Pollution- You Decide!

[Priceless]

It's not entirely correct to suggest that "The Thai limit for daily pollution level is 120 µg/m3", rather the WHO recommend safe maximum level is 120.

But there's hope for this debate yet since I note that now there is finally an acknowledgement that air currents do play an important role in importing pollution from other countries so that's a step in the right direction in correcting the collective thinking. And yes UG I do know that Priceless can't see this but this was just an opportune place to post this message.

Somebody, who is aware that 'chiang mai' is often not that well informed, told me about this post so I looked it up. Some of the more frequently quoted standards for PM<10 pollution, including their sources, are in the following table:

As you can see, the Thai (PCD) standard is 120 µg/m³ whereas the WHO does not quote that number, either for their "Guideline" or any of their intermediate targets.

As for the importance of air currents and inflow from other regions/countries, I have certainly never denied that and I can't recall anyone else doing it either (though I may of course have missed some posts). I can actually recall a thread from not too long ago that discussed the influence of forest fires in Indonesia on air quality in e.g. Phuket. There have also been numerous discussions on forest fires in Laos and (especially) Myanmar.

/ Priceless

In your post number 1,115 you wrote:

"The following are the ambient air quality standards, concerning ozone, for a few countries//areas:

Thailand 100 µg/m3

USA 120 µg/m3

EU 120 µg/m3"

I'm also concious that I've seen the figure of 120 quoted extensively in the many many "discussions" on this subject but frankly I can't be bothered to search all the threads to pull out all the quotes. Regardless, the number is somewhat meaningless here in Thailand it seems since your most recent document suggests that it can never be exceeded (when clearly it is exceeded on occasion), how do they manage to do that I wonder, does the PCD use one of it's two monitoring stations to raise an alert and then all factories in the North are closed down immediately, doubtful. Kinda silly really unless it is just a target/desire and more or less window dressing material.

As for the issue of air currents et al: it was on the order of two years ago or so that I suggested in one of these threads that a study should be done to determine the impact of air currents and imported pollution and you replied that wasn't necessary, that was why I posted my original comment in this thread, give me time and I'll find your quote!

But hey, look, it's Xmas Eve and we've both got better things to do (at least I do) than to carry on this debate at this time of the year so I'll wish you and UG a Merry Xmas and all the best for 2010 and leave you both to it.

You definitely need to brush up your reading skills. If you try to reread your quote from my post number 1,115 you will find: "The following are the ambient air quality standards, concerning ozone, for a few countries/areas". Ozone is a triatomic oxygen molecule which has nothing whatsoever to do with the particulate matter pollution that we have been discussing on this thread.

As concerns the 120µg/m³ "limit", that is what should never be exceeded to fulfil the standard. This is as opposed to e.g. the EU standard where the limit may be exceeded 35 times/year and still be considered to be within the standard.

I honestly don't remember the thread from two years ago, but if you read my earlier post in this thread you will find that the PCD has during 2009 implemented six new measuring stations in northern Thailand which have made these kinds of studies possible. Until and including 2008 there were only three stations in northern Thailand, two in Chiang Mai and one in Lampang. This did not suffice for any serious studies of the spreading patterns of PM pollution.

Merry Christmas and a Happy New Year!

/ Priceless

Edited December 24, 2009 by Priceless

[chiang mai]

It's not entirely correct to suggest that "The Thai limit for daily pollution level is 120 µg/m3", rather the WHO recommend safe maximum level is 120.

But there's hope for this debate yet since I note that now there is finally an acknowledgement that air currents do play an important role in importing pollution from other countries so that's a step in the right direction in correcting the collective thinking. And yes UG I do know that Priceless can't see this but this was just an opportune place to post this message.

Somebody, who is aware that 'chiang mai' is often not that well informed, told me about this post so I looked it up. Some of the more frequently quoted standards for PM<10 pollution, including their sources, are in the following table:

As you can see, the Thai (PCD) standard is 120 µg/m³ whereas the WHO does not quote that number, either for their "Guideline" or any of their intermediate targets.

As for the importance of air currents and inflow from other regions/countries, I have certainly never denied that and I can't recall anyone else doing it either (though I may of course have missed some posts). I can actually recall a thread from not too long ago that discussed the influence of forest fires in Indonesia on air quality in e.g. Phuket. There have also been numerous discussions on forest fires in Laos and (especially) Myanmar.

