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Published byIris Morris Modified over 9 years ago
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COMMON TOXIC POLLUTANTS
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I. BIOCIDES A. SOURCES Pesticides Insecticides Herbicides B. EFFECTS Carcinogenic … meaning?? Nerve damage Liver damage
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I. BIOCIDES C. EXAMPLES Dioxins …ingredient in insecticides Used by paper mills in bleaching process Used by paper mills in bleaching process Used in PVC plastics Used in PVC plastics An ingredient in agent orange An ingredient in agent orange Agent Orange … herbicide Widely used in Vietnam as a defoliantWidely used in Vietnam as a defoliant Caused cancer, birth defects, sterilityCaused cancer, birth defects, sterility
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I. BIOCIDES C. EXAMPLES 24D … common herbicide Causes lymphoma (cancer) in dogs Causes lymphoma (cancer) in dogs DDT … insecticide Caused egg shell thinningCaused egg shell thinning Blamed for the near extinction of eagles, falcons and pelicansBlamed for the near extinction of eagles, falcons and pelicans
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DDT (dichlorodiphenyltrichlorethane) Insecticide used very effectively against mosquitoes, which cause malaria Insecticide used very effectively against mosquitoes, which cause malaria Builds up in plants and fatty tissue in fish, birds and other animals Builds up in plants and fatty tissue in fish, birds and other animals Banned in the US in 1972 Banned in the US in 1972 – Still used in other countries
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BIOMAGNIFICATION A chemical becomes concentrated as it passes through a food chain A chemical becomes concentrated as it passes through a food chain
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DDT The concentration effect occurs because DDT is metabolized and excreted much more slowly than the nutrients that are passed from one trophic level to the next. So DDT accumulates in the body (especially in fat). The concentration effect occurs because DDT is metabolized and excreted much more slowly than the nutrients that are passed from one trophic level to the next. So DDT accumulates in the body (especially in fat).
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DDT This is why the hazard of DDT to nontarget animals is particularly acute for those species living at the top of food chains. This is why the hazard of DDT to nontarget animals is particularly acute for those species living at the top of food chains.
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DDT: A Threat to America’s Bald Eagles
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II. FOSSIL FUELS (coal, oil & gas) A. SOURCES NO 2 + H 2 O HNO 3 (process occurs when burning gas) SO 2 + H 2 O H 2 SO 4 (process occurs when burning coal)
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II. FOSSIL FUELS (coal, oil & gas) B. EFFECTS Respiratory problems Sterile lakes Kills forests Damage to monuments, cars, buildings Global warming Acid rain
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II. FOSSIL FUELS (coal, oil & gas) C. SOLUTIONS Burn higher grade fuels Scrubbers Others??
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III. Hg ( mercury) A. SOURCES Paper mills to treat logs Agriculture to treat seeds Occurs naturally in mines Acid rain releases it naturally from sedimentary rock Latex paint
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III. Hg ( mercury) B. EFFECTS Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system of people of all ages. high levels of mercury in the bloodstream of unborn babies and young children may harm the developing nervous system, making the child less able to think and learn
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III. Hg ( mercury) C. Our inland fish are unsafe to eat due to high levels of Hg Hg cannot be eliminated from the body in any way Found in muscle tissue
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IV. Pb (lead) A. SOURCES Water pipes Gasoline Paints Batteries Ceramic pottery Soldering
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IV. Pb ( lead) B. EFFECTS Hyperactivity Paralysis Brain damage Birth defects High BP
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IV. Pb ( lead) 4% of preschool children have below normal IQ 4% of preschool children have below normal IQ 20% of Americans drink too much H 2 O containing Pb 20% of Americans drink too much H 2 O containing Pb 2 million waterfowl each year die of lead poisoning 2 million waterfowl each year die of lead poisoning
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V. PCB (Polychlorinated Biphenyls) A. SOURCES Insulators for electrical transformers Sealants for wood and cement Hydraulic fluids Paper mills for carbon paper pigments, dyes as plasticizers in paints, plastics and rubber products
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V. PCB (Polychlorinated Biphenyls) B. EFFECTS Carcinogen including effects on the immune system, reproductive system, endocrine system and nervous system
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V. PCB:Contaminating the Hudson River
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V. PCB (Polychlorinated Biphenyls) Polychlorinated biphenyls (PCBs) are a family of 209 chemical compounds for which there are no known natural sources. Polychlorinated biphenyls (PCBs) are a family of 209 chemical compounds for which there are no known natural sources. Even though PCBs are no longer commercially produced in the United States, high levels of the chemicals remain in various parts of the country, in poultry, and in fish. Even though PCBs are no longer commercially produced in the United States, high levels of the chemicals remain in various parts of the country, in poultry, and in fish.
