pollution Flashcards
(126 cards)
1
Q
what is pollution?
A
-a term given to a wide variety of events and processes that do harm to the planet, especially to living organisms
2
Q
what can pollutants be?
A
-either a material (co2, oil) or forms of energy (noise, radiation)
-they do harm by causing changes that wouldn’t normally have occurred
-pollution is usually caused by human activities, but similar effects can be caused by natural events such as volcanic eruptions, natural oil leakage & forest fires
3
Q
what are the properties of pollutants?
A
-state of matter (liquid, solid, gas)
-energy form
-absorption
-bioaccumulation ability
-biomagnification ability
-synergism
-mutagenic action
-carcinogenic action
-teratogenic action
-solubility in lipids/water
-reactivity
-toxicity
-persistence
-density
4
Q
what is absorption?
A
pollutants become attached to the surface of materials
5
Q
what is bioaccumulation?
A
-process by which the amount of 1 substance within an organism increases
6
Q
what is biomagnification?
A
-substances that bioaccumulate may become more concentrated as they pass along a food chain
7
Q
what is synergism?
A
-involves two or more pollutants where their effects interact to create a different effect
8
Q
what is mutagenic action?
A
-agents which cause changes in the chemical structure of DNA
-somatic effects= a change in DNA may cause a cell to behave abnormally. effect cells
-gonadic effects= effects sperm & eggs, can be passed onto future generations
9
Q
what is carcinogenic action?
A
-mutagens that cause cancer
10
Q
what is teratogenic action?
A
-teratogens cause birth abnormalities by preventing normal gene expression
11
Q
what factors affect the dispersal of pollutants?
A
-water currents
-air and wind currents
-temperature inversions
-presents of adsorbent materials
12
Q
what are air and wind currents?
A
-the velocity and direction of air, wind and water currents will affect how pollutants are dispersed:
•how far pollutants are dispersed
•the direction and area it disperse over
•how much the pollutent is diluted
13
Q
how do pollutants normally disperse?
A
-temperature in the troposphere normally decline with increasing altitude
-this allows pollutant gases to rise, disperse and become diluted
-because the warm air causes the pollutants to become less dense & more boyant
14
Q
what is temperature inversion?
A
-a temperature inversion is a break from normal troposphere temperature gradients
-air higher in the troposphere is warmer than air closer to the ground
15
Q
what factors affect the formation of temperature inversions?
A
-valleys- colder,denser air can collect
-low wind velocity- temp layers don’t mix
-cloudlessness- infrared energy radiates out allowing the ground to cool more quickly
-water vapour- if mist or fog forms close to the ground this reflects more sunlight, so ground is warmed less
16
Q
what effect do temperature inversions have on the dispersal of pollutants?
A
-pollutants become trapped by the temp inversion
-they remain more dense and less buoyant
-so don’t disperse and dilute
-the pollutants become concentrated and can form smogs and photochemical smogs
17
Q
what is presents of absorbent materials?
A
-pollutants may absorb onto materials such as clay particles or organic materials in aquatic sediments
-adsorption may immobilise the pollutant and stop it causing problems
18
Q
what factors affect the degradation of pollutants?
A
-link: persistence-measure of the length of time a pollution remains in the environment before it’s chemically broken down
-temp
-light levels
-oxygen
-pH
-interactions with other pollutants
19
Q
how does temp affect the degradation of pollutants?
A
-chemical reactions occur more rapidly when temps are higher, including biological degradation
-warmer temps also cause deoxygenation of water bc oxygen is less soluble
-case study example-insecticides degrade quicker in warmer temps, mosquitoes become resistant to insecticide, mosquito life cycle time shortens, as temps rise so do survival odds of insecticide resistant mosquitoes
20
Q
how do light levels affect the degradation of pollutants?
A
-light levels can provide the activation energy for chemical reactions
-including pollutants, such as photodegradation of pesticides
-case study example- photochemical smog is a mixture of pollutants that form when nitrogen oxides & volatile organic compounds react in sunlight
21
Q
how does oxygen affect the degradation of pollutants?
