Air Pollution

1
Air Pollution
2
Review of last lecture

• Effects of vegetation (1) makes heat/water
  reservoir deeper, (2) enhance evaporation, (3)
  grows and dies in response to environmental
  conditions
• Effects of different surface types desert, city,
  grassland, forest, sea. Deeper heat/water
  reservoir and enhanced convective instability.
• Heat island effect. 7 causes
• Dispersion of air pollution. Dependence on wind
  speed, stability (name of 3 types) and inversion
  (name of 2 types)
• Global atmosphere/ocean circulation linking the
  world together. Therefore we need to protect the
  environment.

3
How do human activities change the global climate?

• Human beings are changing the global climate
  system in three different ways
• Change land cover (deforestation and
  afforestation)
• Release or cleanse pollutants (aerosols)
• Release or cleanse greenhouse gases

4
Introduction

• Air pollutants are gases, liquids or solids in
  the air that can adversely affect plant and/or
  animal life.
• Primary pollutants are pollutants that are
  emitted directly by natural or anthropogenic
  (manmade) processes.
• Secondary pollutants are pollutants that arise
  from chemical reactions of atmospheric gases with
  gases emitted by natural or anthropogenic
  processes.
• There are six major pollutants particulates,
  carbon oxides, sulfur dioxides, nitrogen oxides,
  volatile organic compounds, ozone

5
Major pollutants (1) Particulates

• Particulates (aerosols) are solid or liquid
  matter suspended in the air (from 0.1 to 100 µm
  in size).
• PM10 (lt10 µm) enters lungs (associated with
  asthma) PM2.5 (lt2.5 µm) even more dangerous
  (lung cancer).

6
Global distribution of PM2.5 (2001-2006)
Image from NASA Credit Dalhousie University,
Aaron van Donkelaar
7
U.S distribution of PM2.5 (2001-2006)
Image from NASA Credit Dalhousie University,
Aaron van Donkelaar
8
Major pollutants (2) Carbon monoxide

• Carbon monoxide (CO) is a colorless, odorless gas
  from volcanic eruptions, forest fires and other
  processes.
• Extremely toxic and dangerous to humans and
  animals.

9

• Major pollutants (3) Sulfur dioxide

• Sulfur compounds can occur as gaseous or aerosol
  forms.
• respiratory irritant. contributes to acid fog and
  acid rain.

10
Major pollutants (4) Nitrogen Oxides (NOX)

• Nitric oxide (NO) is a nontoxic, colorless, and
  odorless gas.
• Nitrogen dioxide (NO2) is a toxic, yellow to
  reddish-brown gas that is pungent and corrosive.
  Provides polluted air with the yellow to reddish
  brown color.

11
Major pollutants (5) Ozone

• Ozone, NO2, formaldehyde and other gases combine
  with solar radiation to form Los Angeles-type
  photochemical smog.
• causes respiratory and heart problems.

12
Major pollutants (6) Volatile Organic Compounds
(Hydrocarbons)

• are made of carbon and hydrogen. Examples
  methane, butane, propane, octane, etc.
• Health effects vary

13
Video Science to Protect the Air We Breath (by
EPA)

• http//www.youtube.com/watch?v3PO_3exwN-I

14
Air Quality Index

• The EPA created an index for air pollution
  monitoring called the Air Quality Index (AQI).
• A formula applies to ozone, particulates, carbon
  monoxide, sulfur dioxide, and nitrogen dioxide by
  expressing each pollutant on a scale that ranges
  from 0 to 500.
• The official AQI for any location at a particular
  time is the highest of the five individual
  pollutant values.

15
Air Quality Index
16
History of air pollution(1) The medieval
pollution

• In medieval London, pollution from coal burning
  was seen as such a serious matter that a
  commission was established in 1285 to investigate
  the problem. It was reconvened three years later
  with firm instructions to find a solution.
• In 1307, during the reign of Edward I,
  legislation was introduced to prevent the use of
  sea coal in kilns and by blacksmiths. It proved
  largely ineffective.

17
History of air pollution(2) The 16th 19th
century

• Wood for burning became scarce and expensive, and
  an increasing number of domestic chimneys
  encouraged an ever-wider use of fossil fuel.
• London rapidly changed from a wood-burning city
  to one that relied on imported coal. By the end
  of Elizabeth I's reign in 1603, coal consumption
  in the city had risen to more than 50,000 tons a
  year.
• In 1661, the diarist and proto-environmentalist
  John Evelyn published a diatribe against air
  pollution in London Fumifugium, or The
  Inconvenience of the Aer and the Smoak of London
  Dissipated.

Image source
18
History of air pollution(3) The 20th century

• The Great Fog of 1952. Cold weather, combined
  with an anticyclone and windless conditions,
  trapped the pollution from Thames-side power
  stations, domestic fires and London's new fleet
  of 8,000 diesel buses. The total number of
  fatalities was about 12,000.
• The 1948 Donora smog. A warm air pocket had
  passed high above the town, trapping cooler air
  below and sealing in pollutants. 14,000 residents
  experienced severe respiratory and cardiovascular
  problems. The death toll was nearly 40.
• Led to several changes in practices and
  regulations, including the Clean Air Act 1956.

Source
19
History of air pollution(4) The 21st Century

• As China has industrialized, various forms of
  pollution have increased, which has caused
  widespread environmental and health problems.
  According to the World Bank in 2007, 16 of the
  world's 20 most polluted cities are in China.
• Air pollution in India is a serious issue with
  the major sources being fuelwood and biomass
  burning, fuel adulteration, and vehicle emission.
  The 2012 Environmental Performance Index ranked
  India as having the poorest relative air quality
  out of 132 countries.

Image Source
20
Summary

• Air pollution. 2 categories
• 6 types of major pollutants particulates, carbon
  oxides, sulfur dioxides, nitrogen oxides,
  volatile organic compounds, ozone
• Air quality index
• History of air pollution The Medieval pollution,
  The 16th-19th centuries, The 20th century, The
  21st century