Pollution Flashcards
What is smoke?
Smoke is made up of particles produced from the incomplete combustion of carbon-based materials.
What are the main causes of smoke?
Combustion of coal, diesel cars, crop waste, wood fuel.
Why does particle size matter?
PM1/ Smaller particles will stay in the atmosphere for longer and are more easily inhaled.
What are the toxic chemicals mostly found in smoke?
Fluorides, aluminium, lead, acids and organic compounds.
What are some effects of smoke pollution on humans?
Respiratory disease like asthma, bronchitis and lung cancer.
Chemicals in the smoke may also be carcinogenetic.
What are some effects of smoke pollution on living organisms?
Reduced photosynthesis.
There may be some substances in the smoke that are toxic to plants e.g., heavy metals and acids.
What are some effects of smoke pollution on non-living objects?
Smoke solvents can cause damage to buildings due to the chemicals and acids they contain, smoke can also make buildings appear dirty which is expensive to clean.
What is smog?
Smoke + Fog = Smog
How is fog formed?
When moist air cools until it reaches a dew point and water vapour condenses as airborne droplets of water.
How is smog formed?
The incomplete combustion of fossil fuels releases coarse particles which become suspended in the air.
The ash from forest fires or the burning of wood fuels.
What is the London smog of 1952?
London was positioned in a valley and in December 1952, anticyclonic weather conditions provided clear skies and low wind velocities. This allowed a temperature inversion to form and atmospheric pollutant levels rose as it couldn’t escape. Within a week 12,000 people had died and another 8,000 followed during the month.
How do temperature inversions form?
When warm pollutant gases are released at ground level they are less dense and more buoyant, so they rise and disperse.
As they rise they cool down, but the surrounding air is already cooler so they will continue to rise and disperse.
Basically warm air forming a blanket over cold air, pollutants released will be trapped in the cold air and their concentrations rise.
What is photochemical smog?
Produced in a temperature inversion in warm conditions under UV light in which reactions between primary pollutants, NOx and hydrocarbons, and secondary pollutants, Ozone, produce high concentrations of PANs.
No fog present
What are PANs/ Peroxyacetyl nitrates
A secondary pollutant in photochemical smog’s caused by the reaction of tropospheric ozone, nitrogen oxides and unburnt hydrocarbons .
What are the general methods of controlling air pollution?
Legalisation, Energy conservation and fuel substitution.
Legalisation Examples
Clean air act 1956, the restricted use of fossil fuels that produce smoke in large urban areas of the UK.
The Montreal Protocol, an international agreement to phase out the use of ozone-depleting substances.
How can energy conservation methods be used to reduce atmospheric pollutants?
-Use energy efficient appliances
-Improving insulation
-Reusing industrial energy
-Using public transport
What are some sources of pollution?
-Toxic Leachate
-Chlorofluorocarbons,(Aerosol, fridges)
-Mining, (dust and noise)
-Sewage into water sources
How does density affect the level of harm?
Dense materials don’t get carried very far and stay close to the source at high concentrations.
How does persistence affect the level of harm?
More persistent materials will stay in the environment for longer periods of time and cause more harm, e.g. CFCs, DDT.
How does toxicity affect the level of harm?
-The more toxic a material is the greater the damage.
-Most toxins damage proteins by enzyme inhibition.
How does specificity affect the level of harm?
The more specific a pollutant is the less harm it will cause.
-Pyrethroid insecticide is specific to pests like fleas however it is toxic to fish.
How does reactivity affect the level of harm?
Reactivity can affect the severity of the pollution caused. High reactivity will cause more damage.
-CFCs have a low reactivity, however they breakdown into chlorine and damage the ozone.
How does solubility affect the level of harm?
High solubility means they will be easily dispersed in water, so pollutants can travel further, e.g. nitrates.
-Lipids are insoluble in water.
What is bioaccumulation?
The process by which the amount of a substance within an organism increases. The body cannot excrete these substances so they stay forever.
What is biomagnification?
Where the concentration of a substance increases as it goes through the food chain, e.g. heavy metals.
-Fish-Seals-Polar bears
What is synergism?
Where the effects of two or more pollutants react to cause a greater effect than their individual effect.
