Archive for January, 2012

nyt publishes long article on beijing’s air pollution, but makes mistake in second paragraph

Sunday, January 29th, 2012

Update 1/31/12: The story online has been corrected with a correction issued. Kudos to the NYT for ensuring even a minor mistake like this gets fixed.

Two days ago, the New York Times published a good article summarizing much of the current debate and recent progress regarding air pollution monitoring and reporting in Beijing.

Unfortunately, there is an error in the fourth sentence of the article:

Officials have claimed for years that the air quality in fast-growing China is constantly improving. Beijing, for example, was said to have experienced a record 274 “blue sky” days in 2011, a statistic belied by the heavy smog smothering the city for much of the year.

There are actually two errors here. First, Beijing reported 286 Blue Sky Days in 2011. 274 was simply their target for the year, which they achieved early and then exceeded. This is even stated clearly in the Xinhua article linked to directly from the NYT story. Second, even if Beijing had achieved 274 Blue Sky Days, this would not have been a record; the number of Blue Sky Days was above 274 in both 2009 and 2010.

The mistake doesn’t really impact the overall context or conclusions of the story, so from that perspective I suppose it can be considered minor. However, in my experience the Chinese are very quick to highlight small mistakes in Western media reports, and on this basis discredit entire articles (or even entire news sources). I worry that small mistakes like this undermine the impact of otherwise good reporting by Western journalists here.

I’m also just surprised something so basic got past the NYT’s fact checkers.

beijing claims pm2.5 reductions

Monday, January 16th, 2012

Among all the recent PM2.5 news, this chart from an early January CCTV report caught my eye:

pm25 intensity

I couldn’t find this data on the Beijing EPB website to verify, so if anyone out there does find an original source please let me know. It is a little strange that numbers for 2000 and 2005 are reported, since the Beijing EPB claims to have only monitored PM2.5 since 2006, but let’s ignore that for a moment and assume that CCTV has reported this accurately. This would be the first time that I’ve seen official PM2.5 numbers reported by the Beijing EPB, so they are worth examining. Specifically, let’s look at two questions:

1) Is this declining trend correct?
2) Are these absolute numbers credible?

Let’s look at these questions one at a time. The Beijing EPB claim of declining PM2.5 concentration especially surprised me because, just two months ago, Xinhua cited a Chinese Academy of Science report suggesting that PM2.5 has been increasing 3-4% per year. A more detailed description in the People’s Daily said this trend has been occurring since 1998. I haven’t seen the original CAS report, so I don’t know the details behind the study (e.g. how many monitoring stations, locations, etc.). Nonetheless, it’s not very encouraging to see this contradiction — and one coming from a government source. Let’s see how and if Beijing EPB tries to reconcile this contradiction over the year as more and more PM2.5 data come out.

As for other data sources, I still haven’t seen any public, peer-reviewed studies that show clear long-term PM2.5 trends for Beijing. If anyone out there knows of any, please let me know by e-mail or the comments. My hunch is that the few research teams out there (e.g. universities) who do have continuous PM2.5 monitoring data over a long time series are unwilling to publish them because those data are fairly sensitive, but I may be wrong.

In the absence of clear long-term trend studies, all we have are a few snapshots in the literature. Many reports just cover one or two monitors over a limited time. Still, let’s take a look at the reports as a way of gauging the credibility of the Beijing EPB-reported data. In other words, how do the Beijing EPB-reported PM2.5 numbers compare against the few other independent PM2.5 estimates we have?

Well, the first obvious place to look is the US Embassy’s monitor. The Twitter feed from the US Embassy’s PM2.5 monitor only reports hourly and daily values, although both the new foggybeijing site and Steve Andrews’ chinadialogue piece both present annual summaries suggesting that the annual average PM2.5 from that monitor was around 100 ug/m3 in 2010-2011. This is significantly higher than the Beijing EPB 2010 figures of 70-80 ug/m3. So, we have one dissenting data point, but remember it’s only one point. The Beijing EPB could easily (and perhaps justifiably) attribute this discrepancy to the fact that their data is an average over the entire city, whereas the Embassy monitor is at a single spot in a heavily-trafficked area. We’ll have to wait and see how they explain that.

