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Tywais

Smoke, Smog, Dust 2012 Chiang Mai

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Agree with cloudhopper [the balloonist and pilot who has experienced the winds above the surface] that surface winds are totally different and sometimes opposite of the higher winds and that's why it's hard to pinpoint the sources of the haze. A simple example of the difference in wind directions is just watch the hot air balloons going up during Loi Katrong.......they change directions constantly on the way up.....never straight up.

Another example is to just watch a fire burning and unless there are some [rare] surface winds, the smoke will drift N,S,E, or W....depending on the wind directions way above. Another example of high altitude wind directions is that on a recent trip from BKK to CNX, @ 10,000mtrs, there was a 98kph head wind [from the north]

The point is that when smoke from the surface rises, it can go in any direction and at any speeds so impossible to pinpoint the source.

Also, I remember about a decade ago when most of Indonesia was burning and their cloud [haze] came all the way to northern Thailand and maybe further, so it's not unreasonable to say that the haze is from other sources than local.

Actually this year in the north, there has been minimal burning of the rice fields because most farmers were able to get in an extra crop, as the irrigation water was full and the farmers had little time to burn between crops and we had a brief rainy period in Dec/Jan [?] that was a bit of a soaker for the normally dry soil.

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Okay, I worked as environmental consultant focusing on air quality for several years, and I don't think the figures you've provided are telling the whole story. Granted, I am American, and I'm clearly translating my own standards of air quality to a place hosting me but, that's what we're all doing on this thread, right? So here is what I'm seeing in these, if anyone cares (to tell me how stupid I am).

First. The standards for PM 10 in the EU and USA can't really be compared to Thailand, which doesn't monitor PM 2.5. The EU and the US focus on the more dangerous PM 2.5. The PM 10 measures are just caps that exist to reinforce other air quality standards. It's a liability, ass-covering limit that doesn't really mean anything. All the meaningful regulations and air quality improvement measures in the US that deal with PM target PM 2.5, and in cleaning up smaller particles, generally the larger particles are cleaned up as well, barring natural disasters such as forest fires. The 150 ug/m3 boundary in the US is to provide an exceptional allowances to account for natural disasters or the convergence of three or four unlikely events at the same time (natural fire PLUS traffic-causing tourist event PLUS wind patterns blowing in significant pollution from elsewhere all converging in ONE air district).

Second. Yes, there are a lot of fires. Yes, there are plenty outside of Thailand as well as inside of Thailand. Fires abound.

Third. This chart deals with monthly and yearly averages. The meaningful representation of PM counts are usually 24-hour or 8-hour averages. Why? Because greater concentrations of PM in the air even in a shorter amount of time do disproportionate lung damage compared to medium-levels over a longer time period. So, we look to the number of instances where PM 10 levels exceeded 120 ug/m3. 18 times in 2010 and 16 times in 2009 is A LOT, especially for a region with the size and population of Chiang Mai. While we don't know what the PM 2.5 levels are, we know that PM 10 and PM 2.5 levels generally share a correlation. Sure, there has been a decline from the 39 instances of PM 10 exceeding 120 ug/m3 in 2002, but that doesn't mean 15+ instances is a good record by any means. I guess I'm not sure what this is trying to prove. Certainly air quality is still quite bad during the burn months.

Fourth. It would make sense that particulate matter, on average, would have declined over the past few years, as cleaner equipment and vehicles are implemented across the region. One of the major ways that governments have tried to control air quality without imposing usage limits or other restrictions on personal behavior is by holding engine manufacturers to higher standards every few years. In the US, these regulations focus first on huge, diesel-fueled engines--the type that power giant bulldozers and industrial trucks and last on smaller engines (>25 HP engines are still largely unregulated). What this means, even for Thailand, on the other side of the world, is that newer vehicles and equipment generally emit less pollution during a lifecycle. For instance, a 2006 model year excavator doing the same work as a 2002 excavator could emit HALF the pollution. What's interesting, is if we look at similar charts from areas in the US, we can see a similar rate of decline, just 2 or 3 years ahead of what's in this chart for Chiang Mai.

