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© 2011 Pearson Education, Inc. CHAPTER 22 Hazardous Chemicals: Pollution and Prevention.

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Presentation on theme: "© 2011 Pearson Education, Inc. CHAPTER 22 Hazardous Chemicals: Pollution and Prevention."— Presentation transcript:

1 © 2011 Pearson Education, Inc. CHAPTER 22 Hazardous Chemicals: Pollution and Prevention

2 © 2011 Pearson Education, Inc. An introduction to hazardous chemicals Fish in Lake LeBarge, Canada, have become hazardous to eat because of high DDT levels Arctic fish, birds, and mammals have high amounts of persistent organic pollutants (POPs) in their bodies--DDT, toxaphene, chlordane, PCPs, dioxins The Inuit people have very high loads of POPs. Caribou pick up dioxins in lichens and mosses; Inuit eat caribou How do these toxic chemicals reach remote areas, where there are no pesticides or industries?

3 © 2011 Pearson Education, Inc. Chemicals in remote areas POPs are persistent and bioaccumulate. They are carried to the Arctic in the air They condense on the snowpack and enter water during the spring thaw Plankton pick up the chemicals and pass them up the food chain Feeding birds concentrate the chemicals, which are deposited to the land and water in guano; thus, highest amounts are in Arctic ponds near seabird nests

4 © 2011 Pearson Education, Inc. Toxicology and chemical hazards Toxicology: the study of the harmful effects of chemicals on human and environmental health Toxicologists study acute toxicity effects, chronic effects, and carcinogenic potential Obviously, the higher the toxicity of a chemical, the more concern there is (or should be) about exposure to it

5 © 2011 Pearson Education, Inc. Chemical hazards: HAZMATS Hazardous material (HAZMAT): a chemical that presents a certain hazard or risk (excluding radioactive materials) Ignitability: substances that catch fire readily (gasoline) Corrosivity: substances that corrode tanks and equipment (such as acids) Reactivity: chemically unstable substances May explode or create toxic fumes if mixed with water (explosives, sulfuric acid) Toxicity: substances that are injurious when eaten or inhaled or absorbed (chlorine, pesticides, etc.)

6 © 2011 Pearson Education, Inc. Federal legislation The Emergency Planning and Community Right to Know Act (EPCRA—1986) says industries must report releases of toxic chemicals to the environment The Pollution Prevention Act (1990): mandates collection of data of chemicals treated on-site

7 © 2011 Pearson Education, Inc. The threat from toxic chemicals Many toxic chemicals are naturally broken down, over time. Two classes do NOT readily break down: Heavy metals (lead, mercury, arsenic, cadmium, tin, chromium, zinc, and copper) and their compounds Synthetic organics Still, if diluted enough in air or water, they may not pose a significant hazard

8 © 2011 Pearson Education, Inc. Heavy metals Were once used in paint, glazes, inks, dyes Lead paint once poisoned U.S. children who ate chipped paint; leaded paint was banned in The phase-out of leaded gasoline in the 80s also helped. Heavy metals are extremely toxic used in industry (metalwork, metal plating), batteries, and electronics If absorbed in the body, they interfere with enzyme functioning Small amounts can cause severe consequences Mental retardation, insanity, birth defects

9 © 2011 Pearson Education, Inc. Organic compounds Petroleum-derived and synthetic organics are the basis for plastics, fibers, synthetic rubber, paintlike coatings, solvents, pesticides, preservatives, glues. useful but also potentially dangerous to our health Are readily absorbed and interact with enzymes many cannot be broken down by the body, so they are bioaccumulated. Acute effects: Liver and kidney failure, sterility, cancer, death

10 © 2011 Pearson Education, Inc. Dirty dozen Halogenated hydrocarbons: synthetic organics that contain halogens: chlorine, bromine, fluorine, iodine Chlorinated hydrocarbons (organic chlorides) and other halogenated hydrocarbons include Plastics, pesticides (DDT), solvents (carbon tetrachloride), insulation (polychlorinated biphenyls) Note that we come into contact with these fairly often!

