Sample Answer
Introduction
Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, creating a brown haze above cities.
Body
Formation:
- Nitrogen oxides produced through car fumes combine with water to form nitric acid, which then combine with molecular oxygen to produce ozone.
- The nitric acid may precipitate to the Earth resulting in acid rain, or remain in the smog.
Effects:
- When the chemicals indoors interact with hydrocarbons, they cause eye irritation.
- The nitrogen cycle is hampered by the atmospheric radicals because ground-level ozone cannot be removed.
- Ozone at ground level has the potential to be exceedingly hazardous to people.
- Decreased vision and shortness of breath.
Mitigation:
- Reduction of nitrogen oxide: by a process called ‘catalytic reduction’, which is used in industry and in motor vehicles
- Reduction of VOCs: These include the use of liquefied petroleum gas (LPG) or compressed natural gas (CNG) rather than petrol
Conclusion
The 1999 Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone is a multi-pollutant protocol designed to reduce acidification, eutrophication and ground-level ozone by setting emissions ceilings for sulphur dioxide, nitrogen oxides, volatile organic compounds and ammonia to be met by 2010.