-Ozone damages the leaf cuticles which enables sulfur dioxide to cause more damage to newly exposed cells.
What are the gonadic effects of mutagenic action?
A mutation in an egg or sperm cell which may cause a birth abnormality in the offspring produced.
What the somatic effects of mutagenic action?
A mutation in a body cell can make it behave abnormally, as the damaged DNA cannot control normal cell function, e.g. cancer where uncontrolled cell division produces a tumour.
What is carcinogenic action?
Mutagens that cause cancer.
-Asbestos
-DDT
-Cadmium
What is teratogenic action?
Causes birth abnormalities by preventing normal gene expressions, they inhibit the function of proteins and enzymes.
-THESE ARE NOT INHERITED BY FUTURE GENERATIONS.
What is adsorption?
When some pollutants can become attached to the surface of some materials such as soil particles, clay particles
-Adsorption may immobilise the pollutant and stop it causing problems.
What is mobility?
The ability of a pollutant to move in the environment depends on their other properties. Pollutants that are more mobile are likely to travel greater distances and affect larger areas.
-CFCs
-SO2, acid rain
What is the diffuse source of pollution?
This is where the pollution cannot be traced back to a single source, e.g. cars or pesticides in gardens.
What is the fixed point source of pollution?
This is where the source of pollution can be identified and can be tracked back to a single point.
What is Critical Pathway Analysis/CPA?
It is used to predict the movement of potential pollutants in the environment to assess the severity and location of pollution events.
-Is it mainly used to monitor the dispersal of radioactive waste.
What is Critical Group Monitoring/CGM?
A method to assess the risk of public exposure to pollutants. It labels people as the ‘critical group’ if their risk is high.
How do air and water currents affect pollution?
The direction and velocity of the currents will affect how far a pollutant is dispersed and how much it is diluted.
What happens to pollutants in higher temperatures?
Degradable pollutants will breakdown more rapidly, this will increase deoxygenation.
How mobile is lead dust?
It has high density so not very mobile, it will settle near the source
How does the oxygen level affect pollutants?
More oxygen means more aerobic decomposition of sewage.
More oxidation of sulfide ores producing SO2.
How does pH affect pollutants?
Heavy metals, like lead become more mobile in acidic conditions so will be dispersed more.
What do NOx and hydrocarbons form when they react together?
PANs
Where are temp inversions most likely to form?
Valleys: cold dense air collects here
Low wind velocity: wind currents are not blowing the warm layer away.
What does adsorption do to pollutants?
Pollutants, like aluminium and lead can adsorb onto clay particles and become immobilised this stops them causing problems.
What can the emissions location affect? Give examples
Affects the severity of pollution.
Marine discharges where the pollutant will be diluted and dispersed.
Pollutants released onto permeable rock above aquifers.
How can the time of emissions being released be controlled?
Releasing emissions when the tide is going out will mean they will be carried out and dispersed.
Releasing emissions when the tide is coming in means the pollutants will be bought in and not dispersed.
When released in a temp inversion they wont disperse.
What is the polluter pays principle?
Where the organisation/person is held responsible to prevent pollution.
What is the precautionary principle?
Where it is assumed the emission will cause pollution unless research confirms it wont.
How can smoke pollution be controlled?
Legalisation
Use natural gas/electricity
Diesel particulate filters in diesel cars
How does an electrostatic precipitator work?
Used in coal fired power stations.
A chamber with electrically charged wires, the particles in smoke are attracted to the wires they accumulate and fall as ‘fly ash’.
How do cyclone separators work?
Like a vacuum cleaner.
Effluent gases forced to spin in a cylindrical chamber, this throws the suspended particles to the outer surface where they fall.
Clean gases are produced.
How do scrubbers work?
Uses water sprays to wash out suspended solids and dissolves soluble gaseous pollutants.
How do bag filters work?
Smoke particles from effluent gases get trapped on a fabric filter.
What do turbo chargers do in diesel engines?
They allow more oxygen to pass into the engine so combustion is more efficient, less smoke is produced.
What kind of pollutant is NOx and how is it formed?
A primary pollutants, it forms when nitrogen and oxygen react together in high temps and pressure in exhausts or power stations
Where do hydrocarbons come from?
