Prepared by O.SopelPrepared by O.Sopel

The lectureThe lecture

Hygienic description of physical, chemical and biological factor of production

environment

THE PLAN

1. Hazards and their prevention   

2. Noise, it’s influence of human organism in industry.

3. Vibration , it’s influence of human organism in industry.

4. Ultraviolet radiation

5. Dust, it’s influence of human organism in industry

6. The industrial microclimate. Exposure to heat and cold.

Noise, it’s influence on

human organism in industry

Noise - "Wrong sound, in the wrong place, at the wrong time.“

Man is living in an increasingly noisy environment. The 20th century has been described as the "Century of Noise". Noise has become a very important 'stress' factor in environment of man.

Physical characterization of main parameters

Amplitude

( m)

Sound pressure

( Н/m2 )

Sound Power

(intensity)

( Wt/m2 )I

h

P

Time Тсек =1f

Frequency f = 1

Т (Hz ) 1/sек

Waveм

ג

ג — Wavelenght

С — Frequency of noise in air

ג = С

f=

m/sек

Hz=

m/sек

1/sек= m

С = 334 m/sек

Properties of Noise

1. FREQUENCY

Human ear can hear frequencies from 16 – 20 000 Hz.

Infra audible : Sounds below 16 Hz

Ultra sonic : Sounds above 20,000 Hz

On frequency distinguish noise of low frequency (16… 350 Hz), middle-frequency (350… 800 Hz) and high frequency (more than 800 Hz).

 2. LOUDNESS

It is measured in decibels (dB). It depends upon amplitude of vibrations, which initiated noise. A daily exposure up to 85 dB is about the limit people can tolerate without substantial damage to their hearing.

Interference of sound

•1

•

•

2

1 ― strengthening of sound

2― weakening of sound

Diffraction of sound

2

Noise

In physics In acousticsIn information

theorya subjective

term

noise is a sound

vibrations

of a different

frequency

and different

loudness

“white” noise consists of all audible

frequencies, just as white light consists of all visible frequencies

the term designates a signal that contains

no information

Noise is referring to

any unwanted

sound

Acceptable Noise Levels

RESIDENTIAL: Bed room - 25 dB

Living room - 40 dB

COMMERCIAL : Office - 35-45 dB

Conference - 40-45 dB

Restaurants - 40-60 dB

INDUSTRIAL :

Workshop - 40-60 dB

Laboratory - 40-50 dB

EDUCATIONAL: Class room - 30-40 dB

Library - 35-40 dB

HOSPITALS: Wards - 20-35 dB (45dB )

Decibel Scale

Decibels (dB) Typical sounds

0 threshold of hearing

10 quiet whisper

20 average whisper

20-50 quiet conversation

40-45 hotel; theater (between performances)

50-65 loud conversation

65-70 traffic on busy street

65-90 train

75-80 factory (light/medium work)

90 heavy traffic

90-100 thunder

140-190 space rocket at take off

Deafness,

most simply defined as an inability to hear.

Four types of hearing loss may be described.

• conductive hearing lossconductive hearing loss,

• sensorineural hearing losssensorineural hearing loss,

•mixed hearing lossmixed hearing loss,

• central hearing losscentral hearing loss Continuous or frequent exposure to noise levels above 85 dB can cause a progressive and eventually severe sensorineural hearing loss.

Industrial Noise

A number of industrial operations generate noise. Stamping metal into auto fenders, punching holes into metal plates, riveting plates together, and crashing different materials all produce impact noise, and grinding and drilling metal produce continuous noise. Rapid air motion caused by jets of air, blowers, and fans, and vibration of equipment also cause noise. Although industrial noise mainly affects workers in the industry, some of this noise also reaches nearby homes.

Most hearing loss occurs in workplaces, where workers may be unable to avoid unhealthy noise, and where exposure may

continue for years.

Factory workers

construction workers

farmers

musicians

firefighters

police officers

military personnel

         EFFECTS OF NOISE EXPOSURE

The effects of noise exposure are of two types : auditory and non-auditory.

