Pollution In Lampang As Well?

[Ulysses G.]

Thais also wear them then inside at all times of the year in order to keep out dust. My employees put them on when they clean the floor or put the books in order. Actually, most of these masks are absolutely useless for anything other than dust. If you are going to buy one to protect against pollution, get a good one.

[WinnieTheKhwai]

The good ones are very hard to breathe through. Doesn't work well with exercise.

[anonymouse]

The good ones are very hard to breathe through. Doesn't work well with exercise.

I don't know it might improve your fitness, I bet if you cycled with one of them on for 2 months then cycled without you'd see a marked improvement

[MESmith]

The good ones are very hard to breathe through. Doesn't work well with exercise.

I don't know it might improve your fitness, I bet if you cycled with one of them on for 2 months then cycled without you'd see a marked improvement

Wouldn't be good for you if you passed out in front of a speeding bus, due to insufficient oxygen getting to your system 

[CobraSnakeNecktie]

I can't say I see that many people wearing masks indoors but it makes sense if working with chemicals, dust and moldy books.

It wouldn't surprise me if lots of masks people wear are ineffective or just superficial effect. If nothing else it would keep grime and sun off a persons face also when outdoors.

I have resisted but it might be time to start dressing more like darth vader when I exercise. I suppose it can't hurt health wise especially in the coming months. It could help fitness similar to training at altitude.

Any recommendations for a good exercising mask brand and source?

[elektrified]

a little bit of a tangent but something I would be curious about.

I am not in the habit of wearing a filtration mask as it would be pussy freak city from where I lived in the US. I go out most days and ride my bicycle for a few hours in the outlying areas of CM.

I notice most of the Thai cyclists and a significant percentage of Thai people on motorbikes wear a filtration mask.

Should everybody be wearing one of these masks to exercise at this time of year or is it just being silly and over cautious?

Please spare me any "I have been here for X years and don't wear a mask" statements.

Any science out there and why do so many Thai people wear them when they don't seem to be necessary now?

I happened to walk past a traffic policeman today who was wearing a mask and noticed it was dark brown in the area of his mouth.

Getting back to the OP subject of Lamphang, there was a warning on the radio today that the air quality was dangerous and for residents to stay inside if possible.

[orang37]

Sawasdee Khrup TV Friends,

As always we appreciate Khun Priceless' very thoughtful posts, and the statistical data.

And, as always, in the case of measurement of particulate matter in Chiang Mai : we don't trust the statistics : in the sense that what we've heard of the number of monitoring stations, their location, etc., does not convince us they (the measurements) are robust and generally reliable, and can in any way be compared with pollution monitoring as found in some other countries.

To put it even more bluntly we don't trust most statistics in Thailand, in general : but that is not meant as an "indictment" of "Thai science" specific to Thailand : all over the world, in the most so-called "technologically advanced" societies, statistics are compromised by the co-option of scientific researchers by politics, personal corruption and ambition of individual researchers, the flowing of corporate mega-money into directing, and sometimes stifling, the results of research to promote commercial interests.

The current incredible scandal re the UN collected data on global warming, the recent revelations on the faking of glacial melt data by senior scientists (a whole cabal of them), the sorry history of the manipulation of the data on tobacco and its effects on health in America. Well : we got to that place so well described by Mark Twain a long time ago vis-a-vis statistics : that they are often just one class of lies in the unholy trinity of : "lies, damned lies, and statistics."

Even though we can't back this up with "hard data" : we do accept what seems to be a consensus among economic analysts that a large portion of the statistics on the Thai economy (the GDP, etc.) is probably "off the books." Among other Thai statistics we would question, on principle, would be those on homicide, suicide, violent crime, automobile accidents, and so forth.

Even in the case of data we tend to "trust" : because, we assume, for example, the University of Maryland, probably does not screw around with satellite data on fires burning, the data by iteself is often not enough to make meaningful hypotheses.

Let's take the case of the assumption that less burning was done around Chiang Mai based on the satellite data : while we believe the satellite information is probably very good quality : even if we assume it is "absolutely true" : once we go beyond that data to implying how that might impact conditions "on the ground" in Chiang Mai : we are in another world : a world of hypotheses.

Hypothesis : given conditions of local geography, and patterns of prevailing seasonal winds, Chiang Mai may, at times, serve as a "sink" trapping pollution generated by fires elsewhere.

While no one in our many threads on pollution on TV Chiang Mai has, to our knowledge, ever put forward the idea that seasonal patterns of rainfall don't affect pollution, we have yet to hear mention of one of the most common factors in our day-to-day experience of "being on the ground" : wind.