Unburnt fuel in engine exhaust gases
Oil spills
What is the affect of NOx on humans?
Colds, flu, bronchitis
Makes asthma worse
What is the affect of PANs on humans?
Eye irritation
Asthma
Emphysema
Increased heart attacks
What is the affect of O3 on humans?
Asthma
Bronchitis
Heart disease
How can NOx be controlled?
Platinum or palladium catalytic convertors in engines.
The NOx is reformed into nitrogen and oxygen.
How can unburnt hydrocarbons be controlled?
Catalytic convertors oxidise hydrocarbons to CO2 and H20
Vapours at filling stations collected and returned to fuel tank
Why is it good for primary pollutants to be controlled?
If theyre controlled no secondary pollutants will be produced.
What gases are involved in acid rain?
SO2
NOx
Where does SO2 come from?
Combustion of coal containing sulphur or smelting sulphide ores.
What is the effect of acid rain on non-living things?
Corrosion of metal
Damage to limestone buildings as the acids dissolve it
What are the direct effects of acid rain on living organisms?
Denatures proteins in cell membranes
Inhibits enzyme action
Damage to root hairs, stomata, fish eggs and gills.
Invertebrates with calcium exoskeletons die as the acid dissolves calcium.
What are the indirect effects of acid rain on living organsisms?
Heavy metals becoming more soluble in acidic conditions.
Acidic solutions from acid rain percolating through the soil and leaching metals ions, important plant nutrients are lost.
Lead becoming mobilised, can be leached into water bodies.
What is natural gas desulfurisation?
Removing hydrogen sulfide by dissolving in an amine solution, this prevents SO2 being produced when burnt.
What is dry-flue gas desulfurisation?
Flue gases passed through crushed calcium carbonate.
Solid calcium sulfur is produced, SO2 is not produced when burnt.
What is wet-flue gas desulfurisation?
Flue gases bubbled through a sodium sulfite solution, stops SO2 being produced when burnt.
What is coal desulfurisation?
Iron pyrites removed by washing and streaming, when burnt no SO2 is produced.
How is NOx controlled?
Catalytic convertors
Urea sprays
Low temp combustion, less NOx is produced
How can tropospheric ozone be controlled?
Reducing NOx which contributes to it forming.
What are the effects of carbon monoxide on humans?
It binds to the iron in haemoglobin in red blood cells so prevents oxygen being carried around the body.
Possible brain damage
How is carbon monoxide produced?
The incomplete combustion of hydrocarbons.
How can CO be controlled?
Catalytic convertors
What factors affect degradation?
Higher temps means faster
High dissolved oxygen conc means faster
High lvls of sunlight/UV can cause photochemical degradation.
Where does hot effluent water come from?
Steam turbine power stations
What is the effect of hot effluent water in the environment?
Increased deoxygenation
Denaturing proteins
Increased metabolic rate so less growth
Increased egg development
How is hot effluent water controlled?
Temperature reduction by using cooling towers
How do cooling towers work?
The hot effluent water is sprayed at the bottom of the tower and air inside absorbs the heat.
The hot air rises into the atmosphere, cooler water is produced.
Dissolved oxygen lvls are also increased
How is oil pollution caused?
Waste engine lubricating oil
Accidents like oil spills, oil tanker leaks, pipe leaks, oil rig accidents.
Oil exploration, where the drills used need to be lubricated with oil
What are some effects of oil pollution?
Components of oil are toxic, benzene.
Strong smell of oil so dolphins cannot smell food.
Oil forms a thin layer on the surface of water, this can stop photosynthesis and reduced oxygen lvls.
Birds being caught in the oil, their feathers will stick together and lose their thermal properties so hypothermia occurs, they can also drown.
How can oil pollution be controlled?
Better navigation systems so no crashes.
Better routes, so if an accident occurs the oil isnt washed away by currents.
Reusing lubrication oil.
Double hull, any damage wont reach the 1st hull and release oil.
Twin engines
Separate oil and ballast tanks, when ballast water is released into ocean it wont hold oil residue.
Bund walls
What are some treatments of oil spills?
Polymerisation to make oil more solid and easier to clean.