Next let’s look at some reported values in the peer-reviewed literature. Here’s a good summary “lit review”-style paragraph from Chan and Yao, 2008:

PM2.5 measurements have been widely reported in Beijing in the last 10 years. He et al. (2001) made the first comprehensive PM2.5 measurements in Beijing and reported that the annual average of PM2.5 was 115 ug/m3 at Chegongzhung (an urban site) from September 1999 to September 2000 [Vance edit: the He et al. paper also reports a second site at 127 ug/m3]. The annual average was 96.5 ug/m3 at the same site from August 2001 to September 2002 and the decrease was attributed to the air pollution control measures carried out in Beijing since 1998 (Duan et al., 2006). On the basis of measurements on selected days in four seasons, Zheng M. et al. (2005) and Wang J. et al. (2004) reported annual averages of PM2.5 in 2000 and in 2001 of 101.4 mg m3 and 109.6 ug/m3, respectively. Wang Y. et al. (2005a) reported that the average of PM2.5 from 2001–2003 was 154.3 ug/m3, significantly higher than the values reported by the other studies mentioned above.

One more I found in addition to this was Yang et al. (2011), who reported PM.5 values around 2005-2006 of 118.5 ± 40.6 ug/m3.

So, we can summarize our brief data investigation as follows:

Pm25 estimates

I must emphasize very clearly that all these data are not directly comparable; I present them here merely as a first-order snapshot of the PM2.5 levels at various times and places around the city. (To give a sense of how variable the levels can be across the city, consider this quote from Yang et al., 2001: “In Beijing, annual average PM2.5 concentrations varied by 50 ug/m3 (near three quarters of mean concentration at the rural site) between the paired rural/urban sites over a distance of 70km.”) But it does seem as though many of these reported PM2.5 levels are higher than what the Beijing EPB has claimed (via CCTV), and that no clear trends are visible.

A (brief) review of independent literature studies does not immediately support the Beijing EPB’s reported PM2.5 numbers and declining trend for Beijing. In addition to several individual data points showing higher PM2.5 levels, it’s concerning that there is a Chinese Academy of Sciences study that apparently shows an increasing trend of PM2.5 — the exact opposite of that claimed by the Beijing EPB. However, with such limited data, we can’t really say comprehensively or definitively whether the Beijing EPB data are valid or not. The only thing I can say 100% conclusively is that I’m eagerly awaiting the release of more data that back up their claims (or, alternatively, the public release of more clear long-term PM2.5 trend studies from independent research groups).

translation of beijiing’s pm2.5 announcement

Wednesday, January 11th, 2012

On January 6th, the Beijing EPB made a major announcement regarding the plan for monitoring and reporting PM2.5 this year. This is huge and terrific news, with most media sites characterizing the announcement as a clear and concrete result of the recent public outcry over Beijing’s air quality (for example, see BBC, Reuters, China Daily, AP, NYT, CNN, and two WSJ pieces: “Beijing Caves…” and “Beijing Bows…“).

Because this is such a big announcement, I’m going to translate the entire thing here. I wanted to do so because there are a lot of positive developments in the announcement that weren’t mentioned in most of the brief news stories, and also because I’ve noticed some minor mischaracterizations in the media about what it actually says.

The great news, only some of which was reported by the media (not by error, probably just because of space constraints) includes:

– In addition to PM2.5 reporting, hourly ozone reporting should also start by the end of the year;
– Individual, hourly data points for all stations will be reported as opposed to city-wide averages;
– The language used to describe the pollution will be changed (presumably to reflect the fact that “Blue Sky Days” here frequently aren’t, and China’s current designation of “slight pollution” is, well, not exactly slight.)

These are all enumerated in the final paragraph of the announcement, which reads like an awesomely affirmative response to a Beijing air quality information disclosure wish list.

My only minor complaint with the international coverage is that some of it implies that Beijing will begin widespread PM2.5 reporting by Spring Festival (a couple of weeks from now). Actually, the announcement only states that some “research-type” PM2.5 data will begin to be released by Spring Festival (to give credit, the BBC was the only media I read that really nailed this). Full PM2.5 reporting for the city will (hopefully) be completed by the end of the year. The announcement is filled with all sorts of caveats about how much work it will take, and about the need for the new national standards and relevant regulations to be released, etc. In other words, Beijing is very much downplaying the expectations here. Regardless, it’s still just wonderful news that has been a long time coming.