Yet, we all seem to have no trouble remembering how the really bad pollution from burning in Indonesia several years ago contaminated a lot of S.E. Asia : we can safely assume that Indonesian-born pollution was not delivered by Federal Express

There are also many assumptions made in these discussions about "particlate matter" : let us raise what seems like a reasonable question : within the scope of a range of particulate matter ... all of which exhibit a certain average "density" ... can we assume that all the types of particulate matter of a certain average density have the same surface area and shape ?

Assume, for a moment, that shape (surface area) can vary (hypothesis) : assume that certain shapes could be much more easily moved by wind, lifted up to a certain altitude where certain wind-streams might enable them to be carried quite far compared to other particulate matter that might tend to remain nearer the ground because of aerodynamic features related to shape and surface area.

We have no problem in accepting that sand from the Sahara desert goes on holiday in England, and even reaches the Amazon in Brazil, or that the radioactive pollution from Chernobyl went as far China and Canada.

We would love to hear on TV CM some input from someone who has real depth knowledge about the local wind seasonal conditions in Chiang Mai, and northern Thailand, and, beyond that, conditions around here in the context of wider S.E. Asian climatic cycles.

Deep breaths now (but not in Lampang, thanks).

best, ~o:37;

p.s. by the way is there such a thing as a "good" filtration mask that would not impair breathing while exercising ? will try doing some perusagoogling on this.

Edited February 10, 2010 by orang37

[Ulysses G.]

...all over the world, in the most so-called "technologically advanced" societies, statistics are compromised by the co-option of scientific researchers by politics, personal corruption and ambition of individual researchers, the flowing of corporate mega-money into directing, and sometimes stifling, the results of research to promote commercial interests.

The current incredible scandal re the UN collected data on global warming, the recent revelations on the faking of glacial melt data by senior scientists (a whole cabal of them), the sorry history of the manipulation of the data on tobacco and its effects on health in America. Well : we got to that place so well described by Mark Twain a long time ago vis-a-vis statistics : that they are often just one class of lies in the unholy trinity of : "lies, damned lies, and statistics."

So, if I understand correctly, what you are implying here, Khun orang, is that you do not trust statistics or research that seem to prove that Chiang Mai's pollution problem is not as bad as certain posters make out, but you do trust "feelings" that suggest the opposite.

It seems that many people who are sensitive to the burning at this time of year agree with you, but that leaves out an awful lot of people who are not overly bothered and think that the more positive statistics are absolutely correct.

Edited February 11, 2010 by Ulysses G.

[orang37]

So, what you are implying here, Khun orang, is that you do not trust statistics or research that seem to prove that Chiang Mai's pollution problem is not as bad as certain posters make out, but you do trust "feelings" that suggest the opposite.

Sawadee Khrup, Khun UG,

We can't quite make out what your point is here.

You seem to read into our words a kind of "binary" viewpoint : you trust "statisitcs," or "trust feelings" : and those are mutually exclusive.

From our point of view, the use of the word "feelings" (your choice of words) is a kind of "red herring" in this context which does not characterize what we attempted to convey which is the spirit of "rational skepticism" which is essential to scientific enquiry. Note the use of the word "enquiry" : rather than the word "conclusions," or the idiom : "discovery of the truth."

We are speaking in "technicolor," and, to us, you are replying by saying "what's its going to be : black or white ?"

In fact, we do accept that the "statistics" for this year do fit well with our own current personal experience, and the experiences of many people we know, which does not mean we trust the "statistics" one iota more, or that we discount variant opinions of individuals expressed here one iota less.

When we hear from individual posters on TV CM that say they had a day, or week, or month, of pollution that seemed to them more extreme than some other years (in apparent contradictions of the "statistics") : we take what they say at "face value" as their own individual experience, as valuable data, and if we had the opportunity we'd seek to know what about their location, behavior, etc. might be different from other years of their lives. We'd also like, if we could only know, to examine their thinking for bias and for possible influences of media, participation in social groups where "environmental doom and gloom" are characteristic "currencies of interaction," (the current eco-trendy lifestyle) and so forth.

It seems that many people who are sensitive to the burning at this time of year agree with you, but that leaves out an awful lot of people who are not overly bothered and think that the more positive statistics are absolutely correct.

Find the above very hard to understand : if you read my post carefully you will find that there is no statement in it saying we believe this current month's pollution is unusually bad : so who is it that can be agreeing with a statement we didn't make ?

