Pollution of Air, Water & Soil Flashcards
What was known about pollution before the industrial revolution?
- Hunter gatherers - Nomads invented chimneys to remove smoke from living quarters
- Growth of large settlements - Greek/Romans noticed smoke and sewage problems
- Shelters had poor ventilation so increased incidence of smoke related illnesses
- Eleanor of aquitane (1157) described ‘pollution’ as ‘undurable’
- Coal burning banned in London by royal proclamation
How did the industrial revolution affect the pollution?
- Air pollution problems resulted in increased incidence of some diseases (e.g. rickets) linked with light penetration to earth’s surface
- ‘stinking fogs’ co-incided with peak rates of mortality
- Not helped by high density housing or populations being defined to valleys
- Sulphur emissions increased dramatically
What was done to help prevent sulphur pollution?
- First Public Health Act (1848) and later ones in 1866 & 1875
- Formation of Alkali Inspectorate focussed on curbing emissions from emerging chemical industries
- Robert Angus Smith - first Alkali Inspector. He was the first to introduce the term ‘acid rain’
What were the effects of the industrial revolution?
- Damaged vegetation and species numbers
- Selected pollutant resistant species, which scape our urban environments to date
- Smoke damage to buildings
- Acid deposition
Where was smog first seen and what effects does it have?
- LA and many US cities
- Damages ozone concentrations and vegetation
- Smoke harms buildings
What factors effect the fate/dispersion of pollutants?
- Chemical and physical nature of the pollutant
- Height and extent of emissions
- Wind speed
- Temperature
- Weather
- Atmospheric chemistry
- Nature of receptor ‘surface’
Why does the type of vegetation make the effects of pollution vary?
-Different vegetations have different surface areas, therefore different vegetations are considered
How can pollutants enter the leaf?
- Stomata
- Solutes can enter via the cuticle
What is the simplest way of testing for pollutants?
- Bubble pollutant through a solution of hydrogen peroxide
- Alkali gas would just neutralise the hydrogen peroxide
- Hydrogen peroxide oxidised the the acidic gas to form a acidic solution
What is passive sampling?
- Based on deposition of gas on an absorbant surface
- Cheap, no power required, easily transported, useful for human health assessments, relative ease of analysis
What are the advantages of passive sampling?
- Cheap
- No power required
- Easily transported
- Useful for human health assessments
- Relative ease of analysis
What are the disadvantages of passive sampling?
- Commonly poor quality-control
- Long-term averages?
- Wind-speed dependent
- Not very accurate, high variability and not very sensitive
What are the drawbacks to state of the art technology?
- Cost - £10,000 - 20,000
- Requires power
- Frequent calibration required
- No ‘real time’ instruments available
- Interpolation needed - inevitably
- Doesn’t show any biological impact
Describe biomonitoring and bioindicators?
-Use lichens to map ambient SO2 concentrations
What are the advantages of Biomonitoring?
- No power requirement
- Cheap
- Demonstrates biological effects
- Intergrates effect associated with pollutant dose
What are the disadvantages of biomonitoring?
- Different surfaces can effect the lichens present
- Effects may be historical as lichens take decades to cover
What are tar spots?
- Spots on tree leaves which are correlated with SO2
- More frequent in the tree
Describe mapping of symptoms of pollutants
- Mapping various symptoms of pollution
- E.g Tabacco
Describe pollution pollution collectors
- The use of plants as accumulators
- Put out to collect pollutants then analysed
What are transplants of sensitive taxa? E.g tobacco
-Expose plants to pollution, then go back and measure the rate of pollution
What are problems with using tabacco as a pollutant meaurement?
- Not useful for colder climates
- Visible symptoms not related to yield
- Relationship between injury and ozone does is complex
- Ozone conc cannot be estimated from injury score
Describe NC-S and NC-R mesurements
- NC-S and NC-R clovers are grown in the environment
- The biomass ratio is then compared to ozone conc in a graph
- Problem is that ozone may affect different species in different ways
What is oxidative stress?
- Caused by reactive oxygen species (ROS)
- Free oxyradicals - ‘Any species capable of independent existence that contains one or more unpaired electrons’
- Oxyradicals are formed by loss of a single electron from a non-radical species, the gain of a single electron via a non-radical or via the rupture of a covalent bond
How do plants prevent damage from ROS/AOS?
- Natural product of metabolism and plants have evolved armourt of defences to combat AOS
- These must be overwhelmed for pollutants to result in ‘damage’
List equations which neutralise ROS/AOS
- O2 + 2e- -> H2O2
- O2 + 3e- -> 2H20
What substrate is good at neutralising ROS/AOS
-Vitamin C (Ascorbate)
Describe the Ascorbate-glutathione cycle
- Ascorbate moves to Dehydro-ascorbate turning H2O2 to H2O
- 2H2O converts 202- into H2O2 and O2
How does ozone effect plants?
-It reduces the production of RNA for rubisco small subunit
How many generations can it take for ozone resistance or sensitivity to show?
-4 generations
Why do we need to provide plants with sulphur?
- Crops evolved in 1960s when SO2 levels were high
- Plants now sulphur deficient as SO2 levels have decreased again
How much does ozone pollution cost the US and Europe per annum?
