12.3. Air Pollution Flashcards
Big Fives of Air Pollution
1) Nitrogen Oxides (NOx)
2) Sulphur Dioxide (SO2)
3) Ozone (O3)
4) Particulates Pm10
5) Particulates Pm2.5
Nitrogen Oxides (NOx) Sources
- Mostly take the forms of nitric oxide (NO) and nitrogen dioxide (NO2).
- Released as part of the combustion of fossil fuels
- This occurs in vehicles (estimated 42% in London) and in power generation, as well as (to a minor extent) domestic gas burning.
Sulphur Dioxide (SO2) Sources
- Released as a waste product from the combustion of coal and oil
- A major source comes from coal fired power plants
- No longer permitted to be used in petrol and diesel for cars but still found in marine fuels
Ozone (O3) Sources
- Formed when nitrous oxides and
organic compounds react in sunlight
Particulates Pm10 Sources
- Can include carbon, sulphate, nitrate and metallic particles
- Created by mechanical processes such as mining and
demolishing on building sites, as well as wear and tear on roads - Released as waste from the combustion of coal
- Diesel vehicle exhausts are a major source
Particulates Pm2.5 Sources
- Mostly made up of carbon particles
- Released as a waste product of the combustion process, with most of the pollutant coming from road transport emissions
Nitrogen Oxides (NOx) Health Impacts
- Decreased lung function
- Increased susceptibility to allergens
- Induce asthma attacks in vulnerable people
Sulphur Dioxide (SO2) Health Impacts
- Irritates and narrows the lining of airways, reducing the flow of air to the lungs
- Asthma suffers are more prone to an attack
- In high concentrations, can sting and irritate eyes
Ozone (O3) Health Impacts
- Long term exposure increases chances of mortality from respiratory conditions and diseases
- Increases mortality rates amongst those with pulmonary diseases, and diabetes
- Increases the incidence and severity of asthma
- Reduces lung growth in children
- Reduces cognitive development and increases
chances of premature births
Particulates Pm10 Health Impacts
- Some links to cardiovascular diseases
- Short term exposure can lead to poor breathing and respiratory difficulties
Particulates Pm2.5 Health Impacts
- Blocks gaseous exchange to the blood stream deep inside the lungs
- Strong correlation between high exposures and heart attacks and strokes
- Reduced lung development in children
- Increased development of respiratory diseases such as asthma
- Some links to the prevalence of cancers
- Some links to higher infant mortalities and lower birth weights
Point source pollution
Occurs when the pollutant is issued at one point.
Non-point source pollution
Emanates from an entire area.
Incidental pollution
A one-off event that releases a pollutant.
Sustained pollution
Is long term pollution caused by human activity.
