air quality in urban areas Flashcards
Why is urban air quality poorer than in surrounding rural areas
7X more dust particles due to burning of fossil fuels
How does pollutants affect air quality
increase cloud cover precipitation, cause photo chemical smog, increase temp, reduce sunlight and causes acid rain
what is a primary pollutant
substances directly emitted from a process e.g co2 from vehicles
what are secondary pollutants
a result of primary pollutants which have reacted e.g. ground level ozone
Name some pollutants
sulphur oxidies from fossil fuel
Nitrogen oxides from high temp combustion result in brown haze
Carbon monoxide incomplete combustion which is poisonous
Two types of PM
measure of smoke and dust
PM 10 will get in nasal cavity while PM 2.5 is much smaller and will enter bronchial tubes and lungs causing respiratory problems
What is smog
mixture of smoke and fog, smoke thickens fog by adding additional condensation nuclei to already highly saturated air
what is photochemical smog
forms when sunlight hits pollutants and forms a mix of chemicals that are dangerous, it is a reaction of sunlight, nitrous oxides and volatile organic compounds which produce airborne PM and ground level ozone
where is photochemical smog common
cities with warm, sunny dry climates
When was the Clean air act introduced and why
1952 as a result of the Great Smog of London which was severe air pollution where a period of cold anticyclonic conditions combines with coal particles producing a smog that lasted 4 days
What were the impacts of the great smog
4,000 died as a result and 100,000 ill with respiratory problems
What did the clean air act do to improve situation
introduced smoke free zones into urban areas and in 1990 the act was consolidated by imposing tougher regulations of PM 10
local councils must monitor their own areas
what else has been done to try and improve urban air quality
vehicle control e.g restricting cars, park and ride, congestion charges, public transport etc
define pollution
caused by airborne particles and gases that occur in high enough concentrations to endanger the health and well being of organisms or disrupt the functioning of the environment
