car auction - fumes

[tali122]

when i go to a car auction the smell of exhaust fumes is very evident - given that this is carbon monoxide in a very confined enviroment , surely this poses a great threat of respiratory disease and cancer to regular attenders and long standing employees?

[naz_nomad]

I would imagine you're right...

[brachiopod]

This is a multi-part question, tali, and needs a few clarifications, explanatiuons and 'putting in contexts'.

Exhaust is not all carbon monoxide. Carbon monoxide (CO) occurs as a result of incomplete combustion.

When you burn a fuel (usually a hydrocarbon), in sufficient oxygen (or at least air containing oxygen), the products are carbon dioxide and water. So, in theory, that's all you get in exhaust 'fumes'. In practice, you get a mixture of combustion products (CO2 & water), unburnt fuel, and carbon monoxide (CO).

So, is carbon monoxide gas poisonous? Well, yes and no. It's mere presence will not kill you like, say, hydrogen cyanide would. However, carbon monoxide (CO) binds chemically with your red blood cells, preventing them from taking up oxygen, so you eventually die of suffocation. (That's why it is the "silent killer")

So what about the rest of the combustion products? Well, CO2 is part of the whole debate about global warming as a combustion product. But per se, is not poisonous - (it is the gas in fizzy drinks after all).

Which leaves "unburnt fuel" - this is emitted in exhaust fumes like everything else. What does this consist of?

Well, unburnt 'petrol' (a mixture of alkanes in the C7 to C9 range) and? Additives.

Many and various chemicals are added to make the fuel "behave" - no matter how young you are, you will have heard of "unleaded petrol". This is because previously, a lead compound was added to petrol to prevent (let's call it) "premature ignition".

The combination of unburnt petrol, (including additives) combine with the other combustion products, such as water, to form "particulates". These are possibly the biggest (unquantified) long-term risk to health.......

[cont.]

[brachiopod]

[....cont]

Working in a car auction, in terms of long term exposure to these combustion products / particles etc., is probably no worse than having to walk down the pavement in an urban environment - especially one close to a main thoroughfare or commuter route - (and cossetting your offspring in 4x4's actually concentrates these particulates - despite the sense of isolation and separation from the 'bad air').

We could, of course, protect these car-auction workers by banning cars from starting up within 500 yards of the auction site, or get them (the cars) to have a certificated emission level before being allowed in the 'ring', or force each auction site to comply with "EU Ventilation Standard 459652E ii" and introduce an "Air Quality Standard" -

But if that is what the public (with the help of the papers) wants, then shouldn't the Government comply? And if they do, will we accuse them of being a Nanny State?

Who knows?

I don't want to sound far-fetched, but they'll be banning smoking in pubs next !!

[theprof]

Petrol engine exhaust fumes mainly consist of:

Various Nitrogen Oxides
Carbon Dioxide
Particulates
Ozone
Sulpher Dioxide
Carbon Monoxide
Volatile Organic Compounds
Various Hydrocarbons

Diesel engine exhaust fumes mainly consist of:

Nitrogen
Sulpher Dioxide
Aldehydes
Nitrogen Dioxide
Carbon Monoxide
Water
Polycyclic Aromatic Hydrocarbons (PAH's) (eg Benzopyrene)
Carbon (as Soot - 60% to 80%)

You are correct in your views over the danger posed to health by breathing Carbon Monoxide in a confined environment. Carbon Monoxide is an insidious and very dangerous poison and detection often comes too late. Petrol exhaust fumes contain more Carbon Monoxide but less soot than diesel exhaust fumes.

However, Carbon Monoxide is far from the only danger faced by people at these venues. Many volatile organic compounds and hydrocarbons are known or suspected to be carcinogenic and airborne ingestion is not good for the health. Hundreds of these compounds are emitted daily from exhausts.

PAH's are a group of compound that are even more dangerous as they can interact with DNA and seriously affect bichemical pathways in the human body. These metabolic changes often result in cancer.

Respiratory tract disease can arise from exposure to any of the substances on the list above. Nitrogen Dioxide exposure can lead to bronchitis and even persistent exposure to water vapour can lead to specific type of pneumonia.

Personally, I wouldn't visit these venues too often.

[theprof]

Great explanation brachiopod. Your conclusions are certainly food for thought and your right, there's lots of potential here for intrusion by the Nanny State.

We certainly do need to look at it both impartially and in perspective.

[brachiopod]

No, prof, your answer was so much more succinct - I got so lost in double postings that I didn't even start broaching carcinogens!!

[theprof]

Thanks for that brachiopod. This was one of those questions where it would have been very easy to become too technical and I did try to make my post as succinct as possible.

Clearly, you were posting your post whilst I was still writing mine and I did not see your post until I had pressed the "submit" button.

You certainly did fill in the gaps in my post and I'm very grateful.

Well done!