Friday, July 31, 2009
introducing www.livefrombeijing.com
Greetings,
After a year of blogging here on blogspot, I've decided it's time for a slight upgrade. Most importantly, I need to shift to a domain which will enable my blog to be viewable within mainland China. (Blogspot, along with a host of other sites, has been blocked since mid-May.) I also have some web ideas up my sleeve that I can't realize on blogspot alone.
Therefore, I'm very happy to introduce my new website and blog: www.livefrombeijing.com.
This is my last post at this blog address. All of my old posts have been migrated to the new site. Starting now, please visit / bookmark / link to www.livefrombeijing.com instead of this blog.
Also, for those of you who have subscribed to my feed, please note my new feed:
http://feeds.feedburner.com/livefrombeijing/feed
For now, the new site will be functionally similar to this one. In the coming weeks and months, I hope and expect to be adding some pages and features. For now, though, at least I should be up and posting again.
Comments and questions welcome; as always, you can reach me at livefrombeijing at gmail dot com. Thanks for reading, and see you over at the new site.
Vance
Tuesday, July 7, 2009
livefrombeijing is under construction
Greetings,
I am doing some site maintenance (and have been really busy), so my posting will likely be light for the next little while.
For the record, this is not "maintenance" as related specifically to the massive information control currently occurring in China as a result of the protests / riots in Xinjiang. The maintenance I am doing is, however, related to the fact that blogspot (including this blog), has been blocked in China since mid-May. Especially given the events of the last two days, it seems unlikely that China will unblock blogspot for some time; therefore, I am in the process of setting up a new blog and migrating my posts.
With Twitter blocked again as of Sunday night, I was a little disappointed to see the BeijingAir feed tweet about "routine maintenance":
A more appropriate tweet would be "Site is currently under routine harmonization. Please refer to the last available reading."
Lastly, here is some recent news reading / placeholders for future commentary:
7/2 China Daily: Beijing air cleanest in 9 years
7/3 Time blog: Cleaner Skies in Beijing
7/4 Xinhua: Chinese Minister refutes doubts over air quality results during Olympics
7/6 CELB: Beijing Makes Straw Man of Paper Tiger
I am doing some site maintenance (and have been really busy), so my posting will likely be light for the next little while.
For the record, this is not "maintenance" as related specifically to the massive information control currently occurring in China as a result of the protests / riots in Xinjiang. The maintenance I am doing is, however, related to the fact that blogspot (including this blog), has been blocked in China since mid-May. Especially given the events of the last two days, it seems unlikely that China will unblock blogspot for some time; therefore, I am in the process of setting up a new blog and migrating my posts.
With Twitter blocked again as of Sunday night, I was a little disappointed to see the BeijingAir feed tweet about "routine maintenance":
A more appropriate tweet would be "Site is currently under routine harmonization. Please refer to the last available reading."
Lastly, here is some recent news reading / placeholders for future commentary:
7/2 China Daily: Beijing air cleanest in 9 years
7/3 Time blog: Cleaner Skies in Beijing
7/4 Xinhua: Chinese Minister refutes doubts over air quality results during Olympics
7/6 CELB: Beijing Makes Straw Man of Paper Tiger
Wednesday, July 1, 2009
xinhua's international herald leader on the us embassy air quality monitor
This post contains some translation and commentary on the recent story in Xinhua's International Herald Leader (国际先驱导报) on the US Embassy's independent air quality monitor. The story was reprinted in the Hong Kong-based Phoenix magazine (凤凰) here.
First, title: I think it's noteworthy that, although the stories in the two Chinese-language sources are the same, the title in the IHL is 美国驻华使馆自建空气监测站 ("US Embassy Independently Sets Up Air Quality Monitoring Station"), whereas that in the Hong Kong-based Phoenix is more provocative: 美驻华使馆发布自测北京空气指数 与气象局数据分歧 ("US Embassy in China Issues Independently-Tested Beijing Air Quality Index - Different from the Meteorological Bureau's Data").
And now content: The IHT begins with similar content as the China Daily story: information about the Embassy's twitter feed and concerns about discrepancies with the officially-reported data, followed by assurance from an Embassy official that the numbers are not directly comparable. As in the China Daily, the IHT story then describes the health impact differences between PM2.5 and PM10.
