Pollution

Question 1

explain how features of the environment may affect the dispersal of atmospheric pollutants. (4)

Answer 1

wind velocity- distance travelled
wind direction- dispersal
temperature- rate of degradation
presence of the pollutants- chemical reactions/synergism
presence of UV/sunlight- photodegradation/chemical reactions
topography- reduce movement away from source/shelter

Question 2

Which atmospheric pollutant is controlled by landfill tax? (1)

Answer 2

Methane

Question 3

use tropospheric ozone to explain the meaning of secondary pollutant? (2)

Answer 3

formed by reactions of other pollutant(s);
trop O3 formed by breakdown of NOx to release monotonic O and reaction of O2/ interaction of NOx and O2

NO2–>NO+O
O+O2–>O3
NO+O2–>O3

Question 4

Explain how tropospheric ozone increases the problems caused by acid rain. (3)

Answer 4

synergistic action;
ozone damages wax/cuticle/stomata;
exposes leaf to other acidic pollutant;

reacts with sulfur dioxide to produce sulfur trioxide;
SO3 produces sulfuric acid;
increase damage
e.g.
corrosion
leaching of toxic metals

Question 5

describe how changes to soil, caused by acidic pollution, harm plants. (2)

Answer 5

soil deflocculation;
nutrient leaching/solubility/loss;
enzymes denatured/proteins denatured;
reduced decomposition

Question 6

describe features of lichens that make them useful in monitoring acidic atmospheric pollution. (4)

Answer 6

range of sensitivities (to acidic conditions);
generally distributed;
easy to find;
easy to identify;
normally common;

Question 7

explain how biotic indices may be used to monitor pollution. (6)

Answer 7

sensitivity to pollution;

range of tolerance/different sensitivities;
lichens/aquatic invertebrates

presence/absence;
abundance;
size/state of health

easy to find/catch;
easy to identify;

Question 8

describe the factors that make it more likely that a temperature inversion will occur. (3)

Answer 8

high pressure;
low wind speed;
valley;
clear sky;
night time;

Question 9

outline the differences between smoke smogs and photochemical smogs. (5)

Answer 9

smog:
smoke + fog
colder days
combustion of FF

photochemical smog:
NOx + HC + O3–(>18°C and sunny)–>PANS
warmer days
combustion of FF in car engines

Question 10

suggest how the production of a named pollutant, other than smoke, may be reduced by the name of a secondary fuel. (1)

Answer 10

CO2/SO2/NOx are not released when an there is an increase in use of hydrogen

Question 11

ozone is involved in many environmental issues.
outline how ozone is environmentally important in the following (1 mark for each)

Answer 11

acid rain:
oxidises SO2 to SO3

the stratosphere:
absorbs UV/prevents skin cancer

photochemical smog:
interaction with NOX
production of PANs

directly affecting living organisms:
eye/respiratory/asthma/leaf cuticle damage

Question 12

suggest how the low persistence of ozone affects the severity of the pollution it causes. (1)

Answer 12

only short term/reduced mobility

Question 13

describe how oxides of nitrogen may cause the production of a secondary pollutant. (2)

Answer 13

photochemical reaction to create PANs
NOx + HC + O3–(>18°C and sunny)–>PANS

Question 14

outline methods that may be used to reduce the emissions of oxides of nitrogen. (2)

Answer 14

catalytic conveter;
reduces;
oxygen+nitrogen produced;

urea/ammonia treatment;

Question 15

outline methods that may be used to reduce the emissions of sulfur dioxide… (2)

Answer 15

1) Use of renewable energy such as solar/wind instead.
2) Coal Washing- removes some of the sulfur before combustion
3) Use of scrubbers- installed in power plants, removes SO2 from exhaust gases before they are released into the atmosphere.

Question 16

explain how lichens can be used to monitor atmospheric pollution. (4)

Answer 16

-lichens- sensitive=small range of tolerance as they absorb pollutants directly from the air. Reveal levels of pollution, especially sulfur dioxide.
- Can map populations using lichen indicator scores (LIS) or mapping distribution.
- If air is heavily polluted there may be no lichens present whereas in areas with cleaner air, a greater variety of shrubby and leafy lichens will be found.