A
-oxygen is required for many chemical and biological reactions. including those involving pollutants
-fast flowing and turbulent waters have higher dissolved oxygen levels
-examples- aerobic bacterial decomposition of sewage, oxidation of sulphide ore, producing sulphur dioxide, oxidation of metals
22
Q
how does pH affect the degradation of pollutants?
A
-pH can affect the solubility of substances
-heavy metals (eg lead) are more soluble in acidic conditions and therefore more mobile
23
Q
how does pollutant reactions affect the degradation of pollutants?
A
-the behaviour of a pollutant can be effected by its interactions with other pollutants
-some interactions may increase the effects of a pollutant or its toxicity
-example-allergens, irritants, and pollutants may inc asthma, NOx and hydrocarbons in smogs, phosphates and nitrates in eutrophication
24
Q
what is the point source of carbon?
A
-a single, identifiable source of pollution, such as pipe or drain
-industrial wastes commonly discharged to rivers and sea in this way
-high risk point source waste discharges are regulated by environmental protection authority (EPA)
-EPA receives and assess applications to issue licences and works approvals
-licences cover actual operation of site, & set operating conditions, waste discharge limits and waste acceptance conditions, as appropriate
25
what is the non- point source of carbon?
-often termed ‘diffuse’ pollution and refer to those inputs and impacts which occur over a wide area and are not easily attributed to a single source
-they’re often associated with particular land uses, as opposed to individual point source discharges, e.g.:
•urban land use
•agricultural land use
•forestry land use
26
what is critical pathway analysis?
-used to predict the movement of pollutants in environment
-asses locations that will be affected by the pollutant and the severity with which it will be affected
-if the CPA predicts that the pollutant will be diluted, adequately dispersed or otherwise moved to an area it will cause no damage, no action will be taken.
-if the CPA predicts the pollutant will become concentrated, will not disperse or will be carried to a sensitive location, control measures will be put in place
27
what do the CPA take into consideration?
-involves identifying the most likely route a material will take, based on its properties & features of the environment
-pH, oxygen, light levels, water currents, air & wind currents
-toxicity, biomagnification, bioaccumulation
28
how can environmental sampling be used?
-when pollutant is released environment is monitored to check if it’s becoming concentrated in places that pose a threat to humans or areas we consider important
-e.g. when soil, water, grass, milk, meat, fish, vegetables, atmospheric dust
-monitoring program should confirm the accuracy of the CPA
-if levels are found to be acceptable, then it can be assumed that everywhere else is safe, as long as the CPA has been done accurately
29
what is critical group monitoring?
-assess risk to members of public, who are most likely to be at risk, due to their lifestyle
•where they live
•where their drinking water & food comes from
•what they do in their spare time & where they work
30
what is polluter pays principle?
-if the person that causes pollution is responsible for problems caused, there is an obligation to prevent it
-if cost of preventing damage caused by pollution are less than cost of damage, there is financial incentive to prevent it
31
what is precaution principle?
-assumes waste will cause pollution if released, until research confirms it’s unlikely
-safer than releasing a waste that hasn’t been analysed, then waiting to see if problem occurs
32
what is control method?
-production prevention- desulfurisation of fossil fuels before combustion
-prevention of release- electrostatic precipitators for smoke control
-post release remediation-oil spill clean up methods
-alternative processes- use of electric vehicles rather than diesel or petrol vehicles
33
what is pm10?
particulate matter less than 10 microns in diameter
34
what is atmospheric pollution?
-pollutants in atmosphere often behave differently from those in water or on ground
-they move very rapidly due to winds & hence dispersal over a large area
-can interact easily with EM radiation coming from sun
-can interact either infrared energy radiated from the earth
35
what are particulates?
-smoke is produced by incomplete combustion of material
-smoke made up of atmospheric particulates
-particulates are small particles less than 10 microns
-smoke often contains toxic compounds depending on source
36
what are sources of particulate matter?