Following this, though, the IHT diverges from the China Daily story. A section titled 建监测站应循通行规则 (Regulations Should Be Followed When Setting Up Monitoring Stations) questions whether the US Embassy's data is even valid:
(Side note for future investigation: I think perhaps the US Embassy monitor is at the old embassy near Ritan park, not on site at the new location.)
Moving on, the article briefly mentions Steven Andrews' criticisms of Beijing's air quality management, that Beijing's air quality monitors have been selectively placed in areas of low pollution to yield better overall averages and that officials artificially inflated the statistics on number of blue sky days. Although it is noteworthy that the article mentions Mr. Andrews at all (I haven't seen his analysis directly covered in the Chinese media before), the article immediately quotes experts supposedly refuting his claims:
Finally, the article quotes an anonymous Beijing EPB official saying that the Embassy is breaking no laws by independently monitoring air quality, before closing with this quote:
Although I was initially encouraged by yesterday's direct and somewhat challenging China Daily piece, this Chinese-language Xinhua piece is more of what I would expect from China's state media: convoluted logic and fact-twisting that attempts to shape reality to fit the government's agenda as opposed to strong investigative reporting attempting to uncover the truth.
First, title: I think it's noteworthy that, although the stories in the two Chinese-language sources are the same, the title in the IHL is 美国驻华使馆自建空气监测站 ("US Embassy Independently Sets Up Air Quality Monitoring Station"), whereas that in the Hong Kong-based Phoenix is more provocative: 美驻华使馆发布自测北京空气指数 与气象局数据分歧 ("US Embassy in China Issues Independently-Tested Beijing Air Quality Index - Different from the Meteorological Bureau's Data").
And now content: The IHT begins with similar content as the China Daily story: information about the Embassy's twitter feed and concerns about discrepancies with the officially-reported data, followed by assurance from an Embassy official that the numbers are not directly comparable. As in the China Daily, the IHT story then describes the health impact differences between PM2.5 and PM10.
Following this, though, the IHT diverges from the China Daily story. A section titled 建监测站应循通行规则 (Regulations Should Be Followed When Setting Up Monitoring Stations) questions whether the US Embassy's data is even valid:
中国气象科学院院长张人禾向《国际先驱导报》介绍道,设立空气监测的站点需要在整个区域具备代表性,且50米内不能有污染源,否则将严重影响监测结果。...Although the article does not question the accuracy of the Embassy's data, it clearly indicates that the Embassy's data is disproportionately bad because of poor and non-standard monitor placement. This possibility was not raised in the China Daily piece.
因此事实上,美国驻华使馆自建的空气监测站并不符合通行的国际规范。
According to Zhang Renhe, Director of the Chinese Academy of Meteorological Sciences, an air quality monitor must be installed in a location representative of of the entire city; moreover, there should be no pollution sources within 50m that could strongly impact the monitoring results...
In fact, the US embassy's independent air quality monitoring station is not in accordance with international criteria.
于去年8月建成的美国新使馆区坐落在北京CBD商业圈、背靠亮马河的黄金地段,它毗邻女人街等商业场所,平日里交通繁忙、人群熙攘,这些因素都很可能对监测站的数据收录产生影响。
记者28日在美国使馆的所在地更是发现,其对面原有的星吧路酒吧餐饮街已被大规模拆除,工地上一片狼藉,灰尘扑面。而它南面的其他使馆区仍在建设中...
Completed last August, the US Embassy is located in the CBD business area, near the prime locations around Liangmahe. It is near the Ladies' Market and other commercial areas with high weekday traffic and bustling crowds; these factors all possibly influence the data recorded by the monitor.
On the 28th, this reporter visited the location of the US Embassy and discovered the large scale demolition of Super Bar Street across the street; much dust blew out from the messy construction site. Additionally, on the south side was another embassy area under construction...
(Side note for future investigation: I think perhaps the US Embassy monitor is at the old embassy near Ritan park, not on site at the new location.)
