METHODICAL INSTRUCTION FOR STUDENTS OF THE 3 COURSE

MEDICAL FACULTY

LESSON 15 (PRACTICAL  6 HOURS)

Themes: 1. Tropical hygiene. A hygienical estimation of influencing of tropical climate on the conditions of life, capacity and health of population. 3 hours.

2. Hygienical, toxicological and epidemiological problems of feed of population of tropical regions.

Organization and conducting of sanitary examination of food products and prepared meal in the countries of torrid zone. Methods of medical control  after the feed of population of countries of tropical region. 3 hours.

Aim:

1.           Master hygienic peculiarities of working and living conditions of population in tropic and hot climate.

2.           Master the method of assessment of heat exchange and organism thermoregulation of the body in tropic and hot climate.

3.           Know types of population pathology in tropic and hot climate conditions.

4.           Learn the social and hygienic, toxicological and epidemiological nutrition peculiarities of tropical regions population.

PROFESSIONAL ORIENTATION OF STUDENTS:

The most of the land belongs to tropics: almost all Africa, South Asia, south of East Asia, the most part of Latin America, Oceania. The most part of population lives in tropics and subtropics. Transitional zone adjoins to tropic zone (Mediterranean area, front and middle Asia, the south of the USA etc.) and it is characterized as tropic and mild zones from to medico geographical point of view. WHO and UN specialists have developed medical measures to control living and working conditions in tropic climate and preventive measures which are implemented in countries of this climate. Calculation methods of heat load determination and overheating prevention and its pathology are of great importance among medical measures.

Rational nutrition and its provision in arid and humid areas with tropical climate is considered according to abovementioned natural peculiarities, social development of the countries, natural resources presence, which allow to solve economical and nutrition problems. For example countries of Middle East are rich with oil and despite the Arabian peninsula desert climate they trade and can receive food products from other countries. Due to these circumstances, the qualitative and quantitative sufficiency of population nutrition is satisfied.

METHODOLOGY OF PRACTICAL CLASS (900-1200 hour).

Theme 1. A hygienical estimation of influencing of tropical climate on the conditions of life, capacity and health of population

Work 1. Methods of the assessment of human heat balance by calculation of heat emission

The assessment of human feeling of the heat/cold is performed comparing the heat production during work and heat emission. Heat emission is calculated as a sum of the irradiation, conduction and water evaporation.

The basic data are:

A) the human heat production in a calm state accounts to 0.8 1.5 kcal (3.34 6.27 kj) per 1 kg body weight per 1 hour, during hard work  7-9 kcal/kg×h;

B) the body surface of average human (170 cm of height and 65 kg of body weight) is approximately 1.8 m2 (see table );

C) 100 % of the body surface takes part in heat emission by conduction and sweat evaporation;

D) 80 % of the body surface takes part in heat emission by irradiation (see table ).

40 % of the body surface takes part in heat emission by irradiation relating to the one-sided heat radiation source.

Table

Dependence of the human body surface on body weight

Body weight, kg

Body surface, m2

100 %

80 %

40

1.323

1.058

45

1.482

1.186

50

1.535

1.228

55

1.635

1.308

60

1.729

1.383

65

1.830

1.464

70

1.922

1.538

75

2.008

1.606

80

2.098

1.678

85

2.188

1.750

90

2.263

1.810

95

2.338

1.870

100

2.413

1.930

 

1. Heat emission by irradiation (radiation) can be calculated using the following formula:

Qirr. = 4.5×(1  2) s

(1)

Where: q  heat emitted by irradiation, kcal/h;

  1  body temperature, ;

  2  internal wall surface temperature, ;

  s  body surface area, m2.

2. Heat emission by conduction can be calculated using the following formula:

Qcon = 6(1  2)  (0.5 + √‾v) s

(2.1)

Qcon = 7.2 (1  2)  (0.27 + √‾v)s

(2.2)

Where : q  heat emitted by conduction, kcal/h;

   6; 0.5  constant coefficients if air movement is less than 0.6 m/s;

   1  body temperature, ;

   2  air temperature, ;

   7.2; 0.27  constant coefficients if air movement is higher than 0.6 m/s;

   v  air movement, m/s;

   s  body surface area, m2.