/ Priceless

In your post number 1,115 you wrote:

"The following are the ambient air quality standards, concerning ozone, for a few countries//areas:

Thailand 100 µg/m3

USA 120 µg/m3

EU 120 µg/m3"

I'm also concious that I've seen the figure of 120 quoted extensively in the many many "discussions" on this subject but frankly I can't be bothered to search all the threads to pull out all the quotes. Regardless, the number is somewhat meaningless here in Thailand it seems since your most recent document suggests that it can never be exceeded (when clearly it is exceeded on occasion), how do they manage to do that I wonder, does the PCD use one of it's two monitoring stations to raise an alert and then all factories in the North are closed down immediately, doubtful. Kinda silly really unless it is just a target/desire and more or less window dressing material.

As for the issue of air currents et al: it was on the order of two years ago or so that I suggested in one of these threads that a study should be done to determine the impact of air currents and imported pollution and you replied that wasn't necessary, that was why I posted my original comment in this thread, give me time and I'll find your quote!

But hey, look, it's Xmas Eve and we've both got better things to do (at least I do) than to carry on this debate at this time of the year so I'll wish you and UG a Merry Xmas and all the best for 2010 and leave you both to it.

You definitely need to brush up your reading skills. If you try to reread your quote from my post number 1,115 you will find: "The following are the ambient air quality standards, concerning ozone, for a few countries/areas". Ozone is a triatomic oxygen molecule which has nothing whatsoever to do with the particulate matter pollution that we have been discussing on this thread.

As concerns the 120µg/m³ "limit", that is what should never be exceeded to fulfil the standard. This is as opposed to e.g. the EU standard where the limit may be exceeded 35 times/year and still be considered to be within the standard.

I honestly don't remember the thread from two years ago, but if you read my earlier post in this thread you will find that the PCD has during 2009 implemented six new measuring stations in northern Thailand which have made these kinds of studies possible. Until and including 2008 there were only three stations in northern Thailand, two in Chiang Mai and one in Lampang. This did not suffice for any serious studies of the spreading patterns of PM pollution.

Merry Christmas and a Happy New Year!

/ Priceless

Yes indeed, I must improve in that area! But I'm pleased to note that six new measuring stations have been installed, that's a step in the right direction, perhaps now we'll begin to see more truly representative air quality data of CM as a whole. and I look forward to watching the story unfold.

[anon789]

I live about 25 km outside the city (measured from the middle of the city) and I ride my motobike into the city and back again about 4-5 times a week. I have a helmet with a plexiglass facemask that covers my forehead, eyes, nose and half my mouth. When I get back to the house after a round-trip to the city sometimes I find that I have grown a black soot mustache - I look like pretend-pirate at kids birthday party. It washes off easily, of course, but it is annoying and a little bit scary to think that the air contains this much soot!

The funny thing is that I have lived in Chiang Mai for 6 years, and used a motobike all of that time, and the latter half of this year is the first time I have noticed my fake mustache, it started in September. It is possible, I suppose, that I have been sporting this mustache for the last 6 years and that I just now noticed it... 

Any other Pirates out there? Arrrr!

Maybe I should get a new helmet or just a longer faceplate? It wouldn't remove the soot from the air, but it would save me having to wash my face every time I return from a round-tip to the city...

[Mapguy]

A new indicator, Priceless !!

[PeaceBlondie]

I commuted to and from Lamphun for two years, 2003-2005. In the winter I had to wash my jacket often. The shirt collar had a ring around the neck.

[CobraSnakeNecktie]

One has to wonder how much of the grit and particulate matter in CM air is just dust and dirt and not man made pollution. I guess it's still man created from agricultural practices. Not that its necessarily any less damaging. The most damaging are supposed to be the under 2.5 micron particles created from combustion because they lodge deeply in the lungs. Does the sub 2.5 microns arise from forest fires etc? or just internal combustion engines?

I remember OSHA or maybe it was the EPA did a study of bus drivers who drove the unpaved dirt road in Denali national park in Alaska and the health impact was thought to be similar to smoking 3 packs of cigs a day. This was 20 years ago before <2.5 micron particulates were being considered.