Moving on, the article briefly mentions Steven Andrews' criticisms of Beijing's air quality management, that Beijing's air quality monitors have been selectively placed in areas of low pollution to yield better overall averages and that officials artificially inflated the statistics on number of blue sky days. Although it is noteworthy that the article mentions Mr. Andrews at all (I haven't seen his analysis directly covered in the Chinese media before), the article immediately quotes experts supposedly refuting his claims:
“蓝天数量有目共睹,如何造假?”周凌唏评价到。在她眼中,为了北京奥运会顺利召开,在北京民众的努力下,的确明显提高了首都空气质量,“蓝天多,说明大气透明情况好,在一定程度上说明内含的污染物就少。”I can't quite understand what either of these experts meant, which may or may not be due to the language barrier. Despite that, though, it doesn't seem as if either expert addressed Mr. Andrews' concerns directly, so it doesn't make sense to me that the article would raise them at all.
而张人禾对“监测站多分布在低污染区”的质疑感到“不解”,“别忘了,空气也是流动的。”他说。
"Everyone can see the number of blue sky days, so how can they be faked?" [an analyst with the Chinese Academy of Meteorology] commented. In her eyes, to ensure a smooth Olympics in Beijing, through the effort of all of Beijing's citizens, there was indeed an obvious improvement to Beijing's air quality. "More blue sky days means a more transparent atmosphere, which means to some extent less pollutants."
In addition, Zhang Renhe felt he "couldn't understand" the suspicion that "some of the monitoring stations are located in low pollution areas." "Don't forget, air is also flowing," he said.
Finally, the article quotes an anonymous Beijing EPB official saying that the Embassy is breaking no laws by independently monitoring air quality, before closing with this quote:
“不过,与此相关的我国《环境监测条例》已被纳入国务院今年的立法计划中,有望今年内通过。”他说。In other words, although there is nothing wrong with Beijing's current monitoring system, the Beijing EPB still hopes that it will be improved this year with new, unspecified State Council legislation.
"However, the relevant "Environmental Monitoring Regulations" have already been placed into the State Council's legislation plan for this year; there is hope they will be passed this year," [the Beijing EPB official] said.
Although I was initially encouraged by yesterday's direct and somewhat challenging China Daily piece, this Chinese-language Xinhua piece is more of what I would expect from China's state media: convoluted logic and fact-twisting that attempts to shape reality to fit the government's agenda as opposed to strong investigative reporting attempting to uncover the truth.
Labels:
air pollution,
api,
beijing
china daily features online survey on beijing's air quality monitoring
When I wrote yesterday about the China Daily article on the discrepancies between China's officially reported air quality data and the US Embassy's BeijingAir Twitter feed, I didn't realize that the China Daily story appeared on the site's home page along with an incredibly direct web survey:
Web surveys are, of course, not scientific or reliable at all, but nonetheless here's a screen capture of the results as of around 11am this morning:
It's difficult to imagine such a critical survey happening on a Chinese-language state media site, but I will keep an eye out for anything comparable.
Lastly, for the record, there are several mistakes in the China Daily story that I should point out. Three are in this sentence alone: "A blue-sky day is when the city's air pollution index, the level of five airborne pollutants, falls below 100, indicating that no health implications exist."
First, MEP makes no claim that blue-sky days have "no health implications," only that those days have the poorly-defined "excellent" or "good" air quality. Air quality on blue-sky days can certainly have negative health implications, especially for sensitive populations in the short term and for everyone in the long term. What MEP calls "good," the US EPA calls "moderate," saying, "Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution."
Second, the air pollution index only covers three pollutants, not five. I'm not sure how China Daily made this mistake, because later in the article they describe the number correctly ("the current evaluation system uses only three indices: Sulfur dioxide, carbon dioxide and PM 10s"), although they get the pollutants wrong. (The three are sulfur dioxide, nitrogen dioxide, and PM10.)
Third, this is minor, but a blue-sky day is a day in which the API is technically 100 or below, not below 100.
Web surveys are, of course, not scientific or reliable at all, but nonetheless here's a screen capture of the results as of around 11am this morning:
It's difficult to imagine such a critical survey happening on a Chinese-language state media site, but I will keep an eye out for anything comparable.
Lastly, for the record, there are several mistakes in the China Daily story that I should point out. Three are in this sentence alone: "A blue-sky day is when the city's air pollution index, the level of five airborne pollutants, falls below 100, indicating that no health implications exist."