Question 17

Describe the methods that have been used to reduce the releases of methane. (4)

Answer 17

1) Improved waste management eg capture of gas from landfill.
2) better agricultural practises such as livestock diet and manure management.
3) Use of renewable energy

Question 18

Explain how the environmental impacts of hydraulic fracturing can be reduced (3 marks)

Answer 18

• not near aquifers
• Avoid sensitive areas
• collect and treat gas emissions
• noise pollution can be reduced through baffle mounds

Question 19

The scientists concluded that this species of aerobic bacteria could be used effectively as a bioremediation treatment in the event of a crude oil spill. Suggest three conditions under which bacterial bioremediation of oil spills may not be effective (3 marks)

Answer 19

1) Anaerobic conditions
2) Extreme salinity
3) Extreme PH
4) Areas with low temperatures

Question 20

Chemical dispersants may also be used to clean up oil pollution. Suggest one advantage and one disadvantage of using chemical dispersants (2 marks)

Answer 20

Advantages:
- Breaks up oil slick so oil disperses more readily
Disadvantages:
- may be toxic to organisms

Question 21

Describe the features of species that would make them suitable for use in a biotic index (4 marks)

Answer 21

• normally present/common
• easily identified
  -easily collected
• range of sensitivities
• generally distributed

Question 22

Suggest why the diversity of invertebrate species increased with distance downstream from the mine (2 marks)

Answer 22

-downstream may be within range of tolerance
-due to lower concentrations of pollutants such as toxic metals due to dilution

Question 23

Outline one factor used to identify individuals for a Critical Group Monitoring (CGM) study in Great Britain of the radioactive contamination from Chernobyl (1 mark)

Answer 23

• occupation that experiences high radiation exposure eg farmer, dog walker.
• where individuals live in relation to the source

Question 24

Name different types of control technologies for pollutants

Answer 24

1) oil and radioactive waste- adsorption by polymers.
2) heavy metals and pesticides- bioremediation.
3) heavy metals- leachate collection.
4) oil and pesticides- phytoremediation.
5) satellite monitoring

Question 25

How does a longer half life mean lower risk to health?

Answer 25

less radioactive radiation released per unit of time

Question 26

Explain which type of particle poses the greatest health risk if ingested

Answer 26

alpha particles as they have greater ionising power whereas gamma has the lowest

Question 27

Outline one method that is used to manage high-level radioactive waste from nuclear power stations (2 marks)

Answer 27

deep burial in a seismically stable area

Question 28

Explain why PM10 samples vary at different times of the year (3 marks)

Answer 28

1) Temperature inversions- PM10 trapped in cold dense air. 2) periods of high rainfall- wash particulates out of the atmosphere. 3) Increased demand for heating/energy/fossil fuels/wood. 4) Increased use of vehicles (from exhaust emissions) eg car use on bank holidays

Question 29

Stages in the treatment of sewage

Answer 29

1) Pre treatment- screens/sieves used to trap large floating items. 2) Primary treatment- effluent is stored in tanks and the faecal solids sink to the bottom. The sludge that is formed at the bottom is then removed. 3) Secondary treatment- put into aeration tanks/oxidation ponds where aerobic bacteria decompose the remaining OM. 4) Tertiary treatment- UV light/sterilising chemical used to remove bacteria and pathogens.

Question 30

Compare the environmental effects of different inorganic and organic nutrient pollutants (9 marks)

Answer 30

Inorganic: Nitrates- from artificial fertilisers. Cause eutrophication and also if ingested may cause blue baby syndrome or be a human carcinogen. - Phosphates from sewage- also contribute to eutrophication, increases risks of cardiovascular disease, biodiversity loss. - detergents Organic: - degraded soil particles- increase water turbidity. - manure- eutrophication - sewage- may contain pathogens/bacteria spreading disease

Question 31

State two methods that may be used to reduce the radiation dose received by workers exposed to radioactive materials (2 marks)

Answer 31

1) Clothing/respiratory protection eg face masks. 2) Setting a maximum time for exposure

Question 32

Describe one method that may have been used to obtain noise contour data around an airport (4 marks)

Answer 32

- noise monitoring stations - systematically isolated - 10 or more samples sites - using calibrated sound meters - same wind direction

Question 33

Explain how two named changes in aircraft design have contributed to the reduction in aircraft noise emissions (4 marks)