3. The maximum amount of water evaporated from the body surface can be calculated using the following formula:

evap = 15(fmax   fabs)  (0.5 +√‾v)s

(3.1)

Where: evap  water. Evaporated from body surface under this conditions, ml/h;

15  constant coefficient;

Fmax  maximum humidity under skin temperature of the body;

Fabs  absolute humidity under currant air temperature.

fabs  can be calculated using the following formula:

: : http://intranet.tdmu.edu.ua/data/kafedra/internal/hihiena/metod_rozrobky/%d0%bc%d0%b5%d0%b4%d0%b8%d1%87%d0%bd%d0%b8%d0%b9%20%d1%84%d0%b0%d0%ba%d1%83%d0%bb%d1%8c%d1%82%d0%b5%d1%82/3%20%d0%ba%d1%83%d1%80%d1%81/Eng/Tropical%20hygiene.files/image002.gif

(3.2)

 

Where: f max maximum humidity under air temperature, hg mm. ;

 frel. relative humidity under current air temperature, %;

 (fmax   fabs)  physiological humidity deficit, hg mm.;

 v  air movement, m/s;

 s  body surface area, m2.

Quantity of emitted heat may be calculated by multiplication of the result by 0.6 (calorie evaporating coefficient of 1 g of water). Or by putting the coefficient 9 in formula (3.1) instead of 15 (0.6×15 = 9). It is necessary to remember that an adequate heat self-feeling remains stable if sweat evaporation is not more than 250 ml (it takes 150 kcal).

Work 2. Hygienic standards and calculation methods of heat load of organism in hot and tropic climate conditions

1. Maximum allowable equivalent-effective temperature (EET) indices.

Table 1

Labour mode

Labour intensity

light

medium

hard

Without breaks during the shift

30.4

28.9

26.1

With breaks:

 

 

 

-every 3 hours

32.7

29.9

27.6

-every 2 hours

33.3

31.0

29.9

-every 1 hour

35.0

32.7

30.4

-every 30 min

38.2

35.5

34.4

- every 20 min

40.5

37.7

35.0

For people acclimatized to high temperature

32.2

29.4

28.9

For non-acclimatized to high temperature people

30.2

27.4

26.9

 

EET and resultant temperatures are calculated by means of tables and nomograms

 

Work 3. Wet bulb globe temperature determination method and its hygienic assessment according to Yanglow and Minard (1955).

Wet bulb globe temperature (WBGT) is an integral index of environment temperature which takes into account temperature, air humidity, radiant temperature and it is calculated by the following formula (1):

WBGT = 0.1 tdry + 0.7 twet + 0.2 tbulb,          (1)

 

where, WBGT is wet bulb globe temperature;

tdry  temperature according to dry thermometer of psychrometer indices;

twet  temperature according to wet thermometer of psychrometer indices;

tbulb  radiant temperature according to the black globe thermometer.

According to Yanglow and Minard (1955) if WBGT exceeds 29.40C physical load for non-acclimatized people is limited. Under 31.10C WBGT physical load is excluded. Under 32.20C WBGT physical load is excluded for acclimatized people too.

Work 4. HeatLoad Index (HL) according to Belding and Hatch calculation.

According to this method heat-load is calculated by the formula (2);

HL =     R max. kcal/hour,            (2)

where: M - intensity of metabolism during work: light work 170 kcal per hour; medium - 300 kcal per hour; hard 420 kcal per hour;

 R heat exchange through radiation, kcal per hour;

 C- heat exchange through convection, kcal per hour;

 Emax- maximum acceptable heat loss through sweat evaporation, kcal per hour.

Loss (-) or income (+) of heat by radiation R is calculated by formula (3):

R = 11×(tbulb - 35) kcal/hour,                 (3)

where: tglobe  mild radiation temperature  according to the globe black thermometer;

Losses (-) or income (+) of heat by convection is calculated by formula (4):

= 6×v0.6 ×(tdry - 35) kcal/hour,                 (4)        

where: v - air movement, m/sec. (v is in the table 2);

       tdry  air temperature according to dry temperature of psychrometer;

       35 surface body temperature.

Table 2

v m/sec

0.05

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

v0.6

0.17

0.25

0.38

0.49

0.58

0.66

0.74

0.81

0.87

0.94

0.99

 

Maximum heat loss through sweat evaporation (Emax) is calculated by formula (5):

max. = 12×v0.6 ×(42 - ) kcal/hour,               (5)

where: p - maximum water pressure, Hg mm under dry thermometer of psychrometer.

 

In case of wearing light clothes calculation result of heat load by formula (2) is divided by 3.