A lot of the grime I wash off my body after a rural CM bicycle ride might just be mother natures larger particles if that is any comfort to the reasoned mind.

[Priceless]

I commuted to and from Lamphun for two years, 2003-2005. In the winter I had to wash my jacket often. The shirt collar had a ring around the neck.

I obviously don't know, but I have a suspicion that this, as well as a lot of the apparent discrepancy between some people's perceptions and the PCD's measurements, is due to pollution by particles larger than 10 microns (i.e. PM>10). These particles don't travel that far, and would be more influenced by local factors than the smaller particles (PM<10). The positive side of this, if I am right, is that these larger particles don't really influence health that much since they don't enter the lungs. They may however irritate the throat and nose, which can certainly be irritating but not very unhealthy.

This would also explain the "falling ash" that the OP claims to see. I very much doubt that s/he can see particles <10 microns (i.e. 0.001 mm) in diameter, it would anyway require a quite good microscope

Any comments to my suspicion?

/ Priceless

[chiang mai]

Just a point of clarification here that the PCD only measures particulate pollution in the range of less than 10microns but greater than 2.5microns, data on anything outside that range is not captured or recorded. I've added this clarification so that other readers might more fully understand the extent of the data capture and reporting.

[Thailand]

I commuted to and from Lamphun for two years, 2003-2005. In the winter I had to wash my jacket often. The shirt collar had a ring around the neck.

I obviously don't know, but I have a suspicion that this, as well as a lot of the apparent discrepancy between some people's perceptions and the PCD's measurements, is due to pollution by particles larger than 10 microns (i.e. PM>10). These particles don't travel that far, and would be more influenced by local factors than the smaller particles (PM<10). The positive side of this, if I am right, is that these larger particles don't really influence health that much since they don't enter the lungs. They may however irritate the throat and nose, which can certainly be irritating but not very unhealthy.

This would also explain the "falling ash" that the OP claims to see. I very much doubt that s/he can see particles <10 microns (i.e. 0.001 mm) in diameter, it would anyway require a quite good microscope

Any comments to my suspicion?

/ Priceless

When it starts falling again, not long I am sure, on my patio tables & pool / pool area I will take another picture and you will see that the ash is most definitely visible on the various surfaces- no microscope required- unless of course I have super power vision that a man of my great age should not be entitled to.

Perhaps I should take samples for analysis.?

[Priceless]

I commuted to and from Lamphun for two years, 2003-2005. In the winter I had to wash my jacket often. The shirt collar had a ring around the neck.

I obviously don't know, but I have a suspicion that this, as well as a lot of the apparent discrepancy between some people's perceptions and the PCD's measurements, is due to pollution by particles larger than 10 microns (i.e. PM>10). These particles don't travel that far, and would be more influenced by local factors than the smaller particles (PM<10). The positive side of this, if I am right, is that these larger particles don't really influence health that much since they don't enter the lungs. They may however irritate the throat and nose, which can certainly be irritating but not very unhealthy.

This would also explain the "falling ash" that the OP claims to see. I very much doubt that s/he can see particles <10 microns (i.e. 0.001 mm) in diameter, it would anyway require a quite good microscope

Any comments to my suspicion?

/ Priceless

When it starts falling again, not long I am sure, on my patio tables & pool / pool area I will take another picture and you will see that the ash is most definitely visible on the various surfaces- no microscope required- unless of course I have super power vision that a man of my great age should not be entitled to.

Perhaps I should take samples for analysis.?

I have no reason whatsoever to doubt what you have posted about what you see. What I am suggesting is that it might be ash/soot particles of much greater size (i.e. more than 10 microns diameter) than the particles that may cause serious health problems. The smaller ones would probably need a microscope to be seen, whereas the larger ones are quite obvious.

This would still cause cause visible blackening of your outdoor surfaces and pool filter, but not constitute a significant health danger. It would also not show up in the PCD measurements, since they only cover the finer particles.

/ Priceless

[Priceless]

Just a point of clarification here that the PCD only measures particulate pollution in the range of less than 10microns but greater than 2.5microns, data on anything outside that range is not captured or recorded. I've added this clarification so that other readers might more fully understand the extent of the data capture and reporting.

