evidence of pollution spike from mandarin oriental fire

I posted yesterday that the API of 307 would be classified by the US EPA as hazardous, and I wondered if it was related to the Mandarin Oriental fire. Today, both Xinhua and China Daily mentioned yesterday's highest grade pollution amid stories about the fire. China Daily even hinted that human health impacts from the pollution spike should be counted in the total cost of the fire (though to be fair I'm not exactly sure what they mean by "sphere"):

The total cost of the disaster has not been calculated, the fire department said, but the environmental bureau in the capital recorded a maximum grade for air pollution due to Monday's fireworks sphere.

Also today, we have a new data point implicating the fire as the key cause of yesterday's asphyxiating pollution. Take a look at MEP's graph of the last 30 days of API data:


We've seen some dramatically rapid air quality changes in the past here in Beijing, but I can't remember ever seeing a spike like this that could be directly tied to a single event.

Lastly, I think it is interesting to note in the above graph that there is a slight rise, but no dramatic spike, in pollution just after Chinese New Year's Eve (the impact of which would have shown up in the January 26th data point), despite the fact that the sky that night looked like this:


Image in graph: https://docs.google.com/View?docid=dggh5mp6_0cmqqrrdb
Fireworks image: Boston.com's The Big Picture

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Update 3/11/09
I know this happened a month ago, but I feel I should note that a commenter below pointed out that the Beijing EPB issued an explanation for the 307 API pollution spike. The explanation did not reference the fire, only the fireworks:

燃放爆竹带来今年首个重度污染天
2009-02-10

受不利气象条件和元宵节燃放烟花爆竹的双重影响，今天北京出现了今年以来最严重的污染天气，空气质量五级，污染程度达到了重度污染。

据市环保监测中心的监测数据显示，由于风速小、大气层稳定，大气污染物扩散条件变差，9号白天我市已经出现了轻微污染；晚上19点开始，由于元宵节燃放烟花爆竹，污染物浓度迅速上升，并且长时间维持在较高水平。19点到凌晨4点一直在每立方米400微克以上，其中21点时浓度最高，达到每立方米810微克，早晨5点为399微克每立方米，开始降到每立方米400微克以下。但由于受到静风等不利气象条件的影响，污染物浓度下降速度缓慢。

通过多年不间断的控制大气污染措施，本市出现5级重度污染的天数已经屈指可数，上一次重度污染天气出现在去年的5月29号。

Rough translation:
Setting Off Fireworks Brings This Year's First Heavy Pollution Day
2009-02-10

The dual impact of unfavorable meteorological conditions and the setting off of fireworks for the Lantern Festival led to Beijing's first severe pollution day this year. The air quality grade was 5, heavily polluted.

According to data from the environmental monitoring center, due to low wind and stable atmosphere, the atmosphere dispersion conditions changed to unfavorable. During the day of the 9th, the air quality was lightly polluted, but starting from 7pm, due to the Lantern Festival fireworks, pollution increased quickly and remained high. From 7pm to 4am, the PM10 concentration was above 400 ug/m3; it was highest at 9pm, reaching 810 ug/m3. By 5am, the concentration was 399 ug/m3, and began to drop after that. But because of calm winds and unfavorable meteorological conditions, the drop in pollution concentration was slow.

Through the continuous implementation of air pollution control policies, this city has experienced fewer and fewer grade 5 pollution days. The last grade 5 pollution day was last year on 5/29.
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