Pollution

• What is pollution?


  involves the release of substances or forms of energy into the environment that cause harm, especially to living organisms
• What is the difference between pollution and pollutants?


  - pollution is an undesirable change in the environment, whereas a pollutant causes the damage to the environment ( can be natural or anthropogenic)
• Damage can be...

  direct or indirect
• Give an example of direct damage


  effluent discharge from factories or wastewater treatment plants that kill aquatic organisms
• Give an example of indirect damage


  sulfur dioxide emissions cause acid rain which damages or kills trees and crops
• List all the properties of pollutants (17)


  1. states of matter

  2. energy form

  3. density

  4. the source of pollution

  5. persistence/ degradability

  6. toxicity

  7. chemical reactivity

  8. specifity

  9. adsorption

  10. solubility ( water, lipids)

  11. mobility

  12. bioaccumulation

  13. biomagnification

  14. synenergy

  15. mutagenicity

  16. carcinogenicity

  17. teratogenicity
• What are the states of matter, in relation to properties of pollutants? ( only list)


  states of matter- solid, liquid and gas
• Give three examples of gases which cause pollution

  - sulfur dioxide + CO2 from burning FF

  - NOx from car exhausts

  - CFCs from aerosols
• Give three examples of liquids which cause pollution

  - oil from oil leaks or spills

  - fertilisers

  - sewage
• Give three examples of solids which cause pollution


  - smoke particles

  - suspended solids in water

  - solids domestic waste ( rubbish)
• List all the energy forms as properties of pollutants

  - noise

  - ionising radiation

  - heat

  - light

  - alright= heat waves, radio waves, IR light and visible light

  - meh= UV

  - bad= x-rays and gamma rays
• What is another property of pollutants which is based on how compact something is?


  density
• Describe density relating to solids


  - denser solid particle= closer to source they settle out ( e.g lead dust)
• Describe density relating to gases


  - gases denser than air sink nearer source if there is insufficient wind to disperse them
• Describe density relating to liquids


  in liquids denser particles sink more quickly
• What are the two sources of pollution as a property of pollutants?

  1. point source= from a defined place with a definitive effect ( e.g. oil spills from a tanker)

  2. diffuse source= from many sources with combined impacts ( e.g. car exhausts)
• Describe persistence and degradation as a property of pollutants


  1. persistence= measure of length of time that a pollutant remains in the environment before it breaks down chemically degrades

  - if P is persistent= not very degradable

  - measured by half-life= called environmental half-life ( TI ENV)= but not precise as can be affected by environmental factors (e.g. light)

  2. degradation= process of breakdown

  - categorised according to feature causing breakdown:

  . biodegradation= caused by living organisms

  . photodegradation= caused by light

  . thermal degradation= caused by heat
• Give an example of a high persistent pollutant

  CFCs
• Give an example of a low persistent pollutant


  sewage
• What are persistent organic pollutants? Give examples


  - those which don't degrade the environment

  - e.g. DDT 1 , PCB 1 2, dioxins

  1= intentionally produced

  2. unintentionally produced
• What are some of the effects of persistent organic pollutants?


  - nearly wiping out the bald eagle

  - disease and abnormalities in living creatures

  - reproductive impairments
• What is toxicity as a property of pollutants? Give examples


  - the effect they have on chemicals in the body

  E.G.

  1. CO2= prevents blood from carrying 02 by binding to haemoglobin in RBC

  2. LEAD= inhibits enzyme action in nerve cells

  3. ACIDS= inhibits protein action by chnaging the molecular shape 4 example, the AS of an enzyme

  4. CYANIDE= inhibits enzymes involved in aerobic respiration
• What can DDT break down into and what can it cause?


  - DDE

  - breast cancer

  - diabetes

  - decrease semen quality

  - spontaneous abortion ( miscarriages)

  - impaired neurodevelopment in children
• Describe chemical reactivity as a property of pollutants


  - very reactive chemicals= don't last long in enviro

  - can be highly toxic, but not 4 long (e.g acid)

  - chem can react together to make something worse

  - reactivity of a pollutant can affect severity of pollution cause ( either increase or decrease)
• Define a primary pollutant


  released by human activity
• Define secondary pollutant


  produced by chemical reactions between one or more primary pollutants, often with non-pollutants
• Describe what PANS are


  - made when NOx from car exhausts, 02 in the air + unburnt hydrocarbons react in the sunlight