Second, the use of the word "overly bothered" : that's an ad hominem argument disguised as an implication : are Priceless, or MapGuy, or others here who write at length about pollution, "overly bothered" ? Do you assume that writing at length, or bringing up obvious possible contributory factors, like wind patterns, which have never been discussed in the context of a long series of discussions on this topic, is to be discounted as a symptom of some personal "state" of "being bothered" ?

If it bothers you to read long posts, or read posts that go into depth examining technical issues : well, my friend, that's something you "own." We are not particularly interested in the "depths" of colonoscopy, but we do enjoy your posts on that subject, and their details; we listen to what you say, and think about your words.

For us this whole area of pollution, and its impact on where our meat-package happens to be breathing, is fascinating intellectually; we experience pleasure in exploring it, in constantly questioning our assumptions, comparing our experiences with others; we really enjoy the exchanges we've seen in the last year on this topic where, we think, there have been some good examples of high quality intellectual debate to the benefit of all.

With humble suggestion you might read our post again, and examine your perceptions and assumptions about what is being said in it,

respectfully, ~o:37;

"A human being is a part of the whole, called by us "Universe", a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest : a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody is able to achieve this completely, but the striving for such achievement is in itself a part of the liberation and a foundation for inner security." Albert Einstein, 1950

Edited February 11, 2010 by orang37

[Ulysses G.]

We are speaking in "technicolor,"

Well, we both agree on that.

[anonymouse]

Well you do waffle a bit Orang but from what I can gather forgetting your views on the validity of statistics you are agreeing with UG that you think the burning in neighbouring countries does have a big impact on our seasonal pollution.

I tend to usually avoid the pollution threads because they seem like one big Thai Visa Groundhog day but your 'wind' theory is interesting

'We would love to hear on TV CM some input from someone who has real depth knowledge about the local wind seasonal conditions in Chiang Mai, and northern Thailand, and, beyond that, conditions around here in the context of wider S.E. Asian climatic cycles'.

Me too.

[Ulysses G.]

from what I can gather forgetting your views on the validity of statistics you are agreeing with UG that you think the burning in neighbouring countries does have a big impact on our seasonal pollution.

I could be wrong (again) but I am pretty sure that Khun orang (or his meat package) also agrees with Priceless that the smoke this year has not been that bad so far.

[WinnieTheKhwai]

Well it's early February; of course it's not much of an issue yet. The time of reconing really is March. I don't think there's soul in town who would honestly recommend that as a good month to visit Chiang Mai.

A week or two in March will decide if this is a good or a bad year.

[Ulysses G.]

Yes, very true.

[Ulysses G.]

If it bothers you to read long posts, or read posts that go into depth examining technical issues : well, my friend, that's something you "own."

I have no problem with long posts and just a little with most technical ones. However, I'm sure that you will admit that your rare and unique writing style can take some getting used to.

To be honest, some of your more unconventional posts would take an Enigma machine to decrypt, but even without one I can usually find a nugget or two to savor - like James Joyce or the best champagne.

Because you are unusually clear and coherent today, I thought that I would give translating your post for the common man my best shot, however; it seems that I failed dismally. Please forgive me.

[el jefe]

'el jefe' post='3330124' date='2010-02-09 22:33:14']And the people who blame the burning on the Lao are the "complete screwballs".

Yeah, like the Sydney Morning Herald is just making this stuff up and the satellite photos of fires all over Laos and Burma - that you just insisted do not exist - are fake. Go back and read your own posts.

There is really no BS-ing your way out of it. Why don't you just be honest enough to admit that, in this case, you did not know what you were talking about?

UG, it's amazing how you only address the parts of posts you want to. First you tried to discredit me because I've only been here for 5 years. Now you're using insults and cartoons. It's disingenuous.

You said the pollution in Luang Prabang was "much worse than CM has ever been". While that's certainly possible the day or two you were there, that has not been my experience in my dozen trips. btw, how many times have you been to LP?

You said there were "fires everywhere including the side of the roads and the banks of the river." I jokingly replied that that sounds like CM from Nov to April. Then you insulted me again. But, seriously, I ride a bike 400 kms a week. There is rarely a day during the dry season when I don't see at least one small fire along the side of the road. Sometimes, it's hundreds. If I spent the majority of my time within a one mile radius of Tha Pai Gate I would never know how prevalent the fires are.