-incomplete combustion
-urban areas- burning coal, diesel, combustible waste
-rural areas- burning of crop waste, fuel wood , grassland, forest
37
what are smoke pollution control methods?
-legislation- clean air act (1956): restricted use of fuels that produce in large urban areas
-cyclone separators- effluent gases forced to rotate in cylindrical chamber. throws suspended particles to outside surfaces of chamber where they fall and collect ‘fly ash’
-electronic precipitators l- effluent gases passed through chamber with many electrically charged wires/plates. smoke particles in gases attracted to wires/ plates and collect together. ‘fly ash’
-scrubber-uses fine water sprays to wash out suspended solid particulate matter
-bag filters-remove smoke particles from effluent gases by trapping them on fabric filter
38
what are the effects of smoke pollution?
-on humans- respiratory disease, more difficult to clear inhaled particles & bacteria from lungs
-other living organisms- reduced photosynthesis
-non living objects- smoke particles can damage buildings due to acids
-on climate- reduce temps because high albedo of smoke reflects light. nuclear winter
39
what are smoke smogs?
-smoke+fog=smog
-fog tends to form when moist air is cooled until it reaches dew point. water vapour condenses as airborne water droplets
-smog has high albedo so temp inversion can last long periods of time, allowing pollutant levels to rise
-london smog (1952)- five days where anticyclonic weather conditions produced clear skies & low wind velocities so temp inversion is formed & pollutant levels rose. around 12,000 deaths
40
what are the effects of NOx?
-low MOx levels can ciase irritation to eyes, nose, throat, lungs leading to coughing and shortness of breath
-can damage foliage, reduce growth, decrease crop yields
-can react to other pollutants to form ground level ozone, can damage human health and trigger asthma attacks
41
what are the sources of NOx?
human
-burning fossil fuels
-smoking tobacco
-using explosives
-food manufacturing
-refining petrol and metals
natural sources
-lightning
-bacteria
-volcano eruptions
-oceans
-microbial processes in soil
42
what are NOx cycles?
-NOx= NO and NO2
-uv light splits up NO2 to give NO and an O atom- combines with molecular oxygen to give ozone
-eventually, NO2 is oxidised to nitric acid, absorbed directly at the ground, converted into nitrate containing particles
43
how to control NOx?
-catalytic converters
•NOx->N2+O2
-urea sprays
•adblue in diesel cars
•NO+CH4N2O->N2+CO2+4H2O
-control fertiliser use
44
sources of hydrocarbons
-solvents
-aerosol propellants
-gaseous emissions from fossil fuel exploitation
-unburnt hydrocarbon fuels
45
effects of hydrocarbons
-lead to global warming
-contribute to smogs
-pollute water- harms aquatic life
-contaminates soil- impacts plant growth & food chains
-inhalation- cancer, respiratory disease
-contact with skin- irritate or burn
46
control of hydrocarbons
-catalytic converters
-vaporised- can be re used (electrostatic precipitators)
-cyclone separators
-improved combustion tech
47
sources of CO
-incomplete combustion
-diesel and petrol
48
effects of CO
-binds to haemoglobin
-death
49
what are photochemical smogs?
-toxic at lower concentrations
-secondary pollutant
50
effects of photochemical smogs
-increased risk of respiratory infections
-cause eye irritation, breathing difficulty, asthma
-weak immune systems
-heart and lung problems
51
causes of photochemical smogs
-formed when nitrogen oxides and volatile organic compounds react to sunlight
-NO, O3, hydrocarbons
-caused by secondary pollutant
52
causes of acid rain
-precipitation with pH less than 5.6
primary pollutants
-sulphur dioxide (SO2): from burning fossil fuels and smelting ores containing sulphur. SO2 combines with ozone to form SO3. H2SO4 is stronger than H2SO3
-oxides of nitrogen- from internal combustion engines
-hydrogen chloride- combustion of coal and the incineration or wastes containing chloride
secondary pollutants
-sulphur trioxide (SO3)- sulphur dioxide reacts with atmospheric oxygen
53
abiotic impacts of acid rain
-damage to limestone- acid rain reacts with limestone in building and statues & dissolves them
-corrosion of metal- cause damage to railway lines, metal railings, water pipes, overhead power lines, pylons etc
54
what are direct biotic impacts of acid rain?