Fifth. This chart shows that Chiang Mai's monthly averages for PM 10 over the last 10 years in March greatly exceed those of a district in Bangkok. February and April averages in Chiang Mai also exceed those of Bangkok. During the rest of the year, Chiang Mai's PM 10 count monthly average is 40 or 50 ug/m3 below Bangkok's. This shows that air quality during the burn season in Chiang Mai is worse than air quality during the same time in Bangkok, despite huge differences in population size, construction/industrial economy, and vehicle miles travelled (all of which are obviously greater in Bangkok).

Sixth. Chiang Mai has almost exceeded the EU PM 10 standard in less than a month, and has surpassed the US standard already. Some of our neighbors have already violated both of those Western standards. I'm thinking this chart will/has been used to discredit that air quality is bad in Chiang Mai, when areas to the East are faring worse right now. Air quality IS regional, as many people in this thread have been eager to point out. Yes, it is possible that burning in Southern China, Myanmar, and Lao have contributed to the poor air quality in Northern Thailand. This does not cancel out the fires burning more closely or change Chiang Mai's geographic disadvantages for keeping the bad air in.

I think, if anything, these charts demonstrate that air quality during this time of the year continues to be a problem. It seems like the voluntary, man-made fires are still the triggering factor in these spikes. The best way to improve air quality during the burning season in Chiang Mai proper is to stop the rates of fires near Chiang Mai. Even if all the fires nearby stopped, Chiang Mai would likely still have terrible air quality in February and March, but the huge spikes (like 180 ug/m3 on 18 Feb) that disproportionally affect health would probably decrease.

Another problem with PM 10 is that is can exacerbate the air basin's hold on other emissions and air pollution as well. Ozone/NOx (smog) and carbon monoxide can get trapped in more than usual, making the soupy air extra soupy.

Last, I didn't see this link already in this thread (but, that doesn't mean it's not there). It's an academic paper disputing most of the claimed benefits of the fires.

Okay. I'm done nerding out about air quality. I have chosen to live in Chiang Mai despite the air quality, and I'm quite aware that as a foreign national I have no right to tell the locals how to do things. It certainly would be nice to get my oxygen fix with less labor, but hey, I've given up lots of my home comforts in favor the way of life here.

I have been off-line for some time, so I have not seen your post until recently.

I have never worked professionally with air pollution. However, I have been an almost daily user, and sometimes producer, of statistics. Since you have posted as a direct reply to my earlier post, I feel obliged to reply to what you are saying.

What I posted is obviouslynot 'the whole story', I don't think anybody has access to that. What I have tried is posting some relevant information that I think might be of interest to some forum members.

--------------------

'The standards for PM 10 in the EU and USA can't really be compared to Thailand, which doesn't monitor PM 2.5. The EU and the US focus on the more dangerous PM 2.5.' I am afraid I don't understand this statement. Firstly, I don't 'compare' the standards, I just presented a table listing them, since there seems to be some confusion about them. Secondly, I don't understand why one couldn't compare PM10 standards because of the fact that USA has implemented a limit for PM2.5 (EU will not have a limit for PM2.5 until 1 January 2015).

--------------------

'Second. Yes, there are a lot of fires. Yes, there are plenty outside of Thailand as well as inside of Thailand. Fires abound.' I don't understand what you are trying to say here. I posted an example and the URL from a site that I have found quite useful (in combination with weather and other data) in trying to understand the pollution patterns. Are you saying that one should just shut up, take a deep breath and go on doing something else?

--------------------

'Third. This chart deals with monthly and yearly averages. The meaningful representation of PM counts are usually 24-hour or 8-hour averages.' It appears that you have not grasped the difference between data collection and information presentation. The raw data for my graphs and tables are of course the 24-hour averages posted by the Pollution Control Department (PCD) on their website. However, there are frequent questions on this forum like 'When does the worst air polluution usually occur?' or 'What is the air quality usually like during October?. I somehow doubt that the people asking such questions would feel very enlightened by the following graph, showing the raw 24-hour averages since the turn of the century:

post-20094-0-93819000-1330591817_thumb.j

The individual data points can of course also be found in numerical form on the PCD website.

