1. Local effects- eg:- humans breathing bad air.
2. Regional effects- eg:- fallout from airbourne pathogen, infections and chemicals
and
3. Global effects, which would change the interactions between the atmosphere, oceans and the sun, weather effects, effects on plants and the ocean biosphere.
Nevertheless, exhaust from all the combustion engines in vehicles combine to produce local adverse effects on the health of car users and all innocent by-standers.
We can also see that cities have become islands of toxic chemicals from the unrestrained use of vehicles.
Ethanol combustion engines contribute to the accumulation of green house gas in the atmosphere.
However, emissions from an individual car are generally low. But number of cities across the globe where there is a use of millions of personal automobiles contribute to air pollution. http://en.wikipedia.org/wiki/Motor_vehicle_emissions
It is however said that more people die from car pollution than motor accidents.
Also it is stated by health experts that road traffic is the fastest growing source of pollution in the world. And as a result more are killed from air pollution than road accidents.
A new report by the World Health Organization (WHO) showed long-term air pollution from cars in Austria, France and Switzerland triggered an extra 21,000 premature deaths per year from respiratory or heart diseases, more than the total number of annual traffic deaths in the three countries.Nevertheless, the point is that exhaust emitted by vehicles have become a main reason and a source of air pollution and it keeps on increasing each day. However, some countries have taken measures to control the situation. That will be discussed in another post.
This is the treehugger signing out for today... :)