1. AUDITORY EFFECTS

a. Auditory fatigue : It appears in the 90dB region and greatest at 4000 Hz. It may be associated with whistling & buzzing.

b. Deafness : Temporary deafness appears in frequency range of 4,000-6000 Hz. It disappears after sometime.

Permanent deafness appears after repeated or continuous exposure to noise around 100 dB. Exposure to noise above 160 dB may rupture tympanic membrane

         2. NON - AUDITORY EFFECTS:

a) Interference with speech: Noise interferes with speech communication. The frequencies causing most disturbances to speech lie in 300-500 Hz range.b)   Annoyance: This is primarily a psychological response.c) Efficiency of work: Efficiency of work decreases because there is loss of concentration due to noise.d)Physiological changes: A number of physiological changes occur due to noise, they are :•         Increase in blood pressure•        Increase in intracranial pressure•         Increase in heart rate•        Increase in breathing rate•         Increased sweatinge) General effectsNausea, vomiting, giddiness and fatigue may also occur. Sleep is also disturbed by noise.

Noise makes conversation difficult, interferes with some kinds of work, headache, tiredness, loss of

memory and appetite, and disturbs sleep.

damage of hearing organ

cardiovascular problems, high blood pressure

nervous disorders

Noisy disease is a general illness of an organism

with such symptoms as

         Noise Control Methods

Level of noise can be controlled and changed in some ways.

• Substitution of a quieter machine design, process, or material may be an easy and effective means of eliminating or reducing a noise problem.

• Forces that cause vibration can sometimes be isolated by mounting the equipment on springs or resilient materials such as rubber and by using flexible connections.

• If noise cannot be reduced to acceptable levels in industry, personal protection or special design considerations may be necessary.

 

        NOISE CONTROL

While noise cannot be totally eliminated, much can be done to reduce it.

1. Control at source

2.Control of transmission

3.Protection of exposed people

.

    Vibration , it’s influence of human

organism in industry.

Vibration is characterized by:

frequency (Hz) - (one oscillation for one second) amplitude (m) - (maximal deviation of body from

position of stable balance) Its derivatives on time –

vibrospeed (m/sec) vibroacceleration (m /sec2)

As criteria for hygienic estimation and normalizations of vibration are applied vibrospeed or vibroacceleration as changes in an organism under the influence of vibration depend on the quantity of energy of the fluctuations transmitted to an organism which, in turn, is proportional to a square of oscillatory speed or oscillatory acceleration.

Vibration, especially in the frequency range 10-500 Hz, may be encountered in work with pneumatic tools, such as drills, hammers, and chisels, in mines, quarries, foundries or the machine industry, or with other machines, such as those used in the shoe industry, and motor saws in forestry. 

Vibration local

general

Is transferring on a body of the sitting or worth person

through basic surfaces (a seat, a floor, a working

platform)

is transferred to hands of the

working at contact to the vibrating tool

or the equipment

Vibration is constant (vibrospeed changes less than 6 dB for

1 minute) changeable (changes of the vibrospeed more

than 6 dB for 1 minute)

To changeable vibrations concern: varying in time (the level of the vibrospeed

continuously changes)faltering (contact of the operator to vibration

interrupts and makes more than 1sec)pulse (one or several vibrating influences by

duration less than 1 seс)

The prevention of VibrationThe prevention measures of decline of influencing of

vibration on an organism include:

technological processes (automation of remote control, creation of machines with vibroisolation facilities)

rational regime of labour (time of contact with vibration makes a 20-30% working change, 2 breaks for active rest)

individual facilities of protection (specific gloves and shoes)

periodic medical control

Ultraviolet radiation

In industry workers are affected by ultraviolet rays with the length less than 280 nm.

Occupational exposure to ultraviolet radiation occurs mainly in arc welding. Such radiation mainly affects the eyes, causing intense affects the eyes, causing intense conjunctivitis and keratitisconjunctivitis and keratitis (welder's flash.)

Symptoms are redness of the eyes and pain; these usually disappear in a few days.

