X-ray Diagnostics of Pneumoconiosis

1st stage - interstitial fibrosis of the lungs, formation of small nodules 1 mm in diameter along the bronchial tubes, a moderate bilateral intensification of lung pattern.

2nd stage – exacerbation of interstitial and nodular lung fibrosis and formation of numerous nodules 2-4 mm in diameter on a background of atelectasis areas (symptom of a "snow storm"), deformation of the lung pattern.

3rd stage – amassive lung fibrosis, big masses of connective tissue, marked deformation of the bronchial tree, disturbance of bronchial permeability.

In addition to that metalloconioses are characterized by the increased roentgen contrast of metal dust in the lungs.

Clinical and Functional Diagnostics of Pneumoconiosis

Its symptomatology includes symptoms of bronchitis, lung emphysema, respiratory insufficiency, disturbances of pulmonary blood circulation – hypertrophy of the left cardiac ventricle, changes of ECG readings –"lung heart".

At asbestosis there are asbestine corpuscles in sputum, at anthracosis the sputum is of black color.

Complications of pneumoconiosis: lung cancer, tuberculosis, pneumonia, bronchialasthma, rheumatoid arthritis, etc.

Prevention of Dust Diseases

· The labour legislation, preliminary and current physical examinations.

· Preventive and current sanitary control of working conditions with dust.

· Struggle against formation and spread of dust.

· Biological methods - increase of body resistance - UVR, alkaline inhalations, respiratory gymnastics, clinical nutrition (containing proteins and vitamins).

· Individual means of protection.

Recommendations for Practical Classes on the Theme

Key Questions

1.Basic laws of functioning of various body systems.

2.Physiology of work. Classification of kinds of work.

3.Dynamics of capacity for work during work and after its termination.

3.Methods of studying the capacity for work.

4.Changes in organs and systems during work.

5.Concept of occupational hazards and occupational diseases. Classifications.

6.Order of registration and investigation of occupational diseases.

7.Purpose, types, organization of physical examination of working people.

8.Classification of dust, pathogenesis and types of pneumoconiosis, their diagnostics and prevention.

Learning Objectives and Their Concrete Definition

1. Giving the corrector test at the beginning and at the end of the lesson using the suggested by teacher tests to define the speed of processing information in bit/sec according to Hartridge formula:

 

 

where: S - speed of processing information (bit/sec), N - number of symbols looked through in the table, n - number of overlooks and mistakes, Т - time of viewing the table (60 sec.).

2. The research of muscular capacity for work. To estimate the physical force, the examinee should twice compress a dynamometer with the maximal effort; the greatest value is taken for initial. To determine the exercise tolerance, time (in sec) is estimated, during which the examinee keeps a spring of a dynamometer at a level of 0.5 of his maximal force, up to complete impossibility to continue the effort of this intensity.

3. The research of capacity for work by method of finding numbers. Time is marked during which the examinee names and shows all the numbers printed in the table containing 49 numbers (from 1 up to 25 and from 24 to1) represented by different colours.

4. The investigation of hand tremor is carried out by a tremometer. If rate of tremor movements is 8-12 per second – it is frequent, 5-8 - moderate, 3-5 - slow.

5. Investigation of capacity for work by a chronometric method. The increase of time spent on operation testifies to exhaustion. In hygiene and physiology of work a photochronometric investigation of a working day and detailed selective chronometry are used. Use of chronometry for studying influence of working process on a body state and capacity for workreveals the following: the duration of separate operations, ratio of time spent on performance of basic and auxiliary operations, business activity of a working day, productivity of work and its change within a day. On the basis of analysis of data and their comparison with the data of physiological methods of research the recommendations for rational arrangement of a working day, change of a working rhythm are grounded.

6. The verbal (associative) experiment. This method is more often applied at estimation of mental work (lecturers, announcers, teachers). It allows to estimate a functional condition of the nervous system analyzers (speech, hearing, movement). The purpose of the research is to determine the speed of occurrence in the cortex of associative communications between images of various objects and concepts. The speed of these communications depends on a functional condition of the CNS and primarily on degree of exhaustion. The essence of the method consists in the fact that the examinee is offered from 10 up to 30 words (nouns) with an interval of 10-20 sec. The examinee should name the word matching the given one in sense. For example, table - high, cap – big, etc. The researcher fixes the time of latent period in seconds (time from the moment, when the word is given and answer of the examinee is received) and number of mistakes available in the answer (the word does not match the given). The researches are carried out several times within a working day, the results are compared.

7. Definition of attention stability. Change of attention during work is also connected with a number of reasons and, primarily, with exhaustion. The examinee with the help of a special device is demonstrated consistently a number of figures painted in different colours for the certain period of time. The examinee is offered to count mentally, how many such figures there were. On calculation he should not use a pencil. The researches are carried out several times within a working day, the results are analyzed. The increase of amount of mistakes testifies to approaching exhaustion.