I have no medical background, but I have understood from my readings that long-term exposure is mainly harmful in causing chronic health problems. Short-term exposure, on the other hand, tends to trigger acute conditions, mainly among those with a pre-existing condition, e.g. asthmatics. This should then be the reasoning behind having both long-term (yearly) limits and short-term (24- or 8-hour) limits, with the latter being at much higher levels.

--------------------

'Fourth. It would make sense that particulate matter, on average, would have declined over the past few years, as cleaner equipment and vehicles are implemented across the region.' It would, but does surprisingly not seem to be the case, at least not to any great extent. The most distinguishing feature of air quality (i.e. polllution) in Chiang Mai is the dramatic seasonal swings. If vehicle exhaust were a major factor one would expect to see similar decreases in pollution over the seasons. If you look at the table I posted under 'third', you will see that the monthly averages over, say, May to October (i.e. non-burning season) remain quite stable over the years. Obviously today's vehicles emit less pollutants per vehicle than those of the 1990's or before that. However, you must take into account that the number of vehicles is rapidly increasing here in Thailand. Furthermore, the improvement in emissions per vehicle has not been as dramatic in Thailand as in most Western countries. As far as I know (I am no expert) there are e.g. no particle filtres attached to diesel engines (the vast majority) here. One of the reasons supposedly being that the present quality of diesel sold here does not allow it.

--------------------

'Fifth. This chart shows that Chiang Mai's monthly averages for PM 10 over the last 10 years in March greatly exceed those of a district in Bangkok. February and April averages in Chiang Mai also exceed those of Bangkok. During the rest of the year, Chiang Mai's PM 10 count monthly average is 40 or 50 ug/m3 below Bangkok's. This shows that air quality during the burn season in Chiang Mai is worse than air quality during the same time in Bangkok, despite huge differences in population size, construction/industrial economy, and vehicle miles travelled (all of which are obviously greater in Bangkok).' As you can see in my original post, this graph was directed at one particular poster ('for the poster who was grateful for living in Bangkok rather than CM'). I would never argue that the air quality in Chiang Mai isn't very bad during the burning season. However, the Din Daeng district of Bangkok isn't highly industrialized, as far as I know it's more of a residential and office district. If you want to compare Chiang Mai to the industrial heartland of Thailand, compare it to e.g. Sara Buri:

post-20094-0-29913900-1330594045_thumb.j

--------------------

'Sixth. Chiang Mai has almost exceeded the EU PM 10 standard in less than a month, and has surpassed the US standard already. Some of our neighbors have already violated both of those Western standards. I'm thinking this chart will/has been used to discredit that air quality is bad in Chiang Mai, when areas to the East are faring worse right now.' I don't know where you have got this idea. It is certainly not in anything I have written, and I resent being labelled with an obviously false statement.

What I have said on occasion is that pollution in Chiang Mai appears to be somewhat less severe than that in most of the Upper North. An explanation for this could be that Chiang Mai is 'protected'. by the mountain ranges surrounding it on three sides. A piece of circumstantial evidence could be the following graph (the cause of the odd-looking curve for Phrae is some suspicious-looking numbers for February and March 2010):

post-20094-0-80784100-1330595734_thumb.j

--------------------

/ Priceless

--------------------

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Umm. From Wikipedia "Wind direction":

Wind direction is reported by the direction from which it originates. For example, a northerly wind blows from the north to the south.[1] Wind direction is usually reported in cardinal directions or in azimuth degrees. So, for example, a wind coming from the south is given as 180 degrees; one from the east is 90 degrees.

So I think I'm correct. The prevailing wind is from the south.

I did make a mistake on the wind speed though. The wind speed in meters/sec is c and variability is k (I think). So 40km per day should be about 90km. Unfortunately they massaged the data for their own purposes. Is there a better data set out there?

