The impact of ozone layer depletion and atmospheric pollution on the biosphere

Not only meteorological conditions but also the life activity of the entire biosphere depends on the redistribution and content of ozone, the amount of which in the atmosphere is small (2⋅10-6 % by volume). Ozone prevents dangerous ultraviolet radiation with a wavelength of less than 0.2 μm from reaching the Earth. At the same time, ozone does not let about 20% of terrestrial radiation escape, which prevents the planet from cooling down.

In 1975, Molina and Rowland, employees of the University of California, published the results of theoretical studies in which they predicted that the accumulation of chlorofluorocarbons, in particular freons, in the atmosphere could become the cause of ozone layer depletion and cause a number of problems in the near future that threaten human life.

Freons, or chlorofluorocarbons (CFCs), are widely used in refrigeration units, aerosol fire extinguishers, household aerosol sprays, and in the production of plastics and computer chips.

In the early 80s, British scientists at the Halley Bay station in Antarctica noticed a decrease in ozone concentration over the continent. Research showed that in 1980 the ozone content in the atmosphere over the station decreased by 20% compared to the norm, in 1983 – by 30%, in 1984 – by 35%, in 1985 – by 40%. In 1987, the ozone hole covered an area of 8 million km2, and the amount of ozone in this area decreased by almost 50%. In some places, the hole extended beyond Antarctica, reaching Melbourne. At the same time, the incidence of melanoma, a type of skin cancer, increased significantly in Australia.

What is the threat of freon accumulation in the atmosphere for the ozone layer? It is assumed that by diffusing into the stratosphere, freon molecules, under the influence of solar radiation during chemical decomposition, release chlorine atoms, which catalyze the decay of ozone, especially at low temperatures. Chlorine derivatives also enter the stratosphere with the combustion products of space rocket fuel.

The ozone layer is decreasing not only over Antarctica. In 1994, a giant ozone anomaly covered the territories of Western and Eastern Europe, the former USSR, and the USA, over which – for 12 months

– the ozone layer decreased by 10-15%, and in some months – by 20-30%. In February 1995, a 40% reduction in ozone was recorded over several regions of Eastern Siberia.

In 1985, the Vienna Convention for the Protection of the Ozone Layer was adopted, and in 1987, the Montreal Protocol on Substances that Deplete the Ozone Layer. A phased reduction in the production and consumption of chlorofluorocarbons is provided for.

Sulfur and nitrogen dioxides, the main sources of which are large thermal power plants, traveling at an altitude of several hundred meters, form sulfuric and nitric acids when combined with atmospheric moisture, which fall with precipitation, often dozens of kilometers from the source of emission. For example, Norway, while emitting less sulfur dioxide into the atmosphere than other countries, suffers more than others from acid precipitation. In Sweden and Norway, fish have died in 6,500 lakes and 7 rivers. The damage is not limited to the death of aquatic life. Birds and livestock animals die along the food chain. Emissions reach Norway, which is elongated along the direction of atmospheric pollution migration.

No. Country Emissions, thous. t. per year

Acid precipitation destroys chlorophyll in plant leaves. The leaves darken, and the needles turn red. Cereals, beans, beet, radishes, and tomatoes are very sensitive to acid precipitation. Soil and groundwater acidification occurs, which makes well water unsuitable for consumption.

Sulfur dioxide and its other compounds irritate the mucous membranes of the eyes and respiratory tracts. Prolonged exposure to low concentrations of SO2 leads to the development of chronic gastritis, bronchitis, laryngitis, and lung cancer.

Industrial enterprises, urban transport, and heat-generating plants are the cause of smog - colossal pollution of the air environment over cities. Unfavorable weather conditions – lack of wind and temperature inversion – also contribute to smog.

Under normal conditions, the air temperature over the air basin of a settlement is significantly lower than the temperature of the surface air. Therefore, even in the absence of wind, the air basin is ventilated: warm polluted air, having less mass, rises up, and clean air, having greater mass, moves down. In some places on Earth (London, Los Angeles, Kemerovo, Nizhny Tagil, etc.), temperature inversion often occurs, when the air over the air basin has a higher temperature than the surface layer, and, consequently, a lower mass. Therefore, clean air cannot descend and ventilate the air basin. The situation is further aggravated by the lack of wind – all harmful substances entering the air basin remain over the city.

In 1952, smog in London killed 5,000 people in 5 days, and 10,000 suffered severe illnesses.

There are two types of smog: 1) reductive (smoke, soot, SO2). Maximum pollution levels are observed in the morning during. Irritates the respiratory tract. 2) photochemical. Formed by the interaction of nitrogen oxides with hydrocarbons from exhaust gases. It is a whitish fog, sometimes with a yellowish-brown tint, causing sharp pain in the eyes and lacrimation. The formation of photochemical smog accelerates in the presence of sunlight, so its maximum levels occur at noon.

If one reflects on the current situation, one can come to the conclusion that a process of slow suicide of humanity is being observed. Compared to 1900, the incidence of diseases associated with malignant neoplasms has increased several times worldwide. Medical professionals and environmentalists believe that practically 40% of diseases (oncological, infectious diseases, diabetes mellitus, bronchial asthma, etc.) are caused by environmental factors.

The impact of air pollution and bad habits on the health of workers

Atmospheric air pollution has a direct negative impact on the body and, in severe cases, leads to fatal outcomes. Primarily, people with pre-existing diseases of the respiratory and cardiovascular systems suffer from the adverse environment. The general increase in atmospheric pollution directly leads to an increase in the number of severe diseases and premature deaths.

A separate critical risk factor is smoking, which indisputably correlates with lung and heart damage. When interacting with polluted air, tobacco smoke produces a strong synergistic effect. As a result, smokers in high atmospheric gas pollution are subject to lung diseases to a significantly greater degree than in conditions of clean air.