1 / 31

COMMON TOXIC POLLUTANTS

COMMON TOXIC POLLUTANTS. I. BIOCIDES. SOURCES Pesticides Insecticides Herbicides EFFECTS Carcinogenic … meaning?? Nerve damage Liver damage. I. BIOCIDES. EXAMPLES Dioxins …ingredient in insecticides Used by paper mills in bleaching process Used in PVC plastics

clive
Télécharger la présentation

COMMON TOXIC POLLUTANTS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. COMMON TOXICPOLLUTANTS

  2. I. BIOCIDES • SOURCES • Pesticides • Insecticides • Herbicides • EFFECTS • Carcinogenic … meaning?? • Nerve damage • Liver damage

  3. I. BIOCIDES • EXAMPLES • Dioxins …ingredient in insecticides • Used by paper mills in bleaching process • Used in PVC plastics • An ingredient in agent orange • Agent Orange … herbicide • Widely used in Vietnam as a defoliant • Caused cancer, birth defects, sterility

  4. I. BIOCIDES • EXAMPLES • 24D … common herbicide • Causes lymphoma (cancer) in dogs • DDT … insecticide • Caused egg shell thinning • Blamed for the near extinction of eagles, falcons and pelicans

  5. DDT(dichlorodiphenyltrichlorethane) • Insecticide used very effectively against mosquitoes, which cause malaria • Builds up in plants and fatty tissue in fish, birds and other animals • Banned in the US in 1972 • Still used in other countries

  6. BIOMAGNIFICATION • A chemical becomes concentrated as it passes through a food chain

  7. 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).

  8. DDT • This is why the hazard of DDT to nontarget animals is particularly acute for those species living at the top of food chains.

  9. DDT: A Threat to America’s Bald Eagles

  10. II. FOSSIL FUELS (coal, oil & gas) • SOURCES • NO2 + H2O  HNO3 (process occurs when burning gas) • SO2 + H2O  H2SO4 (process occurs when burning coal)

  11. II. FOSSIL FUELS (coal, oil & gas) • EFFECTS • Respiratory problems • Sterile lakes • Kills forests • Damage to monuments, cars, buildings • Global warming • Acid rain

  12. II. FOSSIL FUELS (coal, oil & gas) • SOLUTIONS • Burn higher grade fuels • Scrubbers • Others??

  13. III. Hg (mercury) • SOURCES • Paper mills to treat logs • Agriculture to treat seeds • Occurs naturally in mines • Acid rain releases it naturally from sedimentary rock • Latex paint

  14. III. Hg (mercury) • 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

  15. III. Hg (mercury) • 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

  16. IV. Pb(lead) • SOURCES • Water pipes • Gasoline • Paints • Batteries • Ceramic pottery • Soldering

  17. IV. Pb (lead) • EFFECTS • Hyperactivity • Paralysis • Brain damage • Birth defects • High BP

  18. IV. Pb (lead) • 4% of preschool children have below normal IQ • 20% of Americans drink too much H2O containing Pb • 2 million waterfowl each year die of lead poisoning

  19. V. PCB (Polychlorinated Biphenyls) • 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

  20. V. PCB (Polychlorinated Biphenyls) • EFFECTS • Carcinogen • including effects on the immune system, reproductive system, endocrine system and nervous system

  21. V. PCB:Contaminating the Hudson River

  22. V. PCB (Polychlorinated Biphenyls) • 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.

  23. 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 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.

  24. VI. CFC (chlorofluorocarbon) • 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.

  25. VI. CFC (chlorofluorocarbon) • EFFECTS • Destruction of the ozone layer which protects us from ??? UV rays from the sun How does this happen?

  26. VI. CFC (chlorofluorocarbon)

  27. VII. PBB (Polybrominated Biphenyls) • 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. • EFFECTS • Carcinogen • More will be observed in the movie Bitter Harvest

  28. VII. PBB (Polybrominated Biphenyls) • 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. • 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.

  29. 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 cattle 1,470 sheep 5,900 pigs 1.5 million chickens

  30. VIII. NO3 and PO4 (nitrates & phosphates) • 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

  31. VIII. NO3 and PO4 (nitrates & phosphates) • EFFECTS • Eutrophication • Algae blooms • Decreasing light and O2 levels • Currently in the news … • Allegan, Ottawa, and Muskegon Counties all have baned the use of fertilizers containing phosphorus

More Related