Urban Air Quality
What is liquefied petroleum gas (LPG)?
A gas produced from fossil fuels that has lower emissions than petrol or diesel.
What do laws in Scotland allow local authorities to do to limit vehicle pollution?
Allows local authorities to do roadside emission tests, where they can issue fines if the vehicle fails.
What is the concentration of particulates in urban areas?
Around 10-40 µg/m cubed.
Why are trams and light railway services invested in?
Don't get caught in road congestion and pollute less then buses.
What is done to manage pollution in Mexico City?
Drivers are banned from using their cars one weekday per week, based on the last digit of their number plate, e.g. number plates ending in 5 or 6 can't be used on Mondays.
What is photochemical smog linked with?
Health problems such as breathing difficulties (coughing, shortness of breath), respiratory disorders (e.g. asthma) and headaches.
What can particulates cause?
Health problems.
What can local authorities in the UK do to limit vehicle pollution?
Issue fines to people leave their engines running unnecessarily.
How do the Road Vehicles Regulations reduce pollution?
Reduce exhaust emissions by ensuring cars pass on emissions test in their MOT.
How does temperature inversion affect photochemical smog?
Keeps the pollutants at ground level.
What is the concentration of particulates in rural areas?
Less than 10 µg/m cubed.
What happens to finer particulates?
Less than 10 µm in diameter (often called PM10) can enter the lungs.
What are drawbacks of electric vehicles?
Need recharge points, and producing and disposing of the batteries can cause environmental problems.
What pollutants come from burning fossils fuels in vehicles and factories?
Nitrogen oxides, sulfur oxides and hydrocarbons.
What is a drawback of public transport improvements?
Often expensive.
Why do cities introduce bus lanes?
So buses don't get caught in slow-moving traffic.
When were the UK Clean Air Acts issued?
1956 and 1968
When was the Metrolink in Manchester opened?
1992
What can petrol and diesel be replaced with?
Cleaner fuels that pollute less.
What does construction, mining and quarrying produce in urban areas?
Coarse particulates (10 µm-100 µm), e.g. tiny fragments of rock, brick and cement dust.
How many cars has the line from Bury to Altrincham in Manchester taken off the roads?
About 2.6 million.
How much of fine particulates in urban areas are from vehicles?
About 80%.
What do plants and moulds in urban areas produce?
Coarse particulates, e.g. pollen and mould spores.
Why may pedestrianisation reduce customers?
Because people can only get to them on foot.
What is an example of a cleaner fuel?
Biofuels (e.g. bioethanol and biodiesel) are produced from plants.
How can biofuels reduce biodiversity?
Biofuels like corn-based ethanol need a lot of land to grow, which means clearing other vegetation.
Which councils run car sharing schemes?
Birmingham, Bristol and London.
What do burning of refuse, cigarettes and fuel produce in urban areas?
Both fine and coarse particulate, e.g. sulphates, nitrates, soot and ash.
How do richer households get around Mexico City's car ban?
Buy two cars.
How can legislation reduce pollution?
By limiting emissions and setting air quality standards.
How have lots of cities tried to reduce pollution?
By reducing traffic.
In Central London, how has congestion charging reduced emissions?
By up to 15% since 2003.
What are park and ride schemes?
Car parks on public transport routes to make it easier to access public transport.
Why is LPG difficult to use?
Cars have to be converted to use LPG and service stations have to be adapted to distribute it.
What can PM10 cause?
Cause or make worse problems like asthma, bronchitis, lung cancer and heart disease.
What can biofuels do?
Directly replace petrol and diesel, and have lower particulate emissions.
How can you reduce the amount of cars in urban areas?
Encouraging people to use public transport instead of their cars reduces pollution.
How can electric vehicles reduce pollution?
Have lower emissions because they run off batteries, rather than conventional fuel.
Where is photochemical smog more common?
In places with hot and sunny climates because there's more sunlight.
Where are more particulates found?
In urban areas rather than in rural areas.
How did the UK Clean Air Acts reduce domestic pollution?
Introducing smoke control areas where only smokeless fuels could be burned.
How did the UK Clean Air Acts reduce industrial pollution?
Introducing the use of tall chimneys (which mean that pollutants are dispersed higher in the atmosphere, so they're less harmful to people in the city).
What cities have pedestrianised zones?
London, Cardiff, Manchester and Liverpool.
Where is photochemical smog a problem?
Los Angeles (USA), Beijing (China), Mexico City (Mexico) and Barcelona (Spain).
How much did the Metrolink cost to construct?
Over £1 billion.
What is a drawback of park and ride schemes?
Shift traffic problems to rural areas.
Why do people not like car sharing?
Some people find car sharing inconvenient or are worried about sharing a car with a stranger.
What is a problem with the congestion charge?
Some people travel around the edge of zones to avoid being charged, which increases traffic in these areas.
What happens when pollutants come into contacts with sunlight?
The UV light causes them to break down into harmful chemicals (e.g. ozone) which form photochemical smog.
Why is it difficult to enforce a congestion charge?
The volume of traffic is so large that it's hard to process all the fines correctly.
What are particulates?
Tiny pieces of solids and tiny droplets of liquids floating in the air.
Why are bus services improved?
To make bus journeys cheaper, faster and more efficient.
Where is ozone helpful?
Useful in the upper atmosphere (protecting us from UV radiation), but when it's in the lower atmosphere it causes health problems.
What happens to coarser particulates?
Usually filtered out by the nose and throat.
What is pedestrianisation?
Vehicles are restricted from entering certain times. It reduces pollution by reducing road road traffic.
What particulates do vehicle exhausts produce?
Very fine particulates (0.01 µm-1.0 µm).
