Ib 105 exam 3

IB 105 exam 3
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Unformatted text preview: Environmental Health and Technology Virus: microscopic particles that can reproduce only by infecting host cells, example: influenza Bacteria: single-celled organisms with no membrane-enclosed nucleus, example: bubonic plague, anthrax, cholera Protozoans: single-celled organisms with a true nucleus, example: plasmodium Communicable/infectious disease: contagious, example: AIDS, SARS, influenza, ebola Non communicable: not contagious, example: many forms of cancer, cardiovascular disease Link between disease and environment: changes in environment increase risk for disease, changing climate patterns change where disease can occur, increased UV can increase cancer risk, lack of sanitary freshwater promotes illness, desertification reduces ability to receive adequate nutrition, we put toxic chemicals into the environment Emergent disease: one not previously known or one that has been absent for at east 20 years, important factor in spread of disease is speed and frequency of travel, SARS and Avian flu, drug-resistant form of tuberculosis Pandemic: occurring over a wide geographic area and affecting an exceptionally high proportion of population (AIDS/ 1918 infuenza) 1918 influenza pandemic: ~25% americans got it, 2.5% died, killed 675,000 american people, (10x as WW), worldwide 5--100 million Why modern technology hasn't eradicated all disease? Antibiotic and pesticide resistance, many disease causing bacteria now resistant to antibiotics, mosquitoes that transmit malaria have developed resistance to many insecticides PCB: polychlorinated biphenyis, various synthetic organic chemicals ranging from oily liquids to waxy solids, used in hundreds of industrial and commercial applications like electrical, heat transfer, and hydraulic equipment, have been demonstrated to cause variety of adverse health effects/cancer in animals, effects on immune system reproductive system, nervous/endocrine, studies in humans provide supportive evidence for potential carcinogenic and non-carcinogenic effects, not used in US Animal testing: most commonly used toxicity test is to expose a population of laboratory animals to measured doses of specific toxins LD 50: dose at which 50% of test population is sensitive Playground: wood made with CCA (chromated copper arsenate), its toxic when it gets wet and so children playing on it is dangerous, no longer produced, antibiotics only kill bacteria Global Climate Change Major greenhouse gases: CO2, methane, nitrous oxides, chlorofluorocarbons (CFCs) Greenhouse effect: heat from sun is absorbed in Earth's surface, some is reflected back up into atmosphere, some is absorbed and re-emitted in a directions by gases warming the Earth and lowering the Earth's atmosphere CO2 increasing: more emitted than absorbed, burning coal, oil, and gas, industrial processes, deforestation, agriculture Global climate change: human activities are changing the composition of Earth's atmosphere, human activities are strengthening Earth's natural greenhouse effect, warming trend of 1 degree since late 19th century Likely but difficult to predict: rising levels of greenhouse gases in atmosphere will increase global warming and average global temps will continue to rise (amount and how fast is uncertain) "big unknowns": exact local impacts on health, agriculture, water resources, forests, wildlife and coastal areas, large-scale predictions easier to make than small-scale, uncertainty about details is evidence of a "controversy" IPCC conclusions: CO2 and temp correlated, 0.6 degrees Celsius is average temp increase since 1861, declines in snow and ice cover since 1960s, 10-20 cm sealevel increase in last 100 years, human activity is cause, CO2 ^ temp^ Population ^ greenhouse gases ^: humans responsible, industrial revolution Effects of global climate change: warmer temps lead to glaciers melting and oceans expanding sea level rise coastal flooding, changes in patterns of precipitation more violent weather, drier forests, kinds of crops change, forests migrate to poles, hotter/drier deserts Air Pollution Kyoto protocol: in Japan 1997, agree to rollback CO2, methane, nitrous oxide emissions, sets different limits for different nations, depending on 1990 output, China and India exempt, US argued too costly for economy and others rollbacks not enough, US and Australia not ratified Primary air pollutants: materials that when released pose health risks in their unmodified forms Secondary pollutant: primary pollutants interact with one another, sunlight, or natural gases to produce new, harmful compounds 6 major pollutants: 1. sulfur dioxide- produced by burning sulfur containing fossil fuels (coal, oil), coal burning power plants, reacts in atmosphere to produce acids, acid rain, 44% reductions since clean air act, can be corrosive to lung tissue, London- 4000 people