Pollution - Physical Flashcards
Define density
Mass per unit volume.
Define persistence
Length of time a pollutant remains in the environment before degrading.
Define toxicity
How poisonous a substance is to a living organism.
Define specificity
Variations in toxicity to different groups of organisms.
Define reactivity
Likelihood to undergo a chemical reaction.
Define adsorption
Attachment to the surface of materials.
Define solubility for:
Lipids
Water
Lipids - How well a substance dissolves in lipids.
Water - How well a substance dissolves in water.
Define bioaccumulation
Amount of a substance in an organism increases.
Define biomagnification
Substance becomes more concentrated at higher trophic levels (up the foodchain).
Define synergism
Pollutants acting together to have a different, greater effect than on their own.
Define mutagenic action for:
Gonadic
Somatic
Carcinogenic
Gonadic - Changes to chemical structure of DNA.
Somatic - Mutation in an egg, sperm, or embryo. Mutations in a body cell.
Carcinogenic - Mutagens that can cause cancer due to uncontrolled cell division.
Define teratogenic action
Non-inherited birth abnormalities.
Define mobility
Ability of a pollutant to move in the environment.
Define primary pollutant
Pollutant released by human activities.
Define secondary pollutant
Pollutant produced from chemical reaction with primary pollutants.
What are some factors that affect degradation?
- Temperature: chemical reactions occur rapidly at higher temperatures.
- Light: Energy to drive chemical reactions.
- Oxygen: Aerobic decomposition of sewage by bacteria etc.
- Pollutant interactions
What are some factors impacting dispersal?
- pH: can affect solubility of substances.
- Wind/water currents: impact direction and how far it is dispersed/diluted.
- Adsorbent materials: pollutants and naturally toxic metal ions may adsorb onto materials like clay particles, immobilising the pollutant.
What are temperature inversions?
- Warm effluent gases usually have lower density than surrounding air, so rise to disperse.
- If the layer of air above is warmer then as these gases cool they are less dense and so are not dispersed.
What are some factors that lead to temperature inversions?
- Valleys: trap cooler air below.
- Low wind: no mixing of air layers.
- Cloudless skies (at night): IR radiation from ground emitted so cools down.
- Fog during day: higher albedo reflects sunlight, warming upper layer.
General strategies to control pollution: Critical Pathway Analysis (CPA)
- Predicts movement of pollutants in environment to predict the severity and location of pollution.
- If pollution is diluted or transported to locations with minimal impact risk then no action needs to be taken.
- If transported to sensitive locations, control of releases required.
- Largely used to monitor the dispersal of radioactive waste.
General strategies to control pollution: Critical Group Monitoring (CGM)
- Assesses risk to member of the public (not workers) who are deemed most at risk due to their lifestyle.
- This is the critical group.
- Used to monitor exposure and assess risks before health impacts occur. Emissions can be controlled to reduce exposure.
What is the Polluter Pays Principle?
Whoever is responsible, pays. Incentive to prevent pollution if costs of payment > benefit from release of pollutant.
What is the Precautionary Principle?
Assumes waste released will cause pollution unless research confirms it is unlikely. Ensures that being unaware of potential problems does not exclude responsibility.
What are the direct effects of acid rain on:
Non-living
Living
Non-Living:
- Corrodes metals
- Damages water pipes, pylons, powerlines.
- Buildings made of limestone damaged.
Living:
- Acids toxic to living organisms.
- Denature proteins in cell membranes.
- Inhibit enzyme action.
What does acid rain do to organisms?
- Inhibits germination of seeds.
- Damages fish eggs and gills.
- Invertebrate exoskeleton dissolves.
- Lichens sensitive to acidic conditions.
- Respiratory problems and increase asthma attacks.
What are some indirect effects of acid rain?
- Increased acidity = metal ions become more soluble.
- Desirable ions leach from soil.
- Mobilises toxic metals.
- Toxic metals that leach out can be harmful e.g. aluminium ions linked to Alzheimers disease.
What are some environmental factors impacting severity of acid rain?
- Limestone neutralises acidity.
- Heavy downpours of acid rain have acute effects.