You didn't insult me or argue against my main point -- that the long term health effects of continued exposure to CM's air when it regularly exceeds the PM10 limit are a problem, no matter how good you feel today. And, of course, Thailand does not even measure PM2.5 levels, which is a bigger health problem. In my opinion, again "my opinion" because there are obviously no statistics to back this up, CM's PM2.5 level is probably exceeds anyone's limits, which might explain the constant haze when the PM10 levels are reported at the current levels.

What's funny is that I actually agree with you on two of your most common points -- and have stated so on this thread -- that complaining gets us nowhere, and other than limited views of Doi Suthep there is no reason for tourists not to come, even in March. But as you said, I'm a "nutter."

[Ulysses G.]

And the people who blame the burning on the Lao are the "complete screwballs". Laos has a population of 6 mil, about 10% of Thailand's population. Thailand is one of the world's biggest rice exporters. I don't believe Laos exports any rice at all. What is it they're burning?

Poor you. Instead of trying to worm out of it, why don't you just admit that you stuck your foot in your mouth? You call me a "screwball" because you claim that there is little or no burning in Laos and then you get all indignant when a bunch of people, including me, post conclusive evidence - which you tried to deny - that you are very wrong.

About your supposed main point, yes, we all know that long term exposure to pollution might harm one's health, but no one knows how a few days a year might affect an average person. Of course, it would bother people with chronic lung problems much more than healthy ones - no one has denied that. However, the truth is that this was not your "main point" until a few posters pointed out how wrong you were with your other one.

By the way, it is very big of you to condescend to "agree" with two of my points, but it would have been more impressive if you had left all the insults out.

As far as you being a "nutter" goes, yes, I would agree that there are a lot of neurotic individuals on the internet who exaggerate the pollution problem in Chiang Mai, but as for using the word nutter, you said it, not me.

"The only thing worse than a liar is a bad liar."

Lisa Liu

Edited February 11, 2010 by Ulysses G.

[orang37]

... snip ... I thought that I would give translating your post for the common man my best shot, however; it seems that I failed dismally. Please forgive me.

Sawasdee Khrup, Dear Esteemed Brother, Khun UG,

Please forgive us if that mangy soi-dog part of our collective of personalities, hopping on only three good legs, has replied to you with a wrinkled forehead, ears drawn back, and muffled growling rather than with relaxed ears, friendly-tongue-lolling-out-from-side-to-side, and pathetic attempts at tail-wagging while remaining upright (about ninety-eight times out of a hundred tail-wagging sessions result in said canine-meat-bucket-of-mange just falling over on his side most ungracefully, frothing at the mouth in shame).

You are correct : pollution, this year, in our experience, so far, has not been as bad as other years : the fact that correlates with the statistics shown by our highly valued TV contributor, Khun Priceless, doesn't stop us a bit from questioning and distrusting those statistics.

And of course we distinguish "questioning statistics" from questioning the intent or motivation, or intelligence, of those who present and discuss statistics. Khun Priceless makes no "grandiose claims," it seems to us.

Nor is it "contradictory" ... to us ... to hear from someone else that their experience of pollution this year is worse.

Where we get skeptical is when we see "grandiose" claims being made from statistical data, or being made via a categoric rejection of statistical data (with the exception, of course, of our own grandiose claims).

To bring this "down to Earth" : we feel that any discussion of meteorologic, geologic, climatic, or atmospheric conditions that is not "grounded" in discussion of winds, rain, seasons, motor vehicle emissions, lunar and solar cycles, and fire (triggered by nature, triggered by humans), dynamics of forests and river systems, tidal estuaries, etc., human demographics, and patterns of human manufacture, consumption, and waste disposal, etc. is ... not as useful as possible.

best, ~o:37;

"A bit beyond perception's reach

I sometimes believe I see

that Life is two locked boxes, each

containing the other's key."

Piet Hein

[chiangmaiexpat]

The Thai official standard limit for PM<10 air pollution is 120 µg/m³ (the corresponding USEPA limit is 150 µg/m³). So far this year, the CM pollution level has on only two occasions (14 January and today, 10 February) exceeded half of that limit (i.e. 40% of the USEPA limit), at 62.3 and 66.3 µg/m³ respectively.

(1) The European PM10 limit is is 50 µg/m³ and in the EU it isn't considered safe if concentrations exceed this limit for more than 35 days per year. I'd rather go with the EU standards in this matter. Doctors in Europe recommend not to exercise outside if the concentration is above that level.

These values are in actual fact unseasonally low and would, to my mind, not warrant the amount of complaints currently recently exhibited on ThaiVisa.