  - note: NOx + unburnt H r Primary P

  - they are toxic + irritating to eyes and lungs

  - they also kill plants
• Name two pollutants, describe their reactivity and give their effect on pollution

  1. CFCs= low, except in the presence of UV light. Relatively stable in the troposphere, but r broken down in the stratosphere where the gases release chlorine

  2. NOx, 03, hydrocarbons= high. React with others to produce PANS which are more toxic
• Describe specificity in terms of a property of pollutants and give an example


  - describes the variations in toxicity to different groups of organisms

  - specific toxins are more toxic to some groups than others

  - non-specific pollutants have similar toxicities to all groups

  E.G. pyrethroid insects= increase toxicity to insects + fish, but decrease to animals + humans
• What is adsorption in terms of properties of pollutants? Give an example and explain the problem


  - molecules stick onto outside of other particles

  - E.G. pollutants sticking to soil particles/ aquatic sediments. Can immobilise them so they can't cause pollution. PROBLEM= can be released later ( e.g. phosphate release after a big storm)- however can be used to clean up pollutants
• Describe solubility of water and lipids, in terms of properties of pollutants

  1. WATER SOLUBLE POLLUTANTS= E.G. nitrates r very mobile in the hydrosphere + lead to eutrophication

  2. LIPOSOLUBLE POLLUTANTS= r more soluble in fats, such as body tissue in animals

  - substances that dissolve in lipids may be able to pass through phospholipid cell membranes + be store in oil or fat deposits within cells= more likely to biomagnify
• Describe two examples of solubility ( property of pollutants)


  1. DDT= famous synthetic pesticide= used since late 1940s

  - kills arthropods as contact poison

  - stored in body fats= releasing its poison over time- both water + lipo soluble

  2. PCBs= used coolants, insulating fluids, adhesives etc

  - hazards recognised in 1937

  - actually banned in 1970

  - very persistent

  - extremely toxic= many illnesses + cancer caused

  - bioaccumulated in body fats
• Describe mobility in terms of properties of pollutants


  - measure of the degree to which a pollutant can be carried by wind, water or organisms

  - for instance= smoke plumes, acid rain

  - pollutants= very mobile= impact wider areas= but dilation can decrease its effect

  - ability of pollutant to move in the enviro depends on other properties= state of matter, density + solubility in water
• Give examples of mobility in terms of POP


  1. LEAD DUST= increase density, so most particles close to source

  2. SMOKE PARTICLES= easily washed out of ATM by rain, or settle if the air is static. Smaller p= settle out more slowly

  3. SULFUR DIOXIDE GAS= soluble in H2O + easily removed from ATM by rain ( usually within 250Km of source)

  4. CFCs= chemically stable + have low solubility in H20= remain in ATM 4 long time + disperse ( dilute) throughout whole ATM
• Describe Bioaccumulation in terms of POP


  - the absorption + storage of pollutants in the tissues if organisms, the amount of substance increases over time

  - often involves LT ingestion of small doses of liposoluble P.

  - original dose= too small ( not toxic)= build up however, reaches toxic levels

  - liposoluble P= excreted from body easily

  - this occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost

  - longer biological half-life= greater risk of chronic poisoning

  - e.g. PCBs
• Describe biomagnification in terms of properties of pollutants


  - increasing in concentration as a pollutant passes along a food chain, becoming concentrated into a progressively smaller biomass with each successive trophic levels

  - later trophic level= longer lifespans + build up even higher concs, especially if endotherms, due to higher metabolic rates= ingest more pollutants
• Describe synenergy in terms of properties of pollutants


  - chemicals have a bad effect, but when combined with others its way worse

  - pollutants themselves don't interact to produce a ew pollutant ( secondary pollutant), it is the effects that interact
• Give 3 examples of synenergy


  1. 03 damages leaf cuticles which enables sulphur dioxide to cause more damage to newly exposed living cells

  2. Lead= neurotoxin worsens when combined with 3. Cadmium which is a carcinogen- leads to heart disease, osteoporosis, learning difficulties
• Describe mutagenicity in terms of properties of pollutants


  - chemical or energy which causes chemical changes to DNA structure, by damaging chromosomes, by rearrangement of the structure

  - this can be inherited

  - if GONADIC= mutates DNA in sperm, egg or embryo

  - if SOMATIC= mutates other cells and makes it act abnormally

  - death of individual cells is a rare problem which can be replaced by division of other healthy cells
• Give three examples of mutagenicity


  1. ionising radiation

  2. UV light

  3. asbestos