- Sudden melting of acidic snow acidifies aquatic habitats.
What are some sources of smoke pollution?
- Incomplete combustion of carbon-based materials.
E.g. diesel, coal, crop waste, wood fuel.
What are some effects of smoke pollution?
- Can be small enough to penetrate deep into the lungs = asthma, bronchitis, cancer.
- Blocks stomata on leaves, reducing photosynthesis.
- Synergistic action with sulfur dioxide.
- Increased albedo = cooling effect.
How does smog form?
Smoke + fog - Moist air cools until water vapour condenses as airborne droplets.
What are the effects of photochemical smog/PANs?
- Toxic at low concentrations.
- Eye irritation
- Mutagen
- Respiratory irritation
- Toxic to plants
Use trophospheric ozone to explain the meaning of secondary pollutant.
- Primary pollutant nitrogen dioxide reacts with UV.
- Monatomic O reacts with oxygen to produce ozone.
- Secondary pollutant as produced from chemical reactions of primary pollutants.
How does tropospheric ozone increase problems caused by acid rain?
- Oxidises sulphur dioxide into sulphur trioxide.
- SO3 in water produces strong sulfuric acid.
- More lake acidification.
What are the main methods to reduce air pollution?
- Clean Air Act (1956): Smoke control (smokeless zones), relocate power stations away from cities, increase chimney heights.
- Kyoto Protocol: Reducing GHGs.
- Montreal Protocol: Banning use of CFCs to reduce ozone depletion.
- Landfill Tax (UK): Reduce amount of land used for landfill = less methane.
Control of acid rain: Fuel Desulfurisation
1) Hydrogen sulphide removed from natural gas by reacting it with iron particles. Reduce corrosion to appliances/pipelines.
2) Sulfur compounds removed from crude oil during distillation.
3) Removing coal sulfur in pyrites by crushing coal and separating pyrites based on density.
Sources of carbon monoxide
Released when carbon-based materials are burned with a shortage of oxygen e.g. incomplete combustion of hydrocarbons in vehicle engines.
Effects of carbon monoxide
Binds to haemoglobin and prevents it from carrying oxygen, leading to brain damage and death.
Control of carbon monoxide
Exhaust catalytic converters can covert carbon monoxide to carbon dioxide.
Why is oil bad for plants?
- Unable to photosynthesise.
- May find it difficult to recolonise afterwards as rocks coated in oil.
Why may oil be bad for mussels?
- Asphyxiation
- Filter feeding can’t happen, they may ingest oil.
Why is oil harmful for fish?
- Oil forms a layer on surface so less oxygen dissolves into water, suffocating them.
- If they rely on scents to find mates/food, the oil will mask this.
Why is oil harmful for birds?
- Can cause birds to drown if covered.
- Causes birds feathers to stick together, losing their insulating properties, may die of hypothermia.
Why is oil harmful for sea otters?
- May affect buoyancy/lose insulating properties.
- Some properties of crude oil toxic.
- Live long so oil bioaccumulates and biomagnifies.
What are booms? Are there any downsides?
+ Surround oil to prevent it from spreading further distance.
- Doesn’t work if waves/currents are too strong.
- Needs deploying soon after oil spill otherwise it’s useless.
What are adsorbent materials? Are there any downsides?
+ Helps absorb oil from surface which removes oil from the sea.
- Needs disposal of which can be wasteful.
What is steam washing? Are there any downsides?
+ Washes oil off beaches so organisms can safely live there.
- Not destroying oil, just removing it.
- Steam jets can kill organisms in beach sediment.
What are detergents and dispersants? Are there any downsides?
+ Break up of oil, becomes more mobile and disperses.
- It does not remove oil from ocean, only makes it look better.
How can oil spills be avoided?
- Better shipping routes, not leaving the mapped out routes. Smaller navigation errors.
- Better navigation systems.
- Inert gas systems - prevents oxygen from getting in tanks and exploding.
- Double hull - inner hull remains intact in an accident.
How can oil be weathered?
- Lightest oil will evaporate.
- Floating oil may disperse.
- Overtime, bacteria will break down oil to water and CO2.
- Bioremediation - adding extra bacteria.