(2) Can we trust the PCD data? I doubt it. Their website publishes data taken from three different measuring stations in Chiang Mai and the individual data points vary wildly. The site has a feature that allows you to plot linear curves for the data from individual sites. If you compare these curves, you will find an enormous variance that IMHO questions the credibility of this data.

(3) The pollutants statistics by the PCD don't include the more coarse particular matter which accounts for a lot of the dust we see right now. This dust causes plenty of discomfort, though, especially for people with allergic reactions. In other words, the air quality is lousy right now, but the PCD site still displays a green icon for Chiang Mai and Lampang (where it's worse).

In my view, that borders on mockery.

Cheers, CMX

[Ulysses G.]

This morning was the first time this year that someone mentioned smoke to me other than on Thai Visa. A fellow who comes here every year came in to the store and immediately started complaining about how bad the air is here at this time of year.

We talked for a little while about how he plans to go down to the beaches to escape from the smoke and he said something interesting. He told me that you "couldn't go anywhere in Thailand where the air isn't polluted", but "Northern Thailand is the worst of all at this time of year".

Saying that all of Thailand has polluted air sounds unbelievable to me, although I would imagine that a good number of Thai Visa posters would agree.

I'm not saying that he isn't right, however - at least in my mind - his remarks confirmed one of my pet theories about some of the more frequent whingers.

Edited February 12, 2010 by Ulysses G.

[Mapguy]

My goodness, leave the room for just a little while, and all hel_l breaks loose! Why aren't people out enjoying the weather! Still quite nice, really.

Regarding statistics, I don't share all of orang37's concerns, but I can't accept slavish use of quantitative analysis. It is too frought with complications. I suggest a couple of things. The Pm<10 readings we work with are "best available" data. There is no real reason to doubt their authenticity, as both Priceless and I have both posted several moons ago; however, as you realize, that while useful, there's not much to go on from three measuring stations, only two of which report regularly. Additionally, what they don't measure (such as PM<2.5) is probably equally if not more important from a public health point of view. Priceless has provided in past threads the useful suggestion that 50-60% is a useful rule of thumb.

You might note, given a very recent post, that the "wild variations" aren't really that at all. The variations, such as they are, are explained very simply by the location of the stations. The major Chiang Mai station is located on the outskirts of town. The Uparaj station is in the old city at the school. It quite understandably reports higher levels on a consistent basis. The third station is near the top of Doi Suthep where the air is understandably much clearer.

Priceless is really working the UM site hard, doing much more than I have time to do with it. They just did an overhaul of the site and have improved it, as well. The data on that site is incomplete, of course, as it will always be unless someone wants to fly a geosynchronous bird with better sensing gear. If you do some "ground truthing," it is easy to see that the sightings are limited. By the way, the number of reported fires is up quite a bit in the last couple of weeks. No surprise there!

Recently, I checked out one farm between Bo Sang and Doi Saket practicing good techniques. They were systematically harvesting the straw and also doing deep plowing. I spotted one very small fire in the field, sort of "tidying up" fire only a meter in diameter. The scene reminded me of Japanese agricultural practices.

Finally, there hasn't been much posted about the impact or wind and wind direction. That's true. There are local, regional and "global" impacts on pollution. No joke about the last, either. Are you familiar with the Krakatoa volcanic explosion << http://en.wikipedia.org/wiki/1883_eruption_of_Krakatoa >> and the subsequent global impact of the particle pollution? Fascinating! BUT, except for those who wish to carp about the uselessness of trying to ameliorate local or Thai conditions so why try, I join those who say nothing indeed will improve until local as well as regional --- and global --- efforts improve and practices change.

Sorry to see the cheap one-liners continuing from time to time as well as the argumentum ad hominem (aka bush league cheap shots and flaming.

I leave this burning question for you: Should open air bars where smoking still goes on be closed down !! (As well as burning lignite, if I may refer a bit to the OP.)

Cheers! I think I'll go out now for a walk ... while it is still relatively pleasant!

Edited February 12, 2010 by Mapguy

[realthaideal]

I suppose any old pollution thread is as good as another at this pt. It seems others feel so as well.