-denatures proteins and enzymes- acid rain can later the pH of outside the range of tolerance of living organisms
-damage to expose tissues:
•damage to leaf waxy layers and cells
•prevent germination of seeds and fish eggs
•invertebrate with calcium based exoskeletons
•abundance of lichens
55
what are the indirect biotic impacts of acid rain?
-soil pH- decreased soil pH can inhibit the action of root hair cells and can immobilise detritivores and decomposers
-metal leaching- metal ions to be leached from soil
-toxins- leached metal ions can accumulate in rivers which can have toxic effects
56
causes of thermal pollution
-turbine power stations use water from nearby rivers and lakes to cool their systems and condense system
-the water is returned to river or lakes at higher temp
57
whats the problem with warm water?
-relationship between temp and maximum dissolved oxygen level
-higher temps causes deoxygenation of water
-a litre of water at 20°c hold max 6cm3 of dissolved oxygen
58
other effects of thermal pollution
-enzymes & proteins
•higher temp will push enzymes & proteins outside their optimum rate range, slowing their rate
•very high temp can cause denaturation to enzymes and proteins
-decreased growth rate
•exotherms-higher metabolic rate-less energy for growth
•eggs hatch earlier, underdeveloped
•toxic pollutants can be spread more rapidly-faster diffusing rate
•introduced species may survive better in warmer conditions so may out compete native species
59
control of thermal pollution
-temp reduction using cooling towers
-cooling towers allow effluent water to cool before it’s returned to rivers and lakes
1.hot water is sprayed into tower
2.air in tower absorbs heat from water, which rises and escapes
3.caused cooler air to be drawn into base of tower, further cooling the water
4.the shower mixes the water with air, allowing oxygen to re-dissolve
60
sources of oil pollution
-waste lubricating oil-often deliberately discarded into environment
-leakage during drilling- drill pipes can be lubricated with oil to reduce friction as they bore through rock
-accidental releases of oil pollution:
•ship tank washing
•shipping tanker activities
•oil refinery spills
•pipeline leaks
61
direct effects of oil pollution
-toxicity- contains benzenes & xylene. most likely to effect planktonic organisms that float near surface
-asphyxiation- can cover aquatic sea life on seashore. organisms like molluscs
-loss of insulation- oil on birds feathers caused them to stick together & lose insulating properties
62
indirect effects of oil pollution
-less time to feed young- birds spend time cleaning feathers
-food chain effects- bio accumulation of oil in food chain. death of planktonic producers affects rest of food chain
63
major oil spill in UK
-sea empress oil spill in 1996
-leaked 72,000 tonnes
-milford haven waterway
64
global shipping oil tanker disaster
-deep water horizon oil spill
-2010
-168 million gallons
-into gulf of mexico
65
preventing release of waste oil
-recycling of waste oil
•used lubricating oil from vehicle engines shouldn’t be treated as waste
•contaminating oils can be chemically reformed to produce chemically valuable lubricant again
-unrecyclable waste oil can be burnt, reducing demand on other sources
-reduced leakage- equipment maintenance
66
tanker designs
-double hulls- protect boat
-twin engines- backup
-ballast tanks- carry water when not carrying oil to balance
67
tanker operations
-shipping routes- further from land in case of mechanical difficulties
-navigation systems- helps avoid collisions
68
treating oil spills
-inflatable booms-restrict movement of oil in sheltered areas, prevent spread of oil
-skimmers-rotating metal disks that pick up oil
