BIOL 4451 Quiz: Exam 3 Study Guide Aquatics

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Georgia State University
BIOL 4451
Henry Edward Murray 

Exam 3 Study Guide Aquatics I. Chapter 10 A. Pesticides 1. Most common pesticides are defined broadly as being either insecticides, herbicides, or fungicides a. Pesticide means a lot of chemicals 2. Total use associated with these 3 categories in the US a. Herbicides: 70% b. Insecticides: 20% c. Fungicides: 10% 3. Until a few years ago the greatest use was insecticides, now herbicides is at the top 4. Chemical classification a. Chlorinated organics i. Example: DDT and its metabolites DDD and DDE • Dichloro-diphenyl-trichloroethane • Problems generally due to DDE  Use DDT, easier to say ii. Persistent iii. Resistant to biodegradation iv. Long “half-life” v. Bioaccumulate • Can also biomagnify b. Organophosphates i. Example: Parathion and related compounds are highly toxic to humans ii. Responsible for the majority of pesticide poisonings throughout the world iii. Biodegradable and non-persistent • Once sprayed, don’t stay very long iv. Do not bioaccumulate v. As a class, more toxic than chlorines • Reports of more deaths vi. Con • Toxic to humans while chorines are not • Organochlorines gave cancer to lab animals c. Carbamates i. Similar to mode of action as organophosphates ii. Biodegradable and non-persistent iii. Do not bioaccumulate • So does not biomagnify iv. Not a s toxic as phosphates d. Pyrethroids i. Synthetic derivative of the natural pyrethrin esters obtained from chrysanthemum flowers ii. Highly toxic to fish iii. A lot of people will plant chrysanthemum because it’s a natural pesticide iv. Relatively safe to use around the house but toxic to fish 5. Malaria control a. DDT (dichlorodiphenyltrichloroethane) i. Chlorinated organic b. Malathion i. Organic phosphate c. Issue with pesticide resistance i. Sri Lanka d. Malaria control on a worldwide basis, there are 2 pesticides that are typically used i. Even though US does use DDT, DDT is still used elsewhere for mosquito control ii. Resistant to DDT (areas in Sri Lanka) so switch to malathion • Both are different classifications iii. Organizations are looking at other pesticides to use for malaria control 6. Mode of action a. Organophosphates and carbamates i. Inhibit cholinesterase ii. Both inhibit cholinesterase but the difference is how each ties up the enzyme b. Pyrethroids i. Sodium channel primary target site ii. Effects sodium channel c. Chlorinated organics i. Nervous system primary target site ii. Ex. DDT iii. Impacts the nervous system 7. Potential sources leading water contamination a. Spills and other accidents i. Most of the time, spills are intentional, so not always an accident b. Back-siphoning i. Problem if you have wells or well heads with a hose hooked up to and check valves that are connected to the well head are not working properly • Well head to tank and then turn it off • Back siphoning: sucked up garbage into the hose and into the well head c. Abandoned wells i. Problem throughout the US particularly in rural areas ii. Moved somewhere and didn’t close the well • Now you have a direct conduit that flows into the well and contaminate the ground water d. Poorly constructed wells i. Problem prior to the 1980s: contaminated water in the groundwater ii. EPA came out with guidelines are constructing wells after 1980s • To prevent contamination e. Seismographic activity i. Send trucks out and drill down and put a charge in the ground ii. Explode it iii. Read on a seismograph to see where oil is iv. Issue • All these holes in the ground • Conduit from surface to water table v. Companies self-regulate on filling the holes B. Pesticide properties affecting movement 1. The physical-chemical properties of a pesticide responsible for its potential to leach into groundwater or runoff into surface water are its mobility and persistence 2. Pesticide mobility in soil a. Inversely related to its degree of sorption to (or within) soil surfaces b. The definitive characteristic is its ability to remain dissolved in soil water as opposed to being sorbed on or in solid soil particles i. This property is usually described by a partition coefficient, K (L/kg) D • Looking at is the concentration in the soil divided by the concentration in the water • The concentration in the soil is measured in microgram/kg • Water is measured in microgram/L • So micrograms cancel out and produce L/kg ii. Sorbs won’t be mobile in clay c. Apparatus for the determination of soil sorption behavior i. Use Teflon or maybe glass ii. Have the soil sample • In a region where interested in • Soil vary from region to region iii. Have the pesticide in question iv. Easiest way to do this is take the pesticide and radiolabel it • Can read the radioactivity  Given in counts: can relate counts to concentration v. Shake for 24 – 48 hours vi. Centrifuge vii. At the end of that period, would take the radiolabeled compound and measure where does the pesticide like to be: water or soil? viii. Develop a D d. K ratio for a pesticide is not constant from one soil to another D e. Variance in K iD associated with many soil properties i. Soil pH ii. Particle size distribution iii. Type of clay present • How much clay is present?  