unit 5 test
What is a pest? Define and give two examples of a pesticide. Describe Rachel Carson's contribution to environmental science. Describe the advantages and disadvantages of modern pesticides. Describe the use of laws to help protect us from the harmful effects of pesticides. Describe seven alternatives to conventional pesticides. Define integrated pest management (IPM) and discuss its advantages.
-Pests are unwanted organisms that directly or indirectly interferes with human activities. -Pesticides are any chemical designed to kill or inhibit the growth of an organism that people consider undesirable. (Examples include insect repellants and toxins) -Rachel Carson greatly increased our understanding of the importance of natural and the harmful effects of widespread use of pesticides. -The disadvantages of pesticides include: environmental pollution, organisms' genetic resistance of the pesticides, harm to wildlife, and the killing of natural predators and parasites that help control pest populations. -The advantages of pesticides include: increased, more profitable food supplies that, if utilized properly, make food safer to consume. -In the United States, three U.S. federal agencies, the EPA, the USDA, and the FDA regulate the sale and use of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act. -Alternatives to the usage of Pesticides are to use insect perfumes, implant genetic resistance, and increase the use of polyculture. -Integrated pest management combines use of biological, chemical, and cultivation methods to in proper sequence and trying to keep the size of a pest population below the size that causes economically unacceptable loss of a crop or livestock animal.
What is a floodplain and why do people like to live on floodplains? What are the benefits and drawbacks of floods? List three human activities that increase the risk of flooding. Describe the increased flooding risks that many people in Bangladesh face. What are three ways to reduce the risks of flooding?
A floodplain is a place where flooding can occur easily. People like to live on floodplains because the soil is rich and good for farming. The benefits of floods are rich soil and loam but the downsides are destruction of things from the water. Three activities that can increase them are the removal of water-absorbing vegetation, draining and building on the wetlands, and climate changes caused by humans. The people in Bangladesh face intense flooding and because of that a lot of people's homes and crops were destroyed. Preserve forests, preserve wetlands, and do not build on wetlands
What are the major harmful environmental impacts of agriculture? What is soil erosion and what are its two major harmful environmental effects? What is desertification and what are its harmful environmental effects? Distinguish between salinization and waterlogging of soil and describe their harmful environmental effects.
Biodiversity loss, harmful effects on soil, harmful effects on water, air pollution, and harmful effects on human health Soil Erosion: Movement of soil components, especially topsoil, from one place to another, usually by wind, flowing water, or both. This natural process can be greatly accelerated by human activities that remove vegetation from soil. Soil erosion causes loss of soil fertility and causes water pollution Desertification: Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting. Desertification causes droughts and degrades topsoil, which could result in severe drops in food production Salinization: Process that occurs when soils in arid areas are brought under cultivation through irrigation. In arid climates, water evaporates quickly off the ground surface, leaving salty residues that render the soil infertile. Waterlogging: saturation of soil with irrigation water or excessive precipitation so that the water table rises close to the surface These can stunt crop growth, lower crop yields, and can eventually kill plants and ruin the land.
What three systems supply most of the world's food? Distinguish among industrialized agriculture (high-input agriculture), plantation agriculture, traditional subsistence agriculture, traditional intensive agriculture, and polyculture. Define soil and describe its formation and the major layers in mature soils and why soil conservation is so important. What is a green revolution?Describe industrialized food production in the United States and in Brazil.
