How to protect itself from influence of heavy metals?Heavy metals are elements of the Periodic Table of D. I. Mendeleyev, with a relative molecular weight more than 40. One of the strongest on action and the most widespread chemical pollution is pollution by heavy metals. More than 40 chemical elements of periodic system of D. I. Mendeleyev which mass of atoms makes over 50 nuclear units belong to heavy metals. This group of elements actively participates in biological processes, being a part of many enzymes. " group; heavy " metals; in many respects coincides with the concept “ minerals “. From here lead, zinc, cadmium, mercury, molybdenum, chrome, manganese, nickel, tin, cobalt, the titan, copper, vanadium are heavy metals. Heavy metals, getting to our organism, remain there forever, it is possible to remove them only by means of proteins of milk and cepes. Reaching a certain concentration in an organism, they begin the pernicious influence - cause poisonings, mutations. Except that they poison a human body, they also purely mechanically litter it - ions of heavy metals settle on walls of the thinnest systems of an organism and litter kidney channels, channels of a liver, thus, reducing filtrational ability of these bodies. Respectively, it leads to accumulation of toxins and waste products of cages of our organism, i.e. organism self-poisoning since. the liver is responsible for processing of the toxic agents getting to our organism and organism waste products, and kidneys - for their removal outside Sources of heavy metals share on natural (aeration of rocks and minerals, eroziyny processes, volcanic activity) and technogenic (production and processing of minerals, combustion of fuel, traffic, activity of agriculture). The part of the technogenic emissions coming to environment in the form of thin aerosols is transferred to considerable distances and causes global pollution. Other part comes to drainless reservoirs where heavy metals collect and become a source of secondary pollution, i.e. formations of dangerous pollution during the physicist - the chemical processes going directly in the environment (for example, education from nontoxical substances of poisonous gas of phosgene). Heavy metals collect in the soil, especially in the top humic horizons, and slowly are removed during the leaching, consumption by plants, erosion and deflations - blowing of soils. The period of semi-removal or removal of a half from initial concentration makes long time: for zinc - from 70 to 510 years, for cadmium - from 13 to 110 years, for copper - from 310 to 1500 years and for lead - from 740 to 5900 years. In humic part of the soil there is primary transformation of the connections which got to it. Heavy metals possess high ability to diverse chemical, physics - to chemical and biological reactions. Many of them have variable valency and participate in okislitelno - recovery processes. Heavy metals and their connections, as well as other chemical compounds, are capable to move and be redistributed in life environments, i.e. to migrate. Migration of compounds of heavy metals happens substantially in the form of body - a mineral component. The part of organic compounds which metals contact is presented by products of microbiological activity. Mercury is characterized by ability to accumulate in links “ food chain “. Microorganisms of the soil can give populations, steady against mercury, which turn metal mercury into substances, toxic for the higher organisms. Some seaweed, mushrooms and bacteria are capable to accumulate mercury in cages. Mercury, lead, cadmium are included into the general list of the most important polluting environment substances coordinated by the countries entering into the UN.
Undesirable changes physical understand environmental pollution
As environmental pollution, physics - chemical and biological characteristics of air, soils, waters which can adversely influence human life, plants necessary for it, animals and cultural property, to exhaust or spoil its raw material resources. These negative changes are result of activity of the person. They interrupt or break processes of an exchange and circulation of substances, their assimilation, energy distribution, properties of environment, living conditions of organisms as a result change, efficiency decreases or ecosystems collapse. Directly or indirectly such transformations influence the person through biological resources, waters and products.
Main sources of pollution of an anthropogenous origin:
. thermal power plants (27%),
. enterprises black (24%) and color (10,5%) metallurgy,
. petrochemical industry (15,5%),
. construction materials (8,1%), chemical industry (1,3%),
. motor transport (13,3%).
Types of pollution and harmful effects: physical pollution - - radioactive elements (radiation), heating or thermal pollution, noise; biological pollution - - microbiological poisoning of respiratory and food ways (bacteria, viruses), change of biocenoses owing to introduction of alien plants or animals; chemical pollution - - gaseous derivatives of carbon and liquid hydrocarbons, detergents, plastic, pesticides, derivative sulfurs, heavy metals, fluoric connections, aerosols, etc.; esthetic harm - - violation of landscapes, remarkable places unattractive constructions, etc. Besides, allocate groups of the polluting factors: material, including mechanical (aerosols, solid bodies and particles in water and the soil), chemical (various gaseous, liquid and firm chemical compounds), biological pollution (microorganisms and products of their activity), power (physical) pollution - - energy thermal, mechanical (vibration, noise, ultrasound), light, electromagnetic fields, ionizing radiation. Radioactive waste - - material and power pollution. Distinguish also dot (concentrated) and dispersed pollution sources, and also sources of pollution of continuous and periodic action.
. resistant not decaying (for example, mercury salts, phenolic connections with a long chain, DDT, aluminum jars, etc.), there are no natural processes decomposing these pollutants with the same speed with what they are entered into ecosystems;
. unstable (household sewage, excess of nitrates, etc.) collapsing as a result of biological processes.
