Air Quality Getting Worse

[Priceless]

Over to you Priceless!

Unfortunately, I am not in CM at the moment and do not have my computer with me. Out of memory I would however say that the last 12 months have had the best air quality since proper (continuous) records have been kept. 2008 has had three (3) days with a PM<10 pollution level in excess of the Thai standard target of 120 microgrammes/cubic metre. If my memory serves me right the 12-month average up to November of this year is somewhere in the region of 38-39 microgrammes/m3.

I'll come back with a proper post as soon as I'm back in CM.

/ Priceless

[Priceless]

That would be the 1890's?

seriously, as im sure every Londoner can tell you. Back Snot every single bloody day. Then it stopped. I think it was to do with unleaded petrol. anyway... yawn.. The air down the road in San K is just fine. If i were a rich man... etc...

that mignt be the catalysimic conbulototators

seriously the air here is awful. If you compare it to dhaka, saraburi, mumbai, et al its great,,,,,,,, but come from any coastal town anywhere and then back to this lovely place youll notice the difference.

Actually the yearly average pollution level in Chiang Mai is better than Phuket and considerably better than Chon Buri (i.e. Pattaya).

/ Priceless

[Pikey]

I was out on my bike earlier in the week for a ride through Chiang Dao and Phrao before returning to CNX and unfortunately I saw many instances of stubble burning - small scale but happening none the less. Yesterday on the road to the Mae Ngat Dam from the 1001 a lot of the verges were blackened from recent burning. Again, small scale yes, but it all contributes to crap air, which as a mild ashtmatic, really gets my goat as I have to use part of my beer money to buy inhalers

Cheers,

Pikey.

[SomNamNah]

'satiariyan' http://www.satiariyan.com/ ... please PM me if you need any english lessons to undertsand my nonsense.

relevant nonsense.

sometimes.

As Thailand has demonstrated to the world, talking nonsense/hijacking tv/vital infrastructure for weeks/months etc is condoned, so why not on Thai Visa?

double standards my friend. Freedom of speech/nonsense. Thailand has shown the world the way!

snot = kii jamuk \ nose shit

edited: took the troll bait.

Edited December 6, 2008 by SomNamNah

[satiariyan]

'satiariyan' http://www.satiariyan.com/ ... please PM me if you need any english lessons to undertsand my nonsense.

relevant nonsense.

sometimes.

As Thailand has demonstrated to the world, talking nonsense/hijacking tv/vital infrastructure for weeks/months etc is condoned, so why not on Thai Visa?

double standards my friend. Freedom of speech/nonsense. Thailand has shown the world the way!

Thanks for the offer somuknamwebnahpro. However, although not a native speaker, I do appreciate the difference between school English and slang. In case you feel like communicating beyond the backyard where you grew up, may I suggest you at least make an attempt to state your opinion in an English that the world - outside your backyard - may be familiar with?

[SomNamNah]

Certainly sati, old chap, no sweat. you've got me banged to rights! I forget that the rest of the farang world speak a bastardised version of English

I will try my level best to post nonsense in international english only. I must commend you on your grammar, better than mine!

stay lucky me old china - lets do some Thai/Anglo web work together!

Edited December 6, 2008 by SomNamNah

[satiariyan]

Certainly sati, old chap, no sweat. you've got me banged to rights! I forget that the rest of the farang world speak a bastardised version of English.

Hopefully, you weren't serious when offering me the opportunity to PM you for English lessons? - Here's one lesson for free: The term "the rest of the farang world" is singularis (that's a latin word). Thus when writing: "the farang world speak_ a bastardised ...." you've sort of ruled yourself out as someone one might consider paying for improving a bit on ones English language skills.

Sorry, I know my posts are all a bit off topic - but frankly, I'm fed up with CM air pollution threads to such an extent that I most certainly don't take them seriously as long as the air quality I encounter isn't even close to the point where it doesn't smell quite right to me.

This year's December air pollution thread was initiated by some guy in an airplane wondering whether or not his memory was functional. Last years December air pollution thread was initiated by bananaman nagging about his farlang ghetto neighbor burning garbage. Next years December air pollution thread - hey, I may have moved from CM inner city to some suburban farang ghetto moobaan, and - consequently - I might actually be the one that ignites next years Chiang Mai December air pollution thread due to my farang neighbor's total lack of skills in getting his barbeque coals burning properly.

Edited December 6, 2008 by satiariyan

[SomNamNah]

suburban farang ghetto moobaan!! haha! you go girl! - spot on! My panoramic view of Thailand is Mrs Pingporn's washing line!, infuriates me when my family think i live near a beach and sip coconut juice!

seriously though, the air quality in town sucks, not having a ghetto farang fortuner with air con, I have managed to avoid the center on bike for about 5 months! . Off to the hills of San K for some fresh mountain air... aahhh!

Be great to have a tram in CM round the moat - old town, its the one thing CM city has going for it. never gonna happen. I avoid.

Cant CM install a big arse extractor fan up Doi S? Bet the chinese could.

Thanks for the english lesson, i owe you one. If only i had paid attention in grammar classes like. innit. Being a programmer like you, ive been talking in instant messages and emails for the last 15 years - often to someone a few desks away! I lost the use of my apostrophe''''s''' about 7 years ago. Like the yanks lost the use of several english letters..