As usual 'chiang mai' is wrong. The PCD measurements cover particles less than 10 microns, including those less than 2.5 microns. According to a WHO report ( http://www.euro.who.int/Document/E90038.pdf page 277) it can be assumed that PM<2.5 constitutes roughly half of the measured concentrations in urban areas in developing countries.

/ Priceless

[chiang mai]

Just a point of clarification here that the PCD only measures particulate pollution in the range of less than 10microns but greater than 2.5microns, data on anything outside that range is not captured or recorded. I've added this clarification so that other readers might more fully understand the extent of the data capture and reporting.

As usual 'chiang mai' is wrong. The PCD measurements cover particles less than 10 microns, including those less than 2.5 microns. According to a WHO report ( http://www.euro.who.int/Document/E90038.pdf page 277) it can be assumed that PM<2.5 constitutes roughly half of the measured concentrations in urban areas in developing countries.

/ Priceless

And just when I thought we were starting to get along so well.

So the measurement of particles smaller than 2.5 microns is assumed rather than actually measured?

[Priceless]

Just a point of clarification here that the PCD only measures particulate pollution in the range of less than 10microns but greater than 2.5microns, data on anything outside that range is not captured or recorded. I've added this clarification so that other readers might more fully understand the extent of the data capture and reporting.

As usual 'chiang mai' is wrong. The PCD measurements cover particles less than 10 microns, including those less than 2.5 microns. According to a WHO report ( http://www.euro.who.int/Document/E90038.pdf page 277) it can be assumed that PM<2.5 constitutes roughly half of the measured concentrations in urban areas in developing countries.

/ Priceless

And just when I thought we were starting to get along so well.

So the measurement of particles smaller than 2.5 microns is assumed rather than actually measured?

There are no figures for PM<2.5 µg/m³ available in Thailand. If you are particularly interested in such figures your best bet is to assume according to the WHO report. In e.g. USA and (some) countries in Europe PM<2.5 is actually measured, but this started quite recently. The EU will have a "target" for PM<2.5 starting 1 January 2010, but no "limit" until 1 January 2015.

As for getting along, all you have to do is desist from posting "clarifications" or "corrections" to other peoples factual posts, unless you are sure and have checked that what you're posting is actually correct. So far your posts on this thread have just been misleading and/or confusing readers

/ Priceless

[Mapguy]

Just a point of clarification here that the PCD only measures particulate pollution in the range of less than 10microns but greater than 2.5microns, data on anything outside that range is not captured or recorded. I've added this clarification so that other readers might more fully understand the extent of the data capture and reporting.

As usual 'chiang mai' is wrong. The PCD measurements cover particles less than 10 microns, including those less than 2.5 microns. According to a WHO report ( http://www.euro.who.int/Document/E90038.pdf page 277) it can be assumed that PM<2.5 constitutes roughly half of the measured concentrations in urban areas in developing countries.

/ Priceless

And just when I thought we were starting to get along so well.

So the measurement of particles smaller than 2.5 microns is assumed rather than actually measured?

It is not a casual assumption. But, yes, as far as we know, <2.5 PM is not measured in Thailand, and , while I have not looked lately, measurement is not generally done anywhere.

By the way, it is more helpful to start reading the report referred to by Priceless on page 275 beginning with "Guidelines." And, you can start reading earlier (just scroll back a few pages) in the report for even more information about pollution in [economically-] developing countries, particularly in regard to agricultural burning.

Edited December 25, 2009 by Mapguy

[CobraSnakeNecktie]

Particulate wiki

some eye opening info for me.

[chiang mai]

Just a point of clarification here that the PCD only measures particulate pollution in the range of less than 10microns but greater than 2.5microns, data on anything outside that range is not captured or recorded. I've added this clarification so that other readers might more fully understand the extent of the data capture and reporting.

As usual 'chiang mai' is wrong. The PCD measurements cover particles less than 10 microns, including those less than 2.5 microns. According to a WHO report ( http://www.euro.who.int/Document/E90038.pdf page 277) it can be assumed that PM<2.5 constitutes roughly half of the measured concentrations in urban areas in developing countries.

/ Priceless

And just when I thought we were starting to get along so well.

So the measurement of particles smaller than 2.5 microns is assumed rather than actually measured?

