Fundamentals of General and Pharmaceutical Hygiene - Dykyi I.L. 2003

Hygiene of the Air Environment
Physical properties of air. Hygienic assessment of the indoor microclimate

The term "microclimate" refers to a complex of Physical factors of the air environment that influence human heat exchange with the environment and the body's thermal state, thereby determining health and working capacity. The indicators of the microclimate in industrial premises include Temperature, relative humidity, air movement speed, thermal radiation, and atmospheric pressure.

For pharmacists, information about the Physical Properties of the air environment, and indoor microclimate in particular, is essential:

— for evaluating working conditions in pharmacy facilities. For example, the microclimate can affect the body both favorably — under an optimal combination of parameters, and negatively, causing hypothermia or, conversely, overheating;

— for increasing the effectiveness of pharmacotherapy, since, alongside other environmental factors, temperature, humidity, atmospheric pressure, and radiant energy have a significant impact on the pharmacokinetics and pharmacodynamics of medicinal products;

— for ensuring appropriate storage conditions for various groups of medicinal products, pharmaceutical raw Materials, and medical devices. Any violation of or deviation from the regulated storage conditions, or failure to account for environmental factors, can lead to a decrease in their quality, changes in activity, and increased toxicity, which is hazardous to the patient.

Objective: to understand The impact of physical factors of the air environment on The Human Body, the effectiveness of pharmacotherapy, and the stability of drugs during storage; to master the Methods for Assessing indoor microclimate; and to develop hygienic measures for its optimization in pharmacy facilities.

QUESTIONS FOR SELF-STUDY

1. Physical indicators of the air environment; their complex impact on the human body.

2. Heat exchange between the body and the environment: the Stefan–Boltzmann law.

3. METABOLISM/18.html">The Influence of temperature conditions On the Stability of medicines during storage.

4. The wind rose and its hygienic significance.

5. Definition of the concept of "microclimate"; microclimate parameters in pharmacy production premises.

6. The influence of temperature, atmospheric pressure, and radiant energy on the effectiveness of drug therapy.

7. Temperature storage conditions for medicinal products.

8. Methods for the Hygienic assessment of the microclimate.

9. Instruments for microclimate assessment, their design, and operating principle.

10. Methods for microclimate optimization in pharmacy facilities.

Task 1. Determination of indoor temperature conditions

Using a thermometer, measure the air temperature at three horizontal points in the room at a height of 1.5 m from the floor: a) near the exterior wall (10 cm away from it) in the corner; b) in the center of the room; c) near the interior wall; and at three vertical points in the center of the room: at a height of 0.1 m from the floor, 1.5 m from the floor, and 0.2 m from the ceiling. The thermometer should be held horizontally, maintaining it for at least 3–4 minutes at each measurement point. The readings are entered into the protocol (see diagram), and the average temperature is determined as the arithmetic mean of all measurements, along with the horizontal and vertical temperature differentials. The obtained data are compared with standard values.

Comfortable air temperature in the production premises of pharmacies and pharmaceutical enterprises should be maintained at 21 ± 2 °C in winter and 23 ± 2 °C in summer. An exception in pharmacies is the customer service area, where a temperature drop to 16 °C is permitted during the cold season.

Horizontal temperature differentials should not exceed 2 °C, and vertical differentials should not exceed 2.5 °C per meter of height.

When storing thermolabile, dry, and liquid medications in stockrooms, an appropriate temperature of 4 °C must be ensured.

Task 2. Determination of air humidity

Air humidity is determined using an Assmann aspiration psychrometer. The device consists of two mercury thermometers — dry and wet. Before determination, the batiste on the reservoir of the wet thermometer is moistened with distilled Water using a special pipette. Then, the clockwork mechanism is wound fully using the key or the device is connected to the electrical mains. Readings are taken 3–4 minutes after switching it on, once the temperature of the wet thermometer reaches its minimum.

The calculation of absolute humidity is carried out using the formula

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where A is the calculated absolute humidity, mmHg;

f is the maximum humidity According to the wet-bulb thermometer readings (see Appendix, Table 1), mmHg;

(t -t₁) is the temperature difference between the dry-bulb and wet-bulb thermometers, °C;

B is the atmospheric pressure at the time of the study, measured with a barometer, mmHg;

755 is the average atmospheric pressure, mmHg.