There's more (not) blowing in the wind than first appears . You have to read the research report closely and look, not just as the prevailing direction of wind, but also at the other factors reported. Also check out the charts at the end of the report reflecting different provinces in the seasons. Compare Chiang Mai and other northern provinces. Wind direction is variable, sometimes in surprising directions. Wind strength is generally very light, a notable exception being the thunderstorms and winds experienced during the SW monsoon season. Nonetheless, northern Thailand is lousy wind turbine country.

The monsoon changes and seasons are variously reported on the web. One thing you'll notice if you check several descriptions out is that February - April are "gap" [my term] months between the NE and SW monsoons. If you look at wind direction posted in daily weather reports, one can wonder if "very light and variable" isn't much more descriptive.

Another factor to throw into the mix is the topography. Chiang Mai is in a "bowl" surrounded by mountains. In conditions of light and variable winds, and with occasional temperature inversions, pollution, once here, can be trapped.

Pollution does not travel through a tunnel, as was once suggested by a poster above, in a discussion of the impact of the surrounding mountains. (Actually, clues to the topography are found in the tunnel that was needed to get the original railroad here, and in planned route of the high speed (China-SIngapore) rail now nearing construction which will bypass this fair city because it is not financially feasible to tunnel a route through the mountains surrounding Chiang Mai. But pollution does move around, which leads us to ask a question.

How high does particulate matter (PM<10) rise and how long is it airborne before it settles to earth? I recall a couple of things. The heavier (most visible) particles don't rise as far as the lighter particles (for example, PM<2.5) which can be airborne higher, longer and further. More observable, if you spray water on the pavement or the road where a lot of dust is stirred up, you will indeed settle the dust; if it rains, the air will be clearer.

While I don't know how high high (altitude) is, I'm willing to guess that most particulate matter we breathe is essentially local to the valley and trapped here by the topography and the light and variable winds February - April. If we are lucky, it rains from time to time. It clears the air and dampens the fires. That is very unusual during this period, however. Last year (2011) was a remarkable clear exception to the smoky norm.

If you want to argue that some particulate matter pollution results from burning elsewhere, you are probably correct to some extent. Even if that is a predominant or even significant cause here, it is very clear that it is a regional problem in SE Asia (and in some of the poorest areas of SW China) that is due fundamentally to the type of traditional agriculture still practiced (especially by small farmers) and land-clearing due to increasing population and the desire to clear forrest areas in favor of commercially profitable crops to produce rubber and palm oil.

These things don't have to be so, but a lot still needs to be done involving economic development, education, encouragement and enforcement. Possible in Northern Thailand ??!! Not terribly long ago, a remarkably successful campaign was waged here by the government to clear out opium agriculture and trade and redirect agriculture. Air pollution is another problem that can be solved.

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This year is extraordinary!

A normally healthy individual, I have been expectorating myself. I have for the first time among my small group 5 that I know of with real symptoms.

One usually fit friend had to stop on a bike ride yesterday for the first time ever for minutes to cough.

One friend has had headaches and clogged chest (I have also noticed mild headaches for the first time).

A 32yo Thai friend tonight had a husky voice and sore throat when I visited her shop. A 20yo customer walked in and had the same strange voice complaint and clogged chest.

Worst a normally robust 76yo friend just got out from several days in hospital. He had developed a lung infection and had been fairly seriously sick and was still weak. It is not impossible he could have turned worse and died from that sort of thing.

The apathy and lack of political will is just typical and ubiquitous.

However, one thing Thai politicians don't like is public embarassment, to be shown up.

How about a MARCH against pollution?

How about everyone wearing masks and carrying stretchers for the potential dead?

How about marching from Maharat Hospital to Thaipei Gate?

How about faking the collapse of a marcher?

How about LIGHTING SYMBOLIC FIRES in front of the press?

How about a (leaked) letter to the ARMY to ask them to control the situation the police will not?