Clay can grab hold of a lot of things because of its charge iv. Soil organic matter content • Most important 3. Pesticide persistence in soil a. Persistence has been described simply by “half-life” of the compound --- misleading concept i. Pesticides do not exhibit true exponential decay ii. Even though we use half life looking at degradation or breakdown b. Different processes are responsible for the dissipation of pesticides in soil i. Volatilization ii. Photolysis iii. Hydrolysis iv. Biological degradation v. Oxidation vi. Each process is affected by soil properties and environmental factors • pH • Temperature • Moisture • Soil variability C. Environmental factors affecting movement 1. Properties of soil most often associated with susceptibility to leaching a. Low organic matter content b. Low field (moisture holding) capacity i. Talking about moisture holding capacity ii. Term that hydrolysis might use c. High permeability D. An excellent and proven mathematical concept, Darcy’s Law, is available for the description of water flow through saturated soils 1. Concept that you need to look up and google a. Equation with it b. Used to describe water flow though saturated soils i. Saturated soils when compared to unsaturated II. Chapter 11 A. Thermal pollution and power plants 1. Heat effects a. Every life form has a temperature tolerance range i. Have a particular life stage that is more sensitive • with aquatic, the life stage would be the hatching eggs • eggs are sensitive to thermal pollution b. Increasing temperature variability i. Impact the species in the water in a number of ways ii. When you have extreme temperature you see a population shift of the types of organisms present iii. Fish that are exposed have got to be able to deal with temperature extremes iv. What’s happening: the natural system is being kept off balance c. Acceleration of metabolic reactions i. Q10 law • Acceleration of metabolic reactions • With every 10C rise in temperature, there’s a doubling of the metabolic/respiratory rate to a point where things are killed • As you increase the temperature every 10C will result in doubling d. Disrupts and changes the chemistry of the abiotic environment i. Heat also affects non-living ii. Changes in the chemistry of the abiotic environment e. Thermal pollution in power plants i. Most of the power plants that release thermal is nuclear B. Thermal pollution 1. Major ways heat can affect aquatic ecosystems: a. Gases dissolve more readily in cold water than in warm water i. As temperature increases the amount of dissolved oxygen is going to decrease b. Higher temperature accelerates metabolism and decomposition i. Depletion in dissolved oxygen ii. Takes oxygen to carry out the decomposition c. Stratification can occur when hot water is discharged into a cooler body of water i. If you have a system that is pretty well mixed and the same temperature and its relatively cold, dump hot water on top of it, now stratify the system ii. Hot is less dense than cold so will sit on top iii. Create artificial stratification 2. Other direct effects: a. May interfere with normal fish migration and spawning i. Temperature is a major key to spawning and reproduction for many species • When fish lay their eggs (late spring) at the same time that all of this is occurring naturally, adequate supply of food (more insects) • In the middle of winter, we are increasing the temperature to what is would be in the summer and now we have egg laying forced on the fish because they go by temperature  Have all these young fish hatching with no insects to eat  Mess up the natural cycle C. Water quality criteria 1. National Technical Advisory Committee: 1968 a. The maximum recommended temperature elevations ranged from 0.8 – 2.8°C D. Effluent from a nuclear power plant 1. We have 18°C water that is drawn into the nuclear reactor that is used for cooling water 2. Eventually after it goes into the system, goes back out and the temperature being discharged is 27°C 3. We jump from 18 to 27°C a. Which is above the recommended level 4. Have an initial impact where the water is discharged and going to affect water downstream before it finally recovers goes back to 18°C a. Have a whole zone impacted E. Toxic effects of effluent waters on biota 1. In addition to kills directly from temperature stress, other factors can affect the