What are we breathing in?

[Greenbank]

Worse in the car though !

But is it worse for cyclists because they're breathing far more heavily than someone driving a car?

 

[jonesy]

Poetry is not dead.


Another piece of misinformation.

Although PM5 and PM10 particulates are inhaled, the body has a mechanism for expelling them.

The exhaust emission that is often not reported, as it might frighten some poor blighter to death, is NOx. NOx are the 'oxides of Nitrogen' molecules such as NO and NO2, Nitric oxide and Nitrogen Dioxide.

http://www.vcacarfueldata.org.uk/searchheadings_help.asp

When NO2 combines with the humidity in your lungs, it forms acid rain. Unfortunately, your body doesn't expel it and it burns its way through the alvioli and drives the nervous system barmy.

The fatal dose is 50 parts per million.

Quote:

14 Nitric oxide is a severe eye, skin and mucous membrane irritant. Nitrogen dioxide is a highly toxic, irritating gas. There has been some reports of exposure to high levels of nitrogen dioxide (as generated by oxy-fuel gas cutting in confined spaces) resulting in severe ill health and even death. Initial exposure to high concentrations of the gas can
however result in only mild irritation followed by a symptom free period of several hours. However, this can develop into a build up of fluid on the lungs which in severe cases can sometimes be fatal. Both nitrogen dioxide and nitric oxide have been shown to have mutagenic potential, which raises possible concerns for lung cancer.​

Paper filters do not filter NO and NO2.​

Quite a bit of garbled information here I'm afraid.

Firstly- Particulate Matter: PM10 etc. The suffix refers to the particle size range in micrometres, which is defined according to the filter used to separate them. So PM10 loosely refers to all particles smaller than 10 microns, or more strictly to particles that have been passed through a filter with a 50% cut off at 10 microns. This corresponds to the particle size range that we can breathe in. I'm not aware of anyone measuring PM5; however PM2.5 is measured, because this size range is small enough to penetrate into the lungs. Now, while it is true that the body has mechanisms for protecting itself from the coarser particles, which isn't surprising as dust particles of this size occur naturally, so we've evolved with them, the sub-micron particles are almost entirely man-made, and are the ones that cause concern. And they include the acid aerosol that you refer to which is formed eventually as a secondary pollutant from the oxidation of NOx and sulphur dioxide. But the evidence is that even inert particles of this size cause respiratory problems, potentially by triggering immune responses.

However, let's get NOx into proportion. NO is not harmful and takes some time to be oxidised to NO2. NO2 is harmful, but at levels far higher than are commonly found, even at the roadside.

See:
http://www.airquality.co.uk/what_causes.php

In particular the air quality 'bands',
http://www.airquality.co.uk/standards.php#band

which you can compare with current readings:

http://www.airquality.co.uk/bulletin.php?type=Current

 

[purplepolly]

No need to worry folks.
.....

Thanks to the cycling, I have a higher than average lung efficiency, even at the age of fifty.

we tested this as at work the other month - mine was off the chart of 'normal' for a woman and roughly what's expected for a man of my height and age, and it's not as though I do any long rides - about 35 miles tops. It's mostly all down to the good urban air of my commute.

 

[HJ]

But is it worse for cyclists because they're breathing far more heavily than someone driving a car?

Well yes and no, inside a car, you are exposed to higher levels of pollutants, but then as cyclists we breath harder. However the general consensus among researchers is there is a trade-off between physical health from exercise and damage from air pollution, and the benefit of regular exercise (such as cycling) is greater than the risk from the pollution. At the same time they suggest that if it's a bad air day you should think twice.

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...

 

[HJ]

Just found the study which I was looking for in the first place (Rank et al. 2001)

It has frequently been claimed that cycling in heavy traffic is unhealthy, more so than driving a car. To test this hypothesis, teams of two cyclists and two car drivers in two cars were equipped with personal air samplers while driving for 4 h on 2 different days in the morning traffic of Copenhagen. The air sample charcoal tubes were analysed for their benzene, toluene, ethylbenzene and xylene (BTEX) content and the air filters for particles (total dust). The concentrations of particles and BTEX in the cabin of the cars were 2–4 times greater than in the cyclists’ breathing zone, the greatest difference being for BTEX. Therefore, even after taking the increased respiration rate of cyclists into consideration, car drivers seem to be more exposed to airborne pollution than cyclists.

 

[purplepolly]

Something about the original BBC report doesn't make sense. I've lived for several years a stones throw away from a very congested 4 lane A road and I've always worked in urban areas. Yet my lung capacity is far higher than normal, which I've attributed to cycling. So if these children have a lung capacity of 5% lower than the national average, couldn't that be balanced out by them getting more exercise?