Self Test

1. Identify the method of research of capacity for work.

*A. a corrector test

B. Eiber’s test

C. Duglas’ method

 

2. Which of the following is most frequently connected with occupational harmful factors?

*A. Production, its technology and equipment

B. Interruption of work (break, dinner, visit to boss, etc.)

*C. Working process, its organization

*D. Intensity and duration of working process

 

3. In a foundry the manual casting of liquid metal into small forms was carried out. In the workers, who repeatedly took part in the casting process, the signs of intoxication by aerosols of heavy metals have occurred. What radical measures of prevention of occupational poisonings can you suggest in the given situation?

A. Regular medical examinations

B. Control of metal aerosols in the air of a working zone and its comparison with MPC

C. Expansion of ventilation

*D. Installation of the automatic line of metal casting with effective ventilation

Problem Solving

1. It is necessary to determine stages of capacity for work of a schoolboy according to the parameters of a corrector test: at the beginning of lessons it is 4.2; at the 3d lesson – 5.5; at the 5th lesson – 5.3. What other methods can be used to investigate the capacity for work of the schoolboy?

2. After accident in the chemical plant there was the environmental pollution with nitrose compounds. Headache, dyspnea, dizziness appeared in people living in this district. What is the reason of hypoxia?

3. Give the hygienic estimation of work in the workshop of a furniture industrial complex, where the general dust content makes up 20 mg/m3. What occupational diseases are possible in the workers? What are the principles of their diagnostics and prevention?

Standard Answers:

1. According to the data of a corrector test, at the beginning of the lessons there was an in-working stage, and then a stage of working excitation was observed. It is also necessary to carry out the similar researches with other pupils in the class for correct arrangement of the lesson and prevention of exhaustion in pupils, and if in some pupils the premature exhaustion develops, it is necessary to investigate the condition of their health. To study the capacity for work it is possible to apply methods of estimation of attention stability, verbal-associative experiment, chronometry researches.

2. The formation of methemoglobinemia.

3. MPC of non-toxic (furniture) dust makes up 10 mg/m3, in this case general dust content exceeds the standard norms by 2 times, in this connection the development of pneumoconioses in working people is possible. Their diagnostics is carried out roentgenologically and clinically (according to degree of respiratory insufficiency). Prevention: change of technology, strengthening artificial general and local ventilation, application of dust-gathering equipment, current sanitary control of a dust content of air, application of individual means of protection of respiratory organs (respirators).

Appendix 1

Ministry of Health
City	Registration form No 163
Medical establishment

Notification

About Acute Occupational Poisoning or Occupational Disease

Enterprise _______________________________________

Workshop (where poisoning occurred)

Full name________________________________________

Date of poisoning _________________________________

Diagnosis._______________________________________

Date of sending notification_____________________________

Signature of the doctor

Appendix 2

Ministry of Health
City	Registration form No 165
Medical establishment

List of persons, in whom chronic occupational poisoning or occupational disease was first revealed in __________ month of year 200 __

Enterprise ____________________________________

Ministry ____________________________________

Branch of industry ____________________________________

 

No

Full name

Concrete profession

Diagnosis

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________

 

Appendix 3

Ministry of Health
City	Registration form № 163
Medical establishment

Registration Card № ___

of Acute Occupational Poisoning or Occupational Disease

Acute poisoning occurred in __________ (month) of 200 __ (year)

Enterprise ______________ Address ________________

Branch of industry

Workshop, department (where poisoning occurred)

Full name ___________

Sex _________ Age _______

Profession ________________

Record of service in the given shop ___________

Record of service in the given occupation ______

Record of service in the previous work _______ what industry_______,

what occupations ____________ (filled in case of chronic disease)

Circumstances, under which poisoning occurred ___________________________

а) What poisonous substances caused occupational poisoning or occupational disease

 

 

Theme No 18.

Hygiene of Work at Effect of Physical Occupational Harmful Factors (Noise, Vibration, Electro-Magnetic Fields)

Concept of Harmful Physical Occupational Factors

During work many physicaloccupationalharmfulfactors can effect a person, including adverse microclimatic factors, non-optimal illumination or excess of its components, laser radiation, noise, vibration, electromagnetic fields (EMF), high or low pressure, radioactive radiation.

Noise as an Occupational Harmful Factor, Its Characteristics

According to WHO’s data, noise is a universal problem for mankind, one of the main physical factors of environmental pollution.

Concept of "Noise"

In physics noise is the chaotic sound fluctuations of different frequency rate and intensity, having no regularity.

In hygiene noise is any sound, preventing recognition of useful sound signals, interfering with rest, rendering a negative effect on a human organism and decreasing his capacity for work.