It is not a casual assumption. But, yes, as far as we know, <2.5 PM is not measured in Thailand, and , while I have not looked lately, measurement is not generally done anywhere.

By the way, it is more helpful to start reading the report referred to by Priceless on page 275 beginning with "Guidelines." And, you can start reading earlier (just scroll back a few pages) in the report for even more information about pollution in [economically-] developing countries, particularly in regard to agricultural burning.

I remain keen to understand the reality of the pollution problems in Chiang Mai, but perhaps even more than that, I want to see any debate on that subject remains factual, unbiased and not open to interpretation - I will therefore take much pleasure in reading said document which from an early glance raises some very interesting questions regarding the links between particulate matter and health issues.

[Priceless]

Particulate wiki

some eye opening info for me.

Thank you, an excellent condensation of what one would otherwise have to search for in many different sources. I had not seen this particular article before and really appreciated it

/ Priceless

[Mapguy]

Yes, agree. It is easy to get lot in the woods in this discussion.

[hmficc]

... For most of human history the average lifespan was about 15 years. Just slightly longer than reproductive age. ...

Sawasdee Khrup, Khun CobraSnakeNeckTie,

May we, respectfully, ask what basis, what sources, you have for this conclusion ?

thanks, ~o:37

Well I wasn't there at the time but it's I learned this in Anthropology classes. Humans have been around for millions of years. For most of that time they died from early diseases, lack of medical care and exposure to the elements and good old starvation.

In the last few thousand years average lifespan has increased dramatically. In just the last century it has nearly doubled. Mind you this does not mean the oldest living people. This statistic is referring to the average life expectancy at birth and there were a lot of variations as I recall depending on conditions and sometimes just luck.

As late as the bronze age the average was as low as 18 years. Classical Grecian period the average was ~25.

World average is now 66 years which is up from about 35 at 1900. There will be different estimates based on the sketchy data and method of calculation.

Enjoy your long lives !!!!!

With the mother dead at 15 who would rear the kids. Not grandma she is dead long ago.

[orang37]

... snip ... I remain keen to understand the reality of the pollution problems in Chiang Mai, but perhaps even more than that, I want to see any debate on that subject remains factual, unbiased and not open to interpretation - I will therefore take much pleasure in reading said document which from an early glance raises some very interesting questions regarding the links between particulate matter and health issues.

Sawasdee Khrup, Khun Chiang Mai,

In spite of the fact this thread originated as a trolling deception by the OP, who knew exactly why his pool filter was black, for us it has been very valuable, and the exchanges between you, Khun Priceless, and Khun Mapguy, very enlightening and appreciated.

We are not hopeful, however, that a discussion of this type, can be "factual, unbiased and not open to interpretation" for the simple fact that the linkage between the extent of particulate matter present is so variable (by location, wind patterns, local sources, and a thousand other variables), and the extent of any individual's, or group's, exposure to the pollution so variable, that the "bottom line" we think you are after : impact on public health is such a "broad-spectrum" target ... that we will be, inevitably, forced to be speaking in broad hypothetical terms; i.e., interpretations.

Yes, we can be "surrounded by facts," but the way we order and rank the importance of those "facts" are going to reflect our values and agendas; i.e., biases. And, the "facts" themselves are based on data collection methods which, as already mentioned here in several posts, are open to interpretation.

We could not believe our eyes when we read, in the comment on the slash-and-burn thread by Khun Priceless :

http://www.thaivisa.com/forum/Slash-Burnin...47#entry3195547

that Chiang Mai's air pollution sample special vehicle evidently spends quite a bit of time up at the Phu Ping palace on the mountain where the air is obviously going to be of a greatly different average, mean, and modal quality than down in the valley where most people live ! Note : Khun Priceless did qualify that observation with the statement that the data it collected was quesionable because you could not be sure exactly where it was collect. Of course just repeating the mantra "This is Thailand" took care of that cognitive dissonance

Saying what we just said is in no way to demean the value of this discussion as is !

But, let's do remember that if we are talking about the significant numbers of people directly engaged in daily agricultural work in the Ping valley and Chiang Mai, their daily exposure is going to be one thing; office workers who commute an hour a day from the outskirts to work in central Chiang Mai, another thing (different for car drivers vs. motosai ?). Farangs who bicycle an hour or more a day in traffic in the city another thing ? Illegal immigrant Burmese workers doing the "crap" jobs, and building all this new construction around Chiang Mai, in daily exposure to dust, sand, chemicals, another thing ?