Answer 33

1) More aerodynamic surfaces/ blended wing aircraft meaning less noise due to turbulence/vibration. 2) engine acoustic liners, absorbs engine noise

Question 34

Outline how two changes in aircraft flight operation may reduce noise pollution around an airport (2 marks)

Answer 34

1) Change flight paths to avoid urban areas. 2) noisy aircraft banned/charged 3) lower altitude flights banned over urban areas

Question 35

Discuss the extent to which improvements in technology have reduced atmospheric pollution on local, regional and global scale (25 marks)

Answer 35

Smoke/smoke smogs- Incomplete combustion of coal, diesel, wood, crop waste. Fixed by Diesel particulate filters (DPV) Trap smoke particles and Reduce particulates in cities. Smokeless coal More efficient combustion technology in diesel engines. Reduced respiratory disease Reduced albedo of atmosphere Reduced smoke smogs during temperature inversions Photochemical smogs- Catalytic converters Vapour collection at petrol stations. Reduced damage to non-living objects: damage to limestone buildings, metal structures * Living organisms * Direct effects of acids * Damage to proteins * Damage to exoskeletons * Respiratory effects in humans Acid rain- Control of NOx – low temp combustion, catalytic converters, urea sprays- Reduced acidification of soil, water bodies, mobilising of heavy metals. Reduced impacts on biodiversity Transboundary pollutant

Question 36

what is mutagenic action?

Answer 36

Mutagens= agents causing changes in chemical structure of DNA by damaging chromosomes by rearrangement of DNA structure. Changes are known as mutations

Question 37

what is synergism and what does it involve?

Answer 37

-Involves 2+ pollutants where their effects interact to create diff effect, usually more serious one -Pollutants themselves don’t interact to produce new pollutant (would be secondary pollutant), it’s their effects that interact, eg ozone damages leaf cuticles & enables sulfur dioxide to cause more damage to newly exposed living cells

Question 38

mutagenic action- what are gonadic and somatic effects?

Answer 38

-Gonadic effects (cells in ovaries/testes); mutation in egg/sperm cell/embryo may cause birth abnormality in offspring produced -Somatic effects (general body cells); mutation in body cell may make it behave abnormally as damaged DNA can’t control normal cell function. Death of individual cells—> rarely issue as can be replaced by division of other healthy cells. Serious consequences of these are if not killed= cancer

Question 39

teratogenic action?

Answer 39

-Teratogens; cause birth abnormalities by preventing normal gene expression. They don’t change DNA structure but inhibit function of proteins & enzymes that DNA would’ve normally controlled.

Question 40

what are the factors allowing temperature inversions to form?

Answer 40

-Valleys; where colder denser air can collect -Low wind velocity; so air layers w/ diff temps don’t mix -Cloudless skies; so infrared energy can be radiated from ground, allowing ground to cool down -Mist/fog during day; water vapour that condenses in cooler ground layer has ↑ albedo & will reflect sunlight + slow heating of ground that would cause temp inversion to ke broken down

Question 41

what is the purpose of the Critical Pathway Analysis (CPA)?

Answer 41

-Predict movement of potential pollutants in environment to assess severity & location of pollution that may occur -If potential pollutant would be diluted & dispersed/carried to locations where impacts would be acceptable—> no further action may be needed

Question 42

General strategies to control pollution; what are the factors that may be included in Critical Pathway Analysis (CPA)?

Answer 42

-Properties of the pollutant; state of matter, density, solubility in water/lipids, chemical stability -Features of the environment; wind & water currents, geology, pH, O2 availability, temperature

Question 43

what are examples of pollution control methods?

Answer 43

-Production prevention; desulfurisation of fossil fuels before combustion -Prevention of release; electrostatic precipitators for smoke control & catalytic converters for control of NOx, CO, hydrocarbons in vehicle exhaust emissions -Post-release remediation; oil spill clean-up methods & phytoremediation of land contaminated w/ heavy metals -Alternative processes; use of electric vehicles instead of diesel/petrol ones, use of pyrethroid pesticides instead of more polluting organochlorines, eg DDT & use of renewable energy resources instead of fossil fuels

Question 44

BATNEEC

Answer 44

the Best Available Technology, Not Entailing Excessive Cost

Question 45

‘ALARA’

Answer 45

As Low As Reasonably Achievable

Question 46

what are the effects of smoke pollution on other living organisms?

