The Air we breath

The maintenance of the Earth’s atmosphere oxygen balance is a major concern of contemporary ecologists. Its regeneration is due to plants with metabolism based on chlorophyll, both of the planktonic and terrestrial plants, especially of the rainforests. In this regard, it is noted that a hectare of forest produces about 50 times more oxygen than the same area covered with grass or agricultural plants.

Reducing the areas covered by forests, destruction of plants and obstruction of their development as produced by environmental pollution, land cover construction and transportation routes, as well as enormous amounts of oxygen consumption by industry and vehicles tend to disturb the equilibrium quantity of this crucial element of life.

Air pollution is due, especially in cities, to following source categories: industrial enterprises, means of transportation, home heating systems, waste removal and treatment.

Phytoplankton is endangered by chlorinated pesticides, biocides with long remanence time characters, whose last place of storage is ocean water, which represents more than two thirds of the planet. Estimated at one billion kgs the annual amount of chlorinated pesticides and their persistent metabolites and around 30 years duration of use, the potential risk for sea water to suffer great destruction of phytoplankton can be a reality, but still cannot be controlled.

A large amount of oxygen is consumed to ensure combustion, among which, lately, means of transport with internal combustion engine have a significant share.

Overall, on the globe, it is consumed annually for combustion about 2 • 10 ¹¹ t oxygen, quantity much smaller than that produced through photosynthesis (3.2 • 10 ¹¹ t / year that is 2.6 • 10 ¹¹ t by plants on land, especially from tropical forests and 0.6 • 10 ¹¹ t by marine phytoplankton).

If  consumed fossil fuels  increase by 5% annually, over about 130 years (in 2140) atmospheric oxygen will decrease by 30%.

Oxygen is the most important substance for life, being the most common gas in the atmosphere. Its proportion in the lithosphere (58%), considered as atomic weight, exceeds all other elements together; otherwise it is also on the first place (47%) with regard to atomic weight. In the air, it is in a proportion of 20.9% and in water (combined) of 89%.

The human body absorbs in relaxation state around. 100 ml of oxygen in each breath, retaining 25-30% (in effort can absorb 10 times more), which represents an air quantity of 8-10 l per minute, that is 15,000 to 20,000 l per day, which places this contribution on the first place from the qualitative point of view, of the permanence and physiological importance between environmental substances penetrated into the body. The oxygen is decreasing proportionally pressure lapse, becoming insufficient for some patients, from several hundreds of meters height, for untrained from 2000-3000 m and 5000-6000 m for everyone.

Low concentrations, with the risk of respiratory failure can be found in confined spaces where gas is consumed by oxidative processes (biological or other nature processes) and where it is often replaced with inert gas (methane) or toxic (CO2, H2S and so on). The relative lack of oxygen, tolerated for a short period of time even to below 10% is fatal if it is prolonged or exceeds excessively, with all attempts to accommodate the body by increasing the frequency and amplitude of respiration. Even small fluctuations from normal lead to negative consequences with regard to susceptible individuals.

Nowadays, consumption for technological purposes is necessary same as for biological purposes and technical quantities consumed by the industrial installations are considerable. Reducing of air pollution caused by vehicles is one of the most difficult issues of contemporary civilization, because in many developed countries, they constitute the most important category of sources of air pollution. From the viewpoint of human ecology, regardless of their sources, atmospheric protection is based on the principle of maximum permissible concentrations (MPC), ie of the dose of pollutants which cause direct or indirect harmful actions on the human body.

Urban air, from houses, like that of collective spaces as public institutions, means of transport and so on, is primarily polluted by dust and irritant gases and other pollutants resulting from combustion as with toxic metals and metalloids in traces, to which pollutants are added often from working places. In this regard, a significant negative contribution in terms of human health is attributed to smoking. Tobacco smoking is one of the most bizarre and harmful habits of contemporary human population, now quite a widespread  practice that finds no basis in any kind of need and whose expansion can hardly be explained in terms of history, psychology and other criteria. Smoking represents an important cause of illness and death for a large proportion of the world, more important than many epidemic diseases and accidents, pollution etc. There were identified about 1200 substances, most of them with carcinogenic role in tobacco and smoke resulting from its burning. Smoking reduces life expectancy and reduces longevity. Life expectancy of smokers is reduced in regard to the number of cigarettes smoked, thus early starting of smoking and its long practice reduce proportionally the longevity. As a general rule, the years of life lost by smokers represent after a study, 3.7 years for people who start smoking after 25 years and 8.2 years for those who start smoking before 15 years.

The worst periods concerning air quality from houses inhabited by people are frosty winter days when no ventilation is made because of the cold.

Carbon dioxide from the air of housing is tolerated, on hygienic bases, only up to 0.07 to 0.1%, a rate that shows that the air is polluted, exerting a number of negative effects to pathogenic action, stronger as the level and duration of exposure are higher.

Earth’s atmosphere receives as a whole, about 2 • 10 ¹º t pollutants in the form of particles and gases (of which more than half is represented by the carbon dioxide). Among gaseous air pollutants that are evacuated annually in large quantities we can mention the following: CO, SO2, various hydrocarbons, NO2. Amounts of Pb, Hg, chlorinated pesticides and so on, got in the air, represent conditions of the high qualities of persistence and concentration in food chains.

Vegetation world is the source of oxygen for the rest of the living creatures. It has been calculated for about 1 trillion tons / year consumed quantity of oxygen for breathing. Of this, approximately 2/3 is generated by terrestrial plants and one third of aquatic plankton. Need of forests is becoming increasingly a more understood issue; lately, it is starting to be planted large free areas in the mass actions. A ha of woodland absorbs annually from the atmosphere, 3.7 mil.t CO2 and generates 2 mil.t. of O2. Rainforest produces 30% of the oxygen generated on land. The oxygen produced by three oaks can maintain the life of a man till death.

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1 Response so far »

  1. 1

    Maria Bors said,

    This article made me thinking, and gives us incentive to plant more oaks ……
    Data are downright alarming.


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