First, MEP makes no claim that blue-sky days have "no health implications," only that those days have the poorly-defined "excellent" or "good" air quality. Air quality on blue-sky days can certainly have negative health implications, especially for sensitive populations in the short term and for everyone in the long term. What MEP calls "good," the US EPA calls "moderate," saying, "Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution."
Second, the air pollution index only covers three pollutants, not five. I'm not sure how China Daily made this mistake, because later in the article they describe the number correctly ("the current evaluation system uses only three indices: Sulfur dioxide, carbon dioxide and PM 10s"), although they get the pollutants wrong. (The three are sulfur dioxide, nitrogen dioxide, and PM10.)
Third, this is minor, but a blue-sky day is a day in which the API is technically 100 or below, not below 100.
Labels:
air pollution,
api,
beijing,
blue sky days
Tuesday, June 30, 2009
china daily questions official air quality statistics
The story about the US Embassy's BeijingAir air quality twitter feed (whose subscribers now top 2,200) was picked up by the China Daily today. Perhaps surprisingly, the China Daily article uses the embassy data to question whether the Beijing EPB's official data present an accurate view of Beijing's air quality:
The article closes with this comment, noteworthy for its open questioning of air quality data. Such questioning is rare in the Chinese state-run media:
As one would expect, the tone of the Xinhua piece is much more defensive of the official data and critical of the embassy. Unfortunately, I don't have time now to write more on this; stay tuned tomorrow for some translation and commentary.
China Daily calculated that only five days were above "moderate" level in May on BeijingAir, but the local environment bureau said on its website on May 31 that the capital's air quality was the clearest during the same period since 2000, with 25 blue-sky days.However, the article goes on to quote both an embassy official and a Chinese expert cautioning that the single station is not representative of Beijing's overall air quality:
"This is a single site," [US Embassy spokesperson Susan] Stevenson said. "It cannot be used to measure the air quality across the city. They can't be compared."Signficantly, the China Daily article does not question whether or not the embassy data is valid for that area, only whether the single data point can be extrapolated out to the rest of the city. To me, this is an important distinction, because collective agreement that the embassy data is valid should ultimately help pressure the Beijing EPB to set up their own real-time PM2.5 monitors across the city (which is the direction we should be driving in).
...
"The embassy is located in the central business district, which has heavy traffic, and its monitoring station cannot represent the overall picture," Zhu Tong, an environment professor with Peking University, said yesterday.
The article closes with this comment, noteworthy for its open questioning of air quality data. Such questioning is rare in the Chinese state-run media:
Some residents expressed doubts about the official air quality data.Within Chinese-language media, Xinhua's International Herald Leader (国际先驱导报) published a story two days ago (also printed with a different title in the Hong Kong-based Phoenix magazine (凤凰) here) on the US Embassy's air quality reporting; the story included this photo that is apparently of the monitor:
Wang Haiyan, a 36-year-old Beijinger living in Chaoyang district, said that even under a different measuring system, there is still no reason to get such different air quality results.
As one would expect, the tone of the Xinhua piece is much more defensive of the official data and critical of the embassy. Unfortunately, I don't have time now to write more on this; stay tuned tomorrow for some translation and commentary.
Labels:
air pollution,
api,
beijing
Monday, June 29, 2009
krugman's indictment of climate change deniers
Paul Krugman's column today is highly recommended. It is a scathing indictment of climate change deniers in the US Congress:
In an aside (and as an economist), he further bolsters his case with this zinger:
In the US-China climate debate, although there is still a lot to be settled, at the very least it seems that the top leadership of both nations agree on the core science of what is causing climate change and where we need to be - in terms of global emission reductions - by what date.
On this point, earlier this month, I was encouraged by what Todd Stern, the US' top climate negotiator, had to say when speaking at the Center for American Progress:
But if you watched the debate on Friday, you didn't see people who've thought hard about a crucial issue, and are trying to do the right thing. What you saw, instead, were people who show no sign of being interested in the truth. They don't like the political and policy implications of climate change, so they've decided not to believe in it — and they'll grab any argument, no matter how disreputable, that feeds their denial.Because the overwhelming - and still increasing - scientific evidence demonstrates that climate change presents a "clear and present danger to our way of life, perhaps even to civilization itself," he calls the denial of climate change "irresponsible and immoral."