died 2. nitrogen oxides- produced from burning fossil fuels, acid rain/smog, automobile engine, main source, 20% increase since CAA 3. carbon monoxide- burning organic material (coal, gas, wood), automobiles biggest source, toxic- binds to hemoglobin, reduces oxygen in blood, New Illinois Law, carbon monoxide alarm detector act 4. particulates- small pieces of solid materials and liquid droplets, ash from fires, ash, dust, soot, easily noticed: smokestacks, more attention, more regulation, decreased 80% 1970 to 2000, can accumulate in lungs and interfere with ability of lungs, miners/installers 5. volatile organic compounds (VOCs)- produced naturally by plants, bogs, and termites, methane, human activity- benzene/formaldehyde, contributes to smog, 40% reduction with CAA, 6. lead- naturally occurring heavy metal, adding lead to gas prevented car engines from `knocking', banned in 1995, adding lead to paint improved durability and color- banned in 1978, millions of children suffer developmental retardation due to lead poisoning. 98% reduction with CAA Photochemical smog- mixture of secondary pollutants formed by reaction of nitrous oxides, VOCs and sunlight, includes O3 (ground level ozone) Bad ozone: ground level ozone Good ozone- layer that protects living things from UV exposure in stratosphere Ozone depletion: CFCs, 1970s noticed decline, UV radiation breaks down CFC and releases atomic chlorine and converts O3 to O2, and ozone depletes Acid rain: water with pH less than normal rainfall, linked to coal burning in England in 1852, caused by airborne pollutants, SO2 HSO4, NO/NO2HNO2, combine with water and falls, damages forests, buildings, lakes, fish die, fro eggs, tadpoles, crayfish Clean Air Act: US/Canada recognized in 1986 and reduced SO2 emissions in 1990, control requirements, federal government implements and sates administer, all sources subject to ambient air quality regulation, new sources subject to more stringent controls, hazardous pollutants and visibility reducing emissions, air pollution cut by 1/3 and acid rain cut by 1/4 Water I Freshwater: 2.4% 2/3: households worldwide get water from outside their home Hydrologic cycle: solar energy evaporates water, warm/moist air rises and then cool/condense air falls, goes back to the soil and returns to ocean, going from gas to liquid moves the water Groundwater: water within the soil Surface water: over the ground Aquifer: porous layer that is saturated with water in between two beds Mahomet Aquifer: we consume our water by it, others want it so we should care Water use: 1. domestic- shower, toilet, dishwasher, laundry, drinking, cooking, 60% worldwide water use 2. agricultural: 70% of water, withdraw higher than consumption, 37% ground water and the rest surface, irrigation for crops can be inefficient and competes with domestic, aquifers drying up 3. industrial: 25%, 90% is for cooling and returned to source, very little consumed, used to dissipate and transport waste, stream and lake degradation 4. in-stream: hydroelectric power, damages rivers, increases evaporation, recreation- dams, navigation Water conservation: not major priority because it's considered limitless and inexpensive Average American: 80-100 gallons/day of water used for other purposes (not survival) Aral Sea: 4th largest river, since 1975 lost a lot of water, lots of people out of work, 2 main rivers diverted since 1960s for cotton and rice fields, dried up Ways to conserve: turn off water while brushing teeth, use gray water, fix leaks, reduce toilet volume Water II Point source of pollution: definite source and place where pollution enters water Nonpoint sources of pollution: diffuses pollutants without distinct source, harder to regulate nonpoint sources, CWA protects paint sources Cultural eutrophication: increases in algae due to human-induced, increases in nutrient N or P input, increases in supply of limiting nutrient, lots of algae produced, oxygen used up, plants dies, dead zones Lake eutrophication: many areas pump raw sewage into lakes (increase phosphorus) Primary sewage treatment: removes solid washer through filtering Secondary sewage treatment: removes dissolved organic material Tertiary sewage treatment: final, most costly and often not completed stage, removes phosphorus and nitrates Industrial water pollution: mining- discharged into surface waters (sulfur, iron, etc), point sources more regulated, developing countries, nothing really regulated Reduce agricultural pollution: buffer strips from pesticides, trees stop fertilizers and pesticides from going to the river Thermal pollution: elevated temperatures from cooling water, affecting spawning behavior, reduces oxygen levels, alters species composition Clean water act: run by EPA, want swimmable, fishable water, limitations for point source pollution, creates civil and criminal penalties, does not apply to nonpoint sources, does not apply to ground water