Car exhaust

The average car emits various carcinogenic chemicals through its exhaust pipe, such as toluene, formaldehyde and PAH's (unburned hydrocarbons) making it a considerable health risk to breathe. They have a similar chemical construction as tobacco smoke. The good news is that there are energy-saving cars that emit greatly reduced amounts of dangerous chemicals, such as hybrids and methane driven cars. In the future we can expect electric cars and hydrogen cars to become much more ecological than the cars now driven.