WHAT ARE THE ORIGINS AND ENVIRONMENTAL IMPLICATIONS OF

POLLUTANTS IN CAR EXHAUSTS GASES?

By Kate Hughes and Jess Hawke

Un-burnt Hydrocarbons Cars cannot always fully combust the hydrocarbons, leaving un-

burnt hydrocarbons in the exhaust.

Health effects Some Hydrocarbons are called Carcinogenic, this classes them as

solvents and as a result, prolonged exposure can cause cancer

Social effects (environmental) These Hydrocarbons are components of Photochemical smog.

This produces a brown haze and can contribute to respiratory problems. Another property of the hydrocarbons is their flammability of the vapour, resulting in an increased danger of Fires igniting.

CHEMICAL ORIGIN Carbon and hydrogen (CH)

CHEMICAL EQUATION Fuel + Air CxHy

Carbon Monoxide Carbon monoxide is formed in the exhaust from un-

combusted reactants.

Health Issues Low to moderate exposure can cause irritation to the mucous

membranes. Higher exposure can lead to comas and death (less likely to be caused by exhaust fumes).

Social/environmental effects Although it’s not a greenhouse gas, it can increase the

concentration levels of methane and ozone, thus contributing to global warming.

Chemical Origins Carbon and Oxygen (CO)

Chemical Equation Fuel + Air CO

Particulates Particulates are spheres of liquids suspended in a liquid or

gas and are commonly found in car exhaust fumes. Are small carbon particles which are not visible to the naked eye.

Health Implications Strongly affects respiratory system, for example irritation to

the lungs. Especially in young children and the elderly.

Environmental problems (Rarely cause environmental issues)

Chemical Origins Carbon particles (C)

Chemical Equation Fuel + Air particulates

Carbon Dioxide Carbon Dioxide is a chemical compound found in high

quantities in Motor Car exhaust fumes. Is formed by incomplete combustion of hydrocarbons.

Health Problems Most common issue caused is Asphyxiation and other

respiratory problems.

Social effects (environmental) Vastly contributes to global warming due to it trapping the

earth’s heat in the ozone layer.

Chemical Origin Carbon and Oxygen (CO2)

Chemical Equation Fuel + Air CO2

Nitrogen Oxides (Nox) Nitrogen oxide is 300 times more potent than carbon

dioxide and is always found in exhausts.

Health Problems Due to acidity, health problems can occur for asthmatics.

Environmental issues Are very acidic, thus contributing to acid rain in the

atmosphere, therefore corrode limestone buildings and damages forests and lakes

Chemical origin Nitrogen and Oxygen (NOx)Chemical Equation Fuel + Air NOx

Sulfur Dioxide Has very similar properties to nitrogen oxides

Health Issues Contributes to respiratory problems

particularly for asthmatics.

Environmental Implications Increases production of acid rain

Chemical Origin Sulfur and oxygen (SO2)

Chemical Equation Fuel + air SO2

Conclusion Fuel + Air Hydrocarbons + Nitrogen Oxides

+ Carbon Dioxide + Carbon Monoxide + water

In conclusion, in the exhaust fumes, pollutants are produced, all having their own implications; most commonly upon the environment involving contribution towards Global Warming. However, there are also effects upon individuals such inhabitants of earth suffering with asthma.