Environmental Geology and Earth Structure of Earth: core-dense/hot metal, mantle- hot/pliable layer/less dense than core, crust- cool/lightweight/brittle/outermost layer Environmental costs/mineral use (naturally occurring organic): economic, energy, and environmental are the costs, cost of mining- energy demands, strip mines, mine tailings, mountain top, require water, pollutes, pollution from smelters Earthquake: caused by grinding and jerking as plates slide past each other, occurs where plates come together Tsunami: waves generated when water is rapidly displaced on a massive scale (Indian Ocean) Landslides: occur when material moves downslope, more people, deforestation increase severity 2005 hurricane season: unique because most active in history, 27 named storms and 15 hurricanes Severity of natural disasters: more people live in areas prone to them, deforestation- landslides, removing vegetation- increases impact of floods/tsunamis and hurricanes Energy Sources I- fossil fuels Energy: ultimate source- sun, producers convert sunlight to biomass, all work first done by human muscle, first alternative was domesticated animals and burning biomass, wood, coil, oil, natural gas, machines and industrial revolution, steam engines Direct ink between economic growth and availability of inexpensive energy: to keep energy prices low government subsidizes energy prices, energy consumption motivated by economics and convenience Resource: naturally occurring substance of use to humans Reserve: amount of a known deposit that can be economically extracted using current technology, levels change as technology advances and new discoveries are made and profit margins change Fossil fuels: 1. coal- most abundant, surface mining and strip mining removes overburden on top of vein, efficient but destructive, underground mining minimizes surface disturbance but costly and dangerous with toxic gases, coal used for generating electricity, coal burned to heat water, high pressure steam turns turbines that spin the generator and create an electric current, dust pollution 2. oil and natural gas- accumulations of dead marine organisms on the ocean floor covered by sediments, high pressure and temperature convert them to energy rich, stripping is used to get them, oil- burns cleaner and easily transported, ideal for automobiles, difficult to extract and causes oil spills, natural gas- drilling like oil, primary use is for heating, least environmentally damaging of fossil fuels Coal- mining destroys habitat, mining creates dust pollution burning releases pollutants, oil- oil spills, natural gas- almost none OPEC- organization of petroleum exporting countries, controls over 75% of known oil reserves, produces ~43% world's known crude oil, last 80 more years Energy Sources II Gas price: affected by crude oil, federal and state taxes, refining costs and profits, distribution and marketing, US has lower gas prices because there are lower taxes US gets oil from: Canada, Saudi Arabia, Mexico, and Nigeria ANWR: drilling is controversial because there are lots of animals but there's also oil and natural gas, some opposed say there's only 6 months worth, 1-1.3 million barrels/day, takes 10 years to reach market and only will meet 4% of oil needs for 6-45 years Alternatives: average fuel efficiency of cars and light trucks were improved by 1 miles per gallon than save more oil than ever from ANWR, hybrid vehicles, improved gas mileage, more costly, biofuel- derived from biomass Hydroelectric power: river water held behind dam, water used to spin turbine, reservoir construction causes significant environmental and social damage, loss of farmland, community relocation, impacts aquatic animals Other energy sources: 1. wind- costly and steady/dependable wind is critical, hazardous to birds, noisy, looks ugly 2. solar- 100x greater than all others combined, intermittent nature is problem, converted to heat, transformed to electrical, calculators, less than 1%, only during day and not in cold/cloudy places 3. tidal- tides to spin turbine, limited applicability 4. geothermal- molten material, steam, electricity, limited applicability, 5. lake source cooling- use cold water to cool buildings 6. biofuels- costly Reduce fossil fuels: reduce gasoline (bike), reduce electricity, change light bulb, thermostat, open windows, clothesline Energy III Nuclear fission: occurs when neutrons impact and split nuclei of certain atoms, chain reaction- splitting nuclei release neutrons, strike more nuclei releasing more neutrons Nuclear reactor: device that permits a controlled fission chain reaction, chain reaction produces heat, converts water to steam, turns turbine, generates electricity Environmental impacts of nuclear power: does not release greenhouse gases but nuclear waste, more than 330 underground storage tanks exist with high level radioactive waste, clean up takes years and costs tens of billions of