Air PollutionAir Pollution

Review of last lectureReview of last lecture

• Effects of different surface types: desert, city, grassland, forest, sea. Deeper heat/water reservoir, decreased Bowen ratio, thinner BL and enhanced convective instability.

• Effects of vegetation: (1) makes heat/water reservoir deeper, (2) enhance evaporation, (3) grows and dies in response to environmental conditions

• 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.

Effects of human activitiesEffects of human activities

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

IntroductionIntroduction

• 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.

Major pollutants: (1) ParticulatesMajor pollutants: (1) Particulates

• Particulates (aerosols) are solid or liquid matter suspended in the air (from 0.1 to 100 µm in size).

• Natural sources: natural fires, volcanic eruptions, salt spray from the oceans, pollen.

• Anthropogenic sources: burning of fossil fuels.

• Although particulates can remain in the air for some time due to their small size, rain removes them.

• PM10 (<10 µm) enters lungs (associated with asthma); PM2.5 even more dangerous (lung cancer).

Major pollutants: (2) Carbon OxidesMajor pollutants: (2) Carbon Oxides

• Carbon monoxide (CO) is a colorless, odorless gas from volcanic eruptions, forest fires and other processes.

• Extremely toxic and dangerous to humans and animals.

• Carbon dioxide (CO2) is an important greenhouse gas but is officially considered a pollutant by the US EPA.

Threshold levels of carbon monoxideThreshold levels of carbon monoxide

Major pollutants: (3) Sulfur Compounds

• Sulfur compounds can occur as gaseous or aerosol forms.

• Natural sources: steam vents, volcanic eruptions, sea spray.

• Anthropogenic sources: burning sulfur containing fossil fuels (particularly coal and oil) and ore smelting.

• Sulfur dioxide (SO2) is a respiratory irritant.

• Sulfur trioxide (SO3) contributes to acid fog and acid rain.

Averaged PH values of precipitation Averaged PH values of precipitation (Acid precipitation)(Acid precipitation)

Major pollutants: (4) Nitrogen Oxides (NOX)Major pollutants: (4) Nitrogen Oxides (NOX)

• Nitric oxide (NO) is a nontoxic, colorless, and odorless gas.

• Natural sources: biological processes in soil and water.

• 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.

• Anthropogenic sources: Vehicle traffic.

• Can cause pulmonary health problems.

Major pollutants: (5) Volatile Organic Major pollutants: (5) Volatile Organic Compounds (Hydrocarbons)Compounds (Hydrocarbons)

• are made of carbon and hydrogen. Examples: methane, butane, propane, octane, etc.

• Natural sources: plant and animal emissions and decomposition of organic matter.

• Anthropogenic sources: primarily combustion from automobiles, trucks, buses, and other fossil fuel motors; also evaporation of gasoline and other chemicals.

Major pollutants: (6) Photochemical SmogMajor pollutants: (6) Photochemical Smog

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

• Ozone causes respiratory and heart problems.

• High levels of ozone result in environmental degradation.

History of air pollutionHistory of air pollution(1) The medieval 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.

History of air pollutionHistory of air pollution(2) The 16(2) The 16thth – 19 – 19thth century 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

History of air pollutionHistory of air pollution(3) The Great Fog of 1952(3) The Great Fog of 1952

• Lasted from Friday 5 to Tuesday 9 December 1952.

• A period of 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, which had just replaced the battered but environmentally friendly electric trams.

• The total number of fatalities was about 12,000.

• Led to several changes in practices and regulations, including the Clean Air Act 1956.

Source

Video: Great London Smog 1952Video: Great London Smog 1952

• http://www.youtube.com/watch?v=rLN0lydEdr8

History of air pollutionHistory of air pollution(4) The 1948 Donora smog(4) The 1948 Donora smog

• In October 1948, Donora, Pa., was enveloped in a lethal haze.

• Over five days, nearly half of the town's 14,000 residents experienced severe respiratory and cardiovascular problems. It was difficult to breathe. The death toll rose to nearly 40.

• Disturbing photos show Donora's streets hidden under a thick blanket of gray smog. A warm air pocket had passed high above the town, trapping cooler air below and sealing in pollutants.

History of air pollutionHistory of air pollution(5) Air pollution in China(5) Air pollution in China

• Various forms of pollution have increased as China has industrialized, 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. Image Source

Pneumoconiosis in ChinaPneumoconiosis in China

• 57,000 workers diagnosed pneumoconiosis every year

• There are about 6 million patients

• 6,000 workers die from the condition every year.

Image source

Video: Video: Beijing experiences terrible Beijing experiences terrible air qualityair quality

• http://www.youtube.com/watch?v=Ksps_1Zwg5o

History of air pollutionHistory of air pollution(6) Air pollution in India(6) Air pollution in India

• is a serious issue with the major sources being fuelwood and biomass burning, fuel adulteration, vehicle emission and traffic congestion.

• The Air (Prevention and Control of Pollution) Act was passed in 1981 to regulate air pollution and there have been some measurable improvements.

• However, the 2012 Environmental Performance Index ranked India as having the poorest relative air quality out of 132 countries.

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

• http://www.youtube.com/watch?v=3PO_3exwN-I

Air Quality IndexAir 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.

Air Quality IndexAir Quality Index

Environmental Performance Index (EPI)Environmental Performance Index (EPI)

• is a method of quantifying and numerically benchmarking the environmental performance of a country's policies.

• Developed by Yale Univ. and Columbia Univ.• Recent reports in 2008, 2010 and 2012

2012 EPI2012 EPI

SummarySummary

• Air pollution. 2 categories• 6 types of major pollutants:

– Particulates– Carbon oxides– Sulfur compounds– Nitrogen oxides– Volatile organic compounds– Photochemical smog

• History of air pollution: – The Medieval pollution– 16th-19th centuries– Great London Smog 1952– The 1948 Donora smog– Air pollution in China and India

• Air quality index and Environmental Performance Index