I will give it to the people living further outside of town in the country that the pollution can locally, in pockets, be quite a bit worse. I had a gig out in Mae On by the San Kampaeng Hot Springs on Weds and while headed out there about 7am (early for RTD!) I did see quite a bit of burning of both leaves and regular hillside burning. The result is pockets of smoke settling into ravines between hills and effectively blanketing entire areas/ villages/ moo baans. If I'd moved out to the country like that to be in nature n then was enveloped by smoke for extended periods, I'd be a little upset too. I know with the extended season it will only get worse as pollution gets concentrated in the atmosphere. So for once, I can actually see that at times the lessened smoke, and increased dust and TukTuk n Songtaew spew (around UG's haunts and Central Thapae/ Muang Gao) might be preferable and less potent than the smoke out in the countryside.

As far as burning of wild lands goes, I will mention that in CA where this is not an annual event, and combustible fuel builds up for sometimes a decade, we then get sudden horrendous wildfires as the place lights up like a tinder box - and causing loss of property and lives, almost every year. There is so much biomass accumulating here annually with all of the rain and water, that in some senses an annual burn makes sense as well. So.....

Alot of the griping is preaching to the choir. The burning happens and is too bad. Nobody likes brown air. I also get the contrast between the super-clean country air that suddenly becomes chokingly brown or gray when the fields or valleys surrounding get lit up. Difficult. Some of it can be solved, and other parts may almost be a good practice, though too.

[Priceless]

The Thai official standard limit for PM<10 air pollution is 120 µg/m³ (the corresponding USEPA limit is 150 µg/m³). So far this year, the CM pollution level has on only two occasions (14 January and today, 10 February) exceeded half of that limit (i.e. 40% of the USEPA limit), at 62.3 and 66.3 µg/m³ respectively.

(1) The European PM10 limit is is 50 µg/m³ and in the EU it isn't considered safe if concentrations exceed this limit for more than 35 days per year. I'd rather go with the EU standards in this matter. Doctors in Europe recommend not to exercise outside if the concentration is above that level.

These values are in actual fact unseasonally low and would, to my mind, not warrant the amount of complaints currently recently exhibited on ThaiVisa.

(2) Can we trust the PCD data? I doubt it. Their website publishes data taken from three different measuring stations in Chiang Mai and the individual data points vary wildly. The site has a feature that allows you to plot linear curves for the data from individual sites. If you compare these curves, you will find an enormous variance that IMHO questions the credibility of this data.

(3) The pollutants statistics by the PCD don't include the more coarse particular matter which accounts for a lot of the dust we see right now. This dust causes plenty of discomfort, though, especially for people with allergic reactions. In other words, the air quality is lousy right now, but the PCD site still displays a green icon for Chiang Mai and Lampang (where it's worse).

In my view, that borders on mockery.

Cheers, CMX

I did not intend to get into a debate on this, but since you quote me directly I feel compelled to reply.

(1) Hopefully you are aware that the EU standard is not complied with in all locations. In London in 2009 nine (9) of their measuring stations exceeded the allowed number of "high levels" (35). Unfortunately they do not publish how many days it was actually exceeded, or by how much.

It is also very hard to find raw (daily) data on this. As a matter of fact, I haven't found any country other than Thailand that regularly publishes its readings on a daily basis. I would be most grateful if somebody could point me to such a website, as I would like to be able to do comparisons.

A consequence of this lack of raw daily data is that there is a risk, outside of Thailand, of either random errors (e.g. typos) or deliberate falsification of results (e.g. as was suggested concerning Beijing before and during the Olympics). A random error in a daily time series, like those of the Pollution Control Department (PCD), is of little significance since it will be "drowned out" by the mass of correct numbers. A deliberate falsification of the Thai data would be highly unlikely, since this (to stand up to various types of statistical testing, like my correlation analyses, see below) would require a highly sophisticated model to generate the data. In my opinion, the creation, maintenance and use of such a model would be far beyond what I believe is the level of competence to be expected from the PCD...

(2) As has been pointed out several times on this forum, the three measuring stations in Chiang Mai are actually two, since the third ('Chiangmai') is in fact a mobile station where it is not published where the reading for a particular date was taken. The values from this site are consequently not comparable to the other two sites, or even to readings from the same station on a different date.

You obviously have no training in statistics. If one compares the two comparable stations ("Chiang Mai" and "Uparaj College") one finds an extremely strong correlation between the two. To be exact, the correlation between the observations for the two stations, using all the data from 4 August 2002 when the Uparaj series started, is 0.920998! This is, as I said, an extremely strong correlation as 1 is the theoretical maximum ( http://en.wikipedia.org/wiki/Correlation_and_dependence ). This can in no way whatsoever be described as "vary wildly".