Booms to restrict the movement of floating oil.
Using adsorbent materials
Detergents to produce oil emulsions which can be broken down by bacteria.
Bioremediation using bacteria to breakdown oil residue.
Oil on beaches washed off by steam sprays removing it from sensitive habitats.
What are the properties of pesticides that cause pollution?
Specificity
Persistence
Bioaccumulation, liposoluble pesticides
Biomagnification
Mobility
What does MDNF mean?
Maximum dose never fatal, the highest dose that can be used without killing any organisms
What does MDAF mean?
Minimum dose always fatal, the lowest dose that will kill every member of a population
What are the direct effects of pesticide pollution?
Inhibit metabolic processes
DDT in low doses caused thin egg shells
DDT in high doses caused sterility
What are the indirect effects of pesticide pollution?
Affects inter-dependent species relationships, because for example a food source, pollinators or seed dispersal have been lost.
Other species could be more common do to less predators and competition
What are the properties of organochlorides and give an example.
DDT is an organochloride.
High toxicity to insects, low toxicity to mammals.
High persistence
High liposolubility
Low water solubility
What were the environmental impacts of the organochloride DDT?
Death of bees, butterflies and beetles.
High persistence/High lipsolubility allowed it to bioaccumulate and biomagnify.
What are the properties of organophosphates?
Low persistence
Low liposolubility
High mammalian toxicity
Exposure to small amounts over long periods of time causes depression, ADHD, cancer, Alzheimers.
What are organophosphate pesticides, give examples.
Neurotoxins, they inactive enzymes which causes nerve damage.
Malathion and Parathion
What are the properties of pyrethroids?
High insect toxicity
Low mammal toxicity
Low persistence
Toxic to fish
What are the properties of neonicotinoids?
High insect toxicity, especially bees
Low vertebrate toxicity as they cannot pass the blood brain barrier.
Water soluble
Persistent
How do neonicotinoids affect bees?
They have neurotoxin effects which reduces the ability of bees to navigate and increasing risk of diseases.
What pesticides are banned or are controlled?
Organochlorides banned, but DDT is allowed to kill mosquitoes.
Organophosphates allowed as an agricultural insecticide
What are some other methods to control pesticide pollution?
Use more specific pesticides like pyrethroids.
Use systemic pesticides
Apply on dry non windy days
Spray at night to stop impact on bees
What pollution causes eutrophication?
Inorganic pollutants like phosphates in sewage and nitrates from chemical fertilisers
What are the effects of nitrates on humans?
Nitrates converted to nitrites in the gut. Nitrites react with haemoglobin, less O2 carried in blood/ blue baby syndrome.
Nitrites possible carcinogen.
What are some methods to control nitrates?
Less nitrate fertiliser
Don’t plough in heavy rain
Use soluble fertilisers
Using waste manure away from water bodies to stop deoxygenation
Less cultivation of crops with high nitrogen needs.
Grow more legumes so less nitrate fertiliser is used.
What are some methods to control phosphates?
Add iron sulfate to sewage to remove phosphates
Add iron sulfur to reduce solubility of phosphates
What are the sources of organic nutrients?
Sewage
Manure
Paper mills
Food processing plants
What are the effects of organic nutrient pollution?
Deoxygenation of water by aerobic digestion.
Pathogens from sewage
What is the treatment process for organic wastes?
Pre-treatment: Screens or grit traps, remove objects and suspended particles.
Primary treatment: Primary sedimentation, faecal solids sink and are removed.
Secondary treatment: Aeration tanks, increases O2 for aerobic breakdown of organic matter left, then secondary sedimentation tanks.
Tertiary treatment: Killing bacteria by using UV/chlorine OR adding iron sulfate to remove phosphates.
How does sludge treatment work?
Sludge removed from sedimentation tanks contains pathogens and smells so is left for microbes to anaerobically digest it. This kills pathogens and reduces the smell
After sludge is treated what happens to it?
Landfill
Agricultural fertiliser
Dispersed in the sea
How is acid mine drainage produced?
Chemical reactions between oxygen and sulfide ores in spoil heaps.
This produces oxides of sulfur which dissolve producing sulfuric acid.
What are the effects of acid mine drainage?