(along with a comparison of deaths from pulmonary reasons compared to deaths from bombings)

But most of all, how about a good old fashioned MARCH?

I personally have a friend who is a boss at Thai public TV who would cover it like a shot. Publicity would be no problem.

ps: On a longer time frame it seems to me a good pyramid to pass information through is the school system.

If kids could be given publicity some of it might get where it's meant to and one can expect that in a few years the kids might become burners they themselves would be more aware.

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My wife blames the side of the road fires on people who want to harvest a type of mushroom and a green leafy plant which grow after the rains come. She says they are expensive and Thai people like to eat them.

We had to replace wooden fencing burnt down during last years dry season. Let try to them burn down the new cement ones. :)

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This year is extraordinary!

A normally healthy individual, I have been expectorating myself. I have for the first time among my small group 5 that I know of with real symptoms.

One usually fit friend had to stop on a bike ride yesterday for the first time ever for minutes to cough.

One friend has had headaches and clogged chest (I have also noticed mild headaches for the first time).

A 32yo Thai friend tonight had a husky voice and sore throat when I visited her shop. A 20yo customer walked in and had the same strange voice complaint and clogged chest.

Worst a normally robust 76yo friend just got out from several days in hospital. He had developed a lung infection and had been fairly seriously sick and was still weak. It is not impossible he could have turned worse and died from that sort of thing.

The apathy and lack of political will is just typical and ubiquitous.

However, one thing Thai politicians don't like is public embarassment, to be shown up.

How about a MARCH against pollution?

How about everyone wearing masks and carrying stretchers for the potential dead?

How about marching from Maharat Hospital to Thaipei Gate?

How about faking the collapse of a marcher?

How about LIGHTING SYMBOLIC FIRES in front of the press?

How about a (leaked) letter to the ARMY to ask them to control the situation the police will not?

(along with a comparison of deaths from pulmonary reasons compared to deaths from bombings)

But most of all, how about a good old fashioned MARCH?

I personally have a friend who is a boss at Thai public TV who would cover it like a shot. Publicity would be no problem.

ps: On a longer time frame it seems to me a good pyramid to pass information through is the school system.

If kids could be given publicity some of it might get where it's meant to and one can expect that in a few years the kids might become burners they themselves would be more aware.

A march in March, too much pollution, need to stay indoors to remain healthy.

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Jeez this year seems really bad.. OMG... does anyone know what happened to the measuring stations in CM? Have they gotten clogged? Last week there were some strange spikes where pollution went to zero, now there's days and days missing...

post-20814-0-32737300-1330653537_thumb.p

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Slightly bored of dust levels , I pulled another high stat. off the chart

http://aqmthai.com/

Numbers for NO2 - these are x10-20 those of other areas being 42-70 ppb in Chiang Mai

However these are in ppb

Found a conversion rate of times 1.91 to put into micrograms per cubic metre which pollutant levels seem to normally be measured in. (there is a longer equation haven't tried that)

http://forum.onlineconversion.com/showthread.php?t=9436

According to this , this would put NO2 levels in Chiang Mai at around 80-130 µg/m3

"There is some evidence that long-term exposure to NO2 at concentrations above 40–100 µg/m3 may decrease lung function and increase the risk of respiratory symptoms.

Nitrogen dioxide is a large scale pollutant, with rural background ground level concentrations in some areas around 30 µg/m3, not far below unhealthy levels."

According to this an NO2 level of over 100 is off the stratosphere and pretty poisonous. Any thoughts on this.

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This year is extraordinary!

[...]

Well not really, I'm afraid. Since the 'Chiang Mai' measuring station suffered a breakdown for four days (25-28 February) I looked at the Uparaj station numbers instead. Of the previous eight years (2004-2011) four had significantly higher February pollution levels than this year (2004, 2005, 2007 and 2009). Two had levels pretty much equal to this year (2006 and 2010). Only 2008 and 2011 were significantly better.

I think what we are facing is the human tendency to remember more recent events (in this case 2011) a lot more strongly and think that these events are the norm. The latter half of February and most of March are usually bad and (so far) this year has followed that pattern.