Edited December 7, 2008 by SomNamNah

[Priceless]

I'm sorry to be reviving this rather boring thread, but I promised earlier to come back with a "proper post".

The OP asked the question 'Is it my imagination, or is air quality getting progressively worse all year round in Chiang Mai'?

Answer: It is your imagination. Actually the last three months (September, October and November) have been the "best" (i.e. with the lowest pollution level) during the period 2000-2008 with levels 30, 38 and 32% lower than the averages for the corresponding months.

For a longer perspective, see the following graph of 12-month averages:

The graph rather clearly shows that the air quality has improved considerably during this period. Please observe, though, that the trend line is not a forecast. We can only hope that the trend will continue, to make a proper forecast would require a lot of information and skills that I don't have access to.

One of the "usual suspects" (Mapguy) claimed that we have had 'relatively high pollution rates in recent days for the season'.

Truth: So far this December the average PM<10 pollution level has been 34.3 µg/m3. This should be compared with the monthly average for the years 2000-2008, which is 49.9 µg/m3.

I certainly agree that further improving the CM air quality would be a very desirable thing. However, I don't think that anybody is helped by the desinformation frequently disseminated on this and other fora.

/ Priceless

[adjan jb]

I'm sorry to be reviving this rather boring thread, but I promised earlier to come back with a "proper post".

The OP asked the question 'Is it my imagination, or is air quality getting progressively worse all year round in Chiang Mai'?

Answer: It is your imagination. Actually the last three months (September, October and November) have been the "best" (i.e. with the lowest pollution level) during the period 2000-2008 with levels 30, 38 and 32% lower than the averages for the corresponding months.

For a longer perspective, see the following graph of 12-month averages:

The graph rather clearly shows that the air quality has improved considerably during this period. Please observe, though, that the trend line is not a forecast. We can only hope that the trend will continue, to make a proper forecast would require a lot of information and skills that I don't have access to.

One of the "usual suspects" (Mapguy) claimed that we have had 'relatively high pollution rates in recent days for the season'.

Truth: So far this December the average PM<10 pollution level has been 34.3 µg/m3. This should be compared with the monthly average for the years 2000-2008, which is 49.9 µg/m3.

I certainly agree that further improving the CM air quality would be a very desirable thing. However, I don't think that anybody is helped by the desinformation frequently disseminated on this and other fora.

/ Priceless

Da man is back!

[Ulysses G.]

I'm sorry to be reviving this rather boring thread, but I promised earlier to come back with a "proper post".

The OP asked the question 'Is it my imagination, or is air quality getting progressively worse all year round in Chiang Mai'?

Answer: It is your imagination. Actually the last three months (September, October and November) have been the "best" (i.e. with the lowest pollution level) during the period 2000-2008 with levels 30, 38 and 32% lower than the averages for the corresponding months.

/ Priceless

I'm right. I'm right!

[adjan jb]

I'm sorry to be reviving this rather boring thread, but I promised earlier to come back with a "proper post".

The OP asked the question 'Is it my imagination, or is air quality getting progressively worse all year round in Chiang Mai'?

Answer: It is your imagination. Actually the last three months (September, October and November) have been the "best" (i.e. with the lowest pollution level) during the period 2000-2008 with levels 30, 38 and 32% lower than the averages for the corresponding months.

/ Priceless

I'm right. I'm right!

But you were wrong, you were wrong!!!!!

Edited December 9, 2008 by adjan jb

[Mapguy]

That would be the 1890's?

seriously, as im sure every Londoner can tell you. Back Snot every single bloody day. Then it stopped. I think it was to do with unleaded petrol. anyway... yawn.. The air down the road in San K is just fine. If i were a rich man... etc...

that mignt be the catalysimic conbulototators

seriously the air here is awful. If you compare it to dhaka, saraburi, mumbai, et al its great,,,,,,,, but come from any coastal town anywhere and then back to this lovely place youll notice the difference.

Actually the yearly average pollution level in Chiang Mai is better than Phuket and considerably better than Chon Buri (i.e. Pattaya).

/ Priceless

I fear your strings of numbers while interesting and useful in some respects are still, well, pretty pointless, Priceless. On the days I referred to, the PCD ratings (PM<10) were indeed above average, if they are accepted as a good way of measuring things. As well, the mean isn't always telling, as you know. An example may be had locally. Averaging the heavy seasonal pollution days here with the rest of the year, which can be really pleasant for much of the time, buries the impact of the rather nasty spikes and even rather extended pollution "bulge," if you will, that characteristically show up late February - early April that we unfortunately have to bear. And we haven't even begun to talk about the increasing year-round vehicular pollution problem in town! Hey, as I have said before, the traffic cops don't wear face masks year round to keep from getting chapped lips!

One significant factor mentioned before is the matter of standards as to what is healthy and what isn't. In some ways, the national standards are much like the legacy of American free market standards of regulation if financial institutions. Actually, there are reasonable economic arguments for not demanding or expecting too much too soon of emerging economies. But that doesn't help get the air as clean as it should be, or the water, or the soil, et cetera.

And so on....

Well, there are lots of very good references posted on the several TV threads about all this. Lots. And they weren't invented by Al Gore, either!

