Description
DUST IN AIR - DANGER OF AIR DUST?
Household dust in the air - large dust particles floating in the air, which can be seen in the bright rays of sunlight falling from a window, does not pose a health hazard - they quickly settle and do not penetrate deep into the lungs.
But dust in the air is not always visible to the naked eye.
The effect of air dustiness on health and well-being can vary depending on the chemical composition, origin, size and density of the particles. By the nature of this can be a slight irritant effect, and acute toxic poisoning.
Dust particles of less than 10 microns (PM10), which easily penetrate the respiratory tract, and less than 2.5 microns (PM2.5), which penetrate deep into the lungs, are the most dangerous.
SOURCES AND CAUSES OF AIR DUST
The causes of dust in the apartments, offices, industries, as well as sources of dust in the atmospheric air - an infinite number. And if dust of natural origin is most often non-hazardous, then anthropogenic sources - emissions from transport and industrial enterprises - cause dust that contains a lot of harmful substances - heavy metals, hydrocarbons, benzo (a) pyrene ... in the air of the working area.
ULTIMATE ALLOWABLE DUST CONCENTRATIONS IN AIR
Maximum permissible concentrations of suspended particles PM10 and PM2.5 in ambient air and in air of residential and public buildings were installed in Russia only in 2010:
Maximum permissible concentrations of dust and aerosols in the air
Indicator Maximum one-time Average Daily Average
Suspended particles PM2.5 0.16 mg / m3 0.035 mg / m3 0.025 mg / m3
PM10 suspended particles 0.3 mg / m 3 0.06 mg / m 3 0.04 mg / m 3
Suspended particles (total dust) 0.5 mg / m3 0.15 mg / m3 -
Soot (carbon) 0.15 mg / m3 0.05 mg / m3 -
MPC DUST IN THE AIR OF THE WORKING ZONE
The standards for the content of various aerosol particles, dust, and soot in the air of the working area, established by GN 2.2.5.1313-03, are on average significantly higher than for atmospheric air and residential premises. Depending on the origin and composition of the maximum one-time MPC of various aerosols in the air of the working area are set within very wide limits. For soot and aerosol containing from 10 to 60% of silicon dioxide, the maximum single MPC is 6 mg / m3, and the medium shift is 2 mg / m3.
WHO REGULATIONS FOR AIR DUST (PM10, PM2.5)
The World Health Organization considers dust particles in the air to be one of the most serious dangers and causes of many diseases of the respiratory tract and cardiovascular system. The limit concentrations of PM10 and PM2.5 particles in the air are set forth in the document entitled “Air quality guidelines” in the form of daily average and annual average values:
WHO recommendations for PM10 and PM2.5 target levels
Indicator Average Daily Average
PM2.5 particulate matter 0.025 mg / m3 0.01 mg / m3
PM10 particulate matter 0.05 mg / m3 0.02 mg / m3
According to WHO experts, only the achievement of such levels of dust concentrations in the air can reduce the mortality from pulmonary and heart diseases associated with air quality. The WHO guidelines for air quality appeared in 2005, and, as we can see, Russian standards adopted in 2010 are less demanding on the quality of atmospheric air and indoor air. However, it should be understood that the recommendations of the WHO - this is just "the ideal to which we should strive."
METHODS OF DETERMINATION OF DUST IN AIR
There are several basic methods for measuring the mass concentration of aerosols in the air.
The most common method is gravimetry, in which air samples are pumped through a filter, and by the difference in filter mass before and after sampling, the concentration of dust in the air is measured. The method has both advantages and disadvantages. It requires very long sampling for the analysis of atmospheric air, in which dust particles, as a rule, are contained in low concentration, but at the same time it has high accuracy in determining high concentrations of dust in the air of the working area. To determine the content in the air of dust of different fractions, special auxiliary devices are used - impactors, allowing to separate particles of different aerodynamic sizes.
Another method of analyzing air for aerosols is optical. For analysis, a dust analyzer (“dust meter”) is used, which allows real-time measurement of total dust concentrations, PM10, PM4, PM2.5, PM1. Technically, the device measures the counting concentration of aerosol particles in the air, and the calculation of the mass concentration is based on the models of particle mass distribution incorporated into the program, depending on their size and calibration dependencies. To calibrate the device, an impactor and a gravimetric method can be used, which allows to achieve high accuracy of measurements.
The main advantage of this method is the ability to quickly and with