I'm crossing my fingers that the pattern will be broken this March rolleyes.gif

/ Priceless

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Slightly bored of dust levels , I pulled another high stat. off the chart

http://aqmthai.com/

Numbers for NO2 - these are x10-20 those of other areas being 42-70 ppb in Chiang Mai

However these are in ppb

Found a conversion rate of times 1.91 to put into micrograms per cubic metre which pollutant levels seem to normally be measured in. (there is a longer equation haven't tried that)

http://forum.onlinec...read.php?t=9436

According to this , this would put NO2 levels in Chiang Mai at around 80-130 µg/m3

"There is some evidence that long-term exposure to NO2 at concentrations above 40–100 µg/m3 may decrease lung function and increase the risk of respiratory symptoms.

Nitrogen dioxide is a large scale pollutant, with rural background ground level concentrations in some areas around 30 µg/m3, not far below unhealthy levels."

According to this an NO2 level of over 100 is off the stratosphere and pretty poisonous. Any thoughts on this.

It is worth noting the expression 'long-term exposure'. The World Health Organization has the following to say about short-term exposure:

'The current scientific literature has not accumulated evidence to change from the WHO guideline value of 200 μg/m3 for

1-hour nitrogen dioxide concentration'. (Air Quality Guidelines, Global Update 2005, p376)

/ Priceless

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Jeez this year seems really bad.. OMG... does anyone know what happened to the measuring stations in CM? Have they gotten clogged? Last week there were some strange spikes where pollution went to zero, now there's days and days missing...

post-20814-0-32737300-1330653537_thumb.p

According to the Pollution Control Department the 'Chiang Mai' measuring station suffered equipment failure from 25-29 February. I would recommend you to look at the 'Uparaj' station instead.

/ Priceless

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Slightly bored of dust levels , I pulled another high stat. off the chart

http://aqmthai.com/

Numbers for NO2 - these are x10-20 those of other areas being 42-70 ppb in Chiang Mai

However these are in ppb

Found a conversion rate of times 1.91 to put into micrograms per cubic metre which pollutant levels seem to normally be measured in. (there is a longer equation haven't tried that)

http://forum.onlinec...read.php?t=9436

According to this , this would put NO2 levels in Chiang Mai at around 80-130 µg/m3

"There is some evidence that long-term exposure to NO2 at concentrations above 40–100 µg/m3 may decrease lung function and increase the risk of respiratory symptoms.

Nitrogen dioxide is a large scale pollutant, with rural background ground level concentrations in some areas around 30 µg/m3, not far below unhealthy levels."

According to this an NO2 level of over 100 is off the stratosphere and pretty poisonous. Any thoughts on this.

It is worth noting the expression 'long-term exposure'. The World Health Organization has the following to say about short-term exposure:

'The current scientific literature has not accumulated evidence to change from the WHO guideline value of 200 μg/m3 for

1-hour nitrogen dioxide concentration'. (Air Quality Guidelines, Global Update 2005, p376)

/ Priceless

Those are the 1 hour average figures and if you look at those statistics on for example the Australian permitted levels. It says the 1 hour average should be only permittable for 1 day per year.

We are clearly exceeding that at present

Averaging time Maximum concentration (µg/m3) Goals within 10 years Maximum allowable exceedences 1 hour 246 (0.12 ppm) 1 day a year 1 year (State of Victoria)

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ตารางที่ ๑ แสดงค่าเฉลี่ย ๒๔ ชั่วโมงของ PM10และ AQI ในภาคเหนือ ณ เวลา ๐๙.๐๐ น. วันที่ ๒ มีนาคม ๒๕๕๕