In fact, I regularly do these kind of analyses to try to determine how reliable the PCD measurements are. One would expect e.g. decreasing levels of correlation with increasing distance, which is also what I have so far found. One can e.g. compare the correlations (for the period 1 January 2009 to yesterday 11 February 2010) for "Chiang Mai" versus "Uparaj College" (0.972738), "Lamphun" (0.871577) and "Lampang" (0.821344), i.e. exactly the kind of decreasing correlation that one would expect. (These dates are what I have in my database for Northern Thailand, which I have recently started in order to analyse patterns in this part of the country.)

I also do correlation analyses between PCD pollution data and the Thailand Meteorological Departments statistics for number of rainy days and amount of rainfall for different PCD measuring stations. These analyses also show very significant correlations. For the seven locations that I analyse, the correlations between the number of rainy days and the pollution levels vary from -0.67 to -0.91.

(3) I haven't found any country where the concentration of coarse particles (e.g. 10<PM<100) are regularly measured. The reason for this seems quite obvious, since these particles apparently cannot enter the lungs, and consequently may be irritating but not detrimental to health (I have neither training nor experience in medicine, so I am here relying on what I have read, mostly on the internet).

Of greater consequence is the unfortunate fact that the PCD so far measure only the PM<10 concentrations and not PM<2.5. This, however, is what one can expect in any developing country (as, until lately, in Europe). The awareness of the negative health effects of PM<2.5, and the wider availability of measuring equipment, is apparently a relatively recent occurrence. E.g. the EU limit for PM<2.5 will not come into force until 1 January 2015. It is, in this context, worth mentioning that two thirds of the Thai provinces do not have even a single measuring station yet, so the PCD has got its work cut out, anyway.

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[chiangmaiexpat]

It is also very hard to find raw (daily) data on this. As a matter of fact, I haven't found any country other than Thailand that regularly publishes its readings on a daily basis. I would be most grateful if somebody could point me to such a website, as I would like to be able to do comparisons.

I was able to find a website with daily data for Germany in about 10 minutes: http://www.env-it.de/luftdaten/map.fwd?comp=PM1 without previous studies. Current and historical data as colour maps, PDF, Excel, graphs and raw numbers. Lucky hit?

A deliberate falsification of the Thai data would be highly unlikely, since this (to stand up to various types of statistical testing, like my correlation analyses, see below) would require a highly sophisticated model to generate the data. In my opinion, the creation, maintenance and use of such a model would be far beyond what I believe is the level of competence to be expected from the PCD...

I didn't mean to imply deliberate falsification, but I doubt their methodology. Their data simply isn't very meaningful. For example, the AQI value displayed on their map for today (51) does not correspond to any of the three measurements (45, 63, 80) nor to their mathematical mean. And then there is the question whether the AQI calculation makes sense at all.

As has been pointed out several times on this forum, the three measuring stations in Chiang Mai are actually two, since the third ('Chiangmai') is in fact a mobile station where it is not published where the reading for a particular date was taken. The values from this site are consequently not comparable to the other two sites, or even to readings from the same station on a different date.

Why should data from a mobile station not be comparable?

You obviously have no training in statistics. If one compares the two comparable stations ("Chiang Mai" and "Uparaj College") one finds an extremely strong correlation between the two.

Since I majored in informatics, I like to believe that I grasp the basics. But judge for yourself. I've done a quick-and-dirty GIMP job overlaying the most recent curves of the three measuring stations. There is correlation and there is also plenty of variance. Enough to see that raw data from a single station is not reliable.

Cheers, CMX

Edited February 12, 2010 by chiangmaiexpat

[Priceless]

I was able to find a website with daily data for Germany in about 10 minutes: http://www.env-it.de/luftdaten/map.fwd?comp=PM1 without previous studies. Current and historical data as colour maps, PDF, Excel, graphs and raw numbers. Lucky hit?

Thank you for that! My German is unfortunately rather rusty, so it will take me a while to penetrate the site. What I will be looking for is time series for individual locations, preferably in Excel format. The ability to query for individual dates is of less use to me, since I would like at least 3,000 observations or so.

I didn't mean to imply deliberate falsification, but I doubt their methodology. Their data simply isn't very meaningful. For example, the AQI value displayed on their map for today (51) does not correspond to any of the three measurements (45, 63, 80) nor to their mathematical mean. And then there is the question whether the AQI calculation makes sense at all.