organisms: a. Chlorine discharge: used as an anti-fouling agent in the heat exchangers F. Siting of power plants 1. For convenience and economics many power plants are located on estuaries a. From the standpoint of water pollution – estuaries are just about the last place where one would want to locate a power plant b. Most power plants are pretty big c. The equipment that goes into building one of these is very heavy i. So often times the material comes in on barges (ships canals) • Not a god thing • Because a lot of plants are located on estuaries • From a standpoint of water pollution estuaries are about the last place you want to put a power plant • But that’s where we see a lot of plants located G. Internal plant kills 1. Screen impingements a. What happens here in the intake from stream to reactor there’s a screen to prevent trash b. What can result are screen impingements i. Smaller weaker fish are trapped on screen and flattened c. Problem with smaller fish, bigger ones can escape 2. Inner plant kills a. Fish larvae b. Planktonic organisms c. Organisms that go through the intake d. Some planktonic are killed, but some, especially blue and green algae, are stimulated by higher temperatures H. Possible beneficial uses of thermal discharges 1. Cogeneration power plants a. Cogeneration facilities i. Not only are they generating power but also heat hot water • When water comes in as a coolant, go to heat rods, steam produced to turn generators for electricity b. District heating/cooling (DHC) i. Provide both very cold and hot water to a small community as a result to the activity I. Case study- the Florida power and light power plant at turkey point 1. Characteristics of the bay a. Circulation is poor b. Shallow c. Naturally thermally stressed during summer months 2. Put a power plant here with poor conditions 3. Correctives a. Cooling systems i. Closed system • Recycle the water but still have some sort of cooling pond ii. Open or once through • Water sucked in and discharged • Not best option unless plant has a cooling farm b. Cooling towers i. Natural draft tower • Coils within the tower, pumped up through • The coils would cool the water • Natural draft of the air going up to the tower ii. Mechanical draft tower • Similar to nature • Water going through the coil but have fans going through instead of wind c. Expensive III. Chapter 12 A. Metals 1. Principal ways in which metals are introduced to aquatic systems a. Weathering of soils and rocks i. Natural leeching b. Volcanic eruptions i. A lot of metals in the atmosphere: atmospheric transport c. Human activities i. Mining • Strip mining ii. Industrial processes • Steel B. Behavior of metals in water 1. Water with a neutral or basic pH a. Absorb rapidly to particulate matter or assimilated (taken up) by living organisms b. Metal contamination occurs in surface waters c. Metals have a tendency to absorb onto particulate matter i. So if metals are absorbed, then living organisms will consume them and metals in their system 2. Water with an acidic pH a. Metals dissolve in the water b. Metals stay dissolved in water and don’t readily absorb to living things c. Problem i. Metal analysis of water, typically a water analysis involves sediments and fish tissue, fish tissue and sediment are analyzed to give indication of the water ii. Easy to collect iii. Problem is if the water is acidic get a misleading concentration iv. The greater the concentration would typically in the water which is often not analyzed for metals because it teaks so much of it 3. The point: the pH of the water can affect the behavior of metals C. Question of biological magnification 1. The Department of Land and Natural Resources (DLNR) of Hawaii and Researchers Montague and Montague reported high concentrations of mercury in tuna, swordfish, marlin, shark a. These are all top-level carnivores b. Reported high concentrations of mercury in tuna, swordfish, marlin, and shark i. Important because upper carnivores ii. Concentrations are higher as compared to the lower level as compared to the food chain iii. Mercury concentrations increase as you go up iv. Would not want to consume a lot of the upper level carnivorous fish v. The problem • Pregnant women • For sure in the US, we consume a lot of tuna, but much of it is canned  A lot of canned tuna is smaller of the tuna, so less mercury  If pregnant need to watch fish consumption particularly with salt water fish vi. Mercury is a neurotoxin D. Mercury 1. Production and use in the US a. Manufacture of batteries b. Production of chlorine and sodium hydroxide 2. Used primarily for manufacture of batteries 3. Used in production of chlorine and sodium hydroxide 4. Used to see mercury in thermometers but those were done away with 5. Toxicology of mercury a. Depends on the chemical form of Hg