-absorbent materials-high surface area material like textile mops. removed & incinerated after use
-steam cleaning- oil on beaches washed off with sprays of steam. save sensitive habitats
-bioremediation-bacteria break down hydrocarbons to remove residual pollution after clean up
69
properties of pesticides that cause pollution
-toxicity
-specificity
-systematic/contact action
-persistence
-liposolubility
-biomagnification
-bioaccumulation
-mobility
-synergism
70
specificity in pesticides
-MDNF-maximum dose never fatal
•lowest dose that will kill every member of population
-MDAF-minimum dose always fatal
•lowest dose without killing any members of population
71
direct effects of pesticide pollution
-cause harm to non-target species by being toxic
-sub-lethal doses may inhibit metabolic processes, cause ill health
-higher doses may kill
-even lower doses that don’t kill can still cause a species to become extinct
-reducing breeding rates to a level below
72
indirect effect of pesticide pollution
-species not harmed directly
•reduction in food availability
•predators could become more common
73
methods of reducing pesticide pollution
-restriction on use- use been restricted where they could cause problems or benefit is greater than disadvantage. examples are DDT (still used to treat malaria)
-use of non persistent pesticides- will breakdown rapidly & can’t become more concentrated
-use of specific pesticides- pyrethroid & organochlorine both toxic to insects but pyrethroid less toxic
-use of systematic pesticides- absorbed by crops & translocated within. don’t need to be sprayed onto all surfaces, not washed off after they’ve been absorbed, will protect new growth
74
types of pesticides
-organochlorines- first used to control pests that transferred human pathogens- advantages- high toxicity to insects. disadvantages- long-term contamination of soil
-organophosphates-controlling pests harmful to crops & livestock. advantages- less bioaccumulation due to faster degradation. disadvantages- high toxicity to mammals
-pyrethroids- synthetic inescticide. advantages- high insect toxicity, not persistent. disadvantages-toxic to fish
-neonicotinoids- neurotoxins. advantages- high insect toxicity, water soluble. disadvantages- toxic to bees
75
nutrients in water
-water bodies like rivers and lakes have nutrients naturally added to them which accumulate & enrich food webs
-human activities can add additional nutrients
-despite enhancing nutrition, these often have negative effects
-phosphates- sewage effluent & eroded soil particles
-nitrates- washed off farmland from maude and artificial fertiliser
76
eutrophication
-enrichment of waters by excess inorganic plant nutrients, usually nitrogen and phosphorus, which inc primary production
-as result, plants & algae grow rapidly in water
-phosphates & nutrients often limiting factor to plant growth
-they can occur naturally over time (natural eutrophication) or as result of human activities (cultural eutrophication)
77
factors influencing rate of eutrophication
-natural eutrophication- natural features of lakes catchment
-cultural eutrophication-anthropogenic influences
-most important factors in temperate lakes:
•fertility of drainage basin
•seasonal behaviour of water
•depth of lake
•rate of turnover of water
•cultural eutrophication
•temp of water
78
stages of eutrophication
1.unpolluted lake with rich food webs & high macrophyte
2.phosphates from sewage effluent & nitrates from farmland. algae absorb nutrients & grow more rapidly than macrophytes
3.livestock may drink water & may die. some algae release toxins. decomposition of dead macrophytes reduces dissolved oxygen lvls
4.algae die when nutrients run out. decomposition by bacteria depletes dissolved oxygen, killing fish & insect larvae.
