Heavy Metals And Solid Waste, Noise pollution and ionising radiation

Question 1

What happens with enzyme inhibition in heavy metals?

Answer 1

Heavy metals inhibit enzymes particularly those in the nervous system (neurotoxins), high doses cause damage to liver and kidney

Question 2

How do heavy metals bioaccumulate?

Answer 2

They are liposoluble so may be stored in fat droplets in living cells so that chronic exposure to small doses may eventually produce toxic concentrations, passage along a food chain may also lead to biomagnification

Question 3

What is the solubility and pH of heavy metals?

Answer 3

They are more soluble at a lower pH. Therefore pollution caused by heavy metal wastes can be reduced by increasing the pH to reduce solubility

Question 4

What are the different chemical forms of mercury?

Answer 4

Liquid- Not easily absorbed in the gut but is easily absorbed in the lungs as vapour
Inorganic compounds- Absorbed through the gut and skin. It is not liposoluble so cannot pass across cell membranes
Organic compounds- Easily absorbed in the gut or as vapours in lungs, they are liposoluble so pass easily into the brain, across the placenta or into breast milk

Question 5

How does lead get into our water?

Answer 5

Lead used to make water pipes or soldering to join pipes, water can corrode the pipes over time- small amounts of lead dissolve in the water which is then drunk- chronic exposure

Question 6

What is the solution to lead pollution in water?

Answer 6

Lead pipes replaced by copper, zinc or tin
In areas that still have lead pipes- phosphoric acid can be added which prevents lead dissolving

Question 7

How does lead pollution occur in industry?

Answer 7

Lead dust from mining
Dust can be inhaled or even absorbed through skin if dissolved in sweat

Question 8

What is the solution to lead pollution in industry?

Answer 8

Water sprays to allow dust to settle and dust masks to reduce inhalation

Question 9

How does lead pollution occur from petrol?

Answer 9

Tera ethyl lead (TEL) formerly added to petrol as valve lubricant and anti-knock agent (prevents pre ignition)
Lead present in exhaust fumes and dust can be inhaled

Question 10

What is the solution to petrol lead pollution?

Answer 10

Most countries have phased out leaded petrol by replacing TEL with other agents or using alternative fuels e.g. diesel, hydrogen

Question 11

How does lead pollution from paint occur?

Answer 11

Lead used to be used in many paints and is still used in some specialised paints
Old flaking/ peeling paint can be dangerous to children (swallowing the paint)
Paint removal with blow lamps may also produce lead vapours

Question 12

What is the solution to lead pollution in paint?

Answer 12

Hot air paint removal guns use lower temps so are less likely to produce lead vapours

Question 13

How does lead pollution occur from fishing and hunting?

Answer 13

Lead has been used for fishing weights and shotgun pellets in the past
Weights may be discarded or lost and swallowed by swans/ ducks while shotgun pellets that miss their target may also be swallowed by water birds

Question 14

What is the solution to lead pollution in fishing and hunting?

Answer 14

Alternative materials such as tungsten steel can be used for shotgun pellets and smaller fishing weights

Question 15

How does Cadmium pollution occur?

Answer 15

Found in old batteries as well as used in certain photovoltaic solar panels
Impacts include lung cancer, paralysis and brain damage

Question 16

What is a property of Cadmium Tin and Iron?

Answer 16

Can bioaccumulate

Question 17

How can Cadmium pollution be managed?

Answer 17

Waste needs to be disposed in hazardous waste landfill or may be recycled e.g. batteries

Question 18

What can be the effect of iron pollution?

Answer 18

Not directly toxic but can lead to deoxygenation in water when leached from spoil heaps

Question 19

How can iron pollution be contolled?

Answer 19

By passing spoil heap drainage water over mesh screens to oxidise and deposit the metal on the mesh

Question 20

How can tin pollution occur?

Answer 20

Used as an antifouling paint on boats to stop the growth of marine organisms
Can damage marine organisms and enter humans when seafood is eaten

Question 21

How can tin pollution be reduced?

Answer 21

Paint now replaced with less toxic metals and paint residues now removed to landfill rather than washed out at sea

Question 22

How does affluence impact waste production?

Answer 22

Buy more goods- less essential
Less incentive to reuse ‘throwaway society’
Many products designed with short shelf life e.g. disposable
Over packaging

Question 23

What are the issues dealing with domestic waste?

Answer 23

Large volume produced weekly
Produced by every household rather than a few larger sources
Composition varies seasonally
Mixture of many different types of waste

Question 24

What are the factors impacting waste treatment?

Answer 24

Population density
Per Capita production
type of industry
land availability
available technology for recycling
environmental awareness
legislation

Question 25

What are the features of good landfill site management?

Answer 25

Separation of different waste types and recording of their composition and locations
Polymer liner to prevent the escape of leachate fluids
Perimeter fence to trap litter blown by winds
Regular covering with soil to reduce pest problems
collection and treatment of leachate fluids
collection of methane and its use as a fuel

Question 26

What are the disadvantages of of landfill?

Answer 26

The potential resource value is lost, metals, glass plastics
They use large areas of land
Organic matter decays anaerobically releasing methane
Toxic leachate may leak from poorly managed landfill sites
wildlife habitats and farmland may be lost

Question 27

What are the advantages of incineration?

