5.1. AIRPOLLUTION Burningof fossil fuels is the main source of air pollution.
Fossil fuels are burnt inpower stations using coal, petroleum and natural gas, in domestic andindustrial boilers and in the internal combustion engines of vehicles. Whenfossil fuels are burnt, the elements in the fuels are oxidised, forming variousair pollutants. These includes carbo monoxide, sulphur dioxide, oxides ofnitrogen, lead, carbon dioxide and fine particulate matter.
POLLUTANT : CARBON MONOXIDE Source :Incomplete combustion of fossil fuels, exhaust of vehicles, factories Effect :Combines readily with haemoglobin and affects the transport of oxygen to bodycells, impairs alertness and causes fatigue as well as headaches. POLLUTANT: SULPHUR DIOXIDESource : Combustion of fossil fuels,particularly in heat and power generation facilities, volcanic gases, largeindustrial boilers, factories.Effect : Health– Irritates eyes, damages respiratory passages, causes bronchitis,causes wheezing, a shortness ofbreath and coughing causes asthmatic attacks.
Climate – Combines with rainwater to form acid rain. Agriculture – Contributes to acid rainwhich damages photosynthetic tissues, lowers pH of soil and rivers. Buildings – Acid rain corrodes iron,limestone, stonework and destroy buildings.Solution : Use low sulphur content fuels. Cleanup emissions from power stations and factories with scrubbers. POLLUTANT:OXIDES OF NITROGENExample: Nitrogen monoxide, nitrogen dioxideSource: Vehicle exhausts, action of bacteriaand fertilisers, combustion of fossil fuels and factories.
Effect: Health– Irritate lungs, nose, throat and eyes, cause respiratory infections, causebronchitis. Climate – Dissolved inrainwater to form acid rain. Agriculture:Contributes to acid rain which lowers Ph of soil and makes it unsuitable forcultivation of crops, damages leaves and roots. Buildings – Acid rain corrodes metal and destroys stonework ofbuildings.
Solution: Clean up emissions from car exhaustsby installing catalytic converters to turn oxides of nitrogen into harmlessnitrogen gas. POLLUTANT:LEADSource: Combustion of fossil fuels, vehicleexhaust fumes.Effect: Health– Retards mental development and damages the liver, can result I coma ordeath.Solution: Use unleaded petrol. POLLUTANT:CARBON DIOXIDESource: Open burning, combustion of fossilfuels.Effect: Health– Affects respiration, Climate –Leads to greenhouse effect and global warming, results in an increase in theatmospheric temperature, climatic changes.
Solution: Reduce the use of fossil fuels. POLLLUTANT:FINE PARTICULATE MATTERSource: Incomplete combustion of fossil fuelsfor example, bonfires, open burning, the burning of oil wells and the burningof dried paddy stalks. Motorised vehicles. Quarries, sawmills and asbestosfactories.Effect: Health– Irritate the eyes, nose and lungs, damage the respiratory passages and lungs.
Haze can cause conjunctivitis, influenza, asthma and lead to bronchitis. Dustfrom sawmills and asbestos factories can cause lung diseases. Haze leads toreduced visibility. Agriculture –Smoke particles (soot) deposit o leaves and block stomata which preventsgaseous exchange.
Both lower the photosynthetic rate of plants whichsubsequently reduces crop yields. Climate-Contributes to the formation of haze and smog. Smoke and haze can reducevisibility. Buildings – Soot darkensbuildings.
Solution: More efficient burning of fuels inwell- designed furnaces. Stop open burning.