The biggest problem appears to be a bright red mass in Northeastern China around the Yangtze River Delta — a rapidly developing piece of China's explosive economy. There doesn't seem to be a lot of acknowledgment from the state media, but blogs are picking it up as one of the few sources of data on air pollution for the area.
The sad fact is that particulate matter in the air less than 2.5 micrometers in diameter is not classified as pollution by the Chinese government, so they have no official measurements to provide. If you're in Shanghai and looking for a breath of fresh air, you've got quite the journey ahead of you."
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