Croplands produce grains, rangelands, pastures and feedlots produce meat, and fisheries and aquaculture produce seafood. Industrialized Agriculture: Using large inputs of energy from fossil fuels (especially oil and natural gas), water, fertilizer, and pesticides to produce large quantities of crops and livestock for domestic and foreign sale. Plantation Agriculture: Production system based on a large estate owned by an individual, family, or corporation and organized to produce a cash crop. Almost all plantations were established within the tropics; in recent decades, many have been divided into smaller holdings or reorganized as cooperatives Traditional Subsistence Agriculture: when each family in a community grows crops for themselves and rely on animal and human labor to plant and harvest crops. Traditional Intensive Agriculture: production of enough food for a farm family's survival and a surplus that can be sold. This type of agriculture uses higher inputs of labor, fertilizer, and water than traditional subsistence agriculture Polyculture: Complex form of intercropping in which a large number of different plants maturing at different times are planted together. Soil: complex mixture of eroded rock, mineral nutrients, decaying organic matter, water, air, and billions of living organisms. Soil forms when bedrock is slowly broken down into fragments and particles by physical, chemical, and biological processes called weathering. Mature soil has different horizons: C horizon parent material, B horizon Subsoil, A horizon Topsoil, and O horizon leaf litter It is important to conserve soil because there are no substitutes for fertile and uncontaminated topsoil, without topsoil, there would be no food and no life on the land. Green Revolution: a large increase in crop production in developing countries achieved by the use of fertilizers, pesticides, and high-yield crop varieties In the United States agribusinesses control the growing, processing, distribution, and sale of foods in the U.S. and global markets. The agricultural system is a massive industry in the U.S. There are agricultural subsidies in U.S. taxes. The prices of food in the United States are artificially low. In Brazil, there is a lot of arable land. The country has a huge agricultural research industry. The country modifies soil and seeds for higher crop yields. Brazil is in danger of losing its biodiversity in some areas due to the intensive farming occurring.
Distinguish between producing crops through crossbreeding and producing crops through genetic engineering. Describe industrialized meat production. What is a fishery? What is aquaculture?
Crossbreeding occurs through artificial selection to develop genetically improved varieties of crops and livestock animals. This causes food to become larger. Genetic engineering occurs when scientists develop genetically improved strains of crops and livestock animals through altering an organism's genetic material through adding, deleting, or changing segments of its DNA Industrialized meat production is when animals are raised in densely packed feedlots and confined animal eating operations where they are fed grain or meal produced from fish. This occurs so that more meat can be produced more quickly. Fishery: area in which fish are caught/farmed Aquaculture: The cultivation of seafood under controlled conditions
Describe how streams can cleanse themselves and how these cleansing processes can be overwhelmed.
Describe how streams can cleanse themselves and how these cleansing processes can be overwhelmed. Streams can recover from moderate levels of degradable, oxygen-demanding wastes through a combination of dilution and biodegradation of such wastes by bacteria. But this doesn't work when streams become overloaded with such pollutants or when drought, damming, or water diversion reduces their flows.Although this process eliminates biodegradable wastes, it does not eliminate slowly degradable and nondegradable pollutants. In a stream, the breakdown of biodegradable wastes by bacteria depletes dissolved oxygen and creates an oxygen sag curve. This reduces populations of organisms with high oxygen requirements. Describe the state of stream pollution in developed and developing countries. Stream pollution is a serious and growing problem in developing countries. Half of the world's 500 rivers are heavily polluted and most of these polluted rivers run through developing countries. Many countries can't afford to build waste treatment plants or don't have laws for controlling water pollution. Industrial wastes and sewage pollute more than ⅔'s of India's water resources, and 54 of the 78 rivers/streams monitored in China. More than half of China's 1.3 billion people live w/o any form of sewage treatment. (2007 report) And nearly 300 million chinese do not have access to drinkable water. In Latin America and Africa, most streams passing through urban or industrial areas suffer from severe pollution. Garbage is purposefully dumped into rivers. Give two reasons why lakes cannot cleanse themselves as readily as streams can. Deep lakes and reservoirs often contain stratified layers that undergo little vertical mixing. Second, they have little or no flow. The flushing