Finally, for those of you who might be new to this ongoing "debate" about air pollution in Chiang Mai, you should know that Priceless is as concerned as anyone probably about the seasonal problem, but this oft-stated position of his is unfortunately obfuscated by his approach to the situation which can be misleading and has clearly been misread by some posters. I encourage Priceless to stay to the real point.

Edited December 9, 2008 by Mapguy

[Priceless]

That would be the 1890's?

seriously, as im sure every Londoner can tell you. Back Snot every single bloody day. Then it stopped. I think it was to do with unleaded petrol. anyway... yawn.. The air down the road in San K is just fine. If i were a rich man... etc...

that mignt be the catalysimic conbulototators

seriously the air here is awful. If you compare it to dhaka, saraburi, mumbai, et al its great,,,,,,,, but come from any coastal town anywhere and then back to this lovely place youll notice the difference.

Actually the yearly average pollution level in Chiang Mai is better than Phuket and considerably better than Chon Buri (i.e. Pattaya).

/ Priceless

I fear your strings of numbers while interesting and useful in some respects are still, well, pretty pointless, Priceless. On the days I referred to, the PCD ratings (PM<10) were indeed above average, if they are accepted as a good way of measuring things. As well, the mean isn't always telling, as you know. An example may be had locally. Averaging the heavy seasonal pollution days here with the rest of the year, which can be really pleasant for much of the time, buries the impact of the rather nasty spikes and even rather extended pollution "bulge," if you will, that characteristically show up late February - early April that we unfortunately have to bear. And we haven't even begun to talk about the increasing year-round vehicular pollution problem in town! Hey, as I have said before, the traffic cops don't wear face masks year round to keep from getting chapped lips!

One significant factor mentioned before is the matter of standards as to what is healthy and what isn't. In some ways, the national standards are much like the legacy of American free market standards of regulation if financial institutions. Actually, there are reasonable economic arguments for not demanding or expecting too much too soon of emerging economies. But that doesn't help get the air as clean as it should be, or the water, or the soil, et cetera.

And so on....

Well, there are lots of very good references posted on the several TV threads about all this. Lots. And they weren't invented by Al Gore, either!

Finally, for those of you who might be new to this ongoing "debate" about air pollution in Chiang Mai, you should know that Priceless is as concerned as anyone probably about the seasonal problem, but this oft-stated position of his is unfortunately obfuscated by his approach to the situation which can be misleading and has clearly been misread by some posters. I encourage Priceless to stay to the real point.

If I recall correctly, you posted on December 4. Let me quote: 'relatively high pollution rates in recent days for the season'. The pollution levels for the first four days of December ('recent days'?) were, in µg/m3:

Dec 1: 28.1

Dec 2: 32.7

Dec 3: 33.9

Dec 4: 41.5

The average (2000-2008) for December has been 49.9, i.e. the levels of 'recent days' were between 17% and 44% below the December average.

A lie does not justify a mistake, Mapguy.

/ Priceless

[chiang mai]

Perhaps you would give us some insight into how the data for your charts is captured, measured and reported. You seem to be very close to that process but others, including myself, don't understand the scale nor the mechanics of the process - perhaps if you outlined those things they may go some way to helping us all understand things a little better?

[CobraSnakeNecktie]

Perhaps you would give us some insight into how the data for your charts is captured, measured and reported. You seem to be very close to that process but others, including myself, don't understand the scale nor the mechanics of the process - perhaps if you outlined those things they may go some way to helping us all understand things a little better?

I don't think anybody here knows about the data and sensors. There are apparently just two sensors for 500,000 people. In the last few days the air smells like farm burnings and in the morning its hard t see the mountains but the PCD numbers have barely budged. I don't put a lot of faith in them.

Does anyone even know where the sensors are? Priceless? anybody?

[Ulysses G.]

The average (2000-2008) for December has been 49.9, i.e. the levels of 'recent days' were between 17% and 44% below the December average.

/ Priceless

I was right. I was right!

[chiang mai]

The average (2000-2008) for December has been 49.9, i.e. the levels of 'recent days' were between 17% and 44% below the December average.

/ Priceless

I was right. I was right!

It doesn't happen that often that you are so best make the most of it, why not post on the same subject for a third time! Whilst I'm waiting for you to do that, I want to learn more about the process and these sensors, sounds fascinating.

[Priceless]

Perhaps you would give us some insight into how the data for your charts is captured, measured and reported. You seem to be very close to that process but others, including myself, don't understand the scale nor the mechanics of the process - perhaps if you outlined those things they may go some way to helping us all understand things a little better?

I don't think anybody here knows about the data and sensors. There are apparently just two sensors for 500,000 people. In the last few days the air smells like farm burnings and in the morning its hard t see the mountains but the PCD numbers have barely budged. I don't put a lot of faith in them.

Does anyone even know where the sensors are? Priceless? anybody?

The sensor for which data is published ( http://www.pcd.go.th/AirQuality/Regional/Q...fm?task=default ) under the heading "Chiang Mai" is placed in the vicinity of city hall, i.e. just over 5 km N by NW of the center of the old town. There is also another measuring station, at Yupparaj College, but this is a street side location and consequently influenced by temporary factors like traffic congestion etc. The latter series was started in August of 2002, whereas the "Chiang Mai" series was started before the year 2000, which I have chosen as the starting point for my studies.