i. Inorganic form • Including metallic mercury such as Hg used in thermometers, and various salts of mercury • At room temperature metallic Hg may occur either as a gas (vapor) or as a liquid • CDC at least 6 times a year where someone has brought home a jar of mercury and pour it on the floor  Silver beads are fun to watch  Kids find it great to play with but disastrous • Room temperature: liquid mercury (the silver stuff) exists both as a liquid and a gas  See it as a liquid but at the same time it is vaporizing into the air and you are breathing it in • Mercury spill  Evacuate  Hazmat crew to clean everything • Back in the 1700s in France, using vats of mercury to treat hats. Intoxicated with mercury and known as mad hatter syndrome (like in Alice in Wonderland) ii. Organic form • Example: methyl Hg  Most common and most dangerous  Major effect is CNS  Major effect is the central nervous system  Minamata Bay Japan  Disaster that occurred there a number of years ago  Still after effects  Waste water mixed with mercury  Bioaccumulated in fish and shellfish in the bay  Eaten by people living around the bay: gave rise to Minamata disease  Minamata disease is a neurological syndrome caused by severe mercury poisoning  Biomagnification of mercury in Minamata Bay Japan  Plastics factory that was releasing inorganic and organic mercury in the water  Into a creek or small stream that led to Minamata Bay  The mercury in the discharge came out, got into the sediments and under anaerobic conditions it transformed the mercury to methyl mercury  Methyl mercury was taken up into the food chain by the algae and then fish  First incident they began to see was where cats would eat the fish and the cats and the cats after a while would jump into the water (cats don’t do that)  Lots of birth defects that occurred when people at these fish  Still after affects and a lot of litigation regarding the plastics factory  First indication of the danger of mercury in an aquatic system E. Cadmium 1. Production and use in the US a. Primarily in Ni-Cd batteries b. Electroplating c. Don’t know its role in metabolism in living animals 2. Toxicology of cadmium a. Of major concern with Cd poisoning is the fact that ingested Cd has a “half-life” of about 16 – 33 years in the human body i. If ingest cadmium looking at a half life of about 16 – 33 years in the human body ii. Mercury which is about 70 days for a half life iii. When comparing cadmium is more of a problem b. Once absorbed by the body concentrates in kidneys and liver i. Due to a low molecular weight protein called thionein ii. If combines with thionein have metal thionen complex c. Post WWII i. Physician that went to a village in Japan and people ate primarily rice ii. Rural area and rice had to be irrigated iii. Water came from mining area • Irrigation water contaminated with cadmium d. Kidney damage occurs when the amount of Cd in the kidneys overwhelms the ability of the kidneys to bind the cadmium in metallothionein e. Unbound cadmium damages the renal tubules, which lose their ability to reabsorb proteins i. If unbound cadmium = damage to internal organs f. Osteomalacia (softening of the bones) and osteoporosis – “itai – itai” i. Japan • Cadmium interfered with kidneys ability to diffuse material • Had a condition called osteomalacia and osteoporosis  “Itai-itai”  Ouch ouch  This was devastating to the people in that area  Believed to be related to cadmium  The problem is that we have never seen this anywhere else in the world  May be other factors associated with this condition ii. Itai is related to cadmium F. Lead 1. Production and use in the US a. Primary use in production of batteries i. Battery in car, exchange because large amount of lead ii. Ammunition • Used for shot guns • Duck and goose hunting: lead shot  Changed in the 1980s to use steel shot  When using lead shot ducks and geese pick up stuff some of it was lead shot b. Use of lead in ammunition (e.g. lead shot) i. Issue of lead shot ingestion by waterfowl c. Much of the information on lead comes from studying water fowl 2. Toxicology of lead a. General metabolic poison i. Also mercury ii. Lead and mercury are considered general metabolic poison b. From human health standpoint, greatest danger is to young children i. Both mental and physical development ii. Both Pb and Hg iii. Neurological damage that can occur • Once it does occur it’s permanent • Neurological and physical damage c. Over the last several years, a number of reports that show that there are still many people in the US that are exposed to lead in the drinking water i. Recent: Flint, Michigan ii. Dealing with plumping in homes that are old • The water companies are responsible for the water lines down the street • Don’t’ know which lines have lead in the pipes d. In the past problems with lead consumption: distills in the woods and make moon shine i. Use radiator coils that make lead G. Fluoride 1. Important issues a. Preventing dental caries among children b. Health issues 2. Hear issues about fluoride into the water 3. Atlanta adds fluoride into the water a. Other areas do not because water has it naturally 4. The main reason that fluoride is added to the water is to prevent dental decay in children a. Add the fluoride, have fluoride in the water during the teeth forming years b. Among children who are less than 8 years old i. After 8 already lost some teeth and permanent teeth coming in ii. Supposedly used to help prevent decay 5. 