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5.7- Air Pollution. Katie Page IB ESS Year 2 October 2 nd , 2014. Assessment Statements. 5.7.1. State the source and outline the effect of troposphere ozone 5.7.2. Outline the formation of photochemical smog - PowerPoint PPT Presentation
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KAT I EPA G EI B E S S Y E A R 2O C T O B E R 2 N D , 2 0 1 4
5.7- Air Pollution
Assessment Statements
5.7.1. State the source and outline the effect of troposphere ozone
5.7.2. Outline the formation of photochemical smog
5.7.3 Describe and evaluate pollution management strategies for urban air pollution.
Statistics
The US is responsible for 30.3% of the world’s gas emissions
33% of Chinese people live in such polluted cities that it is the equivalent of smoking 2 packs of cigarettes a day
In Asia, the pollution and smog is so thick that on some nights, you can’t see the stars
Teachers in Mexico City have reported that, when their kids draw the sky, they don’t draw it as blue.
Causes
Smokestacks of factories and power plantsMotor vehiclesChemicals, fires, and volcanoesFumes from hairspray, paint spray, and
nuclear weapons
Source and impact of troposphere ozone
In the troposphere, the lower atmosphere, ozone is considered a pollutant
Volatile Organic Compounds (VOCs): Organic chemical compounds able to evaporate into gases and take part in photochemical reactions
The main sources of VOCs and nitrogen oxides: Road transport Solvent release from drying paint Glues or inks Petrol handling and distribution
Impacts on Humans
According to the UN, air pollution is the cause of 1 in 8 global deaths
In 2012, air pollution caused the death of around 7 million people world wide
Effects on childrenRange of effects
Impacts on forests and crops
Ozone concentrations are lower in major urban areas
Ground ozone affects plant photosynthesisCrop exposure to ozone levels above a 40 ppb
tends to affect extensive areas of arable farming
The formation of photochemical smog
Photochemical smog: Refers to the poor air quality caused by a mixture of nitrogen and VOCs
Persists for many daysDifferences between Mediterranean and
Monsoon
Summer Smog
Occurs on calm, sunny daysFormed when nitrogen oxides and VOCs react
in sunlightOzone pollution is greater outside the city
center
Winter Smog
Associated with temperature inversions and high levels of sulfur and other pollutants
Under cold conditions, cars operate less efficiently
Urban areas surrounded by high ground are especially at risk Air sinks in from the surrounding hills
Trends
Ground levels of ozone had rise substantiallyPreindustrial was 10- 15 ppbCurrent annual mean is 30 ppb in the UKDifferent factors can impact the ground levels
Effects of smog
Effects are immediateDecreased UV radiationEffects can range from:
Minor- Joint pain, eye irritation Major- Lung Cancer
Air Pollution in Bangladesh
Ranked 4th worst country with urban air pollution
Main causes: Vehicles Industries
Air Quality Management Project works under the Department of Environment
Has yet to implement a National Air Quality Standard
Banned buses more than 20 years old in Dhaka, failed to implement
Case Study: Mexico City
The average visibility has decreased from 1000 km in the 1940s to 1.5 km in the 2000s
Benefits of reducing ozone by 10%Main programmes used to combat air
pollution: Reduce the use of private vehicles Control of vehicle conditions Change of fuels Reduction of lead and sulfur in fuels Implementation of catalytic converters
Governmental approaches
Air pollution may change with administrations
The United States The EPA has set national air quality standards
China Banned cars, closed factories, relocated steel work
Activity
Research methods used by governments to reduce air pollution and create your own five step plan.