In an aside (and as an economist), he further bolsters his case with this zinger:
Given this contempt for hard science, I’m almost reluctant to mention the deniers’ dishonesty on matters economic. But in addition to rejecting climate science, the opponents of the climate bill made a point of misrepresenting the results of studies of the bill’s economic impact, which all suggest that the cost will be relatively low.(Further info on the economic misrepresentation he mentions here and here.)
In the US-China climate debate, although there is still a lot to be settled, at the very least it seems that the top leadership of both nations agree on the core science of what is causing climate change and where we need to be - in terms of global emission reductions - by what date.
On this point, earlier this month, I was encouraged by what Todd Stern, the US' top climate negotiator, had to say when speaking at the Center for American Progress:
Q: I wonder if you might comment, in talking to Chinese officials, do you feel you're speaking on the basis of the same science?(Transcript here). Unfortunately, the same can't be said for the US' own legislature.
MR. STERN: ...I have not had a sense that [the Chinese] are in some completely different place with respect to what the underlying science is...in terms of the overall kind of dynamics – where we're going, where need to go – I don't think it's a dramatically different assessment.
Friday, June 26, 2009
beijing epb responds to us embassy air quality twitter feed
A friend tipped me to an article in today's South China Morning Post (registration required) on the US Embassy's Beijing air quality twitter feed.
Although the majority of the content of the SCMP piece echoes that published last week in other sources, there is one important bit of new information:
FYI, the twitter feed has around 1600 followers now (up from 300 just a week ago).
Although the majority of the content of the SCMP piece echoes that published last week in other sources, there is one important bit of new information:
Du Shaozhong, deputy director of Beijing's environment protection bureau, was unaware of the US embassy's move, but said: "Any attempts to question our figures with a single monitoring station are not authoritative enough."This could get bad. Let's see if it gets picked up by other media and begins to escalate.
FYI, the twitter feed has around 1600 followers now (up from 300 just a week ago).
Labels:
air pollution,
api,
beijing
Monday, June 22, 2009
us embassy outed as source of beijingair twitter feed
On Friday of last week, Time's Austin Ramzy outed the BeijingAir twitter feed as being set up and administered by the US Embassy:
Beijing experienced some bizarre and extremely rapid changes in air quality on Thursday and Friday of last week. On both days, BeijingAir reported maximum pollution levels (hazardous air, AQI = 500) for brief periods in the afternoon. However, hazardous air was never reported by either the Beijing EPB or MEP, presumably because the pollution spikes on both days were short-lived enough that the overall 24-hour averages evened out as just "light pollution." (More discussion here and here.)
Here's a graph showing BeijingAir and MEP-reported air quality over the period noon Tuesday to midnight Sunday last week. Because MEP has no system for real-time reporting, the extreme pollution spikes on the 18th and 19th were never truly reflected in MEP's air quality data:
The events of last week highlight the need for real-time reporting of air quality in Beijing. I wonder if the growing popularity of the embassy's twitter feed will ratchet up pressure on MEP / Beijing EPB to implement such a system here in Beijing.
Final note: the speed of the drop in pollution levels during the afternoon of 6/19 was stunning. With no technical background in air quality modeling or meteorology, I have no idea how this is even possible:
The U.S. Embassy operates a single station in eastern Beijing that records levels of PM2.5, fine particles considered particularly dangerous to human health...Before the story came out, there were around 300 followers of the feed; now there are more than 1,100 and rising fast.
While the U.S. doesn't actively promote the information, it has slowly been getting more attention from Beijing residents concerned about the city's air quality. "The U.S. Embassy has an air quality monitor to measure PM 2.5 particulates on the Embassy compound as an indication of air quality," says Susan Stevenson, a State Department spokesperson. "This monitor is a resource for the health of the Embassy community." She cautions that citywide analyses cannot be done from a single machine, but because the embassy has the data available, it makes it available to others.
Beijing experienced some bizarre and extremely rapid changes in air quality on Thursday and Friday of last week. On both days, BeijingAir reported maximum pollution levels (hazardous air, AQI = 500) for brief periods in the afternoon. However, hazardous air was never reported by either the Beijing EPB or MEP, presumably because the pollution spikes on both days were short-lived enough that the overall 24-hour averages evened out as just "light pollution." (More discussion here and here.)