What are some sources of oil pollution?
- Tanker accidents at sea.
- Accidental spillages from refineries/pipelines.
- Vehicle engine oil leaked into environment.
- Washing out of oil tankers to reduce residue build up.
How can oil be recycled?
Waste lubricating oil can be collected, filtered, refined, to be used again.
What are some effects of pesticides?
Direct:
- Can be toxic to non-target species.
- Higher doses can be fatal.
- Lower doses can lower metabolic processes and reduce breeding rates.
Indirect:
- Reduction of food availability.
Methods of reducing pesticide pollution: Restriction on use
The organochlorine DDT has been banned.
The organophosphate methyl parathion is only used in agriculture.
Methods of reducing pesticide pollution: Use of non-persistent pesticides
Organophosphate insecticide is non-persistent.
Methods of reducing pesticide pollution: Use of more specific pesticides
Pyrethroids are less toxic to mammals than organochlorines.
Methods of reducing pesticide pollution: Use of systemic pesticides
Adsorbed by the crop and translocated within it. Not washed off.
Neonicotinoids.
Methods of reducing pesticide pollution: Timing of application
- Spraying on still days results in less spray drift.
- Spraying at night/when crops aren’t flowering reduces impacts on bees.
- Newer spraying techniques use smaller droplets to produce a more even coverage, reducing amount required.
What’s the difference between eutrophic and oligotrophic?
Eutrophic: Lots of nutrients, high primary productivity.
Oligotrophic: Few nutrients, little plant growth.
What is eutrophication?
1) Excessive nutrients from fertilisers run off from land into rivers/lakes.
2) Cause aquatic plants to grow.
3) Algae blooms occur, preventing sunlight from reaching other plants, depleting the water of oxygen and plants die as no photosynthesis.
4) Dead plants/organisms are decomposed by decomposers and this uses up even more oxygen.
5) No life is possible, fish and others die.
6) Anaerobic organisms flourish.
How to control inorganic nutrient pollution from nitrate fertilisers
- Use organic instead.
- Using crops with lower nitrogen requirements.
- Plant legumes which fix nitrogen.
- Reduce ploughing during heavy rain.
- Avoid dumping waste manure near waterways.
What have nitrates in water/diet been linked to?
Convert nitrite in gut, converted to carcinogen. Linked to stomach cancer in rats.
What happens when nitrates react with haemoglobin?
Methemoglobinemia. Reduces oxygen-carrying ability = Blue Baby Syndrome.
How to control inorganic nutrient pollution from phosphates?
- Add iron sulphate: forms a precipitation that can be removed.
- Dredge phosphate-rich sediments.
What are some sources of organic pollution?
High energy nutrients containing carbon like carbohydrates, proteins, lipids.
Paper mills, sewage effluent, manure, food processing plants, leather tanneries, silage fluid.
What are some effects of organic pollution?
- Deoxygenation: Microorganisms feed off these nutrients. Aerobic digestion increases biological oxygen demand (BOD) in water sources.
- Pathogens: Sewage can contain pathogens which spreads through contaminated food/water, e.g. cholera.
- Release of inorganic nutrients: Decay of organic matter can release inorganic nutrients, e.g. protein broken down to amino acids to ammonium ions.
Pre-treatment of sewage
- Screens remove big debris/material.
- Grit trap for stones and road grit.
- Comminutors chop up suspended faecal solids, increasing surface area.
This is all disposed of in landfills or incinerated. Grit can be sterilised and reused.
Primary treatment of sewage
- Sludge settles out, needs to be disposed of by landfill, incineration, dispersal in sea.
- Some is skimmed off surface.
Agricultural use of sludge: Can be used as a fertiliser, heavy metals transfer to the plant and then eaten by us however.
Secondary treatment of sewage
- Trickling filter beds: rotating arms spray effluent over large cylindrical tank. Invertebrates can digest remaining organic matter.
- Aeration to accelerate decomposition (aerobic bacteria break it down).
Tertiary treatment of sewage
- Remove phosphates, dissolved nutrients you can’t see. Phosphate removed by solution of iron sulfate.
- Effluent strained through very fine sieves (micro-strainers).