2 sides a. Anti b. Pro c. Both groups are from the American dental association 6. Part of the issue, if dealing with 0.7 – 1.2 mg/L it is said that is beneficial 7. Anticarcinogenic a. That means used to prevent tooth decay 8. Point is: if you have fluoride in the water who are under 8 supposed to be helpful 9. When above the range, problems a. Teeth that are modeled (brown spots on the teeth) b. At high levels can have skeletal cirrhosis: bones are deteriorating, crippling disease H. Water hardness 1. Effects a. Shorten the life of appliances that have water in them b. Formation of scale: scale fills up in tea pot, hot water tank, etc. i. Sometimes referred to as lime scale, lime scum 2. Definition a. The sum of the cations dissolved in water b. A measure of the amount of water that is required to cause soap to lather i. Shower where the water is hard water and you can’t get the soap to become sudsy, just slimy c. A lot of calcium and magnesium present i. Soft water does not 3. Principal cations a. Calcium and magnesium i. Cause water hardness 4. United States Geological Survey (USGS) a. Soft: 0 – 60 b. Moderately hard: 61 – 120 c. Hard: 121 – 180 d. Very hard: greater than 180 e. Hardness reported in mg/L as calcium carbonate (CaCO3) 5. In general, hard water produced where there is a lot of limestone present 6. If the water hardness is very low (closer to soft), can be corrosive, ions added to bring up to moderately hard 7. If the water harness is less than 50: corrosive 8. More than 180: scale formation IV. Chapter 13 A. Oil production 1. Oil discharges to the marine environment a. Oil production i. Not producing any oil, but oil incidences • Oil spilling • BP in the Gulf of Mexico b. Natural sources i. Marine seeps: natural seep where the subsurface has oil in it • Leaks in to the surface • California, Alaska have major seeps • Soil going into the water by natural means ii. Sediment erosion c. Offshore production i. Drilling for oil that is already there ii. Accidents that occur iii. Related to BP d. Marine transportation i. Tanker operations: Alaska ii. Accidents that occur periodically e. Municipal and industrial wastes and runoff i. Even though have major accidents, it has been estimated that if look at waste and runoff, majority of the oil come from this source • Continual source  Constant runoff and hydrocarbons that enter surface waters B. Composition of oil 1. Crude oil- major hydrocarbons a. Components that need to be concerned about i. Alkanes • Alphatic compounds: methane, propane, ethane, etc. • Major portion of the crude oil • Straight chain ii. Cyclo-alkanes • Napthenes • Similar to alkanes except a chain is joined into a ring iii. Aromatics • Compounds that contain 1 or more benzene rings  Toluene, naptonene 2. Refined oil a. Contains i. Olefins • Found in refined • They are not found in crude • Ethalene, cyclohexene 3. Every oil that is taken from the ground, there is American Oil Institute that fingerprints oil a. Know where oil originates from based on components 4. Now if we look at the toxicology of oil a. 2 important factors that make oil very toxic to water fowl C. Toxicology of oil 1. Oiling a. Bird covered with oil (usually alkanes, water insoluble) b. Once coated, can drown because heavy and cannot maintain proper temperature 2. Ingestion a. Bird is naturally going to pick the oil to clean themselves and in the process they swallow it b. When ingested, going to disrupt the organisms’ metabolism i. Adverse affect 3. Most toxic to least toxic a. Aromatics > cycloalkanes > olefins > alkanes b. Most toxic: aromatics D. The main physical, chemical, and biological processes governing the fate of a polluting oil 1. Let’s say we have an accident a. A spill b. First, the formation of surface slick i. Oil does not dissolve in water, it floats ii. What happens when it enters the water, depend properties of that particular oil and environmental factors • Temperature • Wind • Wave action • Current • All factors going to affect what happens to this surface slick iii. This slick is going to move and typically it will move at a rate 2 – 4% of the wind speed at the time iv. Key factor: when