Nitrogen oxide (NOx)
NOx is formed when nitrogen combines with oxygen inside the extremely hot and highly pressurized chambers of marine diesel engines. This NOx combines with hydro carbons in the atmosphere forming ozone which produces smog. Ozone is good when it is high in the stratosphere, where it protects earth from the ultraviolet rays of the sun, but when ozone is dangerously low in the atmosphere it traps heat and badly affects human health.
Sulfur dioxide (SOx)
SOx is formed when unburned fuel in diesel engines produces small particles of sulfur and carbon, which together contribute to smog. SOx is directly related to the sulfur content in fuel, which when combined with water vapor, results in acid rain.
Chloroflorocarbons (CFC’s)
Emissions of CFCs from the global shipping fleet is estimated at 3,000-6,000 tons or approximately 1 to 3 percent of yearly global emissions. CFCs are also extremely poisonous as far as air pollution is concerned.