Relative humidity is calculated using the formula

where R is the relative humidity, %;

A is the absolute humidity, mmHg;

F is the maximum air humidity according to the dry-bulb thermometer readings (see Appendix, Table 1), mmHg.

The relative air humidity in production facilities should be 30-50%, taking into account technological requirements. In production areas where control over the content of mechanical particles and Microorganisms in the air is not carried out, the relative humidity is maintained within 40-60%, and in storage rooms (for Medicinal plant raw materials) from 30 to 40%.

Task 3. Determination of air velocity

Air velocity in a room is determined using a spherical or cylindrical katathermometer. The bulb of the instrument is immersed in a beaker of water preheated to 70-80 °C and kept there until the alcohol fills 1/2 of the upper reservoir of the capillary. Then the instrument is wiped dry with filter paper and suspended on a stand.

When using a spherical katathermometer, a stopwatch is used to determine the time (s) it takes for the alcohol Column to drop from the 38 °C mark to the 35 °C mark. The cooling power of the air is calculated using the formula

where H is the cooling power of the air, mcal/cm²·s;

F is the instrument factor, a constant value indicating The amount of heat lost from 1 cm² of the instrument surface during cooling from 38 to 35 °C (indicated on the instrument);

T is the cooling time of the instrument, s.

Air velocity is calculated using the formula

where V is the air velocity, m/s;

H is the cooling power of the air, mcal/cm²·s;

Q is the difference between the average temperature of the katathermometer (36.5 °C) and the ambient air temperature, °C;

Knowing the cooling power of the air, the air velocity can be determined (see Appendix, Table 2).

The standard air velocity in pharmacy premises is 0.1–0.2 m/s. In cleanrooms utilizing laminar ventilation, the air velocity should be 0.3 m/s for vertical airflow and 0.45 m/s for horizontal airflow.

PROTOCOL OUTLINE

Topic of the practical session.

1. Determination of the room temperature conditions.

Horizontal temperature:

a) near the external wall ... .

b) in the center ... .

c) near the internal wall ... .

Horizontal temperature differentials ... .

Permissible horizontal temperature differentials ... .

Vertical temperature:

a) 0.1 m from the floor ...;

б) 1.5 m from the floor ...;

в) 0.2 m from the ceiling ...;

Vertical temperature differentials ... .

Permissible vertical temperature differentials ... .

Average indoor air temperature ... .

2. Determination of air humidity

Instrument used for humidity measurement ... .

Operation time of the instrument ... min.

Dry-bulb thermometer reading ... °C.

Wet-bulb thermometer reading ... °C.

Barometric air pressure ... mm Hg.

Maximum humidity according to the wet-bulb thermometer reading ... mm Hg.

Maximum humidity according to the dry-bulb thermometer reading ... mm Hg.

Calculation of absolute air humidity ... .

Result ... mmHg.

Calculation of relative air humidity ... .

Result ... %.

3. Determination of air velocity

Instrument ... .

Instrument factor (F) ... .

Catathermometer cooling time from 38 to 35 °C ... s.

Calculation of air cooling power (H) using the formula ... .

Result ... mcal/cm² s.

Ambient air temperature ... °C.

Mean catathermometer temperature ... °C.

Calculation of air velocity using the formula ... .

Result ... m/s.

Conclusion. Based on Sanitary and hygienic studies carried out in the room ..., it has been established that the average air temperature is ... °C, which (does not) meet hygienic requirements; horizontal temperature differentials are ... °C, which (does not) meet hygienic requirements; vertical temperature differentials are ... °C, which (does not) meet hygienic requirements; relative air humidity is ... %, which (does not) meet hygienic requirements; air velocity is ... m/s, which (does not) meet hygienic requirements.

Recommendations. To optimize the indoor microclimate, it is necessary to ... .

INDEPENDENT WORK Assignments

1. Test control of knowledge.

2. Solving situational problems.

TESTS

1. One of the factors determining working conditions and drug storage is the indoor microclimate, which is characterized by a combination of factors. Which ones?

A. Chemical.

B. Biological.

C. Physical.

D. Physicochemical.

2. What factors characterize the indoor microclimate?

A. Air temperature.

Б. Microorganisms in the air.

B. Airborne dust.

Г. Air humidity.

Д. Atmospheric pressure.

Е. Air velocity.

Ж. Thermal radiation.

3. Thermal comfort of the body depends on ambient air temperature and humidity. Which combination leads to impaired heat dissipation and body overheating?

A. High temperature and low humidity.

Б. High temperature and high humidity.