the oil is on the water, the weathering process begins • Most important weathering process is evaporation  There are other processes but evaporation is a key factor  When this happens the volatiles will go into the atmosphere  As the oil beings to evaporate the density increases  When it increases it begins to sink  Where it occurs depends on the detriment  When combining with sediment becomes chocolate mousse  Oil and water in sediment emulsion ✓ Once form an emulsion it is difficult to break ✓ Where the emulsion is formed, it’s going to impact the area o Near shore: devastating o More open ocean: not as bad  Precursor to relagic tar on the beach 2. Ixtoc a. Major oil collection production b. Way out 3. Buzzard Bay a. Not much oil, but he environment devastation was greater b. Not enough opportunity for it to be weathered because near the shore 4. Clean up operations a. Listed in book b. Offloading i. Pumping of oil for collection c. Burning d. Chemical dispersion i. Oil is broken up into droplets e. Mechanical containment i. Collection vessels where the oil cannot go past f. Bioremediation g. Sinking h. Look up method that is not recommended by the EPA: sinking not recommended 5. Where spills occur have an environment impact 6. Compare ixtoc with buzzard bay B. Cleanup 1. Offloading 2. Burning 3. Chemical dispersal 4. Mechanical containment and cleanup 5. Sinking a. Sinking not recommended 6. Bioremediation V. Chapter 14 A. Radiation 1. The term radiation refers to “Energy traveling through space. Some types of radiation associated with radioactivity are alpha and beta particles and gamma and X rays.” 2. Radiation also includes neutrons, which are uncharged 3. Concentrating on ion radiation (IR), alpha, beta, gamma B. Atomic bomb development 1. Manhattan project: the U.S. government top-secret program, from 1942 to 1946, to produce an atomic bomb for use during WWII. To accomplish this goal several secret lab, overseen by the Army, were established. Primary among these were the Metallurgical Lab in Chicago (now known as Argonne National Lab-East), for reactor research; Clinton Engineer Works (now known as Oak Ridge National Lab), for isotope separation; Hanford Reservation (Hanford Site), for plutonium production; and bombs (Trinity Test, Fat Man, and Little Boy) were produced at a cost of over $2 billion. At its peak, the Manhattan project employed over 300,000 people. a. Top secret program to produce the atomic bomb b. When this program began, had various labs throughout the US assigned for specific tasks i. One lab did not know what the other was doing C. Ionizing radiation 1. Radiation that “has enough energy to remove tightly bound electrons from atoms, thus creating ions.” 2. Its properties are used to generate electric power, to kill cancer cells, and in many manufacturing processes 3. Enough radiation to remove electrons from atoms and creating ions 4. Used to generate electric power, kill cancer, manufacturing processes (food production, food preservation) 5. Alpha particles a. Positive charged particle emitted during decay of certain radioactive element b. Least penetrating of the 3 common forms of ionizing radiation (alpha, beta, gamma) c. Greatest threat to health when particles such as plutonium, radium, or radon are inhaled, ingested with food or water d. Can cause intense damage within a localized area i. Greatest threat when inhale, and in lung: intense damage in a localized area ii. Do a lot of damage if particularly inhaled 6. Beta particles a. A negatively charged particle b. Easily stopped by a thin sheet of metal i. Wood or metal can stop beta particles c. Exposure to high levels of beta radiation can cause skin burns d. Several beta-emitters (strontium-91, iodine-131) are chemically similar to naturally occurring bodily constituents i. Beta is chemically similar • Strontium 90 will displace calcium • Iodine 131 which will hone into the thyroid e. Both alpha and beta would be considered dangerous primarily as internal emitters i. Once they are in the body, they emit radiation ii. Both of them can cause damage to surrounding tissue 7. Gamma radiation a. High-energy short-wavelength electromagnetic radiation emitted by a nucleus i. Alpha and beta are particles, gamma is not a particle but a wavelength b. Highly penetrating and are best shielded by dense materials like lead and thick concrete i. Best way to shield is by lead or thick cement c. Similar to X-rays (gamma rays and x-rays behave the same in the biologic effects) i. Gamma and x rays are similar D. Radiation exposure 1. Natural sources a. Cosmic rays i. Radiation from outer space • Exposed to at some degree • Exposed to it more if live in higher elevation b. Radiation from geologic formations that contain radioactive elements (radioelements) such as uranium, from which