dollars, thermal pollution Yucca Mountain: long term storage for radioactive disposal, high level radioactive stays radioactive for 500,000 years, by 2010 will exceed storage capacity Thermal pollution: addition of waste heat to environment, dangerous to aquatic systems Electricity generated by spinning turbines: coal, water, wind, geothermal, and nuclear reactors but not solar Three Mile Island: partial core melt-down, pump and valve malfunction, no deaths and little radiation vented, public relations disaster, PA Chernobyl: Ukraine, experiments, safety violations, reactor explodes and 56 deaths and 24,000 evacuees got high does of radiation Solid/Hazardous Wastes 4 main waste sources: agriculture (50%), residues by mining and primary metal processing (30%), industrial waste (3.6%), municipal waste (1.8%) Landfills and incineration: groundwater pollution and foul odors/gritty smoke/air pollution/toxins/costly 3 ways to reduce waste: reduce, reuse, recycle Bottle bill- recycling initiative ? Compost: harnessing natural decomposition to transform organic material into compost, states yard waste bans ? Hazardous waste: contaminates groundwater, costly to restore Household hazardous waste collection program: IEPA, health risks and list for garbage Love Canal: for navigation and hydropower, swimming and recreation, became municipal and chemical disposal site, 20,000 tons of chemicals, then elementary school and homes but complaints Ottawa Radiation Areas: superfund site (contaminated and needs clean up because it poses a threat), readioactive materials, clocks and watches painted with radium Kerr McGee: superfund site, radioactive thorium waste material, partial clean-up Sustainable Development Sustainable development: meets present needs without compromising ability of future generations to meet their own needs, ongoing debate: are we living sustainabley? Ecological vs neoclassical economics: neoclassical believes that resources are interchangeable and classical believes tat resources have a finite amount Worldwide sustainable development is not easy: balance global/local and present/future, economic consequences of another country 5 steps to achieve: 1. renewability- use renewable sources no faster than they can be replaced 2. substitution- use renewable over nonrenewable 3. interdependence- local communities recognize larger system must be sustainable 4. adaptability- can change to take advantage of new opportunities, requires diversified economy, educated citizens, and willingness to change 5. institutional commitment- adopts laws that mandate sustainability that economy supports and citizens value Bet: Paul Ehrlich- argues that American lifestyle is driving global ecosystem to collapse and thinks consumption of resources would drive prices up, Julian Simon- argues human ingenuity not resources limit economic growth and that technology would replace any potential shortages and prices would fall, prices did fall NIMBY- not in my back yard, waste generation not in affluent suburbs EPA Office of Environmental Justice: to promote fair treatment of all races, incomes, and cultures with respect to implementation and enforcement of environmental regulations and policies, racial minority and lower income have higher environmental risk Environmental protection and job loss: only .1% of al layoffs in US were due to governmental regulations Land-Use Planning and Cost/Benefit Analysis Need for land use planning: 1/3-1/2 land surface altered by humans, mostly with minimal forethought to consequences and most land-use decisions bases on economic considerations or short-term needs rather than on unique analysis of landscape Potential problems with city living: slums and shantytowns, pollution and congestion, lack of sanitary water, crime Benefits of city living: more efficient use of resources, public transportation, centralized location of home, work, services Urban sprawl- pattern of unplanned low density housing and commercial development outside of cities, usually on undeveloped and, problemstransportation and traffic, air pollution, energy efficiencies- longer commutes, death of central city, loss of open space, loss of farmland, water pollution, flood plain problems Land use planning: evaluating needs and wants of people, land characteristics and value various solutions to land use before changes made, establish state or regional planning agency, purchase land or use rights, regulate zone Smart growth- growth without sprawl, mix land uses, take advantage of compact designs, create walkable neighborhoods, foster distinctive/attractive neighborhoods, preserve open space and critical areas, provide variety of transportation Cost benefit analysis: used to determine whether policy generates more social costs than social benefits, determine all impacts and the determine values, net benefit is positive - negative ...
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