The data that is published on the above site is the average level over a 24-hour measuring period, according to international standards. In the case of Thailand (I don't know if this is also an international standard) the level is measured from 9 AM one day to 9 AM the following. This means that the data presented as e.g. 11 December 2008 actually covers the last 15 hours of 10 December and the first 9 hours of 12 December.

There are, as far as I know, in total 29 measuring stations in Thailand, 6 in Bangkok and 23 in the provinces. Chiang Mai is the only province with more than one station. Some of the provincial stations appear to only be functioning rather sporadically (e.g. Chiang Rai and Mae Hong Son). It is my understanding that these measuring equipments are comparatively expensive and require specially trained people for their operation, which might explain why there are so few measuring points.

For anyone visiting the PCD website it should be noted that the measuring station "Chiangmai" (as opposed to "Chiang Mai") is a mobile station. This means that a value for one day may not be comparable to the value for another day, as the station may have moved.

/ Priceless

[Ulysses G.]

The average (2000-2008) for December has been 49.9, i.e. the levels of 'recent days' were between 17% and 44% below the December average.

/ Priceless

I was right. I was right!

It doesn't happen that often that you are so best make the most of it, why not post on the same subject for a third time!

Thanks for sharing.

[chiang mai]

Perhaps you would give us some insight into how the data for your charts is captured, measured and reported. You seem to be very close to that process but others, including myself, don't understand the scale nor the mechanics of the process - perhaps if you outlined those things they may go some way to helping us all understand things a little better?

I don't think anybody here knows about the data and sensors. There are apparently just two sensors for 500,000 people. In the last few days the air smells like farm burnings and in the morning its hard t see the mountains but the PCD numbers have barely budged. I don't put a lot of faith in them.

Does anyone even know where the sensors are? Priceless? anybody?

The sensor for which data is published ( http://www.pcd.go.th/AirQuality/Regional/Q...fm?task=default ) under the heading "Chiang Mai" is placed in the vicinity of city hall, i.e. just over 5 km N by NW of the center of the old town. There is also another measuring station, at Yupparaj College, but this is a street side location and consequently influenced by temporary factors like traffic congestion etc. The latter series was started in August of 2002, whereas the "Chiang Mai" series was started before the year 2000, which I have chosen as the starting point for my studies.

The data that is published on the above site is the average level over a 24-hour measuring period, according to international standards. In the case of Thailand (I don't know if this is also an international standard) the level is measured from 9 AM one day to 9 AM the following. This means that the data presented as e.g. 11 December 2008 actually covers the last 15 hours of 10 December and the first 9 hours of 12 December.

There are, as far as I know, in total 29 measuring stations in Thailand, 6 in Bangkok and 23 in the provinces. Chiang Mai is the only province with more than one station. Some of the provincial stations appear to only be functioning rather sporadically (e.g. Chiang Rai and Mae Hong Son). It is my understanding that these measuring equipments are comparatively expensive and require specially trained people for their operation, which might explain why there are so few measuring points.

For anyone visiting the PCD website it should be noted that the measuring station "Chiangmai" (as opposed to "Chiang Mai") is a mobile station. This means that a value for one day may not be comparable to the value for another day, as the station may have moved.

/ Priceless

A couple of questions Priceless:

Can you tell us exactly what it is that the sensors test for? Is it solely for airborne particles below a certain size or is it other things as well?

Secondly, i note that data readings are averaged over a twenty four hour period in order to obtain a graph point for any given day. Is the component data that comprises any given day available for review or perhaps you can tell us the highs and lows by way of an example?

Thirdly and finally: do you feel that one or even two collection points in a city the size of CM is appropriate and do you believe the results from such a limited number of collection stations provides a representative result?

[realthaideal]

Yep, another thread on this issue and all the different camps emerging. Fun.

I believe it's the burning more than the autos that cause the trouble, but it's purely subjective. On a ride home from the city and out to Hang Dong, or alternatively along the River n Super Hwy, I pass thru multiple fire smoke zones and inevitably my eyes tear a bit. And when home I notice the black crud in the corners of my eyes. Gross. I've taken to yelling at the ppl I see lighting their leaves and brush on fire the same words that are written on posters all over town including out in the sticks "Hyut Phao !" or 'Stop Burning!' Doubt it does much good, but I feel better and perhaps letting them know in their language that a Falang knows they're supposed to stop, and may put some pressure. But for them it seems, old habits die hard.

[Priceless]

A couple of questions Priceless:

Can you tell us exactly what it is that the sensors test for? Is it solely for airborne particles below a certain size or is it other things as well?

Secondly, i note that data readings are averaged over a twenty four hour period in order to obtain a graph point for any given day. Is the component data that comprises any given day available for review or perhaps you can tell us the highs and lows by way of an example?

Thirdly and finally: do you feel that one or even two collection points in a city the size of CM is appropriate and do you believe the results from such a limited number of collection stations provides a representative result?

Thank you for your three interesting and concrete questions.

Firstly I have to state that I am in no way an expert on the technical side of these things. If I have any relevant expertise, it is within the area of descriptive statistical analysis. The following must consequently be read as what I have gathered from (mostly) the Internet.