and changing of water in lakes ca take from 1 to 100 years, compared to several weeks for streams. Distinguish between eutrophication and cultural eutrophication. Eutrophication is the name given to the natural nutrient enrichment of a shallow lake, estuary, or slow-moving stream. It is caused mostly by runoff of plant nutrients such as nitrates and phosphates from surrounding land. Cultural eutrophication occurs when excessive fertilizers run into lakes and rivers. This encourages the growth of algae (algal bloom) and other aquatic plants. List ways to prevent or reduce cultural eutrophication. To prevent or reduce cultural eutrophication, we can use advanced waste treatment to remove nitrates and phosphates before wastewater enters lakes. We can also use a preventive approach by banning or limiting the use of phosphates in household detergents and other cleaning agents and by employing soil conservation and land-use control to reduce nutrient runoff. Explain why groundwater cannot cleanse itself very well. Groundwater cannot cleanse itself very well because it flows so slowly that contaminants are not diluted and dispersed effectively. Also, groundwater usually has much lower concentrations of dissolved oxygen and smaller populations of decomposing bacteria. And usually cold temperatures of groundwater slow down chemical reactions that decompose wastes. What are the major sources of groundwater contamination in the United States? The major sources of groundwater contamination in the US are: ⅓ of 26,000 industrial waste ponds and lagoons have no liners to prevent toxic liquid wastes from seeping into aquifers. ⅓ of these sites are within 1.6 kilometers of a drinking water well. Describe the threat from arsenic in ground-water. Arsenic contaminates drinking water when a well is drilled into aquifers where soils and rock are naturally rich in arsenic or when human activities release arsenic into drinking water supplies. List ways to prevent or clean up groundwater contamination. Find substitutes for toxic chemicals Keep toxic chemicals out of the environment Install monitoring wells near landfills and underground tanks Require leak detectors on underground tanks Ban hazardous waste disposal in landfills and injection wells Store harmful liquids in aboveground tanks with leak detection and collection tanks Pump to surface, clean, and return to aquifer Inject microorganisms to clean up contamination Pump nanoparticles of inorganic compounds to remove pollutants Describe U.S. laws for protecting drinking water quality. The Federal Water Pollution Control Act of 1972 and the 1987 Water Quality Act form the basis of U.S. efforts to control pollution of the country's surface waters. The EPA is experimenting with a discharge trading policy, which uses market forces to reduce water pollution in the United States. Describe environmental problems caused by the widespread use of bottled water. American spend 15 billion $'s to buy billions of plastic bottles filled with water. The number of bottles we throw away could circle the earth's equator 8 times.
Define food security and food insecurity. What is the root cause of food insecurity? Distinguish between chronic undernutrition (hunger) and chronic malnutrition and describe their harmful effects. Describe the effects of diet deficiencies in vitamin A, iron, and iodine. What is overnutrition, and what are its harmful health effects?
Food Security: People's ability to access sufficient, safe, nutritious food to maintain a healthy and active life. Food Insecurity: a situation in which members of a household are uncertain whether they will have the resources they need to get adequate amounts of nutritious food Poverty is the root cause of food insecurity. Chronic Undernutrition is when people do not have the ability to buy or grow the basic food they need to live, but Chronic Malnutrition is when people have access to some foods, but are lacking key nutrients and components in their diets. People suffering from hunger can experience mental retardation, stunted growth, early death from infectious diseases. People suffering from malnutrition are weakened, more susceptible to diseases, and hinders physical and mental growth. Vitamin A deficiencies cause people to go blind and die. Iron deficiencies causes anemia which makes people tired and get infections easier. Iodine deficiencies can cause the thyroid gland to function improperly which can cause stunted growth, mental retardation, and goiter. Overnutrition: excess energy or nutrients ingestion of too many calories and improper foods People can face a lower life expectancy, greater susceptibility to disease and illness, and lower productivity and life quality.
Describe three ways in which governments influence food production. List six ways to reduce nutrition-related premature childhood deaths. What is soil conservation? Describe soil erosion and soil conservation in the United States. Describe seven ways to reduce soil erosion. Distinguish among the use of organic fertilizer, commercial inorganic fertilizer, animal manure, green manure, compost, and crop rotation as ways to help restore soil fertility. Describe ways to prevent and clean up soil salinization and desertification.