11 © 2011 Pearson Education, Inc. PERC Perchloroethylene (PERC): a halogenated hydrocarbon Colorless, nonflammable Used in dry cleaning, as a solvent, in home products Is carcinogenic to rats and mice It easily enters groundwater from soil Human exposure occurs in the workplace and from using home products Dizziness, fatigue, headaches, unconsciousness, cancer It is listed in NTP’s 2009 Report on Carcinogens as “reasonably anticipated to be a human carcinogen”

12 © 2011 Pearson Education, Inc. Phasing out PERC Dry-cleaning employees have higher rates of cancer and neurological impairment EPA issued rules to phase it out by 2020 Why is it taking so long? The Obama administration will review these rules The U.S. uses 370 million lbs/year 10% from dry cleaners The rest is used in making hydrofluorocarbons (which replace ozone-depleting CFCs)

13 © 2011 Pearson Education, Inc. Issues with other organics Phthalates: soften plastic (e.g., teethers, rubber duckies) A possible reproductive hormone disrupter It was banned in 2008 from children’s toys Bisphenol A (BPA): used in plastics (e.g., baby bottles) In animals, causes obesity, diabetes, infertility, cancer 2008: the FDA declared it did not pose a health hazard An FDA scientific advisory panel said the ruling was flawed

14 © 2011 Pearson Education, Inc. Mismanagement of hazardous waste We are better at creating new chemicals than figuring out how to safely dispose of them. Where to put hazardous waste? Landfills, where they can leach into groundwater? “Pond-type” enclosures? Injected deep underground? Bioremediation: Oxygen and certain bacteria are injected into the soil; they metabolize the pollutants Midnight dumping: disreputable businesses pocket fees, then anonymously and illegally dump wastes in abandoned warehouses, vacant lots, or landfills

15 © 2011 Pearson Education, Inc. Superfund for toxic sites The most monumental task we face is cleaning up tens of thousands of toxic sites Managers of operating sites are pressured to clean up Many operators simply declared bankruptcy and abandoned their sites The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA; 1980) Known as Superfund A trust fund that uses money from taxes on chemical raw materials

16 © 2011 Pearson Education, Inc. Evaluating superfund Over 47,000 sites are serious enough to be given Superfund status 33,000 sites do not pose a significant threat Assigned “no further removal action planned” (NFRAP) Over 11,300 sites remain on the active list Some of the worst sites are on military bases A totally heedless and unconscionable discarding of toxic materials 13% of NPL sites are federal facilities

17 © 2011 Pearson Education, Inc. RCRA The Resource Conservation and Recovery Act (1976) Cornerstone legislation designed to prevent unsafe or illegal disposal of all solid wastes on land All disposal facilities (e.g., landfills) must have permits Facilities must have safety features Old facilities are shut down and become Superfund sites Toxic wastes destined for landfills must be converted to forms that will not leach Requires “cradle-to-grave” tracking of hazardous wastes

18 © 2011 Pearson Education, Inc. Worker protection: OSHA Industries used to force workers to do jobs that exposed them to hazardous materials without informing them of the dangers involved Occupational Safety and Health Act of 1970 Its amendments make up the hazard communication standard (worker’s right to know) Worker’s right to know: businesses, industries, and labs must make information on hazardous materials available Along with providing suitable protective equipment

19 © 2011 Pearson Education, Inc. Community protection and emergency preparedness A 1984 accident at Union Carbide in India spilled 30–40 tons of methyl isocyanate,extremely toxic gas 600,000 people were exposed; 10,500 (or more) died 50,000 people had visual impairment, respiratory problems, and other injuries Union Carbide had scaled back safety and alarm systems The people and doctors had no idea of how to protect or treat themselves

20 © 2011 Pearson Education, Inc. Toxic chemical disaster, Bhopal

21 © 2011 Pearson Education, Inc. Where is the environmental justice? The largest commercial hazardous-waste landfill in the U.S. is in Emelle, Alabama African Americans make up 90% of the population A Choctaw reservation was going to get a 446-acre hazardous-waste landfill The population is entirely Native American 870,000 federally subsidized housing units are within a mile of factories that emit toxic emissions Most occupants are minorities

22 © 2011 Pearson Education, Inc. What you can do Avoid using products containing harmful chemicals Especially indoors The average American home contains 100 lbs of household hazardous waste! Paints, stains, pesticides, motor oil, etc. They must be safely stored, used responsibly, and disposed of properly Take unwanted chemicals to the annual Hazardous Waste Collection Day in your community


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