1/ From what I understand, each pollutant requires a separate type of measuring equipment. As regards particulate matter, the equipment used in Thailand measures all particles with a size less than 10 micrometers in diameter (whence the name PM<10). To measure e.g. PM<2.5 (which would be desirable, since these ultra-small particles are apparently the most dangerous) would require replacing all the present equpment. The measurement of e.g. sulphur, ozone, CO and so on requires separate pieces of equipment.

2/ I have never seen PM<10 pollution data from any part of the world given for shorter periods than 24 hours. The air quality standards for most countries also seem to be defined in terms of either 24-hour and/or 1-year averages. (Europe has a rather unusual standard for PM<10 pollution in that it states a maximum yearly average of 40 µg/m3 and a maximum daily average of 50 µg/m3, which may however be exceeded up to 35 times/year with no upper limit for the daily level.) I would imagine that e.g. hourly data for PM pollution levels would both be very expensive to obtain and of limited value, because of both the natural diurnal variations in temperature, humidity, wind etc. and possible stochastic variations.

3/ I would of course much prefer if there were more measuring points within the Chiang Mai metropolitan area and province. However, if I were given omnipotence over the Thai air quality measurement system, I would probably prioritize providing each province with at least one measuring system. After that my priority would likely be providing a number of mobile back-up systems and staff, so that each measuring point could provide a continuous data series. The latter is far from being the case today, with most stations missing from 10-30% of all observations. (In my own calculations, I exclude any month or year missing >25% of observations from calculating an average. Since the beginning of 2000, Chiang Mai has had 28 months with more than 25% of data missing.)

As regards your question whether this can be regarded as 'a representative result', that obviously depends on your definition of 'representative'. To get an indication of how representative the data series is, I do at irregular intervals test its correlation with the data from Yupparaj College (in the center of Chiang Mai) and with those from Lampang. These three series seem to correlate quite well (Yupparaj vs Chiang Mai better than 0.9), which would indicate that the Chiang Mai series is fairly representative of a wider area. (The absolute levels are of course different with Lampang being closest to Chiang Mai and Yupparaj, being a roadside measuring point, having the highest values.)

My background is in the social sciences, particularly economics, where one has to learn to live with the data that is available, rather than with the data that one would like to have. I would naturally very much like to have access to complete daily data from, say, 10 points in Chiang Mai. Since this is not possible, I still emphatically maintain that the data that is available is a lot more representative and relevant than e.g. the subjective experience of somebody looking up at Doi Suthep and saying "My, oh my, the pollution is bad today".

/ Priceless

[chiang mai]

A couple of questions Priceless:

Can you tell us exactly what it is that the sensors test for? Is it solely for airborne particles below a certain size or is it other things as well?

Secondly, i note that data readings are averaged over a twenty four hour period in order to obtain a graph point for any given day. Is the component data that comprises any given day available for review or perhaps you can tell us the highs and lows by way of an example?

Thirdly and finally: do you feel that one or even two collection points in a city the size of CM is appropriate and do you believe the results from such a limited number of collection stations provides a representative result?

Thank you for your three interesting and concrete questions.

Firstly I have to state that I am in no way an expert on the technical side of these things. If I have any relevant expertise, it is within the area of descriptive statistical analysis. The following must consequently be read as what I have gathered from (mostly) the Internet.

1/ From what I understand, each pollutant requires a separate type of measuring equipment. As regards particulate matter, the equipment used in Thailand measures all particles with a size less than 10 micrometers in diameter (whence the name PM<10). To measure e.g. PM<2.5 (which would be desirable, since these ultra-small particles are apparently the most dangerous) would require replacing all the present equpment. The measurement of e.g. sulphur, ozone, CO and so on requires separate pieces of equipment.

2/ I have never seen PM<10 pollution data from any part of the world given for shorter periods than 24 hours. The air quality standards for most countries also seem to be defined in terms of either 24-hour and/or 1-year averages. (Europe has a rather unusual standard for PM<10 pollution in that it states a maximum yearly average of 40 µg/m3 and a maximum daily average of 50 µg/m3, which may however be exceeded up to 35 times/year with no upper limit for the daily level.) I would imagine that e.g. hourly data for PM pollution levels would both be very expensive to obtain and of limited value, because of both the natural diurnal variations in temperature, humidity, wind etc. and possible stochastic variations.

3/ I would of course much prefer if there were more measuring points within the Chiang Mai metropolitan area and province. However, if I were given omnipotence over the Thai air quality measurement system, I would probably prioritize providing each province with at least one measuring system. After that my priority would likely be providing a number of mobile back-up systems and staff, so that each measuring point could provide a continuous data series. The latter is far from being the case today, with most stations missing from 10-30% of all observations. (In my own calculations, I exclude any month or year missing >25% of observations from calculating an average. Since the beginning of 2000, Chiang Mai has had 28 months with more than 25% of data missing.)

As regards your question whether this can be regarded as 'a representative result', that obviously depends on your definition of 'representative'. To get an indication of how representative the data series is, I do at irregular intervals test its correlation with the data from Yupparaj College (in the center of Chiang Mai) and with those from Lampang. These three series seem to correlate quite well (Yupparaj vs Chiang Mai better than 0.9), which would indicate that the Chiang Mai series is fairly representative of a wider area. (The absolute levels are of course different with Lampang being closest to Chiang Mai and Yupparaj, being a roadside measuring point, having the highest values.)