Low pH so makes heavy metals more soluble.
How can acid mine drainage be controlled?
Passing it through crushed lime to make solutions more alkaline
What are the properties of heavy metals?
They inhibit enzyme function, cause nerve damage.
Liposoluble so will bioaccumulate and biomagnify.
Soluble at low pHs
What are the affects of lead pollution on humans?
Acute exposure to large doses can cause brain damage or death.
Kidney/liver failure
How can lead pollution be controlled?
Store at high pH to stop solubility.
Lead water pipes replaced with copper.
Lead based paint replaced
Replacing lead fishing weight and shotgun pellets with tungsten.
What are the sources of mercury pollution?
Disposal of batteries, thermometers.
Combustion of coal
How is mercury exposed to humans?
Vapours absorbed through the lungs
Inorganic Mercury oxide absorbed through the gut
Organic mercury like methyl mercury absorbed very easily.
What damage can mercury do to humans?
Passes the blood brain barrier.
Liposoluble so bioaccumulate
Kidney damage
How can mercury pollution be controlled?
Replaced by alcohol in thermometers
Disposal at high pH
Removed from water by activated carbon filters
What are some sources of solid wastes?
Mining: spoil heaps, overburden
Domestic waste: Paper, appliances, plastic, clothing
Industrial wastes
What are the waste management problems?
The amount of waste produced
Expense to collect the wastes
Mixture of wastes collected, domestic and garden wastes.
What are the properties of solid wastes that affect the way they are disposed of?
Flammability
Degradability
Toxicity
Radioactivity
What do industries do to items to increase sales which increases wastes?
Built in obsolescence so items have a short lifespan, iphones.
Disposable products so they cannot be reused.
Over packaging, plastics
What are the advantages of disposing waste in landfill?
Simple as the waste doesn’t need to be treated.
Cheap
What are the disadvantages of landfill?
Resources dumped are lost.
Large areas of land used.
OM decays anaerobically producing methane.
Toxic leachate.
Habitats lost/damaged.
Noise pollution from transport.
Odours from wastes.
What are the features of good landfill management?
Separation of different wastes, like chemicals that will react.
Polymer liner to reduce toxic leachate.
Covering will soil to prevent pests
Collection and treatment of leachate
Collection of methane produced to be used as fuel.
Flammable materials separated.
Covering a complete site with impermeable material so water cannot percolate through.
How can spoil heaps be managed to prevent future problems?
Compacting them to reduce subsidence and increase stability.
Growing plants on spoil heaps to increase stability.
Drainage to reduce landslides.
Increasing the pH so heavy metals stay insoluble.
Toxic leachate collected and treated.
Phytoremediation to adsorb heavy metals.
What are the advantages of incineration?
Volume of ash produced smaller than original waste.
Heat produced can generate electricity.
No sorting of wastes.
What are the disadvantages of incineration?
Resource materials are lost.
Toxic dioxins produced.
Fuel used for combustion is expensive.
Wet wastes may have to be removed, more expensive.
Expensive to treat effluent gases.
How is dioxin production reduced?
Combustion at high temperatures and waste gases cooled rapidly.
How can hydrogen chloride produced from incineration be treated?
Scrubbers using water sprays can be used to remove it from the effluent gases, it can then be treated with lime.
How should heavy metals be stored?
At a high pH so they stay insoluble.
How does asbestos become dangerous?
When its fibres become airborne so they can be inhaled.
What can inhaling asbestos do to humans?
Causes mesothelioma a type of cancer.
Asbestosis, which produces scar tissue in the lungs causing breathing difficulties.
How should asbestos be stored/treated?
Double wrapped in polythene bags in specialised landfill sites.
How should cyanide be disposed of?
Incineration
What is the method for encapsulation?
Heavy metals or intermediate level radioactive wastes are mixed with cement and poured into concrete containers.
This immobilises the wastes.
What is the method for vitrification?
Powdered high level radioactive waste mixed with molten glass and poured into stainless steal containers.
The glass solidifies and the waste is encapsulated.
What does dB stand for and what does it measure?
Decibels, it measures human hearing
What acoustic fatigue?
Stress cracking or structural failure due to frequencies of sound causing them to vibrate
What is vibration damage?
