Subject to the force of gravity, the atmosphere exerts pressure on the surface of the earth and on all objects located on it.
Barometric pressure is measured in millimeters by the height of the mercury column. Atmospheric pressure, capable of balancing a column of mercury with a height of 760 mm at a temperature of 0 ° C at sea level and a latitude of 45 °, is considered to be normal, equal to 1 atm. Under these conditions, the atmosphere presses on 1 cm 2 of the Earth’s surface with a force of 1 kg, which amounts to about 15–18 tons for the entire surface of the human body. Due to the fact that the external pressure is completely balanced by the internal one, we actually don’t feel the weight of the air shell Of the earth.
Daily and seasonal fluctuations in atmospheric pressure are most hygienic, most pronounced when the weather changes abruptly. Healthy people usually do not feel these fluctuations, but in some categories of patients suffering from diseases of the cardiovascular system, the barometric pressure fluctuates even by 10-30 mm Hg. Art. may cause vascular catastrophe. In people with increased nervous excitability, with pathology of the articular-muscular system, sleep, mood deteriorate, a feeling of fear, headache, pain in joints, muscles, etc. may appear.
Under the conditions of human life and work, often there are significant deviations from normal atmospheric pressure, which can serve as a direct cause of health problems. As the atmospheric pressure decreases with height, the partial pressure of oxygen in the alveolar air also decreases, which is practically zero at an altitude of about 15 km. At an altitude of 3000–4000 m above sea level, a decrease in the partial pressure of oxygen leads to insufficient supply of tissues to them, which is accompanied by a number of functional disorders. Headaches, shortness of breath, drowsiness, tinnitus, sensation of pulsation of the vessels of the temporal region, impaired coordination of movements, pallor of the skin and mucous membranes appear. Disorders from the central nervous system are expressed in a significant predominance of excitation processes over inhibition processes; deterioration of smell, decrease in auditory and tactile sensitivity, decrease in visual functions are observed. This whole symptom complex is usually called altitude sickness , and in the case of occurrence when climbing into the mountains – mountain sickness . It is found among pilots and climbers in violation of the requirements that protect a person from the influence of low atmospheric pressure.
Elevated atmospheric pressure is a harmful production factor in the construction of underwater tunnels, subways, and diving operations. The main hazard is the concomitant increase in the partial pressure of nitrogen and oxygen. With a rapid decrease in barometric pressure, decompression (decompression) disease can develop . Its origin is explained
the fact that when staying in conditions of high pressure in the blood and other body fluids, the solubility of gases (mainly nitrogen) increases, which, when quickly exiting the high pressure zone to normal, are released in the form of bubbles and clog the lumen of small blood vessels. As a result of the occurring gas embolism, a number of disorders are observed in the form of itching of the skin, damage to joints, muscles, changes in the heart, pulmonary edema, paralysis, even death. For the prevention of decompression sickness, such an organization of caisson and diving operations is necessary that the exit to the surface is slow, to remove dissolved gases from the blood, without the formation of bubbles. The decompression mode must be respected. The time spent by workers on the ground and when lifting should be strictly regulated.
It should be noted that in medical practice the method of hyperbaric oxygenation is widely used for the treatment of certain diseases of the surgical and therapeutic profiles.
Measurement of barometric pressure in the work of a doctor is necessary when forecasting the weather, when assessing working conditions, to calculate a number of sanitary indicators.