The list of hidden and most dangerous environmental pollutants Bashny.Net

Millions of people every day are exposed to quite small doses of hazardous substances: car exhaust, industrial emissions, do not always comply with health standards, furniture made using the "volatile" fillers, poorly purified drinking water, substandard food. Plus, tobacco smoke, alcohol, counterfeit medicines... In recent decades, the ecological environment people become the subject of attention of the world health organization (who). Discussion of the toxic properties of substances, contact with which it is difficult to avoid city resident, was devoted to a series of meetings at the who.The who list of the most common and the most dangerous environmental pollutants include the following substances: Acrylonitrile, benzene, carbon disulfide, 1,2-dichloroethane, dichloromethane, formaldehyde, polycyclic aromatic hydrocarbons (3,4-benzo(a)pyrene), styrene, toluene, arsenic, cadmium, carbon monoxide, chromium, hydrogen sulfide, lead, mercury, fluorine, and sulfur dioxide. But the air of the cities there are other substances presenting a danger of chronic poisoning, including can cause long-term effects of reproductive disorders and the development of malignant tumors. The basis for hygienic standardization lies the postulate that the concentration of toxic substances are below the MPC (maximum permissible concentration) is safe for humans. For one-time effects it's overall fair. But if the body daily exposed to poisons, even in small concentrations, can we assume it's harmless? What is the threshold of chronic action? Is it enough to set the MPC at the level of 5-10 times below the threshold to maintain the health of the people?
Twenty five million five hundred eighty eight thousand five hundred sixty three

The degree of "toxicity" of substances in toxicology can be characterised in the value of LD50, the so — called lethal dose which killed 50% of animals involved in trials. For human lethal concentration almost the same as for experimental animals. The question is: what is the distance between the LD50 and the threshold of chronic action? For example, consider some comparative data gleaned from the literature on toxicology.The ratio of lethal dose to that which causes primary poisoning, chlorine is 600-800, for ammonia — 1000-1500 for arsenic — 2500. But for other poisons such as carbon monoxide, methanol, ethanol, this ratio is significantly less than, respectively, 60, 9, and 17. It is clear that the smaller this value, the higher the risk to poisoning even at low doses. In addition to differences in the size of the dose that causes acute or chronic poisoning, there are differences of the clinical picture. The symptoms of chronic poisoning may differ materially from those in acute poisoning, but it is more difficult to diagnose. Thus, under the action of low concentrations of carbon monoxide the content of carboxyhemoglobin (the product of a Union of carbon monoxide and hemoglobin) in human blood is 6-8%, which is accompanied by mild headaches and some difficulty during exercise. But if the content of carboxyhemoglobin in the blood reaches 50%, there is an acute poisoning, in which there is shortness of breath, tachycardia, weakening of cardiac activity, convulsion, loss of consciousness and death can occur.The concentration of formaldehyde in the air of 0.1 mg/m3 odor threshold, 0.5 mg/m3 irritation threshold eye, and 37.5 mg/m3 causes a life threatening pulmonary edema. At a concentration of 125 mg/m3, death occurs. The concentration of formaldehyde in the air of residential premises, typically 5-10 times higher than on the street. This is due to the fact that formaldehyde is often used in the manufacture of furniture and construction materials. Formaldehyde released, for example, from new furniture, may be the cause of headaches, nausea, weakness, poor sleep, allergic reactions. Hazardous chemicals enter the body in different ways. For example, benzene is not only in the form of vapor with air or tobacco smoke, but food and water. Benzene is mainly used as raw material for the production of aromatic hydrocarbons, its annual production exceeds 40 million tons. Benzene contained in crude oil and gasoline (up to 5% by volume). Its main source of revenues into the atmosphere — emissions of internal combustion engines and evaporation of hydrocarbon fuel. Benzene may fall on the surface of the Earth with rainfall. Adult person inhales air with the city about 160 micrograms of benzene per day, a smoker receives additional 10 to 30 µg per cigarette.
Forty seven million seventy nine thousand six hundred thirty three

Cigarette smoke contains 150-204 mg/m3 of benzene. The latter occurs as a contaminant in drinking water at 0.1—0.3 ág/L. Toxicology found benzene in some foods: eggs (25-100 mcg per egg), irradiated (to sterilize) meat (19 µg/kg) and canned meat (2 mg/kg). It is also found in different varieties of fish, fried chicken, nuts, fruits and vegetables. In General, the intake of benzene from food can be estimated on average as 250 mcg per day. High levels of benzene (more than 3200 mg/m3) cause neurotoxic symptoms. Chronic benzene poisoning is manifested in disorders of the nervous system and organs of hematopoiesis.published   



Source: www.sethealth.ru/2016/10/04/%D1%87%D1%82%D0%BE-%D1%81%D0%BA%D1%80%D1%8B%D0%B2%D0%B0%D0%B5%D1%82%D1%81%D1%8F-%D0%B7%D0%B0-%D1%82%D0%B5%D0%BC-%D1%87%D1%82%D0%BE-%D0%BC%D1%8B-%D0%BF%D1%8C%D0%B5%D0%BC-%D0%B5%D0%B4%D0%B8%D0%BC/