Topic 6.3 - Photochemical smog

Question 1

What is primary pollution?

Answer 1

Pollution direct from the source (active on emission)

Question 2

What is secondary pollution?

Answer 2

A primary pollutant undergoing a physical or chemical change

Question 3

What are some sources of photochemical smog?

Answer 3

Transport

Cooking

Dust from construction sites

Heating

Power generation

Question 4

What are examples of fossil fuel combustion primary pollutants?

Answer 4

Carbon monoxide

Carbon dioxide

VOCs (volatile organic compounds)

Unburned hydrocarbons

Nitrogen oxides

Sulfur oxides

Particulate matter

Question 5

What is an example of a secondary pollutant?

Answer 5

Trophospheric ozone

Question 6

Where does ozone form naturally?

Answer 6

At ground level in low concentrations

Question 7

What are major sources of ozone?

Answer 7

Hydrocarbons (released by plants + soil)

Small amounts of stratosopheric ozone migrate down to the Earth’s surface

Question 8

How is trophospheric ozone formed?

Answer 8

The infiltration of sunlight (UV-B) with hydrocarbons + nitrogen oxides which are emitted by automobiles, gasoline, vapour, fossil fuel powers, refineries

Question 9

Why is the amount of ozone in the atmosphere increasing?

Answer 9

Increasing populations

More vehicles

More industry

Question 10

What are the effects of ozone on plants?

Answer 10

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

Question 11

What effects does ozone have on materials?

Answer 11

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

Question 12

What are the effects of ozone on humans?

Answer 12

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

Question 13

What is photochemical smog?

Answer 13

A mixture of 100(ish) primary + secondary pollutants formed under the influence of sunlight

Question 14

What does the frequency and severity of photochemical smog depend on?

Answer 14

Local topography - low lying areas

Climate - high air pressure areas

Population density - no. of vehicles

Fossil fuel use

Question 15

When do temperature inversions occur?

Answer 15

When cold air is trapped under warm air. Cold air does not move or sinks from surrounding hills

Question 16

Examples of areas in which thermal inversions trap smog

Answer 16

LA, Santiago, Mexico City, Rio de Janeiro, Sao Paulo, Beijing

Question 17

How does precipitation and wind help with smog?

Answer 17

Precipitation cleans the air + wind disperses the smog

Question 18

How does burning forests increase greenhouse gases in the atmosphere?

Answer 18

Releasing CO2 stored in the biomass + by removing the forest itself so that it cannot store CO2 in the future

Question 19

Case Study: Indonesia + SE Asia

Answer 19

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

Question 20

What are the consecuences of poor air quality?

Answer 20

Health effects: premature deaths (heart + lung disease)

Asthmatic conditions

Reduced quality of life

Increased hospital admissions

Question 21

Give an example of a country damaged due to air pollution?

Answer 21

Mexico city –> economic damages due to air pollution ($1.5 bil per yr)

Question 22

What are other negative impacts of air pollution? Provide a named example

Answer 22

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

Question 23

Pollution management strategies: Cause

Answer 23

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

Question 24

Pollution management strategies: Release and transfer

Answer 24

Cars, buses and taxis –> monitor and regulate exhaust emissions

Electricity and industry –> use cleaner fuels and clean-up emissions

Question 25

Pollution management: Effect

Answer 25

Smog prevention–> design and plan city buildings to promote natural cooling and circulation: promote opening up and cleaning up covered water sources to allow evaporative cooling

Health –> raises awareness of conditions and effects of breathing polluted air + promotes pollution released health check ups, activated charcoal masks +