Answer 27

The volume of ash produced is much less than the original waste
The heat produced may be used for district heating or electricity generation
No sorting or compliment management is needed

Question 28

What are the disadvantages of incineration?

Answer 28

The resource value of recyclable materials is lost
toxic dioxins may be produced by reaction of organic wastes and chlorine
The fuel used to maintain combustion of wet or non flammable wastes is expensive
The wastes may need to be separated to remove wet wastes increasing processing costs

Question 29

How can the topography of spoil heaps be resolved?

Answer 29

Landscaping can be used to reshape the heap although this may require more land

Question 30

How can the instability/ risk of landslides of spoil heaps be resolved?

Answer 30

Stability can be improved through compaction or by constructing buildings on concrete rafts to reduce uneven settling, reducing the risk of subsidence

Question 31

How can the low pH of spoil heaps be resolved?

Answer 31

The addition of lime reduces the acidity of spoil

Question 32

How can the lack of nutrients in a spoil heap be resolved?

Answer 32

The addition of topsoil, sewage sludge and fertilisers are common techniques to improve the nutrient content and incease plant growth

Question 33

How can the toxic materials of spoil heaps be resolved?

Answer 33

These should be collected and treated to prevent them from entering water courses
Deeper layers of soil should be applied during reforestation so that plant roots cannot reach the layer containing toxic materials

Question 34

How can the contamination with petrochemicals in spoil heaps be resolved?

Answer 34

Petrochemical waste can be treated by bioremediation
Certain species of bacteria will digest the oil if appropriate conditions of temperature, water supply and aeration are maintained

Question 35

What are the levels of the waste hierarchy?

Answer 35

Prevention- Avoid waste production in the first place
Preparing for reuse - Referbish and repair when possible
Recycling- turning waste into new materials
Other recovery - Anaerobic digestion and incineration with energy recovery
Disposal- Disposal and incineration without energy recovery

Question 36

What are the issues with recycling aluminium?

Answer 36

Not all material can be recycled unavoidable losses
Energy used to transport and recycle must be less than energy used to extract out the ground initially
Will be less energy efficient if small quantities are used
Alloys are not easily separated and so recycled alloys cannot be used
Identifying from other resources is slow and labour intensive
Public recycling schemes require cooperation

Question 37

What are the different methods of recycling aluminium?

Answer 37

Use of offcuts
Reduced material use in manufacture
Replacing scarce materials with more abundant or more easily recycled versions

Question 38

What is the scale that measures the unit of sound?

Answer 38

DeciBel scale

Question 39

What is the scale modified to weight the frequencies most sensitive to the human ear?

Answer 39

dB(A) scale

Question 40

What is the measure of traffic noise pollution during the noisiest points?

Answer 40

L10 18h

Question 41

What is the measure of traffic noise pollution for noisier and quieter times?

Answer 41

TNI

Question 42

What is the measure to monitor aircraft noise pollution?

Answer 42

NNI

Question 43

Why is using a logarithmic scale dB appropriate?

Answer 43

Human ear sensitive to a very wide range of sound levels
0dB is set as the quitest sound that can be heard at 1000hz and is the threshold for human hearing
Age along with prolonged exposure to loud noises can reduce the sensitivity and range of hearing

Question 44

What are the effects of noise pollution on organisms?

Answer 44

Deafness
Stress
Irritability
Heart diseae
Headaches
Disturbance to breeding birds
Livestock can panic and injure themselves due to sudden noises
reduced feeding success in e.g. owls, dolphins
Behavioural changes in cetaceans e.g. strandings

Question 45

What are the effects of noise pollution of non living objects (acoustic fatigue)?

Answer 45

Sounds that cause objects to vibrate at their resonant ( natural frequency at which they vibrate) can lead to acoustic fatigue by causing stress cracks to appear
Repetitive vibration can also cause damage to buildings, bridges and underground pipes caused by wheel vibrations of trucks
Sonic booms from aircraft can also damage e.g. smashed windows

Question 46

What is ionising radiation?

Answer 46

Energy or particles emitted from a source, which when absorbed produces ions (charged atoms)
These ions may cause abnormal chemical reactions to occur or change the chemical properties of the material that absorbed it

Question 47

What does the unit of radiation becquerel measure?

Answer 47

The level of activity of the source

Question 48

What does the unit of radiation gray measure?

Answer 48

Measures the absorbed dose

Question 49

What does the unit of radiation sievert measure?

Answer 49

The effective dose taking into account the type of radiation

Question 50

What is the difference between exposure and contamination?

Answer 50

Exposure- when a person or object absorbs ionising radiation when within range of a source of radiation
Contamination- Direct contact with a source of radiation

Question 51

What are some examples of sources of radiation?

Answer 51

Radon from the ground- 50 percent
Internal body sources- 11 percent
Medical exposure
gamma rays- 14 percent

Question 52

What are the effects of ionising radiation on living organisms?

Answer 52

Formation of free radicals-
Ions are highly reactive with unpaired electrons
Can cause biologically damaging reactions
They may produce more stable molecules that cause damage within the cell
Damage to the nucleus of the cell-
Impacts existing and future cells
Damage to egg and sperm cells (gonadic effects)
cells that are more genetically active are most impacted (divide rapidly)

Low doses may cause no long term effects
High doses cause rapid cell death, damage to bone marrow