My background is in the social sciences, particularly economics, where one has to learn to live with the data that is available, rather than with the data that one would like to have. I would naturally very much like to have access to complete daily data from, say, 10 points in Chiang Mai. Since this is not possible, I still emphatically maintain that the data that is available is a lot more representative and relevant than e.g. the subjective experience of somebody looking up at Doi Suthep and saying "My, oh my, the pollution is bad today".

/ Priceless

Thank you for that very complete reply.

Based on what has been said thus far it seems we must all be very careful with our terminology in going forward. The term airborne pollution refers to a whole range a of ingredients from common soot to dioxins and beyond - some of those components are likely odorless whilst other smell really bad, some will be largely harmless and others potentially lethal. It seems however that when we discuss the term airborne pollution in Chiang Mai we really don't understand what it comprises in total since it is not measured and recorded. We are aware from your work that a component of the pollution is PM<10 and that seems to be well understood, but that in itself does not represent the entire spectrum of the airborne pollution problem in Chiang Mai in fact it is only a small part of the picture, would you not agree?

[Priceless]

Thank you for that very complete reply.

Based on what has been said thus far it seems we must all be very careful with our terminology in going forward. The term airborne pollution refers to a whole range a of ingredients from common soot to dioxins and beyond - some of those components are likely odorless whilst other smell really bad, some will be largely harmless and others potentially lethal. It seems however that when we discuss the term airborne pollution in Chiang Mai we really don't understand what it comprises in total since it is not measured and recorded. We are aware from your work that a component of the pollution is PM<10 and that seems to be well understood, but that in itself does not represent the entire spectrum of the airborne pollution problem in Chiang Mai in fact it is only a small part of the picture, would you not agree?

I quite agree that particulate matter is but one of many potentially harmful forms of air pollution. Some of the most widely observed other harmful factors are sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3). All these have Thai standards and are being measured by the Pollution Control Department, with their daily values published on the PCD website.

Some other potentially harmful substances are lead (Pb), benzene, arsenic (As), cadmium (Cd), nickel (Ni) and Polycyclic Aromatic Hydrocarbons. None of these have (as far as I know) any Thai standards yet (though there does exist an EU directive which will enter into force in the next few years).

The reasons why I have concentrated on PM<10 are basically two:

1/ When I joined this discussion, it had already been going on for quite a while and (as far as I can remember) been concerned exclusively with PM<10. What caught my attention were the obvious exaggerations, half truths and downright falsifications of information that were so frequently occurring. With my background, I tend to perceive such occurences as something of a personal insult to my intelligence. I decided to collect whatever objective data that I could find, and see if I could distill some kind of "truth" out of this. As an added bonus, I might be able to assist a few people who were looking for information, as opposed to opinions.

2/ The other forms of pollution for which there exist Thai standards (i.e. SO2, NO2, CO and O3) have, as far as I could find during a brief scan of the PCD database, never exceeded their respective standard levels (or even reached half of it) at the Chiang Mai measuring station. I have therefore considered it even more of a waste of time and effort to follow them, than the PM<10 work that I have done. These pollutants may well be of importance in other (more industrialized) parts of Thailand, but since my interest is Chiang Mai I have decided to leave them be, at least for the present time.

To conclude: I obviously agree that there are many potentially harmful substances that may pollute air. However, the only one at present known to occur at harmful levels in the Chiang Mai area is PM<10 (and, most probably, PM<2.5). In other words I think that it is quite reasonable, in this geographical context, to only discuss PM<10.

/ Priceless

[Mapguy]

Perhaps you would give us some insight into how the data for your charts is captured, measured and reported. You seem to be very close to that process but others, including myself, don't understand the scale nor the mechanics of the process - perhaps if you outlined those things they may go some way to helping us all understand things a little better?

I don't think anybody here knows about the data and sensors. There are apparently just two sensors for 500,000 people. In the last few days the air smells like farm burnings and in the morning its hard t see the mountains but the PCD numbers have barely budged. I don't put a lot of faith in them.

Does anyone even know where the sensors are? Priceless? anybody?

The sensor for which data is published ( http://www.pcd.go.th/AirQuality/Regional/Q...fm?task=default ) under the heading "Chiang Mai" is placed in the vicinity of city hall, i.e. just over 5 km N by NW of the center of the old town. There is also another measuring station, at Yupparaj College, but this is a street side location and consequently influenced by temporary factors like traffic congestion etc. The latter series was started in August of 2002, whereas the "Chiang Mai" series was started before the year 2000, which I have chosen as the starting point for my studies.

The data that is published on the above site is the average level over a 24-hour measuring period, according to international standards. In the case of Thailand (I don't know if this is also an international standard) the level is measured from 9 AM one day to 9 AM the following. This means that the data presented as e.g. 11 December 2008 actually covers the last 15 hours of 10 December and the first 9 hours of 12 December.

Aren't you measuring a 48-hour period above, as you have explained it, or am I misreading what you have written? Not that I'm against a 48-hour day when busy.