79
effects of eutrophication on humans
-on babies:
•blue baby syndrome
•bacteria in babies intestine convert nitrates to nitrites- which are highly toxic, by reducing haemoglobins oxygen carrying ability
•leads to methaemoglobinaemia
80
controlling inorganic nutrients
-nitrates-
•reduced use of nitrate fertilisers
•reduced ploughing at times of heavy rainfall
•use of soluble, rapid-release fertilisers
•depositing waste manure where nutrients won’t leach into ground or be washed into river
•using crops with lower nitrogen requirements
•reducing reliance on artificial fertilisers
-especially important in nitrate vulnerable zones where aquifers may be exposed
-phosphates:
•adding iron III sulphate= solid iron phosphate
•dredging lakes and rivers
81
biological oxygen demand (BOD)
-common measure of organic pollution
-how much oxygen is taken up by a sample of water when it’s kept in dark for 5 days at 20°c
-polluted water has a high BOD
82
sources of organic pollution
-many processes involving plant and animal products produce liquid effluents containing organic nutrients: carbohydrates, lipids, proteins
-sources include:
•sewage works •manure disposal
•silage storage •leather tanneries
•paper mills •food processing plants
83
effects of organic pollution
-deoxygenation
•untreated organic nutrients in rivers & lakes provide nutrients for microorganisms and algae
•aerobic digestion deoxygenates the water
•may kill aerobic organisms
•eutrophication will prevent light reaching normal water plants so that photosynthesis is inhibited, killing plants & disrupting food webs
84
water borne diseases from contaminated water
-cholera
-typhoid
-dysentery
85
treating organic pollution
-pre-treatment methods- removal of solid objects. screens, grit traps, comminutors chop up suspended faecal solids
-primary treatment- separation of most organic solids from fluids. effluent left to stand in large tanks where the faecal solids sinks to bottom so they can be treated & removed separately
-secondary treatment- digestion & breakdown of remaining organic matter in fluids. aeration tanks, secondary sedimentation tanks
-tertiary treatments-additional treatment to remove phosphates or bacteria.
86
sources of acid mine drainage
-outflow of acidic water from metal mines or coal mines
-many metal ores are sulphides
-spoil heaps from mining contain small amounts of metal sulphides
-these can be oxidised when exposed to air to produce sulphur dioxide
-this dissolves in drainage water to produce sulphurous acid
-may oxidise further to produce the more powerful sulfuric acid
87
impacts of acid mine drainage
-contaminated water often orange or yellow-orange colour
-indicates high levels of iron and has smell of rotten eggs
-from pyrite from coal and metal mining
-when pyrite is distributed, reacts with oxygen to cause high levels
88
effects of acid mine drainage
-acidic drainage water may cause direct harm to living organisms
-non living: acid deposition corrodes metals (damage to railway lines, water pipes, etc). limestone structures damaged as acid dissolves surface layers
-living: harm living organisms directly, low pHs denature proteins in cell membranes & can inhibit enzyme action
89
control of acid mine drainage
-crushed limestone to neutralise the acid
-will reduce solubility of
90
what are biotic indices?
-different organisms have different pollution sensitivities
-easy to identify, find & are normally present
•easy to identify, normally present if no pollution, normally common if there is no pollution, widely distributed rather than found in groups, easy to find
91
advantages of acid mine drainage
-rapid assessment of current and recent pollution can be made
-expensive equipment isn’t required
-detect low/unknown pollutants
-long term monitoring
-can be very sensitive
92
disadvantages of acid mine drainage
-sorting samples can be time consuming
-identification of different taxa involves some skill
-further tests required using other techniques to detect specific pollutants present
93
what is heavy metal pollution
-become pollutants when found in high concentrations in water & soil
-been inc in heavy metal concentrations since the industrial revolution kg been around for over 3000 years
- general effects at high concentrations:
•toxic to metals
•developmental defects
•cancers
•kidney failure
•immune system failure
94
properties of heavy metals
-liposoluble- can be stored in fat droplets in cells, lead to bioaccumulation within tissues & biomagnify yo food chains
-synergy- reacting with other pollutants e.g cadmium and zinc