Anyway, onto the translation:

Translated by
Bold added by translator

Beijing EPB responds to journalists’ questions about launching PM2.5 monitoring and improving the system for air quality information disclosure

On January 5th, a representative from the Beijing EPB Environmental Monitoring Division answered journalists’ questions on Beijing’s plans to launch PM2.5 monitoring and improve the system for air quality information disclosure.

1. Regarding the status of Beijing’s air quality monitoring

In 1984, Beijing completed the initial phase of construction of an air quality monitoring system, and began operation. At that time there were 8 automatic air quality monitoring stations, mainly distributed in the 8 districts of the city at that time. Beginning in 2000, Beijing began expanding and improving the air quality monitoring system. By the time of the Olympics, Beijing had set up 27 automatic air quality monitoring stations spread out over all the districts and counties in the entire city, and had begun automatic monitoring. According to the requirements of the national ambient air quality monitoring regulations, concentrations of SO2, NO2, PM10, and other pollutants were automatically monitored 24 hours per day. Weekly reports, daily reports, and daily forecasts of air quality started in 1998, 1999, and 2001 respectively.

2. Regarding the status of developing PM2.5 monitoring in Beijing

Currently, Beijing has not comprehensively and systematically developed regular monitoring of PM2.5. In accordance with Beijing’s atmospheric pollution prevention program, since 2006 the Beijing Municipal Environmental Monitoring Center began conducting research-type monitoring of PM2.5 using an integrated observation lab. After the Olympics, we selected a few atmospheric monitoring stations to develop staged research-type PM2.5 monitoring at different times.

3. Regarding plans for monitoring and reporting PM2.5

现在我们已经启动了PM2.5监测网络建设,计划年底前全部完成。根据建设进度,完成一个点站建设就发布一个点站监测信息,同时完善整体空气质量信息发布方式。计划在春节前,首先通过监测中心网站等实时发布各监测子站二氧化硫(SO2)、二氧化氮(NO2)、可吸入颗粒物(PM10)3项常规污染物每小时的浓度数据。同时公布综合观测实验室的PM2.5 研究性监测数据,供市民参考。国家新标准和相关监测规范发布后,将按照监测规范,利用现有仪器设备先在6个监测子站开展PM2.5监测,同时发布实时数据;根据监测设备采购、调试工作进展,会逐步增加PM2.5监测子站,力争年底前完成全市的PM2.5监测站点建设并发布实时监测数据。
We have already begun building the PM2.5 monitoring network, and plan to complete it by the end of the year. In accordance with the construction progress, as we complete each station, we will report that station’s monitoring information. In parallel, we will improve the overall method of reporting air quality information. First, before Spring Festival, we plan to report real-time, hourly concentration data for three pollutants – SO2, NO2, and PM10 –  through the website of the environmental monitoring center. At the same time, we will report the research-type monitoring data of PM2.5 from the integrated observation lab for the public to consult. After the national standard and relevant monitoring regulations have been issued, in accordance with the regulations, we will use existing PM2.5 monitoring equipment to begin monitoring PM2.5 at 6 monitoring stations, and simultaneously report real-time data. In accordance with progress on equipment procurement and adjustment, we will gradually increase the PM2.5 monitoring stations, trying very hard to finish the entire city’s monitoring stations and issuing their real-time monitoring data by the end of the year.

4. Regarding preparation work for developing PM2.5 monitoring

There are four aspects we need to prepare in order to launch PM2.5 monitoring. One, apply for funding and procure the monitoring equipment; two, optimize the placement of the monitoring network, construct the stations, computers, and debug the system; three, upgrade the website of the Beijing Municipal Environmental Monitoring Center and adjust the the information system for collecting and analyzing the air quality monitoring data; four, conduct staff training.

5. Regarding improving the system for air quality information disclosure

We are preparing to improve the method of air quality information disclosure from five aspects. In accordance with the new national standard and technical regulations for monitoring: one, disclose monitoring information from all pollutants obtained by the regular automatic monitor, including PM2.5 and ozone monitoring data; two, learning from international methods, change from the past method of strongly emphasizing the disclosure of one average data point for the city to disclosing the monitoring information from each station, in order that citizens can understand the air quality situation in the area in which they live; three, change from issuing only a daily 24-hour average to issuing hourly data for each pollutant for each station; four, entrust the Municipal Environmental Monitoring Center website to add a special platform for air quality information; fifth, change the notification language for air quality information disclosure in order to be closer to citizens’ lives and serve them better.