Dust, it’s influence of

human organism in industry

Classification of a dust

I. For the origin the dust is divided into three groups:

  1) Organic (-Vegetative: wood, plans, tobacco, cotton, Cane fibre

-Animal: Hay or grain dust);

  2) Inorganic (-Mineral: Quartz, Coal, Silica, Asbestos,

- Metal: Iron and other );

3) Mixed (artificial, plastic).

II. Froom dispersing into two groups:

  1) Aerosol of disintegration

2) Aerosol of condensation

III. For the size:

1)  Visible – the size of speck of dust is more than 10 micrometer,

2)  Microscopic – the size is 10 - 0,25 micrometer,

3) Ultramicroscopic – the size is less than 0,25 micrometer

Dust influences on:      - System of breath and causes such specific illness -pneumoconiosis, pneumonias, chronic bronchitis, and not specific illness such us: cancer, tuberculoses;-        - On skin; - On eyes.

The hazardous effects of dusts on lungs depends upon a number of factors, such as

a) Chemical composition

b) Size of particle

c) Concentration of dust in air.

d) Period of exposure

e) Health status of workers

Forms of pneumoconioses are:

— Anthracosis - Coal dust

— Silicosis - Silica

— Asbestosis - Asbestos

— Siderosis – Iron

— Bagassosis - Cane fibre

-- Byssinosis - Cotton dust

— Tobacossis - Tobacco

— Farmer's lung - Hay or grain dust

Silicosis.Lung tisse Легенева тканина.

Fibrosis of lung

AnthracosisCoal worker's pneumoconiosis, also

known as black lung disease or anthracosis, is caused by inhaling coal dust for prolonged periods, usually at least 10 years. Coal worker's pneumoconiosis is much more common in miners of anthracite coal than in miners of bituminous coal.

Prevention

Prevention is the best course of action. Wear a dust mask and take other steps to prevent exposure to the dust if man is working in an occupation that puts at risk of developing one of these diseases. In addition, do not smoke.

ASBESTOS

Symptoms:

•   Chest pain

•   Shortness of breath

•  Decreased exercise tolerance

• Cough

       Asbestos exposure may cause

asbestosis (a form of interstitial fibrosis or pneumoconiosis),

mesothelioma (a cancer of the lining of the lung or abdomen),

or lung cancer.

The industrial microclimate

         Microclimate of industrial premises consists of meteorological conditions in a working zone, which are defined by the influencing on an organism of the person by combinations of temperature, humidity and speed of movement of temperature, humidity and speed of movement of airair, and also temperatures of environmental temperatures of environmental surfacessurfaces and a thermal irradiationa thermal irradiation. As a working zone is meant the space limited to protecting designs, in height up to 2 m above a level of a floor or a platform on which there are places constant (more than 50 % working hours or more than 2 hrs continuously) or changeable stay working.

Parameters of a microclimate measure

in cold (the daily average temperature of external air +10 °С and is lower)

in warm (the daily average temperature is higher +10°C)

periods of year within one day in the beginning, middle and the end of a labour

shift.

OCCUPATIONAL POISONS

POISONING

•Lead •Mercury

•Phosphorus •Arsenic

•Chromate

Maximum admitted concentration of lead

and its inorganic compounds in air is 0, 01 mg/m3.

Maximum admitted concentration mercury in air of a working zone is

0,01mg/m3

Poisonous Gases and Fumes.

1. Carbon dioxide, CO2

2. Carbon Monoxide, CO 3. Carbon Bisulphide, CS2

4. Sulphuretted Hydrogen, H2S.

5. Sulphur Dioxide Poisoning, SO2

6. Arseniuretted Hydrogen or Arsine, AsH3

7. Chlorine (Cl) and Hydrochloric Acid Gas (HCL). 8. Ammonia, NH3

9. Benzene. 10. Aniline.

Occupational Health in Agriculture

Parametr norm on a class of danger

1 2 3 4

MAC mg/m3

< 0.1 0.1-1.0 1.1-10 > 10

DL50 inh mg/kg < 15 15-150 151-5000 > 5000

DL50cut

mg/kg

< 100 100-500 501-50000 > 50000

Zone of acute action

< 6,0 6,1-18,0 18,1-54 > 54

Classification of the chemical hazards

Modern greenhouse