced by noise is one of the ten

most common occupational diseases in European Union

(EU). It has been also arisen as an occupational disease in

the list of Social Security Institution, in Turkey.

1. NOISE In a workplace, if one needs to raise his/her voice to speak

with someone else at 1 meter distance, it means that there is

«noise» in that workplace.

In a workplace, noise level measurements are made with

noise measuring equipments. During this process, the

noise level should be measured for the total of eight hours of

work and a good frequency analysis should also be made.

These devices;

• can measure the instant levels of noise,

• can be used as workplace dosimeters

• can be used as personnal dosimeters.

Sound level meter

Exposure Limit Values and Exposure Action Values

Section 5 – (1) in respect of the implementation of this regulation, the

exposure limit values and exposure action values are given below:

a) The lowest exposure action values: (LEX, 8 hour) = 80 dB (A) or

(Ppeak) = 112 Pa [135 dB (C) re. 20 μPa].

b) The highest exposure action values: (LEX, 8 hour) = 85 dB (A) or

(Ppeak) = 140 Pa [137 dB (C) re. 20 μPa].

c) Exposure limit values: (LEX, 8 hour) = 87 dB (A) or (Ppeak) = 200 Pa

[140 dB (C) re 20 μPa].

2) when applying the exposure limit values, the determination of the exposure of employees to which the

employee uses personal protective equipment the protective effect of the ear is taken into account.

(3) the effect of the exposure action value of ear protectors are ignored.

“In order to be considered «noise» as occupational

disease risk, it is needed to have worked at a noisy

work place for at least two years below 85 dB or at

least 30 days at the business where the noise

intensity is consistently above 85 dB.

The liability period is 6 months»

Sound can be defined as a vibration in a matter where

it can be transmitted and carry energy by the extraction

and expansion of molecules of the matter.

For determination of «noise» concept in Occupational

Health and Safety; the quantitative terms of noise such

as velocity, pressure and frequency should be

defined.

SOUND

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Audio frequency; is the number of sound waves in unit time.

The human ear can hear sounds in the frequency range of

20 - 20000 Hertz. Frequency vibrations with more than 20,000

Hz is called ultrasound and lower than 16 Hz is called

infrasound.

The frequency of the sound around us, in everyday life, is

often 250 - 2000 Hz range.

Speed of sound is the travelled distance by sound in unit

time interval.

Speed of sound depends on the temperature, flexibility

and density of the medium that sound travels.

Velocity of the sound is 344 m/s in air at 20 C, 1410 m/s in

water and 5200 m/s in steel.

The power of sound is; the transmitted energy to the

environment in unit time. Unit of it is defined as watt (W).

The density of sound is; the sound power dissipated in

unit area and its unit is W/m2. The lowest sound intensity,

that is the hearing threshold is 10-12 W/m2 and the highest

sound intensity that can be heard is in the range of 1-10

W/m2. Above this intensity of the sound level, pain is felt.

SOUND PRESSURE

The vibrational movement of sound waves in the air

creates pressure in the air. Sound pressure is evaluated with

"Pascal (Pa)" unit.

A healthy human ear is sensitive to the sound between the

pressure range of 20 Pa - 200 pascal.

Effects of noise on hearing can be determined by the

measuring the sound pressure level. Thus, noise

measuring equipment are based on the pressure

measuring devices.

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By the result of responding to the sound pressure in the

air, the sound can be heard. High volume pressure sounds

as noise.

Some sound pressures:

whisper-0.0003 Pa;

refrigerator-0.005 Pa;

speaking-0.01 Pa;

vacuum cleaner-0.05 Pa;

chainsaw-5 Pa;

pneumatic breaker-10 Pa;

aircraft (near)-30 Pa.Atmospheric pressure – 101,3 Pa.

The human ear responses to the sound with different

frequency and intensity as logarithmic scale.

Sound intensity and sound pressure variations can be

measured by a logarithmic increase (Bell-1885)

related with hearing threshold value. It is in daily use, one-

tenth of the value of the Bell, which means "decibel dB"

value is used.