Atmospheric pollution - - presence at air of various gases, vapors, particles of solid and liquid substances, including and radioactive, negatively influencing the live organisms worsening living conditions of the person and causing it material damage.
Into the atmosphere of Earth in a year it is released, one million t: carbon oxide 200, carbon dioxide more than 20, dioxide of sulfur 200, nitrogen oxides 53, dust bolee250, ashes 120, hydrocarbons more than 50, freon 1, lead 0,4 etc. of
harmful substances know About pollution of the environment surrounding the person almost everything now. Mass media - the press, radio and television - try to form such knowledge at various groups of the population. It is obvious that to submit the good review of how than and in what quantities our big general house - the biosphere becomes soiled - it is almost impossible. So far the mankind entered more than 4 million xenobiotics (anthropogenous substances, alien for it) into the biosphere and continues to enter 6 thousand substances daily. It is clear, that specific weight, a share of various harmful substances in environmental pollution are not identical. G. V. Novikov and A. Ya. Dudarev (1978), for example, about environmental protection of the modern city provided the following data of Battelevsky institute in the work about “ contribution “ separate substances in environmental pollution in 1970 and 1971. In 1971 first place in this list was won by heavy metals Allocation them in environment happens generally at combustion of mineral fuel. In ashes of coal and oil practically all metals are found. In coal ashes, for example, according to L. G. Bondarev (1984), existence of 70 elements is established. 1 t on average contains about 200 g of zinc and tin, 300 g of cobalt, 400 g of uranium, on 500 g Germany and arsenic. The maximum content of strontium, vanadium, zinc and Germany can reach 10 kg on 1 t. Ashes of oil contain a lot of vanadium, mercury, molybdenum and nickel. Ashes of peat contain uranium, cobalt, copper, nickel, zinc, lead. So, L. G. Bondarev, considering modern scales of use of fossil fuel, comes to the following conclusion: not metallurgical production, but combustion of coal represents the main source of many metals in environment. For example, at annual burning of 2,4 billion t of stone and 0,9 billion t of brown coal together with ashes 200 thousand tons of arsenic and 224 thousand tons of uranium whereas world production of these two metals makes 40 and 30 thousand tons a year respectively dissipate.
It is interesting that technogenic dispersion at combustion of coal of such metals as cobalt, molybdenum, uranium and some other, began long before elements began to be used. “ So far (including 1981) - L. G. Bondarev continues, - about 160 billion t of coal and about 64 billion t of oil were around the world got and burned. Together with ashes many millions of tons of various " metals are disseminated in the Wednesday surrounding the person;.
It is well known that many of the called metals and tens of other minerals are in live substance of the planet and are absolutely necessary for normal functioning of organisms. But, as they say, “ everything is good moderately “. Many of such substances at their excess quantity in an organism are poisons, begin to be hazardous to health. So, for example, have a direct bearing on a disease of cancer: arsenic (lung cancer), lead (cancer of kidneys, stomach, intestines), nickel (oral cavity, large intestine), cadmium (practically all forms of cancer).
Conversation on cadmium has to be special. L. G. Bondarev provides disturbing data of the Swedish researcher M. Piskatora that the difference between the content of this substance in an organism of modern teenagers and the critical size when it is necessary to reckon with dysfunction of kidneys, pulmonary diseases and bones, is very small. Especially at smokers. Tobacco during the growth very actively and in large numbers accumulates cadmium: its concentration in dry leaves is one thousand times higher than average values for biomass of land vegetation. Therefore with each inhaling a smoke together with such harmful substances as nicotine and carbon monoxide, cadmium also comes to an organism. One cigarette contains from 1,2 to 2,5 mkg of this poison. World production of tobacco, according to L. G. Bondarev, makes about 5,7 million tons a year. One cigarette contains about 1 g of tobacco. Therefore, when smoking all cigarettes, cigarettes and tubes in the world in environment from 5,7 to 11,4 t of cadmium are allocated, getting not only into lungs of smokers, but also into lungs of non-smoking people.
Finishing brief information on cadmium, it should be noted also that this substance raises a blood pressure. Rather bigger quantity of cerebral hemorrhages in Japan, in comparison with other countries, naturally connect including with cadmic pollution which in the Land of the rising sun is very high.
Formula “ everything is good moderately “ is confirmed also by the fact that not only excess quantity, but also a lack of the substances called above (and others, certainly) it is not less dangerous and unhealthy the person. There are, for example, data that the lack of molybdenum, manganese, copper and magnesium can also promote development of malignant new growths.
Examples of saturation of the environment surrounding the person heavy metals and minerals collected much. Their considerable number is given in L. G. Bondarev`s monograph. It is even more data on harmful effect of heavy metals, and not only for the person, contains in the third volume of the seventh edition of the reference book “ Harmful substances in the industry “ (1977). For us these examples aimed to show scales of metal pressure upon the biosphere and a possibility of adverse consequences of this process for human health.