Authors recommend allowable values of heatload index in the range of no more than 400-600 kcal per hour. It should be mentioned that with air movement increase sweat evaporation intensity increases proportionally. Thus this method is used in conditions of weak air movement.

 

Theme 2. Hygienical, toxicological and epidemiological problems of feed of population of tropical regions.

Organization and conducting of sanitary examination of food products and prepared meal in the countries of torrid zone. Methods of medical control  after the feed of population of countries of tropical region

Students receive situational tasks (prepared by the chair) and complete them on their own.

 

INDIVIDUAL STUDENTS PROGRAM

Theme 1. A hygienical estimation of influencing of tropical climate on the conditions of life, capacity and health of population

Control questions

1.     Hygienic characteristic of climate and weather in tropic and hot climate.

2.     Hygienic peculiarities of solar radiation in tropic climate.

3.     Hygienic peculiarities of daily and seasonal microclimate fluctuation (air temperature, radiant temperature, humidity, air movement speed) in hot deserts and humid tropic conditions.

4.      meteorological factors complex influence on heat exchange and other physiological processes in the organism in tropic and desert climate conditions.

5.     Hygienic characteristics of savannah, steppe, arid areas and humid tropic forest climate.

6.     Health disorders and diseases typical for tropic and hot climate and their prophylactics.

7.      human adaptation and acclimatization in hot and tropic climate.

8.     Personal hygiene peculiarities in hot and tropic climate: hygiene of skin, clothes, hygienic principles of day regimen and their substantiation.

9.     Peculiarities of inhabited area planning and build-up in arid and humid tropic climate.

10. Peculiarities of sanitary infrastructure of settlements in tropic climate. Water supply, sewerage system, solid waste disposal. The role of green vegetations in microclimate conditions improvement in inhabited areas.

11.  residential hygiene in hot climate. Planning peculiarities of different types of buildings according to their insolation and influence on residential microclimate conditions. Optimal windows orientation, its scientific substantiation. Sun protection devices.

12. Hygienic requirements to natural and artificial residential and industrial premises ventilation in tropic climate.

13. Air conditioning in residential, public and industrial premises as microclimate optimization measure.

14. Peculiarities of requirements to natural lighting of residential premises in tropic conditions. Natural lighting and microclimate optimization measures interrelations. Venetian blind influence on these factors.

15. Hygienic peculiarities of building materials and constructions which are used for building in tropic climate.

16. Organization and working regimen peculiarities in arid and humid climate. Microclimate parameters in which physical work is impossible.

17. Calculation methods of the assessment of tropical climate influence on heat condition of organism.

Theme 2. Hygienical, toxicological and epidemiological problems of feed of population of tropical regions. Organization and conducting of sanitary examination of food products and prepared meal in the countries of torrid zone. Methods of medical control  after the feed of population of countries of tropical region

Control questions

1.     Rational nutrition and conditions of its provision.

2.     Social and hygienic peculiarities of nutrition of different age and sex population groups in tropical regions.

3.     Physiological and hygienic basics of rational nutrition in tropical conditions.

4.     Organism energy, protein, fat, carbohydrate requirements and their quantity and balance peculiarities in tropical climate.

5.            Vitamins, mineral salts, microelements, taste substances (spices) role in nutrition of tropical regions population.

6.            Hot climate influence on food and some its components assimilation. Metabolism and nutrition pattern peculiarities in tropical regions.

7.            Hygienic characteristics of food products, used by population of arid and humid tropical regions.

8.            General characteristic of alimentary diseases of tropical regions population.

9.            Malnutrition and complete starvation diseases (protein and energy insufficiency) among tropical regions population.

10. Vitamin deficiency diseases (hypo- and avitaminosis) among tropical regions population. Polyunsaturated fatty acids deficiency diseases.

11.    Mineral and microelements deficiency diseases among population of tropical regions.

12.    Overeating diseases in tropical regions.

13. Diseases caused by poor quality of food intake (foodborne diseases, helminthosis, food poisoning, ferrnentopathies).

14. Methods of medical control over tropical regions population nutrition.

15.    Calculation methods of the population nutrition assessment. Alimentary calorimetry method.

16.    Sanitary inspection of food products and ready meals, its usage in tropical region counties.

17.    Food products storage and preservation peculiarities in tropical conditions, usage of preservatives and antibiotics.