Hearing threshold level value: 0 dB

Pain threshold level value: 140 dB

NOISE LEVEL VALUES

1. Sound intensity

2. Sound frequency distribution

3. Duration of exposure to noise

4. Personal sensitivity to noise

5. Age of the individual exposed to noise

6. Sex of the individual exposed to noise

The physical risks of noise depends on;

1. Physical Effects: Temporary or permanent hearing

disorders can occur.

2. Physiological Effects: Increase in blood pressure,

circulatory disorders, sudden acceleration during respiration,

decelerations in heart rate, sudden reflexes can be observed.

3. Psychological Effects: behavior disorders, excessive

irritability, stress state can be observed.

4. Performance Effects: Loss of work efficiency, lack of

concentration, slowing of movements can be observed.

5. Social Impacts: Loss in communication can be observed.

EFFECTS OF NOISE

AGE-INDUCED HEARING LOSS

With increasing age, physiological harms will also increase in hearing.

In audiometric measurements, 0.5 dB loss in hearing has been

observed for the workers 1 age older than 40 years old.

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Example: It has been reported that 9% of workers in

Japan and %10 of workers in Denmark have noise-induced

hearing loss as occupational disease.

In the United States, 30 million workers are exposed to

harmful levels of noise in the workplace.

In recent years in our country, occupational noise induced

hearing loss have been observed in the number of

exceeded 200,000.

Health Surveillance

Section 13 – (1) at any noise-induced hearing loss, for the purpose of

early diagnosis and protection of hearing ability of employees;

a) Employer should held health surveillances;

1) According to section 15 of the law situations,

2) According to the results of a risk assessments performed at work,

3) employees should be held to health surveillance at regular intervals

determined by occupational physicians.

To reduce noise in the workplace the

following methods should be applied:

1. Reduce the noise at the source,

2. Reduce the noise between the source and the

receiver path followed,

3. Blocking the noise the person exposed to noise.

Preventing and Reducing Exposure

Section 8 – (1) the employer should control and/or decrease the risks at the

source by taking into account the technical developments and should take

precautions according to 8, 9, 10 and 11 sections of the law.

(2) the employer, in preventing or reducing exposure, should take into account

the prevention principles of Law 5 and in particular;

a) selecting other working methods which contain less noise exposure,

b) selecting the lowest possible level of noise-emitting appropriate business

equipments related with the work done,

c) making appropriate design of company,

d) giving the necessary information and education to employees for the right

and safe usage of business equipments.

Limiting Exposure

Section 10 – the employee shall not exceed the exposure limit values.

Despite the receipt of control measures specified in the regulations, if

the limit values specified in section 5 has been exceeded; the employer

a) should take the necessary precautions immediately in order to

download the exposure under the limit values,

b) should determine the reasons of exceeding the limit values and in

order to avoid duplication of this result, protection and prevention

measures should be checked and developed.

PERSONAL PROTECTIVE

EQUIPMENTS

If the noise exposure cannot be prevented by other means,

personnel ear protectors with full compliance should be

delivered to the employees.

When the noise exposure exceeds the lower exposure

enabled values, the employer should provide workers

protective ear equipments ready for installation.

Personal Protection

Section 9 – If the arised risks induced by noise cannot be prevented with

taking the precautions given in section 8,

a) when the lowest exposure exceeds the action values specified in section 5,

the employee's should provide ear protective equipments for the employees

ready to be used.

b) when the noise exposure reaches or exceeds the maximum exposure action

values specified, ear protective equipments should be forced to be used and

their usages should be checked by the employer.

c) the employers should use their best efforts to ensure and to control the use

of ear protective equipments, in accordance with Law controls.

Personal ProtectionThe ear protective equipments supplied by employer should have these

specifications,

a) related on 2/7/2013 published Official Gazette No. 28695 titled «Usage

of Personal Protective Quipments in Workplace» and 29/11/2006

published Official Gazette No. 26361 titled «Regulation of Personal

Protective Equipments».

b) will be selected to eliminate or minimize the risk associated with the

hearing.

c) is used and maintained correctly by staff.

d) fits exactly to the employee.

e) in the need of hygienic conditions, they should be specific for each

employee.

