Tons Better? Beijng’s Olympic Air Quality Revisited

Yesterday, with little notice, the Beijing Environmental Protection Bureau released its final report on the city’s August 17 – 20 test of traffic and air pollution control measures in advance of the Olympics (mostly accomplished by pulling cars from Beijing’s busy roads). No actual air quality statistics were provided in the Xinhua report published by China Daily, or the CCTV report. Instead, both outlets simply resorted to reporting the claimed tonnage of pollutants removed from Beijing’s air during the four day test. Thus, China Daily:

During the four-day test period ahead of next August’s Olympic Games in Beijing last month, the amount of pollutants discharged was cut by 5815.2 tons, according to a report released by Beijing Environmental Protection Bureau on Saturday … During the test, the emissions of nitrogen oxides, carbon monoxide and inhalant particulate matter (IPM), a major air pollutant, were cut by 87 tons, 1,362 tons and 4.8 tons respectively on each of the four days.

I’ll be blunt: these numbers are stupid and meaningless. Air pollution is about concentration of pollutants, not the actual weight of pollutants. That is, we measure air quality by measuring the amount of it in a given volume of air (parts per million, parts per billion). Removing 5800 mt of pollutants from, say, the new Olympic stadium is a tremendous achievement; removing it from, say, all of China is a lesser one. Point is, without a benchmark, the numbers are empty, and we can make no conclusions other than, “Gee, 5815.2 tons of pollutants sure sounds impressive.” Which is probably why state media limited itself to reporting tonnages.

Now, I don’t want to suggest that Beijing is trying to bury the test results. In this case, at least, Beijing’s environmental authorities are not: the results (if true) are faithfully reported on the Environmental Bureau’s website. And, significantly, they are no different than the middling test results released – with fanfare – to the press immediately after the August tests.

Then, as now, the Bureau reported scores of 91 – 95 on something that the Chinese media called the “Index of Inhalable Particular Matter.” I have tried and failed to find this index, all the while assuming that it is equivalent to the US EPA’s Guide to Particle Pollution which, in fact, is mostly equivalent to Hong Kong’s Air Pollution Index [API]. Fortunately, and finally, the new Beijing report confirms this suspicion by specifically referring to the API. So – by the API, an air quality ranking of 91 – 95 is classified as a “high” air pollution level. According to the Hong Kong Bureau’s website: “Acute health effects are not expected but chronic effects may be observed if you are exposed to such levels persistently for a long time.” If one goes by the almost identical US EPA index, the score indicates a “moderate” air quality ranking, and “[U]nusually sensitive people should consider reducing prolonged or heavy exertion.”

In other words, Beijing’s air quality is not yet Olympic-quality. This should come as no surprise to anyone who has visited the smoggy city in recent months, and it certainly doesn’t come as a surprise to anyone who lives there. What is a surprise is that a government scientist involved in testing Beijing’s air quality admitted that the August tests were a failure to the South China Morning Post [subscriber only] on Monday:

Beijing needs to take up to twice as many cars off the streets as it did in an August traffic control trial, to ensure decent air quality during next year’s Olympics, said a member of the panel of scientists advising the city government on the issue. Zhu Tong , an environmentalist with Peking University, also called for more flexible rules for the ban – based on variation of energy efficiency among the capital’s 3 million-plus cars, instead of an indiscriminate odd-or-even registration plate number policy adopted in the August tests.

“From a scientist’s point of view, I think that we need to take at least 2 million cars off the streets [so that air quality will be up to the standards] and I and my colleagues have already proposed it to the authorities,” said Professor Zhu.

Hats off to South China Morning Post for getting this important interview. Hopefully, other media outlets will pick up the story.

[A couple of weeks ago I noted a recent study in the New England Journal of Medicine that examined the adverse cardiac effects of even brief exposure to air pollution. Though the study only examined men with a prior history of cardiac events, there is good reason to believe that the effects observed in the study’s subjects are replicated -though less dramatically – in healthy individuals, including Olympic athletes.]