Air pollution in China is alarming much of the time, but earlier this year the problem became so acute that it made international headlines. In January, the U.S. Embassy in Beijing reported air pollution levels of 755 on an index that typically stops at 500, embarrassing a Chinese government that had just begun making data on fine particulate matter available for major cities in response to a series of well-publicized citizen demands for more transparency. Fine particulate matter (pollutant particles smaller than 10 microns in diameter -- PM 10 -- and 2.5 microns in diameter -- PM 2.5) is a critical air pollutant of concern for human health because it is small enough to reach the lung's most sensitive tissues, where it can facilitate infections and induce cancers.
Because China's cities so famously suffer from severe air pollution, it might seem impertinent, then, to ask the following question: Is China's air pollution really that bad? In other words, is it a unique environmental catastrophe warranting international concern? Or is its poor air quality instead the natural conclusion of rapid development with high rates of industrial growth, urbanization, and increasing population density, with warnings exacerbated by an over-attentive media?
Does China, in short, truly deserve its reputation as an environmental pariah?
Ramon Guardans, a biologist who studies air pollution and co-chairs a global monitoring plan on toxic chemicals for the United Nations Environment Program, is skeptical.
"The air concentrations of several pollutants in sites in China are certainly comparable to the levels observed in heavily industrialized areas in Europe and North America before the 1970's," he wrote by email. But pound for pound, person for person these pollutant emissions were, and generally still are, much greater than China's.
"So in relation to the population density we see in China," Guardans continues, "the U.S. and Europe did a much dirtier job industrializing."
Archival records indicate that throughout the 1960's daily average PM 10 levels in Los Angeles routinely exceeded 600 micrograms per cubic meter of air (µg/m3). For a city a fraction of the size of Beijing, these levels are very high; far higher, in fact, than Beijing's usual daily averages (which are below100 µg/m3) and well above currently acceptable levels. No PM exposure is safe, but the World Health Organization describes exposure to daily average PM 10 levels below 50 µg/m3 , as well as annual average levels below 20 µg/m3, as "acceptable."
The average annual PM 10 levels in even China's most polluted cities is generally much lower than the peak levels that have grabbed headlines. For example, the average annual PM 10 level in Lanzhou (China's worst offender) was 150 µg/m3 in 2010, while Xining ranked second at 141 µg/m3 . These levels, while dangerous to human health, are pretty comparable to those once witnessed in Eastern Europe's manufacturing centers. The Czech cities of Prague and Mostecko, for example, each achieved average annual PM 10 levels greater than 150 µg/m3 and 130 µg/m3, respectively, in the 1980's.
Data for historical outdoor air pollution comparisons is hard to come by because many pollutants, including ultra-fine particulate matter (PM 2.5), were not widely monitored until recently. Indeed, large gaps in the monitoring of important pollutants still exist around the world for a variety of reasons, most notably the tremendous cost of monitor installation and maintenance; a single mercury monitor, for example, can cost more than $100,000. Nevertheless, comparisons of historical emissions data can tell us a little bit about how polluted a country's air is or used to be.
China's current emissions of a variety of air pollutants is huge: recent estimates hold that nearly 34 million tons of sulfur dioxide and 11 million tons of nitrogen dioxide were released into China's airways in 2010, mostly through automobile exhaust, power plant emissions, and biomass burning. In addition, China emits these pollutants at some of the highest levels in the world - the highest for sulfur dioxide. But, for a country with four times the population of the United States, these are not much higher than our own emissions used to be. In 1980, near peak U.S. output, the country released 26 million tons of sulfur dioxide into the air (about 30 percent less than China currently does) and 27 million tons of nitrogen dioxide (about 68 percent more than China in 2010).
One problem with comparisons between our present age and the 1980s is that we no longer, as Guardans put it, require "several decades of monitoring, modeling, and international action" to convince countries that air pollution has local and global consequences. "In that sense," he says, "China works with the advantage that this [research] job is done."
In addition to better scientific knowledge of the movement and consequences of air pollutants, we now also have better control technologies and more effective regulatory responses. If the days of smog obscured skylines and soot disfigured monuments are gone for the United States, it is in a large part due to effective control of emissions. As a result, while a few notable cities in the U.S. still suffer from dangerous smog levels, overall ambient PM 10 measurements have decreased by more than 80 percent in the last 30 years.
So how does China compare to other developing countries in the present day?
Though long-term data on PM 2.5 does not exist for many developing countries, the 2012 Environmental Performance Index (EPI) for the first time sheds light on this issue. Using both satellite and on the ground measurements, primarily in North America and Europe, scientists at Dalhousie University developed a model to relate satellite data to estimate ground-level exposure to PM 2.5. This method allowed researchers at Yale and Columbia University to create a consistent, comparable look at PM 2.5 pollution for all 132 countries ranked in the EPI -- even in countries who do not yet provide data for the measurement.
According to the 2012 EPI, three countries experience worse average population-weighted PM 2.5 levels than China: Pakistan, Bangladesh, and India. In 2009, the average Indian citizen's exposure to PM 2.5 was more than 53 percent higher than the average Chinese citizen's. And unlike in China, where air is improving (albeit slightly), many of the worst offenders on the list are actually getting worse. While China showed a subtle (just under 1 percent) improvement in its PM 2.5 air quality from 2000 to 2009, India and Bangladesh each saw their countrywide levels increase by nearly 6 and 9 percent, respectively, during the same period. Likewise, according to a recent analysis conducted by scientists at Illinois's Argonne National Laboratory, China saw its emissions of toxic sulfur oxides decrease by more than 9 percent from 2006 to 2010, largely as a result of implementing new desulfurization technologies. In that same time period India's emissions of sulfur oxides grew by 9 percent -- the result, the study authors conclude, of "remarkable energy consumption growth" paired with "lax emissions controls."
The common thread among all these statistics, as Siwani Neupane, a journalist from Kathmandu, recently reported in the Columbia Journalism Review: is that it simply isn't fair to label China as the world's most polluted country. Neupane found that a LexisNexis search for reporting on "Beijing and air pollution" returned more news hits than reporting on all other air-polluted countries combined, and while India's air pollution has received some media attention this year, the level of scrutiny has not been nearly as high as for China.
What accounts for this disparity in media attention? China's meteoric economic rise has sparked fears in the West that its own long-worn global prominence will soon be eclipsed, leading to a natural interest in evidence that China's growth has come at great environmental cost. In other words, many have taken solace in the fact that China seems to be, to quote Joseph Kahn and Jim Yardley of the New York Times, "choking on its own success."
But while the world's attention is focused on Beijing and its suffering residents, there are countless countries and cities that are choking without the other benefits of China's growth - cities like Ahwaz, Iran; Ulaanbaatar, Mongolia; and Ludhiana, India.
"These places need to know what dangers lurk in the air around them", Neupane writes in her Columbia Journalism Review article. In their polluted air lies an opportunity to address this problem with the same solutions that have worked across Europe and North America. Instead of fixating single-mindedly on China, the developed world should give attention to other areas which, while less-publicized, would benefit immensely from efforts to eradicate air pollution.