What are some effects of acid mine drainage?
- Reduced pH: outside range of tolerance.
- Cells inside leaf stomata and plant root hairs sensitive.
- Inhibits germination of seeds.
- Damages fish eggs and gills.
- Mobilises toxic metals.
- Toxic ions inhibit enzyme action.
- Invertebrate exoskeletons dissolve.
What is the coliform count?
Measure of how many e coli there are. Should be 0 in water.
What are features of a good indicator species?
- Easy to recognise.
- Normally present in the area.
- Reasonably common.
- Widely distributed.
- Easy to locate.
- Varied sensitivity to pollution, some should loathe, some should like.
What are some advantages of using biotic indices?
- Monitor current and past pollution.
- Can help trace source of pollution.
- Can be very sensitive.
- Low pollutant concentrations may be detectable if bioaccumulated in organisms.
- No expensive monitoring equipment required.
What are some disadvantages of using biotic indices?
- Can be time consuming to sort samples.
- Results not always clear to interpret without background biology.
- Accurate identification may be difficult.
Chemical forms of mercury: Liquid mercury
Not easily absorbed in the gut but easily absorbed in the lungs as a vapour.
Chemical forms of mercury: Inorganic mercury compounds
Absorbed through the gut and skin. Not liposoluble, can’t pass across cell membranes so little to none enters brain.
Chemical forms of mercury: Organic mercury compounds
Easily absorbed in gut or as vapour in lungs. Liposoluble and can pass into brain, across placenta, or into breast milk. Take, for example, Minamata Poisoning.
Pathways leading to absorption of lead: Water
- Waterpipes, soldering to join pipes.
- Water corrodes pipes, lead drank in water.
- Replace with copper, zinc, tin.
Pathways leading to absorption of lead: Industry
- Lead dust from mining.
- Dust inhaled or absorbed through skin in sweat.
- Water sprays to allow dust to settle, dust masks to reduce inhalation.
Pathways leading to absorption of lead: Petrol
- Lead present in exhaust fumes and dust can be inhaled.
- Most countries phased out leaded petrol by replacing it with diesel, hydrogen etc.
Pathways leading to absorption of lead: Paint
- Used to be in many paints, still used in some.
- Old flaking paint can be picked up and swallowed by children.
- Paint removal could produce lead vapours.
- Hot air paint removal guns use lower temps, less likely to produce lead vapour.
- Use non lead paint.
Pathways leading to absorption of lead: Fishing and Hunting
- Fishing weights, shotgun pellets.
- Weights discarded, lost, or eaten by swans/ducks etc.
- Tungsten steel can be used for shotgun pellets and small fishing weights.
Iron
- Can be controlled by passing spoil heap drainage water over mesh screens to oxidise and deposit metal on mesh.
- Not directly toxic but can lead to deoxygenation in water.
- Can bioaccumulate.
Cadmium
- Lung cancer, paralysis, brain damage.
- Waste needs to be disposed in hazardous waste landfill, may be recycled e.g. batteries.
- Found in old batteries, certain photovoltaic solar panels.
- Can bioaccumulate.
Tin
- Used as an antifouling paint on boats to stop growth of marine organisms.
- Can damage marine organisms and enter humans when seafood eaten.
- Paint now replaced with less toxic metals and paint residues now removed to landfill rather than washed out at sea.
- Can bioaccumulate.
What are some sources of solid waste?
- Mining (spoil heaps).
- Packaging
- Electronics waste
- Clothes
- Paper
- Agriculture.
What are some issues dealing with domestic waste?
- Large volume produced weekly.
- Produced by every household rather than a few larger sources.
- Composition varies seasonally.
- Mixture of many different types of waste.
What are some factors influencing waste treatment?
- Population density
- Per capita production
- Type of industry
- Land availability
- Available technology for recycling
- Environmental awareness
- Legislation
What are the pros and cons of landfill?
+ Easy.
+ Little to no treatment.
- Often poorly managed.
- Potential valuable resources lost.
- Anaerobic decomposition releases CO2 and methane.
What are the pros and cons of landfill?
+ Volume of ash less than waste.
+ Heat produced can be used for district heating or electricity generation.
