Не обращайте внимания
это для школы... (e-mail'ить с библиотеки нельзя)
читать дальшеMERCURY
Mercury is a metal that occurs naturally in the environment. It comes in several odorless forms. It can be a shiny, silver-white liquid, or a tin-white solid. If it is heated, it becomes a colorless gas. The chemical symbol for mercury is Hg.
----------
Mercury is used in some thermometers, barometers, vapor and fluorescent lamps, mirror coatings, dental fillings, batteries, pharmaceuticals, and agricultural chemicals. Mercury salts are sometimes used in skin-lightening and antiseptic creams.
Mercury is used to make electrical equipment, wire, and switching devices; to extract gold and silver from ores; and to produce chlorine gas and caustic soda, a liquid chemical. Mercury compounds were once used in latex paints, but were banned from that use in 1990.
----------
----------
You can be exposed to mercury by eating fish or shellfish contaminated with mercury, or having skin contact with it.
You can be exposed to mercury by breathing contaminated air at work, or by breathinzg contaminated air from spills, incinerators, and industries that burn fuels that contain mercury.
----------
----------
Exposure to high levels of mercury can cause mercury poisoning, which can cause death or permanently damage the brain and kidneys. This brain damage can cause tremors, hallucinations, psychosis, changes in vision or hearing, memory problems, loss of appetite and weight, and irritability.
Exposure to high levels of mercury vapor can damage kidneys. It can also irritate lungs and cause depression, inflammation of the gums and mouth, coughing, chest pain, and shortness of breath. Repeated low exposure may cause skin allergies.
Short-term exposure to high levels of mercury vapors can cause lung damage, nausea, vomiting, diarrhea, increases in heart rate or blood pressure, skin rashes, and irritation or cloudiness of the eyes.
----------
***********************************************************
LEAD
Lead is a heavy, soft, bluish-gray metal that occurs naturally in the rocks and soil of the earth's crust. It is also produced from burning fossil fuels, mining, and manufacturing. Lead has no distinctive taste or smell. The chemical symbol for elemental lead is Pb.
----------
Lead is used to produce batteries, ammunition, pipes, tank linings, solder, casting metals, building construction materials, roofing, scientific electronic equipment, military tracking systems, medical devices, and products to shield X-rays and nuclear radiation. It is used in ceramic glazes and crystal glassware.
----------
----------
You can be exposed to lead if your home was built before 1978, when lead-based paints were often used, or if your home was built before 1986, when lead solder was used on water pipes. You can be exposed at home if old lead-based paints are flaking, chipping, or deteriorating into dust. Small children can be exposed to lead in paint by eating paint chips, chewing on painted objects, or swallowing house dust or soil that contains lead.
You can be exposed to lead if you eat food or drink water that contains lead, or use dishes and utensils that contain lead. Hobby products can contain lead, such as materials for sculpturing and staining glass.
If lead is used where you work, you can be exposed to lead dust and fumes, especially if you are a lead refiner, miner, smelter, automobile finisher, typesetter, sheet metal worker, spray painter, or printer. You may be exposed to lead if you work in a facility that repairs radiators, or makes batteries, pottery, ceramics, brass or bronze products, rubber and plastic products, and lead compounds. Families of workers may be exposed to lead when workers bring home lead dust on their work clothes. Law enforcement officers can be exposed to lead while firing weapons in an indoor firing range.
----------
----------
Lead can affect almost every organ and system in your body. It can be equally harmful if breathed or swallowed. The part of the body most sensitive to lead exposure is the central nervous system, especially in children, who are more vulnerable to lead poisoning than adults.
A child who swallows large amounts of lead can develop brain damage which can cause convulsions and death; the child can also develop blood anemia, kidney damage, colic, and muscle weakness. Repeated low levels of exposure to lead can alter a child's normal mental and physical growth, and result in learning or behavioral problems.
In adults, exposure to lead may be short-term or chronic. Repeated or chronic exposure can cause lead to accumulate in your body, leading to lead poisoning. Lead poisoning can cause metallic taste, poor appetite, weight loss, colic, upset stomach, nausea, vomiting, and muscle cramps.
Short-term exposure to lead can irritate the eyes on contact, and cause high blood pressure, headache, irritability, reduced memory, disturbed sleep, and mood and personality changes. Breathing lead compounds can irritate the nose and throat. Exposure to higher levels of lead can damage the brain; kidneys; reproductive system; blood cells, causing anemia; and the nerves, causing weakness. Exposure may also cause muscle and joint pain, decreased reaction time, poor coordination, and poor memory.
----------
***********************************************************
ASBESTOS
Asbestos is the name given to a group of six different fibrous minerals that occur naturally in some rocks and soil. Asbestos comes in the form of long fibers that are strong, heat-resistant, and flexible enough to be woven; these fibers can be white, green, blue, or gray-green. Asbestos has no taste or smell.
----------
Asbestos has been used in building materials such as insulation and fireproofing; roofing shingles; ceiling and floor tiles; electrical insulation; furnace and hot pipe coverings; friction products such as automobile brake parts; cement products; coatings; plastics; gaskets; textiles; packaging; and heat-resistant fabrics and clothing, such as gloves.
----------
----------
You are most likely to be exposed to asbestos by inhaling asbestos particles in the air, but you can also be exposed through skin contact with asbestos or swallowing asbestos fibers.
You can be exposed to high levels of asbestos at work if you are a miner, make products that contain asbestos, demolish buildings containing asbestos, remove asbestos from buildings, work in the construction industry, repair and service automobiles brakes, work in shipbuilding and ship repair, or wear asbestos safety clothes.
You can be exposed to asbestos if you work or live in a building where asbestos has been incorrectly or poorly removed. Your exposure can be higher if materials containing asbestos are disturbed during demolition work, building or home maintenance, repairs, and remodeling.
You can be exposed to asbestos at home by inhaling asbestos that has drifted into the air from worn down or crumbling insulation, ceiling and floor tiles, and automotive products that contain asbestos. Families of workers exposed to asbestos can also be exposed when contaminated clothing, shoes, and equipment are brought home, and when clothing is laundered. You can be exposed to asbestos in drinking water, or if you use products that contain asbestos.
Simultaneous exposure to asbestos and cigarette smoking significantly increases the chances of getting lung cancer.
----------
----------
Asbestos is a human carcinogen that has been shown to cause cancer of the lungs, the membrane of the lungs, stomach, esophagus, colon, rectum, vocal cords, and kidneys. A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases of mesothelioma, a rare type of cancer of the mesothelium, the membrane that covers and protects most of the internal organs of the body. Repeated exposure to high levels of asbestos in the workplace can also cause asbestosis, a disease that can lead to disability and death; it scars the lungs and can cause the heart to enlarge.
These diseases do not develop immediately, but may appear many years after exposure. The first signs of asbestosis include persistent chest pain, coughing, a crackling sound in breathing, and shortness of breath.
Respiratory exposure to high levels of asbestos at work can cause chest pain, wheezing, low oxygen content in the blood, weight loss, clubbing of the fingers, and warts on the hands. Breathing lower levels of asbestos may cause plaques in the pleural membranes that surround the lungs, which can eventually lead to restricted breathing.