-solubility- more soluble in low pHs. therefore, pollution can be reduced by inc pH
95
environmental impacts of heavy metals
-egg shell thinking- break easily
-interference with mammalian reproduction
-damage to immune system
-carcinogenic
96
lead pollution
-sources:
•fishing weights, lead- acid battery, rainwater flowing over lead roof inhibits growth of lichen and moss
-effects: brain damage, paralysis, death, liver and kidney failure
-control:
•voluntary schemes use alt materials like tungsten steel for shotgun pellets
•fishing weights replaced with tungsten
•lead free solder containing silver, tin, copper
97
mercury pollution
-sources:
•disposal of batteries, fluorescent lights, thermometers
•combustion of coal
•chemical plants that produce chlorine using mercury electrodes
-effects:
•learning, speaking & feeling difficulties
-control:
•ion exchange filters, disposal at high pH to reduce solubility, mercury thermometers replaced with alcohol, mercury removed from effluents by reverse osmosis
98
cadmium pollution
-sources:
•disposal of old nickel- cadmium batteries
•incineration of wastes containing cadmium pigments
•drainage water from cadmium and zinc mines
-effects:
•brain damage & paralysis, lung cancer, kidney failure, skeletal collapse caused by bone decalcification
-control:
•use has been restricted/banned
•disposed of in hazardous waste landfill site or may be recycled
99
tin pollution
-sources:
•fossil fuel combustion, waste incineration, industrial processes
-effects:
•stomach aches, anemia, liver & kidney problems
•skin and eye irritation, neurological problems
-control:
•TBT prohibited in anti-fouling paint
100
iron pollution
-sources:
•abandoned coal mines, iron and steel industry, rainwater
-effects:
•deoxygenation, death of aerobic organisms
-control:
•spoil heap drainage water passed over mesh screens, iron becomes oxidised & is deposited on the mesh
101
sources of solid waste pollution
-domestic & commercial waste:
•paper, packaging & containers, domestic appliances, clothing & textiles, etc
-problems with waste management:
•large quantities of waste produced, household waste collection is expensive & time consuming, waste mix changes through year, etc
-mining & construction waste:
•mine overburden- usually non-toxic, mine spoil heaps- may contain toxic materials, demolition waste- often contains hazardous materials
-industrial waste:
•large industries & factory produce large quantities of waste often requiring very specific treatment
102
how can affluence effect waste production
-inc affluence more likely to inc purchase of consumer goods, trivial purchases, more purchase of disposable items, disposal rather than repair
-sales strategies also inc production of waste:
•obsolescence- products designed to have short lifespan, wear out quickly or fast changing consumerism to upgrade to latest model
•disposable products- items intended to have limited lifespan
•over packaging- items made more attractive if they have unnecessary packaging that will be thrown away
103
landfill advantages and disadvantages
adv:
-separation of different waste types
-collection & treatment of leachate fluids
-deodorising sprays to control odours
-regular covering of soil to reduce pest problems
-cost effective
-land reclamation
dis:
-potential resource value lost
-use large areas of land
-organic matter contributes to global warming
-toxic leachate may leak from poorly managed sites
-habitats & farmland may be lost
-transport generates noise
104
incineration advantages and disadvantages
adv:
-less ash produced
-no sorting/complicated management
-heat produced uses to district heating
-flammable materials can be separated & burnt in purpose built power stations
dis:
-resource value is lost
-toxic dioxins may be produced
-fuel used to maintain combustion is expensive (of wet/non-flammable wastes)
-treatment of atmospheric pollutants in effluent gases increases costs
105
spoil heap advantages and disadvantages
adv:
-stabilised to reduce pollution- compaction
-compacting reduces air spaces, lesson risk of spontaneous combustion
dis:
-prone to erosion
-low water holding capacity, accelerate leaching of nutrients
-acid mine drainage
106
sources of noise pollution
-aircraft noise
-railway noise
-domestic noise
-industrial noise
-road traffic noise
107
controlling military aircraft noise
-military airfields away from urban areas
-low flying not allowed in areas with airports, towns or city’s with pop over 10,000
-MoD publishes monthly timetable
-compensation if damage to property or livestock
-avoid flying near ecological sensitive sites