 

[jonesy]

Something about the original BBC report doesn't make sense. I've lived for several years a stones throw away from a very congested 4 lane A road and I've always worked in urban areas. Yet my lung capacity is far higher than normal, which I've attributed to cycling. So if these children have a lung capacity of 5% lower than the national average, couldn't that be balanced out by them getting more exercise?

I think the answer has to be Yes. Let's not forget that there is also a growing problem of obesity amongst children, linked to lack of physical activity. And sadly the social groups most exposed to traffic pollutants are also very likely to be those most at risk of obesity. Also, pollution levels decline rapidly with distance from their source, so if people were to get out and about on bikes more, then not only would they gain from the exercise but they'd also spend more time away from the higher levels. And of course, if they are cycling instead of traveling by car then they won't have the greater in-car levels that have already been mentioned.

 

[HJ]

I think that one of the messages which the researcher was trying to give in the clip on the BBC site was that children are more effected because of their proximity to source, that was why the leaves were being collected at 30cm above ground level. Whereas when you are on a bike you are generally higher up and further from the source, I can remember off hand the rate of decline with distance from but it is fairly rapid.

Prof. Newby, who I quoted above, has shown that breathing in particulates increases the risk of heart problems, but the benefit of exercise is greater that the risk...

 

[summerdays]

I think the answer has to be Yes. Let's not forget that there is also a growing problem of obesity amongst children, linked to lack of physical activity. And sadly the social groups most exposed to traffic pollutants are also very likely to be those most at risk of obesity. Also, pollution levels decline rapidly with distance from their source, so if people were to get out and about on bikes more, then not only would they gain from the exercise but they'd also spend more time away from the higher levels. And of course, if they are cycling instead of traveling by car then they won't have the greater in-car levels that have already been mentioned.

So if you take the option of quieter roads - which I often do to avoid the stop start of traffic lights, then it should be much better than the main roads? Similarly when walking with the kids we probably choose the side roads as being more pleasant to walk along.

 

[asterix]

Ah well, at least asbestos has been removed from brake pads and lead from petrol.

A plumber I met recently has just had to retire and return to the UK to live in Rotherham due to asbestosis.

Also, pollution levels decline rapidly with distance from their source

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.

 

[jimboalee]

Quite a bit of garbled information here I'm afraid.

Firstly- Particulate Matter: PM10 etc. The suffix refers to the particle size range in micrometres, which is defined according to the filter used to separate them. So PM10 loosely refers to all particles smaller than 10 microns, or more strictly to particles that have been passed through a filter with a 50% cut off at 10 microns. This corresponds to the particle size range that we can breathe in. I'm not aware of anyone measuring PM5; however PM2.5 is measured, because this size range is small enough to penetrate into the lungs. Now, while it is true that the body has mechanisms for protecting itself from the coarser particles, which isn't surprising as dust particles of this size occur naturally, so we've evolved with them, the sub-micron particles are almost entirely man-made, and are the ones that cause concern. And they include the acid aerosol that you refer to which is formed eventually as a secondary pollutant from the oxidation of NOx and sulphur dioxide. But the evidence is that even inert particles of this size cause respiratory problems, potentially by triggering immune responses.

However, let's get NOx into proportion. NO is not harmful and takes some time to be oxidised to NO2. NO2 is harmful, but at levels far higher than are commonly found, even at the roadside.

See:
http://www.airquality.co.uk/what_causes.php

In particular the air quality 'bands',
http://www.airquality.co.uk/standards.php#band

which you can compare with current readings:

http://www.airquality.co.uk/bulletin.php?type=Current

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.

 

[HJ]

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.

It does depend on which pollutant you are talking about...

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.

Many things are safe at low concentrations but can be fatal at high concentrations, try oxygen for instance...

 

[jimboalee]

Many things are safe at low concentrations but can be fatal at high concentrations, try oxygen for instance...

This is a very valid point, and to ensure no-one dies from an overdose of oxygen, we should campaign to chop down all the trees.

Interestingly, O2 is about the most dangerous gas known to man.
When the ambient atmosphere reaches 99.99 % O2, custard powder with spontaneously combust at room temperature.

 

[asterix]

Doesn't that make custard powder the most dangerous stuff known to man? (Possibly not woman as they can deal with these things.)

 

[jimboalee]

Doesn't that make custard powder the most dangerous stuff known to man? (Possibly not woman as they can deal with these things.)

Woman is the most dangerous thing know to man.