The impact of the destruction of the ozone layer on the earth s organisms Encyclopedia

The destruction of the ozone layer increases the amount of ultraviolet rays reaching the earth's surface, making organisms more susceptible to disease.

Above the surface of the earth, there is an atmosphere that protects our earth's surface, it is the ozone layer that we usually ignore, once the ozone layer destroys Sencha, then the blocking effect on ultraviolet rays is weakened, bringing terrible damage to the earth's surface, so what is the cause of ozone layer destruction? Let's find out.

Causes of ozone layer depletion

At present, the main reason for the destruction of the ozone layer is man-made, and the large use of chlorofluorocarbons (CFCs), bromo-bromophobens (halons), N2O and other substances will greatly accelerate the destruction of the ozone layer. For example, the air conditioner we usually use, it needs freon to work, and the use of freon is not to be underestimated to destroy the ozone layer.

Why is the ozone layer so easily destroyed? Because its chemical properties are very active, it is easy to oxidize with some chemicals in the air, such as ozone will react immediately when it encounters elements such as NO, Cl, Br, and H.

Effects of ozone layer depletion on the biosphere

The ozone layer has a good blocking effect on ultraviolet rays, once ozone is reduced, then the ultraviolet rays of sunlight that reach the ground will be greatly enhanced, and ultraviolet rays are very lethal, especially for biological cells, which will lead to the entire ecosystem facing a situation where it is impossible to survive, including humans.

In addition, the enhancement of ultraviolet radiation is also easy to lead to the increase of human respiratory infectious diseases, increasing the incidence of cataracts, cancer and other diseases.

1. The oxygen molecule is composed of 2 oxygen atoms, while the "brother" ozone of oxygen is composed of 3 oxygen atoms, and has a particularly slow and absolutely "smelly" smell. Ozone is found in very small quantities in the atmosphere and is a "trace gas" that is mainly distributed in the ozone layer 20 to 30 km above the ground. At 1 atm and 0, if all the ozone in the atmosphere is collected, the global average cumulative thickness is only about 3 mm, which is only equivalent to the thickness of two 5 cents.

2. Don't underestimate this 3 mm, that is, it absorbs most of the ultraviolet radiation from the sun, so that life on the earth is protected from the fatal damage of the sun's ultraviolet rays.

3. Ultraviolet rays are wavelengths smaller than visible light (400 700 nm) in solar radiation, which are divided into three parts, of which the ultra-short ultraviolet UVC (less than 280 nm) with the shortest wavelength is almost completely absorbed by oxygen when it passes through the atmosphere (emitting atomic oxygen, combining with oxygen to generate ozone); Far ultraviolet UVB (280 320 nm), which is particularly harmful to living organisms, is mostly absorbed by ozone (reduced to oxygen and atomic oxygen, destroying ozone); Near-ultraviolet UVA (320 400 nm), which has a longer wavelength, penetrates the atmosphere almost freely.

4. Ozone is mainly distributed in the stratosphere, and the thinning of the global ozone layer will affect human health, the earth's ecological balance, and the near-surface atmospheric environment. For every 1% reduction in ozone, the incidence of cancer will increase by 2% to 4%, and the number of cataract patients will increase. Intense ultraviolet rays damage plants, cause mass deaths of plankton, fish fry, shrimp, crab larvae and shellfish, and even cause the extinction of certain organisms, thus affecting the global ecological balance.

The thinning of the ozone layer enhances the ultraviolet rays reaching the ground, and the enhanced ultraviolet rays decompose the nitrogen oxides of automobile exhaust in the city, forming photochemical smog with ozone as the main component near the ground. In addition, ozone itself is a greenhouse gas, and changes in its concentration and distribution in the atmosphere will also affect the greenhouse effect of the Earth's atmosphere. In the troposphere near the macroridge ground, ozone levels are not abundant, but near the surface, ozone is a pollutant that is harmful to ecosystems.

It can be said that in the stratosphere at high altitudes, ozone is "good"; And near the ground, ozone is "bad".

Freon acts as a catalyst for ozone to oxygen.