I exclusively go on the raw data, so I can't really comment on the AQI or the map. I agree that the number 51 seems rather odd, my only guess would be that it is based on some kind of average pollution (in µg/m³) which is then converted to AQI. Incidentally, the relationship between absolute pollution level and AQI is non-linear, which makes it rather unsuitable for any kind of time-series analysis. (You'll find a description of AQI here: http://www.epa.gov/ttncaaa1/t1/memoranda/rg701.pdf )

Why should data from a mobile station not be comparable?

Because one day the measurement may be taken at the Phuping Palace at about 1,200 metres above sea level to the west of Chiang Mai city. The next measurement may be from Fang in the far north of the province. Obviously these two measurements would not be comparable to each other, or indeed to the "Chiang Mai" or "Uparaj College" values for the same days. The Pollution Control Department does not (as far as I know, but I do not read Thai) post where each measurement was taken.

Since I majored in informatics, I like to believe that I grasp the basics. But judge for yourself. I've done a quick-and-dirty GIMP job overlaying the most recent curves of the three measuring stations. There is correlation and there is also plenty of variance. Enough to see that raw data from a single station is not reliable.

I beg to differ, I do not consider the result from a three week observation period really significant. I based my calculation of the correlation between the "Chiang Mai" time-series and that of "Uparaj College" on 2,370 observations for "Chiang Mai" and 2,264 observations for "Uparaj College". Obviously you can find shorter time periods when there will be a divergence even between two strongly correlated series. A strong correlation does not mean that the values are equal between the two series but rather that (among other things) if one series moves upwards so does the other and vice versa. A quick look at your graph indicates that this is true between the blue and red curves on ~17 of the 21 days that you show. Not a bad result, in my opinion. (It is difficult to say anything about the green curve, since it is obviously plotted on a different time scale.) Incidentally, I am quite willing to admit that there are probably quite a few errors in the values for individual days at individual stations. After all, to err is human and the measuring equipment is handled by humans, and the reporting and posting is also handled by humans, I believe. Not to mention the further probability of my entering incorrect values into my database

Cheers, CMX

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[Priceless]

I was able to find a website with daily data for Germany in about 10 minutes: http://www.env-it.de/luftdaten/map.fwd?comp=PM1 without previous studies. Current and historical data as colour maps, PDF, Excel, graphs and raw numbers. Lucky hit?

Cheers, CMX

I am apparently having one of my thick days (they're quite frequent) and, as I posted before, my German is rather rusty. Could you please point me to where I find time series with daily values (raw numbers for individual measuring stations) in Excel format.

TIA

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[anonymouse]

It's all got a little technical for my little brain now, that's me out of the pollution threads until next year,

Adios

[MESmith]

It's all got a little technical for my little brain now, that's me out of the pollution threads until next year,

Adios

Makes a change to be choking on the data in the posts, rather than the "air".....

[Ulysses G.]

That's a good one!

[Priceless]

Since I majored in informatics, I like to believe that I grasp the basics. But judge for yourself. I've done a quick-and-dirty GIMP job overlaying the most recent curves of the three measuring stations. There is correlation and there is also plenty of variance. Enough to see that raw data from a single station is not reliable.

Cheers, CMX

I realise that you said "quick-and-dirty", but it may just have been a little too quick. I went to the PCD website and copied the numerical values for the three measuring stations for the last three weeks (i.e. the same data that you used).

The first thing that strikes you is that the station "Chiangmai" has a very low average pollution level, 26.5 µg/m³. To me, this seems to indicate that this mobile station is at the moment located at Phuping Palace, like it usually is at this time of year (i.e. when there are royalty staying at the palace). In other words, the station is at 1,200 metres above sea level, i.e. in a completely different air mass from Chiang Mai city.

Secondly, I calculated the correlations between each pair of the three stations. The values came out like this (the bottom of the picture):

As you can see, the correlation between "Chiang Mai" and "Uparaj" is extremely strong (~0.94), whereas "Chiangmai" is clearly the odd one out. This is of course exactly what one would expect, knowing that "Chiang Mai" and "Uparaj" are within ~5 kms of each other and at the same altitude, whereas "Chiangmai", as stated, is further away and at a vastly different altitude.

I am obviously not stating that this proves that both "Chiang Mai" and "Uparaj" are always and fully reliable, but it certainly does not support the opposite view.

I consequently maintain that I have so far not seen anything that indicates that the PCD figures (raw daily observation data) are not reliable. I have also over time done a number of different analyses that so far indicate that the numbers are, on the whole, correct and reliable. (If you are very much interested, I could point you to a number of occasions where the numbers look "dodgy", but not to the extent that they have made me doubt my overall conclusions.)

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