Breathing in Beijing (and New Delhi, and Tehran, and . . .)

Over the weekend, numerous global news sources reported on the record-breaking concentrations of fine particles—PM2.5—in Beijing, and the health issues that come along with them. Several sources (e.g., here and here) reported an increase in hospital visits for chronic bronchitis, asthma, and other respiratory illness, and another noted a doubling of ER visits for heart attacks. This is not the first choking smog in Beijing, but it was the best documented. Thanks to the new monitoring program established by China’s Ministry of Environmental Protection, Beijing citizens and the world could see that particle concentrations across northern China soared “beyond index” to concentrations that were more than double level classified as “hazardous” by the U.S. Environmental Protection Agency.

It is well established that short periods of exposure to very bad pollution, referred to as “acute exposure,” cause a continuum of health issues.* Not only do they contribute to deaths from heart attacks, strokes, and aggravated respiratory infections triggered by pollution, but they also bring pain, suffering, and days of debilitation for countless asthma and bronchitis sufferers. However, while these acute and local pollution spikes are dangerous and highly unpleasant for those living through it, they are just a small part of the global pollution problem. Over the last month, two groundbreaking reports have highlighted the critical long-term health and climate change impacts associated with fine particles.

Last month, the Lancet published a report identifying outdoor air pollution as one of the top 10 global health risks. The Global Burden of Disease study (GBD) estimated that PM2.5 caused 3.2 million early deaths in 2010, with 1.3 million of those in East Asia. Since 1990, deaths from outdoor air pollution have increased by 11% globally, and 35% in East Asia. The GBD looked at the annual average PM2.5 concentration, smoothing out extreme events like those in Beijing this weekend (or in Tehran last week, or in New Delhi last November). Along with its focus on long-term average pollution levels, or “chronic exposure”, the GBD evaluates only the fatal effects of outdoor air pollution: early deaths from heart and lung disease. Similar to the impacts from acute exposure listed above, chronic exposure to outdoor air pollution is known to have many other non-fatal effects; for example, an article released this week documents the impact of chronic air pollution on lung function of Chinese children.

And this week, the Journal of Atmospheric Research published a comprehensive study carried out over four years reporting that black carbon, an important component of the particles choking the air in Beijing and other highly polluted cities, is the second most important climate pollutant after CO₂. While not all sources of particle pollution are also key sources of black carbon, vehicles—especially diesel vehicles—emit particles that impact both health and climate. Fortunately, a single set of controls is extremely effective at solving both problems. Particulate filters, when used with ultra-low sulfur fuel, can reduce the number of particles emitted and the black carbon by more than 99%.

Vehicle emissions are only one component of the terrible pollution spike that Beijing has lived through in the last week, but they are a critical factor in the regularly elevated PM2.5 levels that still significantly increase the risk of heart attack, lung cancer, or stroke of Beijing’s residents. Plus, they are contributing to a rapidly warming world. Once the national government adopts stringent fuel and vehicle standards, Beijing and all of China—as well as our climate—will breathe easier.

*For an in-depth discussion of health impacts associated with air pollution, looking specifically at Asia, see this report.