B. Low temperature and low humidity.

Г. Low temperature and high humidity.

4. Prolonged and frequent exposure of the body to cold leads to the following consequences:

A. Increased metabolic rate and increased heat production.

Б. Decreased metabolic rate and decreased heat production.

B. Increased metabolic rate and decreased heat production.

Г. Decreased metabolic rate and increased heat production.

5. Ambient air temperature can significantly affect the pharmacodynamics of medications. Administration of which drug in hot weather can be fatal due to the suppression of sweating and body overheating?

A. Atropine sulfate.

Б. Magnesium ascorbate.

B. Lidocaine hydrochloride.

Г. Metacycline hydrochloride.

6. The body's thermal balance is achieved by coordinating the processes of heat production and heat dissipation. Which pathway of heat dissipation dominates under comfortable microclimatic conditions?

A. Radiation.

B. Convection.

C. Conduction.

D. Evaporation.

7. Which heat dissipation pathway is suppressed under conditions of high air humidity?

A. Convection.

B. Conduction.

C. Evaporation.

D. Radiation.

8. Which instrument is used to measure air humidity in indoor environments, including pharmacies?

A. Anemometer.

B. Thermometer.

C. Barometer.

D. Psychrometer.

9. Which instrument is used to measure air movement speed in enclosed spaces?

A. Anemometer.

B. Thermometer.

C. Barometer.

D. Kata thermometer.

10. Relative air humidity is one of the key microclimate parameters for indoor spaces. Specify its optimal value for pharmaceutical manufacturing areas:

A. 30-60 %.

B. 10-30 %.

C. 70-100 %.

D. 110-140 %.

11. Specify the optimal air velocity value for pharmacy premises:

A. 0.1 - 0.2 m/s.

B. 0.3 - 0.4 m/s.

C. 0.5 - 0.6 m/s.

D. 0.7 - 0.8 m/s.

12. For an objective Assessment of the indoor microclimate, the correct choice of instrument Location is essential. At what distance from doors should they be placed?

A. 1 meter.

B. 2 meters.

C. 3 meters.

D. 4 meters.

13. In settlement N., north-easterly winds prevail throughout the year. Indicate on which side relative to an operating industrial enterprise, which is a potential air pollutant, the residential buildings and pharmacies should be located.

A. North-eastern.

B. South-eastern.

C. South-western.

D. North-western.

SITUATIONAL PROBLEMS

Solve one of the situational problems. Based on the data from the aspiration psychrometer, katathermometer, and barometer, calculate the absolute humidity, relative humidity, and air velocity in the pharmacy premises. Write a general conclusion regarding the microclimatic conditions and, if necessary, provide hygienic recommendations to improve the microclimate.

Example of solving a situational problem

When studying the microclimatic conditions in a pharmacy washing room, the following was revealed: the sources of heat emission are a gas stove and hot water, which is constantly used for washing glassware. The washing sinks and wet glassware during drying are sources of significant vapor generation. The washing staff perform their work while standing and carry light loads (up to 10 kg). To normalize the air temperature, the dishwashers are forced to open transom windows, windows, and doors, and arrange cross-ventilation.

The Study of microclimate parameters was conducted in 4 locations within the room: near the washing sinks, the gas stove, the outer and inner walls, and in the center of the room. At each location, measurements were taken at 3 levels from the floor (1.5, 1.0, and 0.15 m). The determination of microclimatic conditions was carried out three times during the shift.

As a result of the studies, the following data were obtained: average air temperature 28 °C, effective radiation temperature 32 °C, horizontal temperature differentials 4 °C, vertical temperature differentials 3 °C, relative air humidity 85%, air velocity 0.4 m/s, air temperature fluctuations during the shift 4 °C.

Conclusion. A comparison of the actual microclimate parameters with regulatory values indicates that the microclimatic conditions in the washing room do not meet either optimal or permissible standards. The impact of the microclimate combined with high humidity, high air velocity, and significant horizontal and vertical temperature differentials may contribute to the disruption of thermoregulation processes in workers, the onset of colds, and the Exacerbation of chronic inflammatory processes.

Recommendations. To create favorable microclimatic conditions in the washing room, it is necessary to install an efficiently functioning general exchange ventilation system and equip exhaust hoods over the washing sinks.

Problem 1.

