Monday, November 07, 2011

On Measurement and Air Pollution

Here is a picture we snapped one day this summer out our living room window. As you can see, it wasn't the clearest of days in Beijing. And, apparently, the air has been at least this soupy in recent weeks.

The US Embassy in Beijing maintains a microwave-sized device on its rooftop. This device measures the amount of particulate matter in the air. If you check out the Twitter feed that is dedicated to reporting these data on an hourly basis, you can get a quick, real-time assessment of conditions on the ground.

Or can you?

(By the way, as I write this, the most common recent reading has been "Unhealthy for Sensitive Groups.")

The Chinese government has publicly questioned these readings on a number of grounds. One official put it this way..."I'm not clear about their monitoring tools and methods, and how they ensure accuracy." According to the city's own measurements, Beijing has enjoyed record numbers of blue sky days in recent years.

Part of the discrepancy between the American and Chinese stories derives from differences in measurement standards. Chinese public measurements track particles down to 10 micrometers. Due to reforestation and the strategic relocation of coal-burning operations, these types of relatively large particles indeed are less commonly blowing their way into Beijing.

As for the US Embassy, it counts particles as small as 2.5 micrometers. Although such particles can penetrate into the lungs and bloodstream, the Chinese government is not prepared to release its own parallel figures, for the following reason..."The public sees world standards, and they expect China to adopt the most advanced ones. But we must accept that the nation can't reach these standards quickly."

Once again, as I like to point out to my research methodology students, what is at first glance a technical measurement issue, turns out to be derivative of conceptualization. How does one conceive of "air pollution?" What is the conceptual phenomenon that one is trying to describe or explain?

So whose purposes and arguments do you find most relevant and convincing?



At 2:00 PM, Blogger The Balla Family said...

Well, the Chinese government has now in effect come down on the side of the US Embassy in this battle over measuring air pollution...

Thanks for the head up, Robert!

At 9:21 AM, Blogger The Balla Family said...

One more thing on fine particulate matter, this time in the context of the US Environmental Protection Agency and its regulatory activities...


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