สถานี PM10* AQI** คุณภาพอากาศ

เชียงราย

สนง.ทรัพยากรธรรมชาติและสิ่งแวดล้อม.เมือง๒๕๐.๖ ๑๕๗ มีผลกระทบต่อสุขภาพ

สาธารณสุขแม่สาย.แม่สาย.เชียงราย๓๒๓.๔ ๑๘๘ มีผลกระทบต่อสุขภาพ

เชียงใหม่

ศาลากลาง.เมือง.เชียงใหม่๑๗๑.๖ ๑๒๒ มีผลกระทบต่อสุขภาพ

โรงเรียนยุพราชวิทยาลัย.เมือง.เชียงใหม่๑๔๙.๐ ๑๑๓ มีผลกระทบต่อสุขภาพ

พระตำหนักภูพิงคราชนิเวศน์.เชียงใหม่ (Mobile)*** ๓๒. ๔๑ดี

ลำพูนสนามกีฬาอบจ. .เมือง.ลำพูน๑๕๐.๒ ๑๑๓ มีผลกระทบต่อสุขภาพ

Trying to copy this off aqmthai website, doesn't really copy the table but you can get the gist .

Basically all bad but huge difference and improvement up at Phuping if these are correct.

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According to this an NO2 level of over 100 is off the stratosphere and pretty poisonous. Any thoughts on this.

Too bad it's NO2 and not N2O.

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Slightly bored of dust levels , I pulled another high stat. off the chart

http://aqmthai.com/

Numbers for NO2 - these are x10-20 those of other areas being 42-70 ppb in Chiang Mai

However these are in ppb

Found a conversion rate of times 1.91 to put into micrograms per cubic metre which pollutant levels seem to normally be measured in. (there is a longer equation haven't tried that)

http://forum.onlinec...read.php?t=9436

According to this , this would put NO2 levels in Chiang Mai at around 80-130 µg/m3

"There is some evidence that long-term exposure to NO2 at concentrations above 40–100 µg/m3 may decrease lung function and increase the risk of respiratory symptoms.

Nitrogen dioxide is a large scale pollutant, with rural background ground level concentrations in some areas around 30 µg/m3, not far below unhealthy levels."

According to this an NO2 level of over 100 is off the stratosphere and pretty poisonous. Any thoughts on this.

It is worth noting the expression 'long-term exposure'. The World Health Organization has the following to say about short-term exposure:

'The current scientific literature has not accumulated evidence to change from the WHO guideline value of 200 μg/m3 for

1-hour nitrogen dioxide concentration'. (Air Quality Guidelines, Global Update 2005, p376)

/ Priceless

Those are the 1 hour average figures and if you look at those statistics on for example the Australian permitted levels. It says the 1 hour average should be only permittable for 1 day per year.

We are clearly exceeding that at present

Averaging time Maximum concentration (µg/m3) Goals within 10 years Maximum allowable exceedences 1 hour 246 (0.12 ppm) 1 day a year 1 year (State of Victoria)

Yes, I don't intend to argue with you. I have concentrated my interest on PM10 and know very little about other pollutants. Just thought I'd add something that I'd come across 'by accident'.

/ Priceless

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This year is extraordinary!

[...]

Well not really, I'm afraid. Since the 'Chiang Mai' measuring station suffered a breakdown for four days (25-28 February) I looked at the Uparaj station numbers instead. Of the previous eight years (2004-2011) four had significantly higher February pollution levels than this year (2004, 2005, 2007 and 2009). Two had levels pretty much equal to this year (2006 and 2010). Only 2008 and 2011 were significantly better.

I think what we are facing is the human tendency to remember more recent events (in this case 2011) a lot more strongly and think that these events are the norm. The latter half of February and most of March are usually bad and (so far) this year has followed that pattern.

I'm crossing my fingers that the pattern will be broken this March rolleyes.gif

/ Priceless

Hi Priceless

As a student of the mind I'm with you on the human tendencies to forget the past and emphasise the present....however in this year's case it's the number of affected people I personally meet regularly which to me is extraordinary.

I know anecdote is not the gold standard, but two more people are now added to the 5 on my sick list.

My 30yo girlfriend has a bad allergic reaction, and Howard Graves is off colour and has just called off all operas for the month.

As for CM residents actually doing something instead of navel gazing....what do you think of a MARCH?