Where constant vibration causes structural damage.
What can shock impacts do?
Loud sudden noises can cause damage like broken windows.
What are some effects of noise on living organisms?
Hearing damage
Long term exposure to loud noise can cause high blood pressure
Noise can decrease concentration
How can noise affect livestock?
Sudden noises can scare them, could lead to injury.
Breeding failure.
How does noise affect breeding birds?
Bird songs being drowned out by background noise.
Sudden noises can scare birds from their nests leaving eggs vunerable.
How should airports be designed to reduce noise pollution?
Should have baffle mounds/embankments to absorb or deflect noise.
Multiple runways to allow more time to slow down, reverse thrusters dont have to be used which are loud
How should buildings close to airports be designed to reduce impacts from noise pollution?
Acoustic insulation, like double glazing.
Living areas placed furthest away from noise.
What is a high bypass ratio engine?
An engine with a turbofan and 2 tubes which forces bypass air around the inner tube, this ALLOWS SMOOTHER MIXING OF AIR SO LESS NOISE POLLUTION Higher ratio = quieter
What is an engine acoustic liner?
Absorbs noise, this reduces noise pollution
How can pesticide pollution be reduced?
Application timing- apply at night no bees, spray with smaller droplets so less used, don’t use in wind or rain.
Restrict the use
Use non-persistent pesticides, organophosphates less persistent than organochlorides.
Use more specific pesticides, pyrethroids are less toxic than ophosphates and ochlorines.
What are the environmental impacts of neonicotinoids?
Bc they’re persistent they will remain in the soil long enough to be absorbed by roots, translocated by plant.
Toxic to bees as they are neurotoxins, they affect their navigation and decrease their immunity to disease, this leads to less pollination and disrupts foodwebs/inter-species relationships.
More toxic to bees if used with a funigcide
Draw a mindmap on the methods to manage spoil heaps to reduce impacts
photo on phone!
What happens every 3dB?
The sound energy doubles, so you should half your exposure/double your distance to reduce damage
What can long term exposure to high noise frequency cause in humans?
Ulcers
High blood pressure
Heart disease
What does an increasing blood pressure due to exposure to high sound frequencies cause?
High blood pressure can lead to irritation/anger, so behavioural changes.
Aggression, outbursts, anger
Lack of concentration
What affect does high frequency sounds have on aquatic organisms?
Reducing feeding success, dolphins etc cannot find food due to background noise.
Frequencies used to warn organisms can cause hearing damage if the animal gets too close, e.g. sonar on submarines
How can an airport be designed/located/managed to reduce noise?
Fly at higher altitudes, less noise at ground level and a steeper take off angle to reach altitudes higher.
Flight paths away from urban areas and nature reserves etc.
No night flights over urban areas.
Quotas on the number of flights.
Baffle mounds/acoustic barriers to deflect and absorb noise.
Multiple runways on an airport, this allows time to slow down wheel can be used instead of reverse thrusters.
Charges for nosier aircrafts
Restricted flight times.
How can aircraft design/bodies be designed to reduce noise?
More aerodynamic surfaces to allow smoother flow of air.
High bypass ratio engine, so smoother mixing of air.
Acoustic engine liner, absorbs noise
Blended wings, engines on top of the aircraft so the body is a barrier for noise
Lighter aircrafts by using carbon fibre, less engine thrust needed
How can railway noise be reduced?
Aerodynamic surfaces
Polish tracks to stop wheel vibrations
Sound absorbing suspension to reduce engine noise
Lubricating tracks to reduce wheels squealing
How can road traffic noise be reduced?
Improved aerodynamics
Acoustic insulation to reduce engine noise
Embankments by roads
Sound absorbing road materials to reduce wheel noise
How can industrial noise be reduced?
Baffle mounds in mining
Drilling instead of pile driving
Air bubble curtains around pile drivers at sea to absorb noise, less harm to dolphins etc
Workers using ear protection
Remote controlled machinery
Sound absorbing surfaces
Restrictions on times of operation
How can domestic noise be controlled?
Appliances with acoustic absorbers
Volume limiters on music
Quieter appliances
Control dogs
What are some sources of ionising radiation?