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Ear protectors should be used all the time at work, if

needed.

Ear protectors that reduce noise level of 30 dB (if used

100%) will only reduce noise level in the range of 15 dB if

they are used 95% percentage.

Headphones should be weared before entering to the

noisy environment and should not be removed before

existing

Informing and Training of Employees

Section 11 – If the lowest or more noise exposure exist in the

workplace, the employer should inform and train the employee about

the topics given below which are specified in section 5,

a) arise from the noise risks

b) avoid or minimize the risks which may arise from noise and the

precautions

c) exposure limit values and exposure action values.

2.VIBRATIONVibration can be produced by the oscillation motion of the

tools and machinery, while working.

Vibration is a kind of mechanical oscillation around its

equilibrium point. This oscillations can be both periodical

as the motion of a pendulum or random as movement of

the wheel on a rough way.

The specifications of vibration can be determined by its

frequency, intensity and direction properties.

Vibrations, like sound waves, has certain number of

waves per second. The main difference between sound

and vibration is their entering ways to the body. Sound

enters the body by the vibration of air while vibration

(according to Occupational Health and Safety concept)

enters the body by hard body parts.36

People perceive vibrations between 1-1000 Hz.

They feel jolt when the people exposed to low frequency

vibration. High-frequency vibrations can effect as tingling and

burning sensation in the person.

Vibration is examined in two types in terms of the format of

affecting the body:

1) Hand-Arm vibration

2) Whole body vibration

Hand - Arm Vibration

Hand-arm vibrations is one of the risk to the health and safety

of workers. They are the mechanical vibrations that can cause

damages at cardiovascular, bone, joint, muscle and nerves.

The sources of such vibrations can be: stone crushing

machineries, hammers used in coal or mininova, saws

used in forestry, polishing and planing machines, etc.

Hand - Arm VibrationVibration can cause circulation disorders in the fingers, in a long time

working intervals. Blanching of the fingers, cooling or pain may ocur in

the fingers. This disease is called as «vibration-induced white finger

syndrome». Symptoms increase in the cold.

To decrease this effect, the devices with corners can be used where the

vibration can be absorbed. Besides, the hands can be kept warm.

White Finger Syndrome

Hand-arm Vibration

For 8 hours daily working duration;

Exposure limit value is 5 m/s²

Exposure to the effective value is 2.5 m/s²

Hand-arm vibration is a condition frequently encountered in

working life. Vibrating handsets (pneumatic hammers,

pneumatic drilling etc.) users are in the risk in this regard.

Work with breaking, drilling and washing machine for long

years with hand-arm bones can cause harms. Internalbleeding and damage on the hand nerves may occur.

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Whole Body Vibration

When mechanical vibration passes all of the body, it can form

risk to the health and safety of the workers, especially at the

spine trauma and discomfort in the lumbar region.

The vibration sources that whole body can remain under

their influence can be; tractor and truck use, weaving

looms, road-building-maintenance-repair machinery, steels

structures causing vibration machine and machine tools, etc.

Whole-body vibration for the duration of the

working day for 8 hours

Exposure limit value 1.15 m/s ²

Exposure to the effective value of 0.5 m/s ²

WHOLE BODY EXPOSURE INDUCED BY VIBRATION

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Very low frequency vibration effects (f < 2 Hz);

• Central nervous system complaints may occur while travelling

with horse, car, airplane, ship, etc vehicles.

• Nausea, vomiting, cold sweat can be observed.

• The symptoms are temporary and they can be eliminated after a

certain period of time.

Low frequency vibration effects (2 Hz < f < 30 Hz):

• Circulatory disorders in the hands can be observed for the

workers using vibrating hand tools.

• If the exposure will continue, shoulder pain, fatigue, sensitivity to

cold can increase.

• Sleep disorders, headaches and fatigue can be seen.

• After a short time exposure to 8 -10 C heat, fingers and palms

can go blanching. Pain can be seen in muscles of the forearm and

shoulders.

• Some workers exposed to whole body vibration can also show

slipped disc diseases.

Mechanical vibration-reducing methods

1) Considering the work to be performed, appropriate ergonomic design and

business equipment with minimum possible vibration should be selected.