18. Methods and measures of prevention of the foodborne diseases, infections and invasions with alimentary transmission mechanisms, food poisoning.

 

SEMINAR DISCUSSION OF THEORETICAL ISSUES (1230  1400 hour).

 

1.     Hygienic characteristic of climate and weather in tropic and hot climate.

2.     Hygienic peculiarities of solar radiation in tropic climate.

3.     Hygienic peculiarities of daily and seasonal microclimate fluctuation (air temperature, radiant temperature, humidity, air movement speed) in hot deserts and humid tropic conditions.

4.      meteorological factors complex influence on heat exchange and other physiological processes in the organism in tropic and desert climate conditions.

5.     Hygienic characteristics of savannah, steppe, arid areas and humid tropic forest climate.

6.     Health disorders and diseases typical for tropic and hot climate and their prophylactics.

7.      human adaptation and acclimatization in hot and tropic climate.

8.     Personal hygiene peculiarities in hot and tropic climate: hygiene of skin, clothes, hygienic principles of day regimen and their substantiation.

9.     Peculiarities of inhabited area planning and build-up in arid and humid tropic climate.

10. Peculiarities of sanitary infrastructure of settlements in tropic climate. Water supply, sewerage system, solid waste disposal. The role of green vegetations in microclimate conditions improvement in inhabited areas.

11.  residential hygiene in hot climate. Planning peculiarities of different types of buildings according to their insolation and influence on residential microclimate conditions. Optimal windows orientation, its scientific substantiation. Sun protection devices.

12. Hygienic requirements to natural and artificial residential and industrial premises ventilation in tropic climate.

13. Air conditioning in residential, public and industrial premises as microclimate optimization measure.

14. Peculiarities of requirements to natural lighting of residential premises in tropic conditions. Natural lighting and microclimate optimization measures interrelations. Venetian blind influence on these factors.

15. Hygienic peculiarities of building materials and constructions which are used for building in tropic climate.

16. Organization and working regimen peculiarities in arid and humid climate. Microclimate parameters in which physical work is impossible.

17. Calculation methods of the assessment of tropical climate influence on heat condition of organism.

18. Rational nutrition and conditions of its provision.

19. Social and hygienic peculiarities of nutrition of different age and sex population groups in tropical regions.

20. Physiological and hygienic basics of rational nutrition in tropical conditions.

21. Organism energy, protein, fat, carbohydrate requirements and their quantity and balance peculiarities in tropical climate.

22.    Vitamins, mineral salts, microelements, taste substances (spices) role in nutrition of tropical regions population.

23.    Hot climate influence on food and some its components assimilation. Metabolism and nutrition pattern peculiarities in tropical regions.

24.    Hygienic characteristics of food products, used by population of arid and humid tropical regions.

25.    General characteristic of alimentary diseases of tropical regions population.

26.    Malnutrition and complete starvation diseases (protein and energy insufficiency) among tropical regions population.

27. Vitamin deficiency diseases (hypo- and avitaminosis) among tropical regions population. Polyunsaturated fatty acids deficiency diseases.

28.    Mineral and microelements deficiency diseases among population of tropical regions.

29.    Overeating diseases in tropical regions.

30. Diseases caused by poor quality of food intake (foodborne diseases, helminthosis, food poisoning, ferrnentopathies).

31. Methods of medical control over tropical regions population nutrition.

32.    Calculation methods of the population nutrition assessment. Alimentary calorimetry method.

33.    Sanitary inspection of food products and ready meals, its usage in tropical region counties.

34.    Food products storage and preservation peculiarities in tropical conditions, usage of preservatives and antibiotics.

35. Methods and measures of prevention of the foodborne diseases, infections and invasions with alimentary transmission mechanisms, food poisoning.

 

TEST EVALUATION AND SITUATIONAL TASKS

TEST QUESTIONS:

1. In condition of comfortable microclimate human feels himself good, because

A.   A room is well lighted.

B.    Present air moving in room;

C.   Absent psycho emotionally stress;

D.   Atmospheric pressure is low;

E.    Heat production equal to heat loss.  

2. What parameter of microclimate does not influence on loss of heat by evaporation.

A.   Humidity;            

B.    Radiation temperature;  

C.   Velocity of air moving;

D.   A and c;

E.    None of the above.

3. The most of the heat humans organism loses

A.   By radiation,  

B.    By transfer

C.   By convection

D.   By conduction,

E.    By evaporation.

4. What illness is characterized by next symptoms: edema, mental changes, anemia, and hair changes?

A.    Cretinism;

B.    Nutritional marasmus;  

C.    Kwashiorkor;

D.    Pellagra;

E.     Fe-deficient anemia.

5. Which disease is the clinical manifestation of vitamin a deficiency?

A.   Kwashiorkor;

B.    Pellagra;

C.   Fe-deficient anemia;

D.   Xerophthalmia;  

E.    Scurvy.

SITUATION TASKS

Task 1.

