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Open Chat:Thoughts and debates
Titles: Air Quality Indexes Update time: Jan 23, 2013
This post is probably a bit late since Wuhan's "Airpocalypse" has passed but I'm sure it will return one day so think of this as being ahead of its time ;) Recently read an informative article (http://www.livefrombeijing.com/2013/01/demystifying-air-quality-numbers/) about how the air quality rankings work. As most everyone knows China's standards are less stringent than America's but that's not all there is to know about how it works. Here are the pertinent facts: ::Click

Observations: 1) The US is more strict at low concentrations. 2) The systems are identical above a concentration of 150 (AQI of 200). 3) Neither system is linear which is annoying and non-intuitive. 4) It is also very annoying that the numbers are so close (as opposed to a 1-10 index for example). This means it is very easy to confuse AQI and concentration.

Summary - Concentration is the most accurate way of describing air pollution but isn’t good for public awareness and comparing multiple pollutants. - Both the US and China use AQI systems. Both systems go from 0-500 and are not technically defined above 500. - The US and Chinese systems are identical above an index value of 200 (PM2.5 concentration of 150) but slightly different below this level. - Because the systems aren’t identical and have different slopes you have to be very careful when saying something like “PM2.5 is 150.” The meaning of this statement is different depending on if you mean concentration OR US AQI OR Chinese AQI.
Titles: Update time: Jan 23, 2013
Oh and here's a nice graphic from the Beijinger showing how those particle sizes compare: (original article: http://www.thebeijinger.com/blog/2012/01/16/Particularly-Bad-A-Look-at-PM-25-Pollution) ::Click
Titles: air purifiers Update time: Jan 23, 2013
are like 1500 rmb at wal-mart jesus christ
Titles: Update time: Jan 24, 2013
Apparently clean air is considered a luxury? You'd think there'd be enough of a market over here that they could bump the price down a bit. We paid around 1000 for ours (Metro).
Titles: Update time: Jan 24, 2013
Yes I consider clean air and water is a luxury in China. Yadu makes a good air filter also quiet expensive if you consider it's just a box and a filter but still cheaper than international brands. My friend's have used the circular one which worked out quiet well. http://yadu.tmall.com/shop/view_shop.htm?spm=a220m.1000858.1000719.1.meGK64 I use Honeywell and a generic brand from B&Q which was on sale for 900 at the time. Both use HEPA filters.