Classification of Noise

According to sources it is classified into:

· household

· transport

· industrial

· building

· agricultural

According to duration it may be:

· stable – a fluctuation level of noise is not more than 5 dB

· unstable - more than 5 dB

· impulsive - intermittent

According to frequency, noise is classified into:

v audible sounds (16 - 20000 Hertz):

Ø low-frequency - up to 400 Hz

Ø medium-frequency - 400-1,000 Hz

Ø high-frequency - over 1,000 Hz

v infrasound - frequency up to 20 Hz – produces marked effect on internal organs since its frequency can coincide with frequency of fluctuations of internal organs; the most dangerous frequency is 8 Hz causing the disturbance of alpha-rhythm of the brain; 1-3 Hz results in disorder of respiration, etc.;

v ultrasound - more than 20,000 Hz - produces a mechanical and chemical effect resulting in cavitation (formation of cavities in interstitial tissues), destruction of molecules, their ionization; a thermal effect results in tissue heating – this phenomenon is used in physiotherapy; at high levels the local damage of peripheral nervous and blood systems, disorders of the CNS, etc. occur).

Level of Noise. Units of Its Measurement

Effect of noise on organism depends not only on frequency, but also on its level. In acoustics loudness of sound is a sound pressure in Newton/m2 (difference between atmospheric and sound pressure).

Unit of measurement of sound level in hygiene is a logarithmic unit, which expresses the excess of sound pressure above a sound threshold: 0-14 Bell, or 0-140 dB:

 

 

Sound threshold = threshold of perception - 2 х 10-5 Newton/m2 = 0 dB

Painful sound threshold is 14 Bell = 140 dB.

SON – a comparative unit of level of sounds different by frequency

Abroad the unit of sound is FON (sound with frequency of 1000 Hz at a level of 1 dB).

Effect of Noise on Organism

Specific and nonspecific effect of noise is distinguished.

Specific effectis manifested bydisturbance of function of acoustic analyzer due to a long angiospasm resulting in degenerative changes in the nerve endings and neuritis of acoustical nerve (occupational deafness).

Three stages of noise disease are distinguished at audiometry, i.e. estimation of hearing level:

· Acoustical adaptation– at action of noise the acoustical threshold increases by 10-15 dB, but in 1-3 min it returns to normal (a physiologic phenomenon);

· Acoustical exhaustion - decrease of hearingby 15-20 dB within hours or days after stopping the noise effect;

· Progressing deafness – a gradual complete loss of hearing in connection with organic changes of the auditory center in the CNS (noise at the level of more than 80 dB quickly causes the decrease of hearing and development of deafness at length of service up to 5 years).

Nonspecific effect of noise is manifested by excitation of the cortex, hypothalamus and spinal cord, quick development of CNS inhibition, then exhaustion of the nervous cells and consequently irritability, emotional instability, deterioration of attention, memory, capacity for work; via the vegetative nervous system the functional changes of different systems and organs occur.

As a result of long effect of intensive noise the so-called noise illness develops - a general disease with affection of organs of hearing, CNS and other systems.

The struggle against noise in industry and inhabitedplacesincludes:

v Administrative-legislative measures.

v Architectural-planning measures (functional zones in cities, sanitary-protective intervals, transport highways).

v Hygienic measures, including:

Ø preventive sanitary control - normalization of noise - establishment of MPL according to different criteria:

Table 36

Maximum Permissible Levels of Noise for Various Premises

Kind of premise	MPL, dB	Criteria of harmful activity
Habitable rooms	30	protection of sleep at the night
Wards in hospitals	25	maintaining a therapeutic-protective regimen in hospital
Classrooms	50	maintenance of information perception
Industrial premises	65* - 85	prophylaxis of noise illness

Note: * - for high-frequency noise

Ø current sanitary control - the control of noise levels and its limitation.

v Medical-preventive measures - preliminary and current medical examination of workers at noisy industries.

v Technological measures: sound-suppressing linings, wall coverings, automatization, etc.

v Individual measures: headphones, over 100 dB - flannel helmets.

Hygienic Characteristics of Vibration

Vibration is oscillations of elastic bodies with frequency over 1 Hz.

It is characterized by amplitude, frequency, direction.

Vibrationis classified into:general and local.

According to frequency vibration is subdivided into:

· low-frequency vibration

· middle-frequency vibration

· high-frequency vibration

According to direction vibration can be:

· horizontal

· vertical

Local vibration of small intensity gives a positive effect (a vibrating massage); at general vibration of high intensity there are changes of the CNS; through the vegetative nervous system the changes of internal organs occur.

Local vibration causes long angiospasms and mechanical trauma of the peripheral nerve endings in fingers – disturbance of trophism in tissues, polyneurites, arthroses - vibration illnesses of various degree of severity.