Yul Kwon:
As we just heard, there isn't even agreement on how to measure air quality. To help us explain this, we have Angel Hsu on Skype from Beijing. Angel is a researcher from Yale, studying Chinese environmental policy, and she's taking part in air quality seminars in Beijing. Thanks for joining us today, Angel. We heard in the report that the Chinese measure pollution differently than we do. They measure pollution particles that are 10 micrometers in size. But the U.S. thinks the even smaller 2.5 micrometer particles are more important to measure. Why is that?

Angel Hsu:
Those particles are very important for human health because they very easily penetrate human tissue, the lungs, and so it's a more health-relevant measure. And in places in China, PM2.5 has been found to compose around 50% of the particular matter in the air.

Yul Kwon:
Why aren't the Chinese measuring the smaller particles?

Angel Hsu:
Currently a lot of cities lack the equipment to measure PM2.5, so that's one part. The second part has been more political sensitivity surrounding the pollutant itself. And so the problem is if cities and citizens were aware of what the PM2.5 pollution levels are, there is a fear that there could be some sort of social unrest or some concerns from the citizens that the government is not doing their part to protect citizens against this harmful pollutant.

Yul Kwon:
As of today, the government says it's going to measure the 2.5 micron particles, but only in 11 cities. Why aren't they doing this for the entire country?

Angel Hsu:
I think it's politically easier to first pilot PM2.5 measurement in these model environmental cities. Because by setting PM2.5 as an aspiration for cities to obtain this model city designation-- it's not a mandate, and so it's not a requirement. And so this way, following the old Deng Xiaoping saying that we cross the river by first feeling the stones underneath, they can try to ease the nation into PM2.5 measurement and try to send a policy signal from the very top level that this is something that cities should be aspiring towards and that they should want to measure.

Yul Kwon:
It seems there is a public groundswell of support to adopt the 2.5 micron standard across the country. Have you been able to find out when these measures will be adopted in larger cities like Beijing and Shanghai?

Angel Hsu:
It is unclear what the timeline for rolling out these new standards will be, even if the congressional meetings end up passing the new standards, it's still unclear. But I think the fact that the Chinese government is now considering measuring PM2.5 it's really just a first step, and so once they're able to measure the pollutant then they can take the first step to try to manage the pollution, and then they can start to formulate policies that can control the pollutant. So I think it's just really a first step.

Yul Kwon:
Thanks so much, Angel. Angel Hsu is a researcher at Yale who focuses on China, air quality and climate change.