-The government controls the prices and subsides of our food in the United States. -Six ways to reduce nutrition-related premature childhood deaths are 1) contour planting 2) strip cropping 3) ally cropping 4) establishing windbreaks 5) minimizing tillage and 6) eliminating plowing -Soil conservation involves using a variety of ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil covered with vegetation. -Soil erosion refers to the wearing away of a field's topsoil by the natural physical forces of water and wind or through forces associated with farming activities such as tillage. -In the U.S., the Soil Conservation Services (SCS) have formed soil conservation districts throughout the country, providing farmers and ranchers with technical assistance to set up soil conservation programs. -Organic fertilizers are organic material such as animal manure, green manure, and compost applied to cropland as a source of plant nutrients. -Animal manure is the dung and urine of cattle, horses, poultry, and other farm animals. -Green manure consists of freshly cut or growing green vegetation that is plowed into the topsoil to increase the organic matter and hummus available to the next crop. -Crop rotation is planning in a field or an area of a field, with different crops from year to year to reduce soil nutrient depletion. A plant such as corn, tobacco, or cotton, which removes large amounts of nitrogen form the soil, is planted one year; the next year a legume such as soybeans, which adds nitrogen to the soil, is planted. -Commercial inorganic fertilizer is commercially prepared mixture of plant nutrients such as nitrates, phosphates, and potassium applied to the soil to restore fertility and increase crop yields.
What percentage of the earth's freshwater is available to us? Define groundwater, zone of saturation, water table, aquifer, surface water, surface runoff, watershed (drainage basin), reliable surface runoff, and drought. What percentage of the world's reliable runoff are we using and what percentage are we likely to be using by 2025? How is most of the world's water used? Describe the availability and use of freshwater resources in the United States. How many people in the world lack regular access to safe drinking water, and how many do not have access to basic sanitation?
.024% of freshwater is available to us. Groundwater- Water that sinks into the soil and is stored in slowly flowing and slowly renewed underground reservoirs called aquifers. Zone of Saturation- Area where all available pores in soil and rock in the earth's crust are filled by water Water Table- Upper surface of the zone of saturation, in which all available pores in the soil and rock in the earth's crust are filled with water. Aquifer- Porous, water-saturated layers of sand, gravel, or bedrock that can yield an economically significant amount of water. Surface Water- Precipitation that does not infiltrate the ground or return to the atmosphere by evaporation or transpiration. Surface Runoff- Water flowing off the land into bodies of surface water. Watershed- Land area that delivers water, sediment, and dissolved substances via small streams to a major stream. Reliable Surface Runoff- Surface runoff of water that generally can be counted on as a stable source of water from year to year. Drought- Condition in which an area does not get enough water because of lower-than-normal precipitation or higher-than-normal temperatures that increase evaporation. We are using 34% of the world's reliable runoff and predicted to reach 70%. By 2025 at least 3 billion people out of 7.9 billion are likely to lack access to clean water. Irrigation accounts for 85% of water use. Water is taken from groundwater sources, rivers, and lakes, but farmers and cities are depleting the resources so fast they cannot be replenished. Water is becoming more and more scarce. More than 30 countries lack regular access to water.
Describe ways to produce meat more efficiently and sustainably. Describe ways to make aquaculture more sustainable. What are three factors that contributed to the growth of the current industrialized food production systems? What are the major components of more sustainable agriculture? What are the major advantages of organic agriculture? Describe the advantages of relying more on polycultures of perennial crops. What can individuals do to promote more sustainable agriculture?
A more sustainable form of meat production and consumption involves shifting from less grain-efficient forms of animal protein, such as beef, pork, and carnivorous fish produced by aquaculture, to more grain-efficient, such as poultry and herbivorous farmed fish.
How are coastal waters and deeper ocean waters polluted?