108
aircraft design
engine designs to reduce noise emissions:
-high bypass radio engines
-chevron nozzles
-engine acoustic liner
aerodynamic surfaces:
-blended wing aircraft
-welded panels create less turbulence
-lighter aircraft
109
airport operations
-flight paths
-altitude restrictions
-constant descent angle
-night flight restrictions
-noisy aircraft banned
-fines for excessive noise
-reduced use of reverse thrusters
110
sources & controls of railway noise
-wheel vibration- track polishing, sound absorbing ballast
-engine noise-sound absorbing suspension
-pantograph turbulence-aerodynamic fairing
-wheel squeal on corners- lubrication
-wheel noise- good carriage suspension
111
sources & controls of industrial noise
-air compressors & pumps-silencers to reduce explosive expansion of air
-stamping machines-alt process eg pressing
-metal conveyors-use nylon bearings, wheels
-mine blasting-regular timing to reduce public concerns
-pile driving on land-drilling instead of pile driving
112
sources & controls of rod traffic noise
-wheel noise-sound absorbing road materials such as proud asphalt
-vehicle air turbulence-improved vehicle aerodynamics
-engine noise-acoustic insulation around the engine- quieter exhaust pipes
113
using ionising radiation in nuclear radiation
-nuclear weapons- processes of nuclear fusion & fusion releasing radioactive particles
-nuclear electricity generation-uses processes of fission of uranium & plutonium to create heat & electricity
-ship propulsion- high energy density nuclear fuels can be used to propel ships using nuclear reactors. rarely requires refuelling, o2 not needed for combustion, often used in submarines
114
using ionising radiation in manufacturing industry
-measuring thickness- paper & metal
-testing aircraft jet engine turbines
-strengthening polymers- creates cross links between molecules
-testing rock porosity- oil and gas exploration
115
using ionising radiation in healthcare
-sterilising heat sensitive surgical equipment
-cancer treatment (radiotherapy)
-x rays
-ct scans
-radio labelled tracers used to track movement of material with an organism or environment
116
using ionising radiation in agriculture
-food storage and sterilisation
-sterile insect pest control
-produce mutations in crops
117
defects of ionising radiation
-free radicals:highly reactive & cause damage to tissues & biological damaging reactions
-DNA damage:mutations in DNA. disrupt cell cycle leading to tumorous cells
categories-
-acute & chronic effects:slowly developing & worsening effects, acute appear quickly as result of free radicals
-somatic & gonadic effects: normal body cells or gametes
118
risk benefit analysis
difficulties:
-symptoms may take years to develop-no immediate harm-symptoms can also be linked to other conditions not necessarily radiation
-accurate data on exposure and effects no always available
-risk of using radioactive materials may be offset by the dedication of other risls
119
principles of control
-exposure should be as low as reasonably achievable (ALARA)
-equipment should be best available technology not entailing excessive cost (BATNEEC)
-the use of risk: benefit analysis
120
control strategies
closed sources to prevent contamination:
-prevent workers coming into direct contact with radiation- protective clothing
-remote handling techniques
radition absorbers:
-barriers stop radiation reaching workers
-type & thickness considered to contain different types of radiation
distance from source:
-radiation dose follows inverse square law
-dose received= 1/(distance)2
reduced period of exposure:
-worker monitoring at work
-decontamination- washing, scrubbing
121
high level waste
-origin- spent fuel rods
-waste storage method- vitrification: powered solid waste mixed with molten glass. solidified in steel containers. air cooling system. uk-stored at sellfield
122
intermediate level waste
-origin- metal tubes that surround fuel rods
-waste storage method- mixed with cement and sorted in stainless steel containers
123
solid low level waste
-origin- general equipment
-waste storage method- seekers inside steel drums, concrete lined landfill
124
liquid low level waste
-origin- fuel processing and storage
-waste storage method- filtered, ion exchange, discharged
125
monitoring workers
-personal dose meters- reading of current exposure
-photographic film badges- measure long term measure exposure
-air monitors- detect atmospheric particles
126
environmental sampling- radiation
-atmospheric dust
-water
-soil
-seas weeds, molluscs, fish
-milk, vegetables, meat