2) Appropriate maintenance programs should be organized for workplace,

workplace systems and business equipments.

3) Design and layout of work place must be supplied.

4) Education and instructions should be given to the workers about decreasing

the mechanical vibration exposure on the equipments.

5) Exposure intensity and duration should be limited.

3. PRESSURE

«Pressure» is defined as the force applied to the unit

surface (P = F / A )

The unit of pressure is; pascal (N/m²), bar (kg/cm²)

or atm (1 atm = 760 mmHg = 1,013 kg/cm²).

For the working conditions at higher or lower than

atmospheric pressure, heart, circulatory or

respiratory diseases can be observed.

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Health Problems Related With Pressure Changes

Normally, 4.5 N/cm2 pressure change does not create any

health problems on the people except some uncomfortable

feelings. But some workplaces have high pressure medium,

while others have low pressure medium.

Liability period for acute events due to change in pressure

is 3 days but for other events this duration is 10 years.

For employee can be effected by high pressure who are

working underwater or artificially constructed pressurized

environments.

Air pressure at sea level is 1 atm and for every 10

meters depth in water, the pressure will increase will

the level of 1 atm.

Example: Divers, sponge hunters, employees working on

several construction types at underwater will be effected

by high pressure conditions.

High Pressure

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When the pressure exceeds 4 atmosphere, people will

get more nitrogen during respiration and nitrogen

narcosis can be observed.

Errors can be observed on decision making, thinking,

movement, etc.

In the advanced stages, coma can be observed by

increasing oxygen partial pressure.

Derinlikler Saat

20-25 (20 hariç) metre derinlik veya 2-2,5 (2 hariç) kg/cm² basınçta 20-25 7

25-30 (25 hariç) metre derinlik veya 2,5-3 (2,5 hariç) kg/cm² basınçta 25-30 6

30-35 (30 hariç) metre derinlik veya 3-3,5 (3 hariç) kg/cm² basınçta 30-35 5

35-40 (40 hariç) metre derinlik veya 3,5-4 (3,5 hariç) kg/cm² basınçta 35-40 4

Dalgıçlar için bu süreler; 18 metre derinliğe kadar 18 3

Dalgıçlar için bu süreler; 40 metre derinliğe kadar 40 0,5

Sağlık Kuralları Bakımından Günde Ancak 7,5 Saat veya Daha Az

Çalışılması Gereken İşler Hakkındaki Yönetmelik (Madde: 5)

«Su altında basınçlı hava içinde çalışmayı gerektiren işler (iniş, çıkış,

geçiş dahil)»

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At diver's rooms, at least 40 m3 air per hour per person

should be provided and the amount of carbon dioxide in the

air should not be exceed 0.1%.

The working time shall be determined in accordance with

the pressure at under water for diver's rooms. Duration of

the worker at high pressure will be regulated basing on

"health care needed jobs where the working duration is

limited as 7.5 hours or less per day".

A diver can not dive to a depth 22 meters of water more

than twice in a day and the duration between these two

divings should be at least 5 hours.

Employees working on road construction, electricity, telephone, and TV

service stations are examples for the employees working at low

pressure.

The higher the altitude, the lower the pressure of the oxygen in the air.

Thus some problems can be observed at workers with this lack of

oxygen.

There is not a special precaution

in terms of low pressure conditions. Slow movements are

recommended and each 400 meters in elevation is suggested to be

taken daily.

Low Presssure

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By dropping pressure, the molten gases in the tissues

can be released and such occasions can be observed;

Tingling in various organs,

Pain in the arms and legs,

Ear aches,

Blurred vision,

Anok Thalassemia (O₂ reduction in blood),Increase in heart rate

Prevention Methods from Low and High

Pressure Effects

For low and high pressure required jobs, young and

experienced workers, if possible, should be selected as

employees

These employees preferred to be lack of fat, alcohol abuse

and lack of chronic diseases related to respiratory system

During the continuation of the work, periodically

investigations on the employees should be done and the

workers who have acute symptoms about ear, nose, throat

and respiratory system should be removed from work for a

certain time.