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V. PCB (Polychlorinated Biphenyls) The very characteristic of the PCBs that made them wonderful for use in manufacturing makes them problematic in the environment. PCBs are very persistent: they are generally unalterable by microorganisms or by chemical reaction, so they do not readily degrade. The very characteristic of the PCBs that made them wonderful for use in manufacturing makes them problematic in the environment. PCBs are very persistent: they are generally unalterable by microorganisms or by chemical reaction, so they do not readily degrade. The stable nature of PCBs also lends to accumulation in the fatty tissues of animals once the PCBs are released into the environment. These accumulations increase as the tissue from contaminated animals moves through the food web. Because of _________, the concentration of PCBs found in fish tissues is expected to be considerably higher that the average concentration of PCBs in the water from which the fish were taken. The stable nature of PCBs also lends to accumulation in the fatty tissues of animals once the PCBs are released into the environment. These accumulations increase as the tissue from contaminated animals moves through the food web. Because of _________, the concentration of PCBs found in fish tissues is expected to be considerably higher that the average concentration of PCBs in the water from which the fish were taken.
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VI. CFC (chlorofluorocarbon) A. SOURCES aerosol-spray propellants refrigerants Solvents Styrofoam (pre, CFC-free styrofoam) foam-blowing agents They are well-suited for these applications because they are nontoxic and nonflammable and can be readily converted from a liquid to a gas and vice versa.
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VI. CFC (chlorofluorocarbon) B. EFFECTS Destruction of the ozone layer which protects us from ??? UV rays from the sun How does this happen?
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VI. CFC (chlorofluorocarbon)
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VII. PBB (Polybrominated Biphenyls) A. SOURCES PBBs are manufactured chemicals They are added to the plastics used to make products like computer monitors, televisions, textiles, plastic foams, etc. to make them difficult to burn. PBBs can leave these plastics and find their way into the environment. B. EFFECTS Carcinogen More will be observed in the movie Bitter Harvest Bitter Harvest
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VII. PBB (Polybrominated Biphenyls) Exposure to PBBs is most likely to occur by ingesting contaminated foods and drinks. Exposure to PBBs is most likely to occur by ingesting contaminated foods and drinks. People living in the lower peninsula of Michigan, where animal feed was accidentally contaminated with PBBs in 1973, may still be exposed by eating contaminated fish, dairy products, and meat. People living in the lower peninsula of Michigan, where animal feed was accidentally contaminated with PBBs in 1973, may still be exposed by eating contaminated fish, dairy products, and meat. If you don't live in Michigan, exposure to PBBs is likely to be very low. If you don't live in Michigan, exposure to PBBs is likely to be very low. You can be exposed to PBBs in the air if you live near a waste site that contains PBBs. You can be exposed to PBBs in the air if you live near a waste site that contains PBBs.
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C. The movie Bitter Harvest … PBB contamination resulted in the most devastating disaster in agricultural history In 1973 in St. Louis, MI The government did not eliminate PBB from the food chain until 1977 Farmers sold cows to an area baby food company Firemaster (flamestar) vs. Nutrimaster (MgO) All livestock had to be killed 30,000 cattle1,470 sheep 5,900 pigs1.5 million chickens 5,900 pigs1.5 million chickens
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VIII. NO 3 and PO 4 (nitrates & phosphates) A. SOURCES Soil … background concentrations Fertilizers … agricultural & residential Sewage … wastewater treatment plants remove 90-95% of P & N in solids, and the sludge is then land applied as fertilizer
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VIII. NO 3 and PO 4 (nitrates & phosphates) B. EFFECTS Eutrophication Algae blooms Decreasing light and O 2 levels C. Currently in the news … Allegan, Ottawa, and Muskegon Counties all have baned the use of fertilizers containing phosphorus
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