Thread: Exhaust fumes

What are the most harmful chemicals emitted by car and airplane engine exhausts (besides carbon dioxide greenhouse gas)? Which ones are most detrimental to human health? Would it be nitrogen oxides and particulate matter?

Thank you

I don’t know how you can rank them since their effects are so varied and complex, and there have been great improvements in emissions reduction with the use of clean fuels, efficient engines and catalytic converters. The latest push in the US is to reduce benzene which can leave a car exhaust unburned and is a carcinogen. Refineries are required to install facilities by (I think) 2012 that will drastically reduce the amount of benzene in gasoline.

I agree. Twenty five years ago I would have said lead without giving it a second thought. Todays that's not really a problem at all.

Carbon monoxide molecules bond to lung tissue. Your lungs have to heal every time you breath it. I don't know all the details, but this is a very common gas emitted from automobile exausts. Because of it's nature, it also bonds to oxygen to create carbon dioxide, and therefore, it doesn't stay long in the air we breath unless we are in a garage, for instance.

What are the most harmful chemicals emitted by car and airplane engine exhausts (besides carbon dioxide greenhouse gas)?

The NOx. In adition of being very polutant themselves they can intermediate a lot of reactions, creating ozone, PAN's and aldehydes... Smog is particulary rich in such compounds.

OVC's (organic volatile compounds) are also very common, they come from incomplete combustion of gasoline or diesel.