Pollution is the introduction of contaminants into the environment that leads to ecological damage. These harmful contaminants are known as pollutants. Pollution can have a negative impact on the quality of air, water and soil and have a dramatic effect on both climate and wildlife. Noise pollution is often caused by vehicles, aircraft and industrial machinery.
Although, carbon dioxide (CO2) is the most notorious pollutant in the automobile industry due to its contribution to the greenhouse effect, other gases must not be forgotten or overlooked: nitrogen oxides (NOx), carbon monoxide (CO), unburned hydrocarbons (HC) and particles as they too have a negative impact on the environment and on our health.