Here's a graph showing BeijingAir and MEP-reported air quality over the period noon Tuesday to midnight Sunday last week. Because MEP has no system for real-time reporting, the extreme pollution spikes on the 18th and 19th were never truly reflected in MEP's air quality data:
The events of last week highlight the need for real-time reporting of air quality in Beijing. I wonder if the growing popularity of the embassy's twitter feed will ratchet up pressure on MEP / Beijing EPB to implement such a system here in Beijing.
Final note: the speed of the drop in pollution levels during the afternoon of 6/19 was stunning. With no technical background in air quality modeling or meteorology, I have no idea how this is even possible:
Labels:
air pollution,
api,
beijing
Friday, June 19, 2009
more info on beijing's 6/18 air quality
Yesterday, beginning at around 10am, there was a sudden and dramatic spike of air pollution here in Beijing. I blogged about it here, and it was covered in the Guardian and Time's blog, with surely more to come. The pollution spike lasted until close to midnight yesterday. I presume yesterday evening's rain is what ended the event, although it should be noted that, as I write this, the pollution seems to be creeping up again.
Yesterday's pollution spike may be seen very clearly in the BeijingAir tweeted hourly data over the past couple of days. Shown here are PM2.5 concentration and AQI:
Note the missing data points in the afternoon of 6/18 and the maxing out of AQI at 500 during the same period.
Despite yesterday afternoon's stifling pollution, MEP's officially reported Air Pollution Index (API) for 6/18 was just 104 - indicating "slightly polluted" air quality. The reason, as noted yesterday, is that MEP's API does not report real-time air quality; it is an average air quality indicator covering noon to noon beginning from the previous day. Therefore, we wouldn't expect the afternoon pollution spike of 6/18 to show up until the 6/19 reported data point.
However, the API for 6/19, which was released a few minutes ago, is just 159 ("lightly polluted"), which is significantly lower than I would have expected.
--
Edit: An API of 159 - corresponding to a PM10 concentration of 266 ug/m^3 - still represents awful air quality, despite my use of the word "just." China's daily/yearly goals for PM10 are 150/100 ug/m^3, while the WHO's recommended targets are 50/20 ug/m^3.
--
The following graph shows MEP PM10 and API data, as well as BeijingAir PM2.5 and AQI data, for the last few days. Note that the absolute magnitudes of the BeijingAir and MEP data are not directly comparable due to slightly different measurements and scales. But the trending should be the same:
Although the MEP data increases beginning noon on 6/18, as one would expect, the increase just doesn't seem commensurate with the seemingly atrocious pollution yesterday afternoon and evening.
What's going on here? Well, there are a few options, but I'm not sure which one is correct:
First - it's theoretically possible that, because MEP averages over 24 hours over a number of different monitoring stations, the overnight reduction combined with lower pollution outside the city center brought the overall average down. Here is the daily individual monitor data from the Beijing EPB:
There are certainly some high readings, e.g. Dongsi, but there are also some that report only half as bad (Pinggu, Miyun).
Second - it is possible that the BeijingAir monitor is either not calibrated correctly or suffered some unusual activity (e.g. a car idling for an extended period outside the monitor). This seems unlikely.
Third - I'm not sure if this is correct or not, but it may be possible that the pollution event was largely PM2.5 - particles of diameter smaller than 2.5 microns - that do not register in the EPB's monitoring stations designed to measure PM10. Can anyone comment on this?
Fourth - I don't think I need to write this option explicitly.
More info as I learn it.
Yesterday's pollution spike may be seen very clearly in the BeijingAir tweeted hourly data over the past couple of days. Shown here are PM2.5 concentration and AQI:
Note the missing data points in the afternoon of 6/18 and the maxing out of AQI at 500 during the same period.
Despite yesterday afternoon's stifling pollution, MEP's officially reported Air Pollution Index (API) for 6/18 was just 104 - indicating "slightly polluted" air quality. The reason, as noted yesterday, is that MEP's API does not report real-time air quality; it is an average air quality indicator covering noon to noon beginning from the previous day. Therefore, we wouldn't expect the afternoon pollution spike of 6/18 to show up until the 6/19 reported data point.