In addition let's not forget the variations in human strength, immune system competency, health, and vulnerability that lead one person at certain levels of exposure to particulate matter to develop bronchitis, and another to remain irritated, or affected, by the exposure, but not become ill.

No, we don't think you can automatically say that if a person is well-fed, and their diet provides them essential vitamins and minerals, as well as nutrients, they won't get "sick" from particulate matter : at least not without considering their lifestyle, employment, and behavior.

An interesting question to ask yourself : "do I believe children and old people are more vulnerable to pollution related illnesses;" if your answer is "yes," ask yourself exactly what that belief is based on; if your answer is "no," ask yourself what in your experience leads you to conclude that. ioho a similarly valuable question to ask yourself is : "are people already 'sick' in any way more vulnerable to exacerbation of their existing condition, or pollution related illness, than others who are, nominatively, 'well' " ?

And saying (all) the above in no way discounts the fact that at certain "toxic thresholds" of exposure to air pollution (as, say, were reached in Lamphun

http://www.nationmultimedia.com/2007/03/02...al_30028253.php

last year) you are going to see significant and widespread illness cutting across a broad socio-economic spectrum and age-range, across occupational types, across life-styles.

One of our favorite essays of all times in the sciences is by one of our favorite authors of all times, Stephen J. Gould :

http://www.mesotheliomahelp.net/median_is_...he_message.html

We first encountered this essay when my human component, not yet miraculously hooked-up into an "us" with a dying Orangutan, had cancer, and was attempting to make sense of the statistics about mortality rates for throat and tongue cancer. This essay gave him comfort, as well as "common sense," to try and make sense of the fact that of folks with his kind of tongue cancer only 4-5% (like him) had no history of smoking or drinking alcohol, and what that might mean, or not mean, in terms of future recurrence.

But the "wisdom" about statistics found in the above essay, ioho, go far beyond being helpful to people with cancer; which is why we mention it here.

We hope these comments have added something to this thread; if they have not, we apologize.

best, ~o:37;

Edited December 26, 2009 by orang37

[Oneman]

The ash is definitely from the burning of rice fields, leaves etc. We can see the smoke rising, smell the burning and watch the ash come down. It is very noticeable because of the colour of our pool and the surrounding patio area.

My observations match what 'Thailand' has posted; no doubt about it.

Like the OP, I can also smell the smoke.

The leaves of plants outside on the balcony are covered with a fine, gray, ash.

That wasn't happening two months ago.

In my air conditioner, I've added a second layer of filter material, which can be removed for cleaning.

Washing it in the bathtub, the water runs dark gray.

I recently purchased two large air filters: substantial units at 28,000 baht each.

Similar dirt/ash/dust accumulates in those.

Looks like we in for a bad year.

What else can be done?

-- Oneman

Chiangmai

.

Edited December 26, 2009 by Oneman

[chiang mai]

... snip ... I remain keen to understand the reality of the pollution problems in Chiang Mai, but perhaps even more than that, I want to see any debate on that subject remains factual, unbiased and not open to interpretation - I will therefore take much pleasure in reading said document which from an early glance raises some very interesting questions regarding the links between particulate matter and health issues.

Sawasdee Khrup, Khun Chiang Mai,

We are not hopeful, however, that a discussion of this type, can be "factual, unbiased and not open to interpretation" for the simple fact that the linkage between the extent of particulate matter present is so variable (by location, wind patterns, local sources, and a thousand other variables), and the extent of any individual's, or group's, exposure to the pollution so variable, that the "bottom line" we think you are after : impact on public health is such a "broad-spectrum" target ... that we will be, inevitably, forced to be speaking in broad hypothetical terms; i.e., interpretations.

Yes, we can be "surrounded by facts," but the way we order and rank the importance of those "facts" are going to reflect our values and agendas; i.e., biases. And, the "facts" themselves are based on data collection methods which, as already mentioned here in several posts, are open to interpretation.

best, ~o:37;

An interesting and perceptive post. Perhaps I should have added the words, "in as far as is possible" to my phrase regarding bias and fact in recognition that few things in this world are ever 100% factual and free of subjectivity. But the intent here is to try to keep the argument nearer to the centre line and away from the, "every thing's OK really", side of things, until such time as it can be proven decisively. The reason I feel this way is because I do believe that the anecdotal and subjective evidence produced by so many posters to date has a role to play in this discussion and that it's probably an important indicator as to what the real pollution picture looks like.