- £6-10 billion in crops lost
- Significant variation in ozone sensitivity
- Oxidant pollution appears to be a driving shift in the composition of native herbaceous vegetation
What are the symptoms of ‘new forest decline’?
- Yellowing of tops of tree branches, Mg deficiency
- The premature dropping of needle in older branches
What was first said to be the main cause of ‘new forest decline’?
- Ph of soils decreasing (more acidic) therefore more Al is released into the soil causing symptoms
- Ozone is the cause as decline is shown to be in a greater number in areas with increased ozone
What is the main cause of ‘new forest decline’?
-A combination of different pollutants
How many types of forest decline are there?
- 4
- Rehfuess et al 1989
What four scopes of water pollution are there?
- Episodic - accidents
- Point - source
- Chronic - multi-point source
- Diffuse - field/urban run-off (non-point)
What are the two forms of water pollution?
- Non-accumulating - biodegradable
- Accumulating - persistent non biodegradable
Define ‘Bio-Accumulation’ and ‘Bio-Magnification’
- An organism absorbs a pollutant at a rate greater than which it is lost
- Increase in concentration of a substance that occurs in a food chain
Define Eutrophication
- The over fertilising of crops causing a biological acitivity
- Enrichment of lakes rivers and sea waters with nutrients N and P (but also Si, K, Ca, Fe, Mn)
Describe the natural process of eutrophication
- Natural and slow process
- Production very slowly exceeds consumption
List processes which contribution to cultural eutrophication
- Natural/fertiliser run-off
- Sewage
- Nitrogen compounds produced by cars
What is the principle of limiting factors?
-Rate of ecological process determined by the environmental
factors present in least supply relative to demand
List all 5 trophic categories
- Ultra-olgiotrophic - non-biological
- Oligotrophic -some biological activity
- Mesotrophic - (intermediate state)
- Eutrophic - biologically very productive
- Hypereutrophic
- biologically very productive with almost all species
What is BOD?
- Biochemical oxygen demand
- pollutants decrease O2 levels therefore cause absent of fish
Define ‘Hypoxia’
-Low O2 levels from pollution
What are the three zones of stratification in summer?
- Epilimnion - top
- Thermocline - middle
- Hpolimmion - bottom
What are the effects of eutrophication?
- Penetration of light is diminished, O2 is depleted
- Changes in species composition
- Plant biomass increases
- Anoxia
- Increase of sedimentation
What are the human impacts of Eutrophication?
- Injurious to health as algal growths can release toxins
- Blocking of commercial waterways
Why is precipitation’s pH around 5-6?
-CO2 dissolves into H2O
What problems does acid rain cause?
- Decline of fish populations
- Lake acidification
- Forest decline
What is natural acidification of freshwater?
- Action of atmospheric carbonic acids, forming humic acids by litter decomposition and podzolisation
- Land use change, reduced animal grazing and increase nitrogen fertiliser
Which tree is the most acidifying?
-Pine tree
What is a critical load?
-The highest deposition of acidity that will not cause chemical changes leading to long-term harmful effects
What is the mineral titration theory?
- Base-rich oils have high buffering capacity
- Acidic organic soils have little buffering capacity, runs directly into soil
What is the order by which minerals buffer?
- Carbonate pH 6.2-8
- Silicate weathering pH 6.2-5
- Cation exchange pH 5-4.2
- Aluminium pH 4.2-3
- Iron pH >3
Whats difference in Loch Chon catchment and Loch Kelty catchment?
- Chon is Norway spruce, whereas Kelty is Sitka
- Chon has podzolic soils, Kelty has gleyed clay soils
- Chon has Reduced viable fish population, whereas Kelty has no fish population
- pH of Chon is 4.7, pH of Kelty is 4.1
Why is there more Mg2+ in Loch Kelty then in Loch Chon?
-Rain is more acidic so Mg2+ is leached from leaves
What is Preferential elution?
- The rapid melting of acid snow in the spring causing pH to drop
- Can cause problems with fish hatching as occurs during hatching time
- Invertebrate communities are changed
How are invertebrate communities affected by acidification of water?
- Less diversity but greater abundance
- Mayflies, caddis flies vulnerable
- Ca deficiency so shells unable to form
How are fish communities affected by acidification of water?
- Ca deficiency cause skeleton deformity
- Decrease in reproductive success
- Sodium potassium deficiency disrupts osmo-regulation
- Aluminium hydroxide ppt on gill mucus membranes
How is acid rain being reduced?
- Limestone scrubber - used to take SO2 and Hg out of coal
- Liming of lakes - very expensive, 1000 tons used at Loch Fleet, kills sphagnum
What are the sources of toxic elements?
- Geochemical - Mineral weathering
- Anthropogenic - Metal mining, Agricultural materials, fossil duel combustion, metallurgical industries, electronics, sewage sludge and waste disposal
What pH releases toxic metal?
-Acidic pHs
Why is Pb so bad?
- Non-essential, can accumulate in the human body
- Sources include mining and smelting, paint, petrol, shooting, landfill electronic equipment
Why is Cd so bad?
- Non-essential, more labile and less strongly absorbed
- Sources include mining, sewage sludge, phosphate fertilisers, landfill
Cd in japan
- Cd in rice field due to Zn/Cd mine nearby, rice main part of diet
- Zn phytotoxic