Calculate the wet bulb globe temperature (WBGT) by yaglow and minard (1955) if the air temperature according to dry and wet thermometer of aspiration psychrometer is tdry = +350c, twet = +280c, the globe thermometer shows, that t = +280c . Is it possible to do any physical work in such microclimate conditions?

Task 2.

Calculate the wet bulb globe temperature (wbgt) by yaglow and minard (1955) if dry thermometer index is tdry = 380c, wet thermometer twet = 350c, globe thermometer tbulb = 400c:

Task 3.  During the first part of summer (june) workers brigade is working on cotton plantation performing work of medium intensity. Metabolism intensity rate m = 300 kcal per hour. Mild radiant environmental temperature according to black globe thermometer t = 400c; air temperature according to dry thermometer of psychrometer tdry = 380c; air movement v = 0.05 m/sec.; maximum air humidity according to dry thermometer (380c) p = 48 hg mm.

Task 4

A standard men (body surface is 1.8 m2, height  170 cm, body weight  65 kg) in light clothing with body temperature of 360c works physically hard (570 kcal/h) in a room. Microclimate characteristics of the room are: air temperature 320c, average radiant temperature 220c, air movement 0.7 m/sec., relative humidity 70%. Evaluate the feeling of this man. Estimate the heat emission by irradiation (heat emission from 80% body surface) and conduction using the formula (1)

Task 5.

Adult person has excessive body mass of 10 kg, and in order to decrease it to ideal theoretical body mass he gets limited ration of l 000 kcal instead of necessary 3000 kcal per day. How long can this intake be used without pathological changes in the organism?

Task 6.

Person performs medium intensity physical work, and receives intake, worth 3 000 kcal, during 15 days. During this period, person looses 1 kg of body mass. How can the daily intake be optimized?

 

CORRECT ANSWERS OF TEST EVALUATIONS AND SITUATIONAL TASKS:

1.     E;

2.     B;

3.     A;

4.     B;

5.     D;

 

Answer on situation task # 1:   

Dry thermometer of assman psychrometre tdry =350c, twet = 280c, tbulb = 370c. Wbgt is:

WBGT = 0,1×35 + 0.7×28 + 0.2×37 = 28

Conclusion: human can work and perform light physical work.

Answer on situation task # 2:   

WBGT = 0.1×38 + 0.7×35 + 0.2×40 = 36.3

Conclusion: under these circumstances physical work is impossible for acclimatized people too.

Answer on situation task # 3:   

At first loss (-) or income(+) of heat through radiation should be calculated: r= 11×(40 - 35) = 11×5 = + 55 kcal/hour.

Then loss (-) or income (+) of heat through convection should be calculated c = 6×0.17×(38 - 35) = + 3.06 kcal/hour.

Then the maximum heat loss by sweat evaporation is calculated max. = 12×0.17× (42 - 48) = - 12.24 kcal/hour.

Consequently, heat load index (hl) will equal hl = 300 + 55 + 3.06 12.24 = 345.82 kcal per hour, and for 6 hours of 7 hours working day (1 hour for break and lunch) the heat load will equal 345.82×6 = 2 074.92 kcal.

Conclusion: the heat stress doesnt exceed allowable level (400-600 kcal per hour).

Answer on situation task # 4:   

Qirr = 4.5(36-22)×1.8×0.8 = 90.72 kcal/h

Qcond = 7.2×(36-22)×(0.27 + 0.83)×1.46 = 160 kcal/h

For calculation of the maximum amount of water evaporated from body surface, the maximum humidity under 36  is determined according to table maximum pressure of water vapour at different temperatures. Maximum humidity is 42.2 hg mm according to this table.

