Presentation on theme: "Hazardous Chemicals: Pollution and Prevention"— Presentation transcript:
1 Hazardous Chemicals: Pollution and Prevention CHAPTER 22Hazardous Chemicals: Pollution and Prevention
2 An introduction to hazardous chemicals Fish in Lake LeBarge, Canada, have become hazardous to eat because of high DDT levelsArctic fish, birds, and mammals have high amounts of persistent organic pollutants (POPs) in their bodies--DDT, toxaphene, chlordane, PCPs, dioxinsThe Inuit people have very high loads of POPs. Caribou pick up dioxins in lichens and mosses; Inuit eat caribouHow do these toxic chemicals reach remote areas, where there are no pesticides or industries?
3 Chemicals in remote areas POPs are persistent and bioaccumulate.They are carried to the Arctic in the airThey condense on the snowpack and enter water during the spring thawPlankton pick up the chemicals and pass them up the food chainFeeding 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 Toxicology and chemical hazards Toxicology: the study of the harmful effects of chemicals on human and environmental healthToxicologists study acute toxicity effects, chronic effects, and carcinogenic potentialObviously, the higher the toxicity of a chemical, the more concern there is (or should be) about exposure to it
5 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 substancesMay 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 Federal legislationThe Emergency Planning and Community Right to Know Act (EPCRA—1986) says industries must report releases of toxic chemicals to the environmentThe Pollution Prevention Act (1990): mandates collection of data of chemicals treated on-site
7 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 compoundsSynthetic organicsStill, if diluted enough in air or water, they may not pose a significant hazard
8 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 toxicused in industry (metalwork, metal plating), batteries, and electronicsIf absorbed in the body, they interfere with enzyme functioningSmall amounts can cause severe consequencesMental retardation, insanity, birth defects
9 Organic compoundsPetroleum-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 healthAre readily absorbed and interact with enzymesmany cannot be broken down by the body, so they are bioaccumulated. Acute effects: Liver and kidney failure, sterility, cancer, death
10 Dirty dozenHalogenated hydrocarbons: synthetic organics that contain halogens: chlorine, bromine, fluorine, iodineChlorinated hydrocarbons (organic chlorides) and other halogenated hydrocarbons includePlastics, pesticides (DDT), solvents (carbon tetrachloride), insulation (polychlorinated biphenyls)Note that we come into contact with these fairly often!
11 PERC Perchloroethylene (PERC): a halogenated hydrocarbon Colorless, nonflammableUsed in dry cleaning, as a solvent, in home productsIs carcinogenic to rats and miceIt easily enters groundwater from soilHuman exposure occurs in the workplace and from using home productsDizziness, fatigue, headaches, unconsciousness, cancerIt is listed in NTP’s 2009 Report on Carcinogens as “reasonably anticipated to be a human carcinogen”
12 Phasing out PERCDry-cleaning employees have higher rates of cancer and neurological impairmentEPA issued rules to phase it out by 2020Why is it taking so long?The Obama administration will review these rulesThe U.S. uses 370 million lbs/year10% from dry cleanersThe rest is used in making hydrofluorocarbons (which replace ozone-depleting CFCs)
13 Issues with other organics Phthalates: soften plastic (e.g., teethers, rubber duckies)A possible reproductive hormone disrupterIt was banned in 2008 from children’s toysBisphenol A (BPA): used in plastics (e.g., baby bottles)In animals, causes obesity, diabetes, infertility, cancer2008: the FDA declared it did not pose a health hazardAn FDA scientific advisory panel said the ruling was flawed
14 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 pollutantsMidnight dumping: disreputable businesses pocket fees, then anonymously and illegally dump wastes in abandoned warehouses, vacant lots, or landfills
15 Superfund for toxic sites The most monumental task we face is cleaning up tens of thousands of toxic sitesManagers of operating sites are pressured to clean upMany operators simply declared bankruptcy and abandoned their sitesThe Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA; 1980)Known as SuperfundA trust fund that uses money from taxes on chemical raw materials
16 Evaluating superfundOver 47,000 sites are serious enough to be given Superfund status33,000 sites do not pose a significant threatAssigned “no further removal action planned” (NFRAP)Over 11,300 sites remain on the active listSome of the worst sites are on military basesA totally heedless and unconscionable discarding of toxic materials13% of NPL sites are federal facilities
17 RCRA The Resource Conservation and Recovery Act (1976) Cornerstone legislation designed to prevent unsafe or illegal disposal of all solid wastes on landAll disposal facilities (e.g., landfills) must have permitsFacilities must have safety featuresOld facilities are shut down and become Superfund sitesToxic wastes destined for landfills must be converted to forms that will not leachRequires “cradle-to-grave” tracking of hazardous wastes
18 Worker protection: OSHA Industries used to force workers to do jobs that exposed them to hazardous materials without informing them of the dangers involvedOccupational Safety and Health Act of 1970Its 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 availableAlong with providing suitable protective equipment
19 Community protection and emergency preparedness A 1984 accident at Union Carbide in India spilled 30–40 tons of methyl isocyanate,extremely toxic gas600,000 people were exposed; 10,500 (or more) died50,000 people had visual impairment, respiratory problems, and other injuriesUnion Carbide had scaled back safety and alarm systemsThe people and doctors had no idea of how to protect or treat themselves
21 Where is the environmental justice? The largest commercial hazardous-waste landfill in the U.S. is in Emelle, AlabamaAfrican Americans make up 90% of the populationA Choctaw reservation was going to get a 446-acre hazardous-waste landfillThe population is entirely Native American870,000 federally subsidized housing units are within a mile of factories that emit toxic emissionsMost occupants are minorities
22 What you can do Avoid using products containing harmful chemicals Especially indoorsThe 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 properlyTake unwanted chemicals to the annual Hazardous Waste Collection Day in your community
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