Air pollution is most severe in the atmosphere of a few meters or so

Why Air Testing? The reason is that indoor environmental pollution has become one of the killers that seriously affects human health.

The importance of indoor air quality We spend more than 70% of our time in the indoor environment. Good indoor air quality is the most important factor to ensure good health, substandard indoor air can lead to physical discomfort and poor health (such as headache, chest tightness, drowsiness, allergies, eye strain, frequent colds, etc.). Pregnant women, children, the elderly, office workers, and people with respiratory and cardiovascular diseases are more susceptible to poor indoor air quality.

Common Indoor Air Pollutants 1Contamination of building materials. The gypsum board used in modern building decoration breeds bacteria, viruses and other microorganisms; 2.

Pollution caused by enclosed buildings. The fully enclosed building isolates the flow of natural fresh air....

from air quality.

From the perspective of altitude above 30 meters, the air quality is even worse.

There's a kind of canyon effect called the canyon effect.

It can be explained that the canyon effect refers to the surrounding bus arteries or factories, as well as high-rise residential buildings. Under the action of the street wind, the air flow containing dust does not move smoothly, but "hovers" up and down in a certain area between the tall buildings. Pollutants near the ground rise to a certain height with the airflow and then dissipate downward or horizontally.

It is a phenomenon that causes certain substances to enter the atmosphere due to human activities or natural processes, present sufficient concentrations, reach sufficient time, and thus endanger human comfort, health and welfare or the environment.

The atmosphere is layered into five layers, from bottom to topTroposphere, stratosphere, mesosphere, warm layer rubber rock, and fugitive layer.

1. Troposphere.

The troposphere is the lowest layer of the Earth's atmosphere. Major atmospheric phenomena such as clouds, fog, rain and snow occur in this layer. Decreasing air temperature with altitude: Since the troposphere gets its heat mainly from the ground, air temperature decreases with altitude.

2. Stratosphere.

In the stratosphere, as the altitude increases, the temperature initially remains constant or rises slightly. This air temperature distribution in the stratosphere is characterized by the fact that it is not affected by ground temperature, especially because there is a large amount of ozone that can directly absorb solar radiation.

3. The middle layer.

From the top of the stratosphere to about 80 km is the middle layer. This layer is characterized by a rapid drop in air temperature with increasing altitude and a fairly strong vertical movement.

4. Warm layer. Warm layer: It is located above the top of the middle layer. In this layer, the air temperature increases rapidly with altitude. This is due to the fact that the sun's ultraviolet radiation, which is smaller in wavelength, is absorbed by atmospheric material in the layer.

5. A fugitive layer.

This is the highest layer of the atmosphere, also known as the outer layer. The air temperature in this layer changes little with altitude. Due to the high temperature, the high speed of air particles, and the low gravitational attraction due to the distance from the center of the earth, the main feature of this layer is that atmospheric particles often escape into interstellar space, and this layer is the transition zone between the atmosphere and interstellar space.

According to the different characteristics of each layer of the atmosphere (such as temperature, composition and degree of ionization, etc.), it is divided into troposphere, stratosphere, mesosphere, thermosphere (ionosphere) and outer atmosphere from the ground. The thickness of the whole body is more than 1000 kilometers.

The tropospheric core bends at the lowest level of the atmosphere, close to the Earth's surface, and is about 10 to 20 kilometers thick.

Above the troposphere is the stratosphere, about 20 to 50 kilometers above the Earth's surface.

In addition to this, there are two special layers, namely the ozone layer and the ionosphere. The ozone layer is 20 to 30 kilometres above the ground, effectively between the troposphere and stratosphere.

The ionosphere is thick, about 80 kilometers above the Earth's surface. The ionosphere is a gas in the high air, irradiated by the ultraviolet rays of sunlight, ionized into charged positive and negative ions and some free electrons.

