Environmental Problems, Their Causes, and Sustainability 1

Figure 24-23 Solutions: securehazardous waste landfill.ImperviousclayBulk wasteGas ventTopsoilEarthSandPlastic coverImpervious clay capClay capof more than 500,000 people.Most communities do not havethe equipment and trained personnelneeded to deal with hazardouswaste spills. How well isyour community prepared todeal with such spills? In the future,some of the risks might bereduced by using solid nanoparticlematerials to absorb thehazardous liquids.Figure 24-24 lists ways youcan reduce your environmentalinput of hazardous waste.EarthWatertableGroundwaterDouble leachatecollection systemPlasticdoublelinerReactivewastesin drumsLeakdetectionsystemGroundwatermoniteringwellWhat Are Brownfields? Recycling DangerousSitesMany abandoned industrial and other hazardouswaste sites are being cleaned up and put to use.Brownfields are abandoned industrial and commercialsites usually contaminated with hazardous wastes. Examplesinclude factories, junkyards, older landfills,and gas stations. Some 450,000–600,000 brownfieldsites exist in the United States, often in economicallydistressed inner cities.What Can You Do?Hazardous WasteBrownfields can be cleaned up and reborn asparks, nature reserves, athletic fields, ecoindustrialparks (p. 536), and neighborhoods. But first old oil andgrease, industrial solvents, toxic metals, and other contaminantsmust be removed from their soil andgroundwater. Such efforts have been hampered byconcerns about legal liability for the contamination.However, Congress and almost half of the states havepassed laws limiting the liability for developers andtheir lenders.Brownfield redevelopment is now seen as a wayto rebuild parts of cities, create jobs, and increase thetax base. By 2004, more than 40,000 former brownfieldsites had been redeveloped in the United States andmany other projects are under way.• Use pesticides in the smallest amount possible.• Use less harmful substances instead of commercialchemicals for most household cleaners. For example,use liquid ammonia to clean appliances and windows;vinegar to polish metals, clean surfaces, and removestains and mildew; baking soda to clean householdutensils, deodorize, and remove stains; borax to removestains and mildew.• Do not dispose of pesticides, paints, solvents, oil,antifreeze, or other products containing hazardouschemicals by flushing them down the toilet, pouringthem down the drain, burying them, throwing theminto the garbage, or dumping them down storm drains.Figure 24-24 What can you do? Ways to reduce your input ofhazardous waste into the environment.24-8 CASE STUDIES: LEAD, MERCURY,AND DIOXINSWhat Is the Threat from Lead? A Toxic MetalLead is especially harmful to children and is still usedin leaded gasoline and household paints in about100 countries.Because it is a chemical element, lead (Pb) does notbreak down in the environment. Lead is a potent neurotoxinthat can harm the nervous system, especiallyin young children. Each year, 12,000–16,000 Americanchildren under age 9 are treated for acute lead poisoning,and about 200 die. About 30% of the survivors sufferfrom palsy, partial paralysis, blindness, and mentalretardation.554 CHAPTER 24 Solid and Hazardous Waste