radon gas is formed as a decay product i. Mineral springs ii. Formations that contain radioactive elements iii. If uranium is present there will be radon gas iv. Places with hot water springs • Visit to believe to be healthy • It’s been known that these springs are high in radon and uranium • Somewhat radioactive E. More than half the dose of natural radiation received by the American public comes from daughters of Rn-222 1. Polonium daughters 2. Damage that comes from radon is primarily due to polonium F. Radiation exposure 1. Human generated sources a. Medical applications i. X-rays ii. Therapy: radio isotopes • Radio isotopes down the sink are a problem at treatment plants b. Nuclear weapons fallout i. 1950s and early 60s • Race for nuclear power • Bombs that were being exploded in the Pacific • A lot of fallout at the time • St-90 and iodine • Cows eat grass that contain this fallout that produce milk that we drink • Fallout get into the food chain c. Nuclear power plant emissions i. Some level of emissions ii. Emission is generally from neutron activation products • Formed during the process of evaporation • Stable radionuclide produced  Low concentration d. Consumer products i. Amersium in smoke detectors ii. Pigments: uranium used for pigments in pottery (bright red and yellow) iii. A lot of radiation out there, not aware of iv. Brazil nuts G. Medical uses of X-rays and radioisotopes are responsible for the largest amount of non- background radiation exposure 1. For the public, ignore this a. Medical use should be added into it when seeing what we are exposed to 2. Non background radiation exposure = medical 3. Source for background a. Radon: natural H. Radiation and nuclear power generation (nuclear fuel cycle) 1. Mining a. Takes place in mainly underground b. Concern to workers because there is a lot of radon present i. Studies on exposure to radon and radium • Increase in cancer among uranium workers that smoked and worked in mine vs. those that didn’t smoke 2. Milling a. Yellow cake (U3O8) i. Produced in beginning of milling process b. When uranium is first taken out of the ground primarily talking about U238 c. U238 is not what we want, want U235 d. Where public has greatest exposure to ionized radiation because waste piles i. Piles exposed to wind and rain and contaminate air and water 3. Enrichment a. Want U235, but most is U238 b. The gas is forced through the ceramic filters that have a specific size that will 235 and 238 is held back c. In that process have a buildup of 235 d. When taken out of the ground we’re looking about 0.7% 235 and the rest 238 i. Need to get percentage up to 2 – 4% ii. Purpose of the gas going through the filters to build up the concentration e. If use for military production then 235 is greater than 90%, but for commercial looking at 2 – 4% f. Reason why we need 235, is that 235 is what maintains the chain reaction in the nuclear reactor i. Heat rods, water to create steam 4. Fuel fabrication a. Taken the uranium and about to fabricate the fuel b. Once we have removed the 235 from 238, what we now have is depleted uranium (DU) c. Use for DU i. Does not have the radioactivity but it’s very dense ii. Use for shielding and armor piercing projectiles • Military use • Gulf War: stuff hit uranium, would be a reaction and then radiation: adverse health affects d. Fuel fabrication i. Uranium dioxide put into fuel rods ii. Contain the fuel that will now go to the nuclear power plant • Lowered into a reactor, reactor core • Fuel rods surrounded by water iii. Main concern is major accidents • Typically from a core meltdown  Occurs if the coolant (water) leaks out and the rods overheat and have a melt down of the reactor  If the circulation of the water ceases of exists = loss of coolant accident  Chernobyl 5. Power production a. Steam turns the turbines and power is produced 6. Reprocessing a. Issue: fuel rods only last about a year b. Spent fuel rods: have a buildup of a lot of material within the fuel rods that will not maintain the chain reaction, have waste products, buildup of plutonium, buildup of uranium 92 c. Have to replace the fuel rods with new ones d. Rods removed and have to be put somewhere e. Been done in France and UK f. US shyed away from reprocessing g. Right now being stored in pools that are adjacent to the reactor h. Fuel rods continue to give off heat i. Typically due to Cs-137 and Sr-90 7. Waste disposal 8. Nuclear fuel cycle a. Mining and milling operation where the ore is taken from the ground in open or enclosed b. Then goes to the enrichment process after mining and milling c. Then fabrication of fuel assembly d. Then reactor e. After the reactor the rest of this is kina nebulus i. Have a spit fuel ii. Some areas the spit fuel is repress
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