Environtmental and Global Health

Archive for the ‘Ozone – Protective Earth’ Category

In big cities and in the vicinity of the high density of population and industry causes air pollution, usually from combustion processes such as automobile engines, is very high. Among the pollutants are nitrogen oxides. And these are very reactive, for example when reacting with oxygen in the air

NO (g) + O2 (g) —-> NO2 (g)

turn nitrogen dioxide by the action of sunlight, it decomposes into carbon monoxide

NO2 (g) + light —-> NO (g) + O (g) Read the rest of this entry »

Ozone is present naturally in the troposphere. One part comes from that in the upper atmosphere (stratosphere) which is transported to lower levels, the air layers near the surface. Another part comes from natural processes that take place in the biosphere and that lead to the formation of ozone from nitrogen oxides emissions that are caused by biological processes and the emission of volatile organic compounds from vegetation, fermentation processes or volcanoes.

Ozone amounts that give rise to these processes are small and their concentration in the air does not reach dangerous levels. However, tropospheric ozone can be a problem when it causes an increase in concentration by artificial means: pollution. Many activities performed by the man now emit air pollutants that are precursors of ozone. By the action of sunlight, these chemicals react and cause the formation of ozone. This usually occurs mainly in large cities, the process favored by high concentrations of pollutants in the air. Read the rest of this entry »

The ozone-related problems are present regularly in the media and received numerous reports that for many people it can be contradictory. Thus, in recent years, we read information how are you two that we have collected in the summer of 2000.

“They fire warning levels. During the summer, in the Community of Madrid, have exceeded the levels ‘desirable’ ozone on numerous occasions, according to officials of the Ministry of Environment. Municipalities hardest hit are those in Henares Corridor, where there have been maximum of 241 micrograms per cubic meter of air. ”

“European scientists have launched the alarm to the drastic reduction of the ozone layer in the Arctic Circle. Recent studies show that this winter was lost up to 60% of the thickness of this layer that protects living things from sun’s harmful rays, ultraviolet radiation.” Read the rest of this entry »

There are two ways to obtain the ozone in the industry. The most common method is to pass air through glass tubes with metallic surfaces arranged concentrically (ozonators) including shock is blown high potential difference (about 15 kV) and high frequency (50 Hz ) acting on the molecules of dioxygen (O2) causing the formation of ozone (trioxygen). Later ozone can be separated by fractional distillation. In this way we get ozone mixed with air in concentrations of about 2%.

Another method of production, at lower concentrations, air is irradiated with ultraviolet light. Ozone is also obtained as a byproduct of the distillation of water. Read the rest of this entry »

Ozone is a triatomic molecule composed of atoms of oxygen. A standard temperature and pressure (25 ° C and 1 atm) is in a gaseous state and has a pale blue, one of the most toxic inorganic compounds that exist in nature. This is found in small concentrations in the atmosphere (the famous ozone layer), but when in the lower atmosphere, causes harm to the lungs. On the other hand, when in the upper parts of the atmosphere serves to protect the ecosystem by preventing the radiation of ultraviolet rays.

Ozone is a gaseous substance. Van Marum in 1781 predicted their existence when he noticed the smell of the air traversed by electric shock, but was not discovered until 1839 by Christian Schönbein that gave the name of ozone. Read the rest of this entry »

The effect of ozone depletion on the Earth’s surface is the increased levels of ultraviolet-B radiation. This type of UV-B radiation is harmful to humans, animals and plants. The increases in UV-B radiation have been observed not only under the ozone hole in Antarctica but in other places like the Alps (Europe) and Canada (North America).

1. Effects on human health.

1.1 Skin cancer.

Today it is estimated that skin cancer rates increased due to stratospheric ozone depletion. The most common type of skin cancer, the so-called non-melanoma, is due to exposure to UV-B radiation for several years.

There are already people who have received the dose of UV-B can cause this type of cancer. It is estimated that between 1979 and 1993 this type of UV-B dose was increased by 8.9 percent in the 55 ° north latitude (approximately the height of Copenhagen and Moscow), 11.1 percent to 45 ° N (Venice and Montreal) and 9.8 percent at 35 ° north latitude (Cyprus, Tokyo and Memphis). The average between 55 ° and 35 ° north latitude was 10 percent and estimated that the increases were greater in the southern hemisphere. Read the rest of this entry »

Between 19 and 23 kilometers above the earth’s surface in the stratosphere, a thin coat of gas, the ozone layer, surrounds and protects Earth from harmful sun rays. Ozone is produced by the effect of sunlight on oxygen and is the only substance in the atmosphere that can absorb the harmful ultraviolet radiation (UV-B) from the sun. This thin coat makes life possible on earth.

Since 1974, scientists have warned about a potential global crisis as a result of the progressive destruction of the ozone layer caused by chemical substances made by man, such as chlorofluorocarbons (CFCs). It took the world too long to understand these early warnings. Read the rest of this entry »

Between 19 and 23 kilometers above the earth in the stratosphere, a thin layer of gas, the ozone layer, surrounds and protects the earth from harmful solar rays.

Ozone is produced by the effect of sunlight on oxygen and is the only substance in the atmosphere that can absorb harmful ultraviolet radiation (UV-B) from the sun. This thin layer makes life possible on Earth.

Read the rest of this entry »

Between 19 and 23 kilometers above the earth in the stratosphere, a thin layer of gas, the ozone layer, surrounds and protects the earth from harmful solar radiation. Ozone is produced by the effect of sunlight on oxygen and is the only substance in the atmosphere that can absorb the harmful ultraviolet radiation (UV-B) from the sun. This thin layer may make life on earth.

Since 1974, scientists have warned about the potential of the global crisis as a result of progressive damage to the ozone layer caused by the chemicals made by humans, such as chlorofluorocarbons (CFCs). The world needs too long to understand this early warning.

Read the rest of this entry »