A report says 80-90% of the municipal sewage from most coastal developing countries and in some coastal developed countries is dumped into oceans without treatment. This often overwhelms the ability of these coastal waters to biodegrade these waters. Some U.S. coastal waters have found vast colonies of viruses thriving in raw sewage and it effluents from sewage treatment plants and leaking septic tanks. What causes harmful algal blooms and what are their harmful effects? Runoffs of sewage and agricultural wastes into coastal waters introduce large quantities of nitrate and phosphate plant nutrients, which can cause explosive growths of harmful algae. These harmful algal blooms are called red, brown, or green toxic tides. They can release waterborne and airborne toxins that damage fisheries, kill some fish-eating birds, reduce tourism, and poison seafood. Describe oxygen depletion in the northern Gulf of Mexico. The low oxygen levels suffocate fish, crabs, and shrimp that cannot move to less polluted areas. This is a result of oxygen-depleting algal blooms. It is created mostly by huge inputs of nitrate plant nutrients from farms. cities, factories, and sewage treatment plants. How serious is oil pollution of the oceans, what are its effects, and what can be done to reduce such pollution? V serious . Effects: The oil immediately kill many aquatic organisms. Other chemicals in oil form tar-like globs that float on the surface and coat the feathers of birds and the fur of marine animals. This oil coating destroys their natural heat insulation and buoyancy, causing many of them to drown or die of exposure from loss of body heat. Heavy oil components that sink to the ocean floor or wash into estuaries can smother bottom-dwelling organisms. Oil spills have killed coral reefs. Research shows that populations of many forms of marine life recover from exposure to large amounts of crude oil within about 3 years. But recovery from exposure from refined oil can take to 10-20 years. Some estimate that current clean-up methods can recover no more than 15% of the oil from a major spill. Thus, preventing oil pollution is the most effective. One of the best ways to prevent tanker spills is to use only oil tankers with double hulls.
What are the advantages and disadvantages of withdrawing groundwater? Describe the problem of groundwater depletion in the world and in the United States, especially in the Ogallala aquifer. Describe ways to prevent or slow groundwater depletion, including possible use of deep aquifers. What is a dam? What is a reservoir? What are the advantages and disadvantages of large dams and reservoirs? Describe the California Water Project. Describe the Aral Sea disaster. Define desalination and distinguish between distillation and reverse osmosis as methods for desalinating water. What are three limitations of desalination?
Advantages: Useful for drinking and irrigation, Available year-round, exists almost everywhere, renewable if not over pumped or contaminated, no evaporation losses, cheaper to extract than most surface waters. Disadvantages: Aquifer depletion from over pumping. Sinking of land from over pumping. Aquifers polluted for decades or centuries. Saltwater intrusion into drinking water supplies near coastal areas. Reduced water flows into surface waters. Increased cost and contamination from deeper wells. Groundwater is being withdrawn four times faster than it can be replenished. The Ogallada Aquifer is the largest in the nation and is being pumped out at a rate that is 10-40 times higher than the natural recharge rate. Ways to Prevent and Control Ground Water Depletions: Waste less water, subsidize water conservation, limit number of wells, do not grow water intensive plants in dry areas, raise price of water to discourage waste, tax water pumped from wells near surface waters, set and enforce minimum steam flow levels, and divert surface water in wet years to recharge aquifers. Dam- Structures built across rivers to block some of the flow of water. Reservoir- Stores of water collected behind the dams. Advantages: Capture and store runoff, generate electricity, and supply water for irrigation. Disadvantages: Displaced 40-80 million people because of flooding issues, fish and plant species are becoming extinct from the decrease in water flow, and sometimes droughts are caused. The California Water Project uses underground tunnels to transfer water from the water-rich northern part of the state to the water-weak southern part. They diverted water flow into the sea and since then the salinity of the water has risen sevenfold and 85% of the local bird and mammal species have vanished. Desalinization- Removing dissolved salts from ocean water or from brackish water in aquifers or lakes for domestic use. It's another way to increase supplies of freshwater. Distillation involves heating saltwater until it evaporates and condenses into fresh water. Reverse osmosis uses high pressure to force saltwater through a membrane filter with pores small enough to remove the salt. Disadvantages: Expensive, lots of energy required and kills marine life, and problems with disposing the waste water.
