Environment of Pakistan
The Air pollution is the release of chemicals and particulates into the atmosphere. Common gaseous pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM to PM. The air in Karachi is rapidly polluted by automobile smoke, especially Rickshaws and Buses, industrial emissions, open burning of garbage, house fires, and other particles but the government and environment organizations seems non-serious to tackle the issue timely.
The two-stroke engines on rickshaws and motorcycles are one of the major polluters of air in Karachi and the rest of Pakistan. The two-stroke engines as well as defective or unturned vehicles are major polluters with carbon dioxide emissions. Two-stroke engines as well as defective vehicles using substandard lubricant are major emitters of sulfur dioxide and smoke. Automobiles operating on compressed natural gas and liquefied petroleum gas are major air polluters.
Environmental impact of aviation in the United Kingdom
Air quality around airports is another major issue and a 2006 study found that levels of nitrogen dioxide exceeds EU guidelines at more than two thirds of airports surveyed. Whilst aircraft contribute to the problem the study states that "…cars, buses and taxis ferrying passengers to and from these sites are dominant sources of pollution." Birmingham airport dismissed the findings, asserting that the results were skewed by M42 motorway traffic unrelated to the airport, whilst studies at Southampton Airport attribute 5.55 per cent of total pollutants to airport activities, the majority of the remainder being generated by non-airport related road traffic. The government recognises Heathrow as the only UK airport where national and European air quality limits are being exceeded.