The altitude of the atmosphere is more than 1000 kilometers. The atmosphere is divided into:Troposphere, stratosphere, ozone layer, mesosphere, thermosphere and fugitive layer. According to the temperature changes at different altitudes, the atmosphere is divided into five layers, including the troposphere (10 km left wide cover right), the stratosphere (about 10-50 km), the middle layer (about 50-85 km), the thermosphere (about 80-800 km), and the fugitive layer (about 800-2000 km).

Expansion: The role of the atmosphere:

One,The atmosphere is soaked with gaseous water from the Earth, and every day sunlight evaporates gaseous water, and can return to Earth in the form of rain and snow or, in the morning, fog. It can ensure the circulation of the earth's hydrosphere, complete the timely replenishment of water in the biosphere, and contribute to the benign life of the biosphere.

2. Make the oxygen distributed by the terrestrial and animal sphere every day not disperse from outer space, and insist on excessive oxygen on the surface of the earth, which will help the biosphere to supply oxygen to life.

IIIIt can reduce the ultraviolet radiation of sunlight to the earth's biosphere, and the range of life compliance is conducive to the benign growth of the earth's biosphere.

FourthUnder the action of atmospheric enclosure, it can adhere to the liquid water body on the surface of the earth. Volatility to ensure the stock of liquid water bodies such as land, rivers and lakes. Contributes to the healthy life of the Earth's biosphere.

Fifth, it is to maintain the volatility of the surface environment.

The atmosphere refers to the area above the ground and below the space where there is air.

In the case of air pollution, the distribution of pollutants is constantly changing, ranging from tens of meters to hundreds of meters, and does not stay fixed at one height, so there is no need to say how many meters are the most polluted.

Under normal circumstances, pollutants in the air continue to settle and flow with the airflow, and in the absence of pollution sources in the air, the higher the floor, the cleaner the air is. The higher the altitude of the atmosphere, the lower the temperature, and the air is prone to convection, which allows pollutants to disperse.

In autumn and winter and under special climatic conditions, the temperature will increase with the altitude, and the atmosphere will appear "inversion layer". The thickness of the inversion layer varies from tens of meters to hundreds of meters, like a thick quilt covering the city, hindering the dispersion of urban pollutants. However, the height of the inversion layer is variable, and the distribution of pollutants under inversion conditions is also constantly changing, and does not stay fixed at one height.

It's hard to say.

The thickness of the atmosphere is about 800,1000 kilometres, but there is no clear boundary with outer space. That is, the higher above the ground, the thinner the atmosphere becomes, until the molecules of the atmosphere can no longer be detected, and it is in outer space. At altitudes of 2,000 to 16,000 km above the earth's surface, thin gas molecules are still present.

In the last century, the American physicist von. Carmen once pointed out that because at an altitude of about 100 kilometers, the air is too thin to provide lift for the aircraft, so this position can be seen as the dividing line between the atmosphere and outer space.

This dividing line was named the "Kármán Line" and was later widely adopted. So,Normally, we can simply think of the atmosphere as 100 kilometers, or 100,000 meters

However, the troposphere, which has an average thickness of about 12 kilometers above the surface, is the densest layer of the atmosphere, concentrating about 75% of the atmosphere. Add to this the stratosphere, which is 12,50 kilometres above the surface, and it accounts for 90 per cent of the total mass of the Earth's atmosphere. Hundreds of kilometers into the atmosphere, it is so thin that it can't even transmit sound well.

The density of the atmosphere becomes thinner and thinner as the height above the ground increases. Sounding rockets still found a rarefied atmosphere at an altitude of 3,000 km, so the upper limit of the atmosphere may extend to about 6,400 km above the ground.

The atmosphere generally refers to the ground up to 1,000 kilometers high. In other words, the Earth's atmosphere is about 1,000 kilometers thick. The atmosphere is divided into:

The troposphere (0 to an average of 12 km), the stratosphere (10 to 50 km), the mesosphere (50 to 85 km), the ionosphere (above 60 or 85 km to 1000 km) and the fugitive sphere (above 85 km to 1000 km). In fact, there are no strict limits to the outer surface of the atmosphere.