What are we breathing in?

[jonesy]

...


I'm sure I read a report once that pollution was often worse in rural areas downwind of London than in the capital itself. Depends on the type of pollution no doubt.

Yes. The distinction is between primary pollutants, those that come directly out of the exhaust like soot particles, carbon monoxide and NO; and secondary pollutants which form from primary pollutants as they react in the atmosphere. NO2 forms relatively quickly from NO, so concentrations are higher in urban areas; and generally still a greater problem near a busy road than away from it. However, with Ozone the situation is reversed, as not only does it take a while to form, through photochemical reactions (which is why it is worse on sunny days) but it reacts with NO, so is actually destroyed by fresh vehicle emissions. As a result, ozone is usually at its highest in rural areas and very low at the side of a busy road. For this reason the first network of ozone monitors was set up in rural areas, as that was where the highest concentrations were to be found, whereas monitoring for other pollutants is focused on urban areas.

 

[jonesy]

I have been giving this some thought.

Although the vast majority of you will not be working in the motor car engine exhaust emissions R&D environment, I have to comment this is a misleading statement.
The 50 ppm, 100ppm and 1000ppm cylinders I worked with were seperated from all the other span gases by storing them in a partial vacuum cabinet. This is because, as far as I am concerned, they are dangerous when inhaled.

If you ever do have the misfortune to be asked to handle these bottles ( Aluminium, silver body with a Yellow top ), NEVER NEVER sniff the gas up your nose.
If you do, and you get a stonking hard-on, the chances are you will not survive the ordeal.

Err on the side of safety and stay well away.

Note that your cylinders start at 50ppm, wheras levels measured in the environment are measured in ppb. If you look at the air quality website I gave a link to earlier you will see that NO is not considered to be a health problem, which is why a standard is only set for NO2. And hourly limits for NO2 are rarely considered high enough to be a health problem for the majority of people.

 

[Randochap]

I particularly liked a quote from David Newby, Professor of Cardiology at The University of Edinburgh, "I ride my bike back and forth to work every day. If everyone else did that, too, we wouldn't be having this problem at all, would we?" Well said that man...

Added that to my bike quotes collection. Do you have a source?

 

[Randochap]

Woman is the most dangerous thing know to man.

I'd rather observed that it was man fighting other man over the "possession" of woman.

 

[HJ]

Added that to my bike quotes collection. Do you have a source?

I think he said to some journalists reporting on a scientific paper he had written it pops up on various news web sites such as this one, it is at the bottom of the page...

 

[jimboalee]

I'd rather observed that it was man fighting other man over the "possession" of woman.

Ah, you might be right.

The most dangerous substance known to man is Testosterone...

 

[jimboalee]

Note that your cylinders start at 50ppm, wheras levels measured in the environment are measured in ppb. If you look at the air quality website I gave a link to earlier you will see that NO is not considered to be a health problem, which is why a standard is only set for NO2. And hourly limits for NO2 are rarely considered high enough to be a health problem for the majority of people.

I've been looking for Motor car exhaust emissions regulations on an easily obtainable website which reflects what I can get on Jaguar's internal net. No luck thus far.
My question is "Why is NOx a regulatory pollutant if it is indeed harmless?"

 

[jonesy]

I've been looking for Motor car exhaust emissions regulations on an easily obtainable website which reflects what I can get on Jaguar's internal net. No luck thus far.
My question is "Why is NOx a regulatory pollutant if it is indeed harmless?"

The concentrations in the vehicle exhaust are vastly higher than those at the roadside because even in that short distance they have been heavily diluted.

I didn't say NOx is harmless, I said NO was not considered to be a threat to health (at the levels found in polluted air).

NOx is NO + NO2

It is NO2 that is considered to be a threat and so has air quality standards for it. Furthermore, NO2 is formed from NO in the emissions, so you have to control NO emissions if you want to limit NO2.