What percentage of the world's water is unnecessarily wasted and what are two causes of such waste? Describe four irrigation methods and list ways to reduce water waste in irrigation in developed and developing countries. List four ways to reduce water waste in industry and homes, four ways to use water more sustainably, and four ways in which you can reduce your use and waste of water.
About 66% of the world's water is wasted, caused by 1) the low cost of water and 2) lack of government subsidies to improve water usage. Irrigation methods: flood irrigation, drip irrigation (tubes deliver water to plants), center pivot (water pumped from underground, such as sprinklers) and gravity flow (water comes from aqueduct system or nearby river). Ways to reduce water waste in developed and developing countries: irrigate at night to reduce evaporation, polyculture, irrigate with treated wastewater, monitor soil moisture. Ways to reduce water waste in industry and homes: recycle water in industry, raise water prices, collect and reuse household water to irrigate lawns and water nonedible plants, fix water leaks. Ways to use water more sustainably: preserve water quality, do not deplete aquifers, raise water prices, slow population growth. Ways in which you can reduce your use and waste of water: use water saving toilets, turn off sinks while brushing teeth, repair water leaks, short showers instead of taking baths.
compare the main components of organic agriculture with those of conventional industrialized agriculture.
Organic agriculture attempts to prevent soil erosion and uses organic fertilizer while industrialized agriculture uses synthetic inorganic fertilizers to supply plant nutrients. Organic agriculture uses crop rotation and biological pest control and does not use genetically modified seeds while industrialized agriculture uses synthetic chemical pesticides and also uses genetically modified seeds. Organic agriculture uses more renewable energy sources while industrialized agriculture produces pollution. Industrialized agriculture often uses antibiotics and growth hormones and exports food globally while organic agriculture is local and does not use antibiotics or growth hormones.
Review the Key Questions and Concepts for this chapter on p. 239. Discuss the stresses on the Colorado River basin in the United States that have resulted from overuse of this resource.
The Colorado River is being overused. It has become a huge source of water for many of the areas around it. People are drawing water from it to support cities and to grow crops. Because of the massive use of the River people are starting to see shortages of water making for many complications; causing the people who rely on the River to have some troubles.
What are this chapter's three big ideas? Describe the relationships among organic agriculture (Core Case Study), more sustainable food production, and the three principles of sustainability. The chapters three big ideas are food, soil, and pest management.
The chapters three big ideas are food, soil, and pest management. Organic agriculture relates to sustainable food production because it does not depend on nonrenewable fossil fuels, uses the recycling of animal wastes and crop wastes, doesn't accelerate soil erosion, preserves agrobiodiversity and can improve wildlife habitats and natural species interactions which help to control pest population sizes. These relate to the three principles of sustainability by promoting the use of solar energy, recycling different chemicals back into the ecosystem, and allowing the area to have biodiversity.
What are this chapter's three big ideas? Describe relationships between water resource and pollution problems in the Colorado River basin (Core case Study) and the three principles of sustainability.
The three big idea are: The water resource strategies in which dams and other big engineering schemes have made it possible to provide much of the world with food, electricity, drinking water, and flood control, but also degraded the aquatic natural capital needed to ensure sustainability by disrupting rivers, streams, wetlands, aquifers, and other aquatic systems Water pollution and which methods of pollution control are in reach and the hope of shifting emphasis from cleaning up water pollution to preventing it The three principles of sustainability and how they can be used to help manage the growing threat of a lack of freshwater In the Colorado River Basin, there is a limited resource of water available because the river is being tapped to provide water elsewhere The three principles of sustainability are: Cutting water waste Raising water prices Protecting aquifers, forests, and other ecosystems that store and release water
What is water pollution? Distinguish between point sources and nonpoint sources of water pollution and give an example of each. List nine major types of water pollutants and give an example of each.