There are, as far as I know, in total 29 measuring stations in Thailand, 6 in Bangkok and 23 in the provinces. Chiang Mai is the only province with more than one station. Some of the provincial stations appear to only be functioning rather sporadically (e.g. Chiang Rai and Mae Hong Son). It is my understanding that these measuring equipments are comparatively expensive and require specially trained people for their operation, which might explain why there are so few measuring points.

For anyone visiting the PCD website it should be noted that the measuring station "Chiangmai" (as opposed to "Chiang Mai") is a mobile station. This means that a value for one day may not be comparable to the value for another day, as the station may have moved.

/ Priceless

Thank you, Priceless for the description of the measuring stations.

There is actually another measuring station I know of that we ordinarily don't hear from, and when we do, only in general terms, as I have been able to find. It is on the palace grounds on Doi Suthep.

I think Priceless can improve what he writes about the implications of the numbers and usefulness of the readings from these stations.

As he points out, there are only three stations in the province which have readings reported and data are not necessarily comparable from day to day for the mobile unit (which data sometimes doesn't appear on the PCD site). That limits their usefulness for analysis. Slavish reliance upon them, useful as they are where they are, is not commonsensical. Which one do your read? The readings can be quite different among them. I tend to look most at the "Yuparaj" readings which are in town and are most likely closest to recording the experience of --- comparably --- most people most of the time in the metropolitan area. But I always look,too, at the "Chiang Mai" site readings. The mobile ratings? Well, who knows!

I am attaching two screen shots from the PCD site (leaving out the mobile readings) for a recent three-week period. Now, Priceless is very good at doing graphs, so I invite him to plot the readings on the same graph. It is much easier to compare them that way than eyeballing them separately. But, while waiting, check out what you think about the differences in the trend line over the past three weeks. Ask yourself which one would appear to be most useful to understanding your experience.

Well, these readings are "best available data," which is what number crunchers use to do their thing. But the true grist for the analytical mill, as any decent scientist will tell you, must include more field study: rising from your calculator--- oops, turning off the statistics program that is crunching your numbers --- looking out the window, and taking a walk from time to time. Or, as someone has suggested, checking your snot regularly. But don't do that at Kevin Hunt's classy place!

Chiang_Mai_1.pdf

Uparaj_21_Day_Graph.pdf

[Mapguy]

Thank you for that very complete reply.

Based on what has been said thus far it seems we must all be very careful with our terminology in going forward. The term airborne pollution refers to a whole range a of ingredients from common soot to dioxins and beyond - some of those components are likely odorless whilst other smell really bad, some will be largely harmless and others potentially lethal. It seems however that when we discuss the term airborne pollution in Chiang Mai we really don't understand what it comprises in total since it is not measured and recorded. We are aware from your work that a component of the pollution is PM<10 and that seems to be well understood, but that in itself does not represent the entire spectrum of the airborne pollution problem in Chiang Mai in fact it is only a small part of the picture, would you not agree?

I quite agree that particulate matter is but one of many potentially harmful forms of air pollution. Some of the most widely observed other harmful factors are sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3). All these have Thai standards and are being measured by the Pollution Control Department, with their daily values published on the PCD website.

Some other potentially harmful substances are lead (Pb), benzene, arsenic (As), cadmium (Cd), nickel (Ni) and Polycyclic Aromatic Hydrocarbons. None of these have (as far as I know) any Thai standards yet (though there does exist an EU directive which will enter into force in the next few years).

The reasons why I have concentrated on PM<10 are basically two:

1/ When I joined this discussion, it had already been going on for quite a while and (as far as I can remember) been concerned exclusively with PM<10. What caught my attention were the obvious exaggerations, half truths and downright falsifications of information that were so frequently occurring. With my background, I tend to perceive such occurences as something of a personal insult to my intelligence. I decided to collect whatever objective data that I could find, and see if I could distill some kind of "truth" out of this. As an added bonus, I might be able to assist a few people who were looking for information, as opposed to opinions.

2/ The other forms of pollution for which there exist Thai standards (i.e. SO2, NO2, CO and O3) have, as far as I could find during a brief scan of the PCD database, never exceeded their respective standard levels (or even reached half of it) at the Chiang Mai measuring station. I have therefore considered it even more of a waste of time and effort to follow them, than the PM<10 work that I have done. These pollutants may well be of importance in other (more industrialized) parts of Thailand, but since my interest is Chiang Mai I have decided to leave them be, at least for the present time.

To conclude: I obviously agree that there are many potentially harmful substances that may pollute air. However, the only one at present known to occur at harmful levels in the Chiang Mai area is PM<10 (and, most probably, PM<2.5). In other words I think that it is quite reasonable, in this geographical context, to only discuss PM<10.

/ Priceless

I agree with Priceless that the PM<10 measurement is geographically relevant, especially in an area subject to burning off vegetation as well as trash. And I am glad he mentioned PM<2.5 measurement, which not reported (or measured widely) in Thailand, as I recall reading a while back. Same stuff, only smaller particles. These particles, I believe, more insidious in its impact on respiratory health basically because they are so much smaller and therefore so much more intrusive. I wonder what cigarette smoke particles measure? Anyone know?