However, the API for 6/19, which was released a few minutes ago, is just 159 ("lightly polluted"), which is significantly lower than I would have expected.
--
Edit: An API of 159 - corresponding to a PM10 concentration of 266 ug/m^3 - still represents awful air quality, despite my use of the word "just." China's daily/yearly goals for PM10 are 150/100 ug/m^3, while the WHO's recommended targets are 50/20 ug/m^3.
--
The following graph shows MEP PM10 and API data, as well as BeijingAir PM2.5 and AQI data, for the last few days. Note that the absolute magnitudes of the BeijingAir and MEP data are not directly comparable due to slightly different measurements and scales. But the trending should be the same:
Although the MEP data increases beginning noon on 6/18, as one would expect, the increase just doesn't seem commensurate with the seemingly atrocious pollution yesterday afternoon and evening.
What's going on here? Well, there are a few options, but I'm not sure which one is correct:
First - it's theoretically possible that, because MEP averages over 24 hours over a number of different monitoring stations, the overnight reduction combined with lower pollution outside the city center brought the overall average down. Here is the daily individual monitor data from the Beijing EPB:
There are certainly some high readings, e.g. Dongsi, but there are also some that report only half as bad (Pinggu, Miyun).
Second - it is possible that the BeijingAir monitor is either not calibrated correctly or suffered some unusual activity (e.g. a car idling for an extended period outside the monitor). This seems unlikely.
Third - I'm not sure if this is correct or not, but it may be possible that the pollution event was largely PM2.5 - particles of diameter smaller than 2.5 microns - that do not register in the EPB's monitoring stations designed to measure PM10. Can anyone comment on this?
Fourth - I don't think I need to write this option explicitly.
More info as I learn it.
Labels:
air pollution,
api,
beijing
Thursday, June 18, 2009
air in beijing hazardous
BeijingAir is currently reporting hazardous air quality in Beijing (there was an error in the most recent hour, but you can see the PM2.5 concentration slowly creeping up over the course of the morning and early afternoon):
Note, though, that with the AQI maxed out at 500, the air quality is theoretically worse than "hazardous," whatever that might be.
On the other hand, MEP is reporting an API today of 104, "slightly polluted."
A few people have asked me about this blatant discrepancy, so here's a brief comment:
It's important to remember that MEP's reported API for 6/18/09 is actually an average API for the period noon to noon 6/17 to 6/18. Given that this current pollution spike seems to have rolled in over the course of the late morning and early afternoon, it is reasonable that the impact has not yet registered in the MEP reported data. From the perspective of MEP's official reporting, we will have to wait until around 2pm tomorrow to see the results of this episode.
Of course, this discrepancy highlights the necessity of working towards a system of real-time air quality reporting (like the AIRNow program in the US) in Chinese cities. (More on this in another post.)
Final note: during my time in Beijing (3.5 years), I've only experienced a handful of days in which MEP reported a 500 API. The most recent ones were 12/28/2007 and 12/12/2006, plus a few during the sandstorm season of the spring of 2006. I am curious to know if tomorrow will yield another.
Note, though, that with the AQI maxed out at 500, the air quality is theoretically worse than "hazardous," whatever that might be.
On the other hand, MEP is reporting an API today of 104, "slightly polluted."
A few people have asked me about this blatant discrepancy, so here's a brief comment:
It's important to remember that MEP's reported API for 6/18/09 is actually an average API for the period noon to noon 6/17 to 6/18. Given that this current pollution spike seems to have rolled in over the course of the late morning and early afternoon, it is reasonable that the impact has not yet registered in the MEP reported data. From the perspective of MEP's official reporting, we will have to wait until around 2pm tomorrow to see the results of this episode.
Of course, this discrepancy highlights the necessity of working towards a system of real-time air quality reporting (like the AIRNow program in the US) in Chinese cities. (More on this in another post.)
Final note: during my time in Beijing (3.5 years), I've only experienced a handful of days in which MEP reported a 500 API. The most recent ones were 12/28/2007 and 12/12/2006, plus a few during the sandstorm season of the spring of 2006. I am curious to know if tomorrow will yield another.
Labels:
air pollution,
api,
beijing
Subscribe to:
Posts (Atom)