Water pollution is any chemical, biological, or physical change in water quality that has a harmful effect on the integrity of the water and the organisms living in it. Point source is a term given to a direct cause of pollution(chemical companies dumping waste) whereas nonpoint source is a term given to any source that a pollutant cannot be directly traced back to (runoff). Examples: Nutrient Pollution (fertilizers, nitrate) Pesticides (runoff from farms) Sediment (when forests are clear cut) Industrial and Chemical Waste (improper waste dumping) Gasoline, Oil, and Additives (B.P. oil spill) Mining (chemicals used in mining flows from rivers to lakes) Plastics (littering) Household Chemicals and Pharmaceuticals (travels from the drain) Sewage (raw sewage is prevalent in water in India)
List ways to reduce water pollution from (a) nonpoint sources and (b) point sources. Describe the U.S. experience with reducing point-source water pollution. What is a septic tank and how does it work? Describe how primary sewage treatment and secondary sewage treatment are used to help purify water. How would Peter Montague improve conventional sewage treatment? What is a composting toilet system? Describe John Todd's use of living machines to treat sewage. Describe how wetlands can be used to treat sewage. List six ways to prevent and reduce water pollution. List five things you can do to reduce water pollution.
Ways to reduce water pollution from a non-point source are reducing soil erosion by keeping cropland covered with vegetation. Also, another way to reduce water pollution from a nonpoint source is reduce the amount of fertilizer that runs off into surface waters and leaches into aquifers by using slow-release fertilizer, using no fertilizer on steeply sloped land, and planting buffer zones of vegetation between cultivated fields and nearby surface waters. Ways to reduce water pollution from a point source are by the laws the U.S. has enforced. These laws are: having a certain amount of levels of key water pollutants and requires polluters to get permits limiting how much various pollutants they can discharge into aquatic systems. U.S. experience with reducing point-source water pollution: The number of Americans served by community water systems that met federal health standards increased from 79% to 94%. The percentage of U.S. stream lengths found to be fishable and swimmable increased from 36% to 60% of those tested. Annual wetlands losses decreased by 80%. Septic tank-underground tank for treating wastewater from a home in rural and suburban areas. bacteria in the tank decompose organic wastes, and the sludge settles to the bottom of the tank. Primary sewage treatment-a physical process that uses screens and a grit tank to remove large large floating objects and to allow solids such as sand and rock to settle out. Secondary sewage treatment-a biological process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, oxygen-demanding, and organic wastes Composting-toilet system- helps reduce sewage outputs and reduce water usage. John Todd- his purification process begins when sewage flows into a passive solar greenhouse or outdoor site containing rows of large open tanks populated by an increasingly complex series of organisms How wetlands can be used to treat sewage-the water can be made pure enough to drink by using ultraviolet light or by passing the water through an ozone generator Six ways to prevent and reduce water pollution- 1.) prevent groundwater contamination 2.) reduce nonpoint runoff 3.) reuse treated wastewater for irrigation 4.) find substitutes for toxic pollutants 5.) work with nature to treat sewage 6.) reduce air pollution Five things you can do to reduce water pollution- 1.) minimize your use of pesticides, especially near bodies of water 2.) prevent yard wastes from entering storm drains 3.) do not use water fresheners in toilets 4.) do not flush unwanted medicines down the toilet 5.) do not pour pesticides, paint, etc down the drain
What factors can limit green revolutions? Describe the use of energy in industrialized agriculture. Describe the advantages and disadvantages of genetically engineered foods. Explain how most industrialized food production systems reduce biodiversity and agrobiodiversity. Describe the advantages and disadvantages of industrialized meat production. Describe the advantages and disadvantages of aquaculture.
Without inorganic fertilizer, pesticides, and water green revolutions could not occur. Nonrenewable oil is used as energy in industrialized agriculture and fossil fuels are used to process and transport food When forests are cleared and grasslands are plowed up and replaced with croplands used to produce food or biofuels, biodiversity is reduced Agrobiodiversity is reduced because we are shrinking our world's genetic variety of animals and foods due to overproduction. Industrialized meat production increased meat production, reduces overgrazing, and yields higher profits. However, it also uses a large amount of energy, water, and creates pollution. Aquaculture produces a lot of seafood, but it can deplete populations of wild fish and can contaminate fish with toxins.