An important factor generally missing in TV discussion is the inclusion of public health statistics of respiratory disease in Chiang Mai. There is work being done and reported on that, and that is apparently improving in reliability. Research continues at CMU on Chiang Mai.

I have posted numerous references to research on Chiang Mai, Thailand, in Asia and beyond on several factors at issue and have quite specifically pointed out individuals and organizations in town who have done much more than research. Just use key words, as indicated in a post above.

Start by reading Dr. Duongchan Apavatjrut Charoenmuang's Sustainable Cities in Chiang Mai: A Case of City in A Valley (published in 2007 by Chaing Mai Sagilp Printing Ltd., Part., Chiang Mai ([email protected]). She addresses more than pollution, but you can read just those nasty bits by checking out the index. The English translation isn't good, really, and there are numerous printer's errors, but you'll be going down the right road. Maybe UG will invest in a couple of "check out" copies!

And Khun Duongchan has done much more. For example, she has created some very, very good public information mateial to discourage burning trash and rice straw. But she is feeling quite frustrated at present on the pollution issue. Most recently, she is heading up the organized resistance to the new Chiang Mai city plan.

Otherwise, by the way, if you want to take an even broader view of the sustainability of Chiang Mai, you should become interested in the much respected Urban Development Institute Foundation (www.udif.or.th). The motto: "Chiang Mai. Proud to Live Here and Determined to Improve it."

Or you can be a farang on the fringe and spend your time in Kevin Hunt's place careful to avoid limp bodies on the floor.

[chiang mai]

I agree in respect of PM<10 and PM<2.5, my intention was not to suggest otherwise but to try and identify which other components of airborne pollution were not being measured and Priceless indicates that many if not most candidates are already being profiled and reported by the PCD.

I also agree that a key missing component of the pollution picture is public health data and I wonder if this can be obtained from some source?

In the absence of the public health data we seem to have a divide. On the one hand we have a large number of reports from individuals claiming that they suffer from what appears to be pollution related maladies ranging from stinging and watery eyes through to chest infections and bronchitis. On the other hand the results from PCD and indeed from Priceless's work indicate that by comparison there is nothing untoward in the Chiang Mai air that would likely cause such symptoms. An earlier statement that the airborne pollution problem in Phuket is worse than in CM seems to support the views of Priceless and the PCD that CM has relatively clean air.

So what is the answer, are TV readers all mistaken or hypochondriacs, are there problems with the way air quality data is captured and/or reported or is there something fundamental here that is being overlooked? I suspect the public medical records may hold a key although from my past discussions with Doctors at Chiang Mai Ram on this subject I doubt they will hold any surprises.

[Priceless]

I agree in respect of PM<10 and PM<2.5, my intention was not to suggest otherwise but to try and identify which other components of airborne pollution were not being measured and Priceless indicates that many if not most candidates are already being profiled and reported by the PCD.

I also agree that a key missing component of the pollution picture is public health data and I wonder if this can be obtained from some source?

In the absence of the public health data we seem to have a divide. On the one hand we have a large number of reports from individuals claiming that they suffer from what appears to be pollution related maladies ranging from stinging and watery eyes through to chest infections and bronchitis. On the other hand the results from PCD and indeed from Priceless's work indicate that by comparison there is nothing untoward in the Chiang Mai air that would likely cause such symptoms. An earlier statement that the airborne pollution problem in Phuket is worse than in CM seems to support the views of Priceless and the PCD that CM has relatively clean air.

So what is the answer, are TV readers all mistaken or hypochondriacs, are there problems with the way air quality data is captured and/or reported or is there something fundamental here that is being overlooked? I suspect the public medical records may hold a key although from my past discussions with Doctors at Chiang Mai Ram on this subject I doubt they will hold any surprises.

Firstly, yes there is a problem with the air quality capture and reporting, in that only PM<10 and not the more harmful PM<2.5 is measured. It should however be noted that the European Union only recently have included it in their new air quality directive (http://ec.europa.eu/environment/air/quality/standards.htm). The directive's PM<2.5 value is 25 µg/m3 (one year average), but this will enter into force as a "target value" on 1 January 2010 and not as a "limit value" until 1 January 2015. The measurement, and setting of standards for, this pollutant is consequently quite a recent thing even in the industrialized world (the US Environmental Protection Agency is of course lagging, as usual).

I do think, though, that there is a more urgent (and more difficult) problem that needs to be solved. This concerns the possible health effects of air pollution on the population of Chiang Mai. I have not seen any credible data in this field, and very much doubt that there is any. A proper epidemiological study of this kind would, I believe, entail among other things regular and recurring health controls of a large random sample of the total population of Chiang Mai. These results would then have to be analysed to eliminate all other possible causes for any unually high occurrences of respiratory disease, causes like e.g. smoking, working conditions, previous exposure to air pollution (many people have moved to Chiang Mai in latter years), genetic factors and so on. Altogether this would constitute a very major interdisciplinary research project. I am somewhat doubtful whether a project of this kind would be within the capabilities of the Thai scientific community, but I would be very glad if it is and actually will be carried out.

/ Priceless

[chiang mai]

I'm grateful for that response Priceless, thank you. I'm offline until Saturday evening and will continue the discussion then but do not wish to do so hurriedly in the short time available to me right now. Stay tuned as our American friends might say!