Edited December 26, 2009 by chiang mai

[CobraSnakeNecktie]

... For most of human history the average lifespan was about 15 years. Just slightly longer than reproductive age. ...

Sawasdee Khrup, Khun CobraSnakeNeckTie,

May we, respectfully, ask what basis, what sources, you have for this conclusion ?

thanks, ~o:37

With the mother dead at 15 who would rear the kids. Not grandma she is dead long ago.

are you serious? I hope not. An average lifespan does not imply everyone dies at the average. These days the world average is 65 or so years average lifespan. Age at death will be distributed longer and shorter and used to calculate an average. In man's early history the average age of death may have been in the 20's for example but that does not mean some members of the population could not live many many decades past the average. These longer lived members could have reared many children over the years.

[Mapguy]

There a few factors in determining changes in the average historically. By far, the most significant ones have been changes in the rates of infant and under 5 mortality.

Edited December 26, 2009 by Mapguy

[Priceless]

[...]

And saying (all) the above in no way discounts the fact that at certain "toxic thresholds" of exposure to air pollution (as, say, were reached in Lamphun

http://www.nationmultimedia.com/2007/03/02...al_30028253.php

last year) you are going to see significant and widespread illness cutting across a broad socio-economic spectrum and age-range, across occupational types, across life-styles.

[...]

A lot of people expect me to be nitpicking so I might as well...

Firstly, the article is not from last year, but rather from the infamous 2007.

Secondly, it strikes me as a piece of typical Nation reporting in certain ways It mentions concentrations in "microgrammes per square meter (mpsm)". This is of course a nonsensical unit, a square meter of anything weighs nothing unless it has volume. The proper unit of measurement is microgrammes per cubic metre.

Thirdly, it also states "Dust particles of 10 microns and 2.5 microns found at certain times of the day were two times higher than the standard air quality." There is no standard in Thailand (and, I believe, anywhere in the world) for particulate matter pollution other than 24-hour and 1-year arithmetic means.

Fourthly, it mentions a standard of 35 "mpsm" for PM<2.5 pollution. As far as I have been able to find out, and according to the PCD home page, there is no Thai standard for this kind of pollution. It is also not measured on a regular basis anywhere in Thailand. There is a USEPA standard of 35 µg/m³ though, this may be what they are referring to.

Fifthly, I feel a little bit surprised by the mention of Lamphun, since i did not know of any measurements taken in that town before December of 2008 (though there are measurements from Lampang). This may however have been specific series of measurements conducted by CMU outside of the work done by PCD, so I will not claim faulty reporting in this case.

In the above I may have been influenced by my generally negative impression of reporting in The Nation, so I would advice strongly against taking my comments too seriously

What I did find very interesting was the mention of Polycyclic aromatic hydrocarbons (PAHs) in PM<10 particles. This is something that I have not heard of before and will try to find out more about. Wikipedia ( http://en.wikipedia.org/wiki/Polycyclic_aromatic_hydrocarbon ) says the following (among a lot more information) about PAHs:

"Natural crude oil and coal deposits contain significant amounts of PAHs, arising from chemical conversion of natural product molecules, such as steroids, to aromatic hydrocarbons. They are also found in processed fossil fuels, tar and various edible oils.

PAHs are one of the most widespread organic pollutants. In addition to their presence in fossil fuels they are also formed by incomplete combustion of carbon-containing fuels such as wood, coal, diesel, fat, tobacco, or incense."

The "incomplete combustion of carbon-containing fuels" would be what Professor Dr Pongthep Wiwanthanadech is thinking of when he claims "that [PAHs] came from burning dried grass and leaves, and cooking fires". I can, however, not avoid thinking of the Mae Moh lignite mine and power plant in Lampang. This would appear to me to be a prime suspect in the "PAH case".

In all an interesting, though somewhat confusing, article.

/ Priceless

Edited December 26, 2009 by Priceless