When studying the microclimate in the public service hall of a pharmacy (the area where workstations for the sale of medicines and medical products are located), the following results were obtained: average air temperature is 14 °C, vertical temperature differentials 3 °C, horizontal temperature differentials 4 °C, the difference between the wall temperature and the ambient air temperature is 3 °C, the dry-bulb temperature of the aspiration psychrometer is 14 °C, the wet-bulb temperature is 11 °C, the cooling time of the katathermometer is 120 s, the instrument factor (F) is 237, and atmospheric pressure is 743 mm Hg.

Problem 2.

When studying the microclimate in the pharmacy dispensing room, the following results were obtained: average air temperature 23 °C, vertical temperature differentials 2 °C, horizontal temperature differentials 2.5 °C, the difference between the wall temperature and the ambient air temperature 3 °C, the dry-bulb temperature of the aspiration psychrometer 23 °C, the wet-bulb temperature 16 °C, the cooling time of the katathermometer 110 s, the instrument factor 237, and atmospheric pressure 768 mm Hg.

Problem 3.

When investigating the microclimate in the aseptic unit, the following results were obtained: average air temperature 22 °C, vertical temperature gradients 2.5 °C, horizontal 3 °C, difference between the wall and ambient air temperatures 3 °C; dry-bulb temperature of the aspiration psychrometer 21 °C, wet-bulb 16 °C, katathermometer cooling time 104 s, instrument factor 237, atmospheric pressure 755 mm Hg.

Problem 4.

When investigating the microclimate in the dosage form sterilization room, the following results were obtained: average air temperature 26 °C, horizontal temperature gradients 4 °C, vertical 3.2 °C, difference between the wall and ambient air temperatures 4 °C; dry-bulb temperature of the aspiration psychrometer 26 °C, wet-bulb 24.5 °C, katathermometer cooling time 195 s, instrument factor 237, atmospheric pressure 745 mm Hg.

Problem 5.

When investigating the microclimate in the washing room, the following results were obtained: average air temperature 23.5 °C, horizontal temperature gradients 3.5 °C, vertical 3.8 °C, difference between the wall and ambient air temperatures 4 °C; dry-bulb temperature of the aspiration psychrometer 24 °C, wet-bulb 22 °C, katathermometer cooling time 175 s, instrument factor 237, atmospheric pressure 758 mm Hg.

Problem 6.

When investigating the microclimate in the medicinal plant raw material storage room, the following results were obtained: average air temperature 20 °C, vertical temperature gradients 1.5 °C, horizontal 2 °C, difference between the wall and ambient air temperatures 2 °C, dry-bulb temperature of the aspiration psychrometer 19 °C, wet-bulb 17 °C, katathermometer cooling time 102 s, instrument factor 237, atmospheric pressure 735 mm Hg.

Problem 7.

When investigating the microclimate in the purified water production room, the following results were obtained: average air temperature 23 °C, vertical temperature gradients 4 °C, horizontal 3 °C, difference between the wall and ambient air temperatures 2.4 °C, dry-bulb temperature of the aspiration psychrometer 21 °C, wet-bulb 17 °C, katathermometer cooling time 110 s, instrument factor 237, atmospheric pressure 759 mm Hg.

Problem 8.

When investigating the microclimate in the analytical pharmacist's office, the following results were obtained: average air temperature 18 °C, horizontal temperature gradients 2 °C, vertical 1.5 °C, difference between the wall and ambient air temperatures 2 °C, dry-bulb temperature of the aspiration psychrometer 18 °C, wet-bulb 14.5 °C, katathermometer cooling time 101 s, instrument factor 237, atmospheric pressure 754 mm Hg.

Problem 9.

When investigating the microclimate in the storage room for medicines and medical devices, the following results were obtained: average air temperature 12 °C, temperature gradients horizontally

2 °C, vertically 2 °C, difference between the wall and ambient air temperatures 3 °C, dry-bulb temperature of the aspiration psychrometer 13 °C, wet-bulb 11 °C, katathermometer cooling time 80 s, instrument factor 237, atmospheric pressure 749 mm Hg.

Problem 10.

When investigating the microclimate in the pharmacy manager's office, the following results were obtained: average air temperature 20 °C, vertical temperature gradients 2 °C, horizontal 1.5 °C, difference between the wall and ambient air temperatures 3 °C, dry-bulb temperature of the aspiration psychrometer 19 °C, wet-bulb 10 °C, katathermometer cooling time 102 s, instrument factor 237, atmospheric pressure 747 mm Hg.