Topic 6.3 - Photochemical smog Flashcards
What is primary pollution?
Pollution direct from the source (active on emission)
What is secondary pollution?
A primary pollutant undergoing a physical or chemical change
What are some sources of photochemical smog?
Transport
Cooking
Dust from construction sites
Heating
Power generation
What are examples of fossil fuel combustion primary pollutants?
Carbon monoxide
Carbon dioxide
VOCs (volatile organic compounds)
Unburned hydrocarbons
Nitrogen oxides
Sulfur oxides
Particulate matter
What is an example of a secondary pollutant?
Trophospheric ozone
Where does ozone form naturally?
At ground level in low concentrations
What are major sources of ozone?
Hydrocarbons (released by plants + soil)
Small amounts of stratosopheric ozone migrate down to the Earth’s surface
How is trophospheric ozone formed?
The infiltration of sunlight (UV-B) with hydrocarbons + nitrogen oxides which are emitted by automobiles, gasoline, vapour, fossil fuel powers, refineries
Why is the amount of ozone in the atmosphere increasing?
Increasing populations
More vehicles
More industry
What are the effects of ozone on plants?
High concetrations can cause the stomata to close –> slows photosynthesis and plant growth
May enter plant cells through the stomata and directly damage internal cells
What effects does ozone have on materials?
Rubber, textile dyes, fibres and certain paints may be damaged due to exposure to ozone
Some elastics can become brittle and crack
Plants and fabric dyes may fade quickly
What are the effects of ozone on humans?
Smog can damage respiratory tissues through inhalation
Ozone linked to tissue decay, the promotion of scar tissue and cell damage by oxidation
Can impair athlete’s performances
Creates more frequent asthma attacks
Causes eye irritation, chest pain, nausea, headaches and chest congestion + discomfort
Can worsen heart disease, bronchitis + emphysema
What is photochemical smog?
A mixture of 100(ish) primary + secondary pollutants formed under the influence of sunlight
What does the frequency and severity of photochemical smog depend on?
Local topography - low lying areas
Climate - high air pressure areas
Population density - no. of vehicles
Fossil fuel use
When do temperature inversions occur?
When cold air is trapped under warm air. Cold air does not move or sinks from surrounding hills
Examples of areas in which thermal inversions trap smog
LA, Santiago, Mexico City, Rio de Janeiro, Sao Paulo, Beijing
How does precipitation and wind help with smog?
Precipitation cleans the air + wind disperses the smog
How does burning forests increase greenhouse gases in the atmosphere?
Releasing CO2 stored in the biomass + by removing the forest itself so that it cannot store CO2 in the future
Case Study: Indonesia + SE Asia
Smog has caused diplomatic flare-ups between Indonesia and neighbours in SE Asia
Has caused threats to human health + disrupted flights in the regions
Burning trees are pumping heat-trapping gases in the atmosphere
What are the consecuences of poor air quality?
Health effects: premature deaths (heart + lung disease)
Asthmatic conditions
Reduced quality of life
Increased hospital admissions
Give an example of a country damaged due to air pollution?
Mexico city –> economic damages due to air pollution ($1.5 bil per yr)
What are other negative impacts of air pollution? Provide a named example
Reduces food production + timber harvests because high levels of pollution impair photosynthesis
e.g. Germany $4.7bil per year on agricultural production is lost to high levels of sulphur, nitrogen oxides and ozone
Pollution management strategies: Cause
Cars, buses and taxis –> reduce demand for private transport, promote cycles, bus lanes and promote cleaner fuels and hybrid or electrical models
Electricity –> consumption of electricity through building designs: use small scale green power on city buildings e.g. solar, wind
Enforcement –> greater enforcement of emission standards
Further public information
Pollution management strategies: Release and transfer
Cars, buses and taxis –> monitor and regulate exhaust emissions
Electricity and industry –> use cleaner fuels and clean-up emissions