X-rays
Cancer treatment
Oil and gas exploration
Pest control, sterile males etc
Nuclear fission and fusion
Why is nuclear fuel good to use in ships?
Has a high energy density so they rarely need to be refuelled and no air is needed for combustion.
What are the risks of ionising radiation?
Chronic exposure to low doses will produce symptoms very slowly
Symptoms difficult to detect as they may be similar to something else.
No accurate data
Those who benefit aren’t usually in direct contact with the radiation,
What does RBE stand for?
Relative biological effectiveness, the higher the value the more damaging
What are the risks of alpha radiation?
Absorbed very easily into skin, clothes etc and travels short distances, this means particles will be absorbed into a small mass of tissue increasing the concentration of alpha particles and increasing free radical interactions.
What are the risks of beta radiation?
Moderately easy absorption, travels medium distances.
Sources close to the body can pose a risk
What is background radiation measured in?
mSv
Why are isotopes with short half-lives preferred?
They take less time to release their radiation, so while they are still a risk they aren’t a risk for long.
Why is damage to cell nucleus bad?
Affects the chromosomes so will affect all future cells.
Mutations can lead to cancer
What are somatic effects?
Only affects tissue cells
What are gonadic effects?
Affects the gametes so therefore any offspring produced
What are chronic affects?
Affects that appear slowly due to a low exposure over a long period of time
What are acute affects?
Affects that appear rapidly due to high exposure in a short amount of time.
Death, damage to bone marrow
What is expsoure?
Where a person has to be close enough to the source of radiation for it to be absorbed
What is contaimination?
Where a person has to be physically carrying radioactive materials to be affected.
e.g. ingested
What are activation products?
This is where stable nuclei are exposed to neutrons, this makes them radioactive as the absorption of a neutron produces a new isotope.
Where are activation products mostly found?
In the structures of nuclear reactors
What 2 basic principles are used in radioactive waste management?
ALARA
BATNEEC
What are the strategies to reduce exposure to radiation?
Inverse square law
Protective clothing
Materials used should absorb radiation
Closed sources, so no direct contact and prevents contamination.
Remote handling techniques
Maximum exposure time
How should low level radioactive gases be stored?
Filtered then released
How should low level radioactive liquids be stored?
Filtered, ion exchange then released
How should low level radioactive solids be stored?
e.g. clothing or general equipment
Sealed in polyethene bags, inside steel drums then sealed inside concrete lined landfill sites
How should intermediate level radioactive wastes be stored?
Mixed with cement and stored in stainless steel drums
What does intermediate level radioactive wastes include?
Metal tubes that surrounded fuel rods in nuclear reactors
How should high level radioactive wastes be stored?
Vitrification
What do high level radioactive wastes include?
Used uranium fuel rods
What is becquerel used to measure?
The activity of the source
What is Gray used to measure?
The dose absorbed
1 Gy is one joule absorbed per kg
What is the weighting factor for alpha?
20
What is the weighting factor for gamma and beta?
1
How do you calculate sieverts?
no of grays X radiation weighting factor
How can workers be monitored for radiation?
Dosemeter
film badges to measure exposure
contamination monitors which detect radiation of workers when they leave the building
What factors does CPA analyse?
State of effluent
Density
Ocean/river currents
Wind currents
half life of isotopes involved
What factors does CGM analyis?
How much time the critical group spent outside
Where people live in relation to the radiation
Sources of food consumed
Sources of water
What are some organic pollutants and their environmental impacts
Sewage- Decomposition causes deoxygenation, indirectly causes eutrophication, may contain disease, increases turbidity of water.
Manure
What are some inorganic pollutants and their environmental impacts
Nitrates from runoff/artificial fertilisers- cause eutrophication, blue baby syndrome if in water, possible carcinogen.
Describe the process of eutrophication
Nutrient enrichment of water from excess nutrients, this increases the growth of algae and cyanobacteria.
Cyanobacteria can release toxins harmful to animals in contact with water.
The rapid growth of algae shades submerged plants, no photosynthesis so they die, can disrupt food webs.
The decay of plants by aerobic bacteria produces a BOD, this causes aquatic animals to die as there is low O2.