Answer 46

-↓ photosynthesis as smoke blocks -Substances in smoke particles may be toxic, eg heavy metals & acids

Question 47

Smoke and smoke smogs; what are the effects of smoke pollution on non-living objects?

Answer 47

-Smoke particles can damage buildings due to acids & organic solvents they may contain -Cleaning dirty buildings → expensive

Question 48

how can transport sources be smoke pollution control measures?

Answer 48

Diesel Particulate Filters (DPF) fitted in exhaust pipes of diesel engines trap up to 80% of smoke particles

Question 49

Smoke and smoke smogs; industrial sources- how can bag filters be used as smoke pollution control measures?

Answer 49

Remove smoke particles from effluent gases by trapping them on fabric titter

Question 50

industrial sources- how can scrubbers be used as smoke pollution control measures?

Answer 50

Uses fine water spray to wash out suspended solid particulate matter & dissolve soluble gaseous pollutants

Question 51

Use the information in the text and your own knowledge to explain why the discharge of low levels of inorganic mercury compounds caused such serious health effects. [5 marks]

Answer 51

* Lack of dilution/dispersal as bay is enclosed * Liposolubility allows storage in fat * Bioaccumulation as concentration in organisms increases * Biomagnification as concentration increases along food chains * Persistence as compounds do not degrade * Neurotoxic as mercury inhibits nerve cell enzymes * Teratogen as gene interference causes birth abnormalities * Adsorption onto sediment particles increases concentration in sediments

Question 52

Explain why smoke samples collected at different times in the same location during this study may have produced results that show great variability. [4 marks]

Answer 52

* Traffic levels vary over different timescales: weekday/weekend/ rush hour * During temperature inversion smoke is trapped in cold, dense air * Rainfall washes smoke out of atmosphere * Changes in wind velocity and direction affect dispersal * Smoke production by heating fuel fluctuates with seasons and weather.

Question 53

How do the presence of adsorbent materials help to reduce pollution?

Answer 53

Pollutants may adsorb onto materials such as clay particles in aquatic sediments. Adsorption may immobilise the polltant and stop it causing problems

Question 54

How can oil pollution be fixed

Answer 54

1) Skimmers 2) Adsorbent materials 3) Detergents/dispersants 4) Polymerising agents 5) Steam washing 6) Bioredmediation

Question 55

What are the pollutants involved in acid rain?

Answer 55

Sulphur dioxide dissolves in water to produce sulphurous acid

Question 56

Organochlorines (DDT)

Answer 56

- high toxicity to insects (can lead to non target insect deaths eg butterflies) - low toxicity to vertebrates, including mammals so farmers unlikely to suffer toxic effects. - High persistence - Heavy liposolubility and low solubility in water - bioaccumulates and biomagnifies

Question 57

Organophosphates

Answer 57

- low persistence - low liposolubility - don't bioaccumulate/biomagnify - high mammalian toxicity so farmers at risk

Question 58

Pyrethroids

Answer 58

- high insect toxicity - low mammal toxicity - not persistent - don't bioaccumulate/biomagnify - toxic to fish

Question 59

Neonicotinoids

Answer 59

- high insect toxicity - relatively persistent - relatively water soluble - very toxic to bees

Question 60

Explain three properties of pesticides that cause pollution in an environment (3 marks)

Answer 60

Specificity- no pesticide is entirely specific to one species, harm to non-toxic species is often caused. Persistence- pesticides may remain in the environment for a long time, this leads to them dispersing and more likely to bioaccumulate Bioaccumulation- some pesticides may be liposoluble and therefore bioaccumulate in the body. Biomagnification- pesticides may build up along the food chain affecting predator species. Mobility- can widen the area affected and increase the number of non-target organisms affected

Question 61

Explain two features of the environment that need to be considered when completing a CPA for mercury compound containing water being released (4 marks)

Answer 61

1) Water currents must be assessed as this can carry mercury compounds to other sites that may be more sensitive . 2) Oxygen availability must be assessed as anaerobic conditions can change the type of mercury compound and therefore lead to more significant affects. 3) PH must be assessed as solubility of heavy metals changes with PH.