+ No sorting or complicated management.
- Toxic dioxins produced (organic waste + chlorine)
- Fuel used to maintain combustion costly.
- Releases atmospheric pollutans.
How could the following problems of spoil heaps be solved: topography (steep slopes of spoil heaps)
Landscaping to reduce slope incline.
How could the following problems of spoil heaps be solved: Instability and Landslides
Compaction, planting vegetation, concrete raft, drainage
How could the following problems of spoil heaps be solved: Low pH
Liming
How could the following problems of spoil heaps be solved: Lack of Nutrients
Addition of topsoil or fertilisers, planting legumes.
How could the following problems of spoil heaps be solved: Toxic Materials
Specialised storage, immobilising heavy metals by raising pH.
How could the following problems of spoil heaps be solved: Contamination with Petrochemicals
Bioremediation - facilitating conditions to support this.
What are some impacts of noise pollution?
- Deafness
- Stress
- Irritability
- Heart disease
- Headaches
- Disturbance to breeding birds
- Livestock can panic and injure themselves
- Reduce feeding success in owls, dolphins etc
How do aircraft design impact surroundings and how can this be controlled?
- Cowling-thrust exhaust noisy.
- Turbulence flaps up = drag = noisy.
- Engine thrust.
- Reverse thrust (landing) to stop planes.
- High-by-pass-ratio engines - 2nd cowling to ‘bypass’ air = smoothens exhaust.
- Acoustic liners: inside outer cowling and inner to make it quieter.
- Have longer runways so not as much braking needed.
- Fairing on undercarriage decreases turbulence around wheels (aerodynamics).
How do aircraft and airport operations impact surroundings and how is this controlled?
- Location (near populated areas).
- Taxi areas.
- Engine test areas.
- Mainly take off and landing.
- Single runway uses reverse thrusters to get off it quickly.
- Put in places with less people so less affected.
- Put away from residential areas.
How does industry impact surroundings and how is this controlled?
- Air compressors.
- Mine blasting.
- Pile driving.
- Marine seismic surveys.
- Sound absoring in room and around equipment.
- Workers ear protection.
- Machinery placed on acoustic mat.
- Use of alternative processes.H
What is ionsing radiation?
- Energy or particles emitted from a source, which when absorbed produces ions.
What are the risk:benefit of nuclear reactors?
Used to make electricity, propel ships, power stations.
+ Clean source of power, GHG production decreased, high energy density.
- Release of radioactive waste.
What is the risk:benefit of radiotherapy cancer treatment?
Kills cells that have mutations using gamma radiation.
+ Increases survival from cancer.
- Other tissues damaged may lead to long term health risks.
What is the risk:benefit of medical and scientific research?
Radio-labelling: Tracing movement of molecules in body using beta/gamma radiation.
+ Discovery of metabolic processes and how the body works.
- Exposure for workers in these areas.
What is the risk:benefit of sterilisation techniques using gamma rays?
Kills microorganisms that may infect wounds.
+ Reduces risk of infection.
- Staff are exposed to radiation.
What are some difficulties determining a risk:benefit analysis?
- Not always aware of risks.
- Difference in location with those who benefit and those at risk.
- Relation to other risks not using radiation e.g. X-rays are a must for diagnostic surgery.
What is the risk:benefit of plant breeding programmes?
Artificially inducing mutations in plant species using X-rays and gamma rays.
+ Development of new varieties with desirable characteristics.
- Exposure of workers.
Effects of ionising radiation: Formation of free radicals
- Highly reactive with unpaired electrons.
- Cause biologically damaging reactions.
- Produce more stable molecules that cause damage within the cell.
Effects of ionising radiation: Damage to the nucleus of the cell
- Cells that are genetically active are most impacted as they divide rapidly e.g. skin.
- Damage to egg and sperm cell may impact future babies.
Methods to reduce exposure of radiation: Closed Sources
- Enclosing radioactive sources so doesn’t come into direct contact with workers.
- Protective clothing.
Methods to reduce exposure of radiation: Absorbing Materials
- Materials used to act as barriers between radiation sources and workers.
- e.g. lead for gamma radiation.