I remember there's a highly respected older Thai activist who has a big network of schoolkids who could perhaps do something.

I know there used to be an activist group about this.....know anything about it?

Cheeryble

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ตารางที่ ๑ แสดงค่าเฉลี่ย ๒๔ ชั่วโมงของ PM10และ AQI ในภาคเหนือ ณ เวลา ๐๙.๐๐ น. วันที่ ๒ มีนาคม ๒๕๕๕

สถานี PM10* AQI** คุณภาพอากาศ

เชียงราย

สนง.ทรัพยากรธรรมชาติและสิ่งแวดล้อม.เมือง๒๕๐.๖ ๑๕๗ มีผลกระทบต่อสุขภาพ

สาธารณสุขแม่สาย.แม่สาย.เชียงราย๓๒๓.๔ ๑๘๘ มีผลกระทบต่อสุขภาพ

เชียงใหม่

ศาลากลาง.เมือง.เชียงใหม่๑๗๑.๖ ๑๒๒ มีผลกระทบต่อสุขภาพ

โรงเรียนยุพราชวิทยาลัย.เมือง.เชียงใหม่๑๔๙.๐ ๑๑๓ มีผลกระทบต่อสุขภาพ

พระตำหนักภูพิงคราชนิเวศน์.เชียงใหม่ (Mobile)*** ๓๒. ๔๑ดี

ลำพูนสนามกีฬาอบจ. .เมือง.ลำพูน๑๕๐.๒ ๑๑๓ มีผลกระทบต่อสุขภาพ

Trying to copy this off aqmthai website, doesn't really copy the table but you can get the gist .

Basically all bad but huge difference and improvement up at Phuping if these are correct.

I think that you rather safely assume that the Phuping figures are correct. Doi Pui is at an altitude more than 5,000 feet above mean sea level, and particulate matter pollution rarely reaches that high in any significant concentrations.

/ Priceless

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This year is extraordinary!

[...]

Well not really, I'm afraid. Since the 'Chiang Mai' measuring station suffered a breakdown for four days (25-28 February) I looked at the Uparaj station numbers instead. Of the previous eight years (2004-2011) four had significantly higher February pollution levels than this year (2004, 2005, 2007 and 2009). Two had levels pretty much equal to this year (2006 and 2010). Only 2008 and 2011 were significantly better.

I think what we are facing is the human tendency to remember more recent events (in this case 2011) a lot more strongly and think that these events are the norm. The latter half of February and most of March are usually bad and (so far) this year has followed that pattern.

I'm crossing my fingers that the pattern will be broken this March rolleyes.gif

/ Priceless

Hi Priceless

As a student of the mind I'm with you on the human tendencies to forget the past and emphasise the present....however in this year's case it's the number of affected people I personally meet regularly which to me is extraordinary.

I know anecdote is not the gold standard, but two more people are now added to the 5 on my sick list.

My 30yo girlfriend has a bad allergic reaction, and Howard Graves is off colour and has just called off all operas for the month.

As for CM residents actually doing something instead of navel gazing....what do you think of a MARCH?

I remember there's a highly respected older Thai activist who has a big network of schoolkids who could perhaps do something.

I know there used to be an activist group about this.....know anything about it?

Cheeryble

I must admit that I somewhat fear the coming March. Luckily, there's not a very strong correlation between the PM10 values for February and for March (0..63 for the 'Chiang Mai measuring station) so I'm still keeping my fingers crossed rolleyes.gif

/ Priceless

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ME and Mrs Smith did a circular hike from Ban Doi Pui up to the peak of Doi Pui at 1685m. Air very clean up at the top. From the view point above Ban Doi Pui, however, I could see that we were still in the smog, as we gazed at light brown haze hiding the view of anything but the nearest ridges, though much better than down at the valley floor. No coughing up there, & no sore eyes. Those returned back on the valley floor. The forest is very green up there. Worth the trip, & will go again soon :)

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BANGKOK 24 May 2017 14:56
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