Absolute humidity under the air temperature 32  is determined using the formula (3.2):

Fbs. = : : http://intranet.tdmu.edu.ua/data/kafedra/internal/hihiena/metod_rozrobky/%d0%bc%d0%b5%d0%b4%d0%b8%d1%87%d0%bd%d0%b8%d0%b9%20%d1%84%d0%b0%d0%ba%d1%83%d0%bb%d1%8c%d1%82%d0%b5%d1%82/3%20%d0%ba%d1%83%d1%80%d1%81/Eng/Tropical%20hygiene.files/image004.gif = 29.5 hg mm

Insert the calculation results into the formula (3.1):

evap =15× (42.2 29.5)×(0.5 = 0.83)×1.8 = 456 ml/h.

Heat emission by evaporation under this condition is:

456×0.6 = 273.6 kcal/h.

Calculate the total heat emission:

Q = 90. 72 + 160.0 + 273.6 = 524.32 kcal.

Conclusion: comparing the heat emission and heat production (570 kcal/h) for the assessment of the feelings of the human, we can conclude, that the heat production exceeds the heat emission, and thus the microclimate of this room causes the heating.

Answer on situation task # 5:   

Calculation:    : : http://intranet.tdmu.edu.ua/data/kafedra/internal/hihiena/metod_rozrobky/%d0%bc%d0%b5%d0%b4%d0%b8%d1%87%d0%bd%d0%b8%d0%b9%20%d1%84%d0%b0%d0%ba%d1%83%d0%bb%d1%8c%d1%82%d0%b5%d1%82/3%20%d0%ba%d1%83%d1%80%d1%81/Eng/Tropical%20hygiene.files/image006.gif

Answer on situation task # 6:   

Calculation: Body weight decrease by 1 kg during 15 day means 4 100 kcal shortage. Thus, addition to the daily intake is:

Addition : : http://intranet.tdmu.edu.ua/data/kafedra/internal/hihiena/metod_rozrobky/%d0%bc%d0%b5%d0%b4%d0%b8%d1%87%d0%bd%d0%b8%d0%b9%20%d1%84%d0%b0%d0%ba%d1%83%d0%bb%d1%8c%d1%82%d0%b5%d1%82/3%20%d0%ba%d1%83%d1%80%d1%81/Eng/Tropical%20hygiene.files/image008.gif

 

 

Individual student work (1415-1500 hour)  are checked by solving situational tasks for each topic, answers in test evaluations and constructive questions (the instructor has tests & situational tasks).

 

INITIAL LEVEL OF KNOWLEDGE AND SKILLS

 The student must know:

1.     Physiologic peculiarities of thermoregulation mechanisms in hot microclimate conditions and its influence on the organism and health.

2.     Main types of pathology which are common for tropic and hot climate.

3.     Basics and conditions of rational nutrition and ways of its realization in tropical climate.

4.     Food poisonings classification and their peculiarities in hot and tropical regions.

5.     Alimentary diseases and foodborne infections typical for hot and tropical regions.

A student must be able:

1.     To determine parameters of the microclimate and its impact on the organism.

2.     To carry out medical control of nutrition sufficiency and safety, use methods and measures for prevention of diseases among certain population groups in tropical regions.

 

REFERENCES:

1.     Principal:

1.          Practical classes materials http://intranet.tdmu.edu.ua/data/kafedra/internal/hihiena/classes_stud/en/med/lik/ptn/hygiene%20and%20ecology/3/15.%20Tropical%20hygiene.htm

2.          Hygiene and human ecology. Manual for the students of higher medical institutions/ Under the general editorship of V.G. Bardov. K., 2009.  pp. 664-691. http://www.nmu.edu.ua/kaf55-8.php

3.          Datsenko I.I., Gabovich R.D. Preventive medicine. - K.: Health, 2004, pp. 697-788.

4.          Lecture on hygiene.

additional:

1.          Kozak D.V., Sopel O.N., Lototska O.V. General Hygiene and Ecology. Ternopil: TSMU, 2008. 248 p.

2.          Dacenko I.I., Denisuk O.B., Doloshickiy S.L. General hygiene: Manual for practical studies. -Lviv: Svit, 2001. - P. 230-247.

3.          A hand book of Preventive and Social Medicine. Yash Pal Bedi / Sixteenth Edition, 2003   p. 26-36, 92-97.

 

                        

Methodical instruction has been worked out by: ass-prof. Lototska O.V.

Methodical instruction was discussed and adopted at the Department sitting

30 august 2011, Minute 1

Methodical instruction was adopted and reviewed at the Department sitting

28 august 2013, Minute 1