Air properties

The properties of air are its temperature, atmospheric pressure, humidity, mobility, solar radiation, the state of the electric field. All these factors affect the human body.

A complex of physical factors determines the climate. These are the basic properties of air, such as the values of its temperature, relative humidity and mobility, which affect the regulation of human heat exchange.

Temperature

Thermophysical properties of air are determined by its temperature. This factor characterizes the thermal state of the human body and the environment, i.e. Heat exchange, which consists of heat production and heat transfer.

Heat production is the result of oxidation of food and release of heat with muscle contractions, solar heat, heated objects, hot food and warm air.

Heat transfer occurs due to conducting or convection, radiation or radiation, evaporation.

When exposure to the body at high temperatures, immunity decreases and overall morbidity increases. According to the laws of heat radiation (Stefan-Boltzmann, Kirchhoff, Wine), the radiation of the heat of heated objects occurs more intensively than their temperature rises, and the radiation spectrum shifts toward short waves, which contributes to a deeper, penetrating effect of heat on the body.

A low air temperature causes an increase in heat loss due to radiation and convection, which leads to cooling of the body due to heat deficiency. There is a decrease in skin temperature, loss of pain sensitivity, weakening of muscular activity, muscle weakness and drowsiness appear.

Humidity

The properties of air are characterized by its humidity, which is determined by the content of water vapor in the air.

Absolute humidity of air is the content of 1 cubic meter. Meter of water vapor in grams. Hygienic practices usually take into account the relative humidity of the air.

Relative air humidity is the degree of its saturation with water vapor (%). This ratio of absolute humidity to the amount of humidity that saturates the air. Deficiency of saturation is the difference between maximum and absolute humidity.

Mobility of air

The mobility of air characterizes the speed of its movement. It is determined by the number of meters that the air passes for a second. With moderate air mobility and high temperature, cooling of the skin occurs, and with high air mobility and low temperature, supercooling occurs. Frosty, calm weather is easier to tolerate than during a strong wind.

The most favorable speed is the speed of air mass, equal to 1-5 m / sec, and on the premises - 0.1-0.3 m per second.

Atmosphere pressure

The properties of air determine its atmospheric pressure, i.e. Its pressure on the surface of the earth. The higher above the ground, the lower the pressure and density of air.

Significant increases and decreases in atmospheric pressure adversely affect the human body.

Lowering the atmospheric pressure causes hypoxia (oxygen starvation), to which the brain is sensitive, since it consumes oxygen 30 times more than other cells.

Ionization of air

This is the decomposition of molecules and gas atoms under the action of ionizers, i.e. Radioactive radiation, ultraviolet and light radiation of the sun, cosmic rays, heating surfaces, water spraying, etc.

In the atmosphere, ion-destructing and ion-formation processes occur constantly, as a result of which, some ionization equilibrium is established.

In clean air contains more light ions, in the polluted - heavy. At waterfalls and on river banks the content of light ions reaches 40 thousand in 1 cubic meter. Cm of air, in villages - 2-3 thousand, in cities this number is reduced to 4 thousand in 1 cubic meter. cm.

The ionization regime is determined by the pollution coefficient, i.e. Ratio of the number of heavy ions to the number of light ions and the unipolarity coefficient.

Air properties also determine the electric field of the earth, the radioactivity of the air and the magnetic field.