ULAANBAATAR, Mongolia--As the sun rises over the frozen steppes, mothers and grandmothers across Mongolia emerge from their homes--white, felt-covered, round tents called gers. Hands hidden from the cold in the long sleeves of their warm deels, they clutch a ladle in one hand and an urn of milk tea in the other. Offering tsainii deej urguh, they throw a ladle-full of milk tea into the sky to honor the heavens. For many Mongolian women, the view is of blue sky and the open steppe, the horizon perhaps dotted with their family's herd of goats and sheep. But for those who live within sight of the capital, the panorama is quite different. Before them lies a vast city, home to more than a million people, jammed into an urban sprawl of closely packed gers, Soviet-era apartments, and new high-rises. Yet in the heart of the Mongolian winter, they can see none of this. Instead, a thick, gray layer of pollution obscures the horizon. Ulaanbaatar, capital of the most sparsely populated country on the planet and renowned for its pristine countryside and nomadic herdsmen, has some of the world's most toxic air.
The pollution is at its most intense in the winter, when over 100,000 ger stoves must work overtime to offset frigid outdoor temperatures that can dip as low as 40 degrees below zero--where Fahrenheit and Celsius overlap. In addition to generating heat, the ger stoves spew a hazardous type of pollution called particulate matter (PM) in the form of soot. Other sources, such as coal-fired power plants and vehicles, also contribute to the city's pollution problem. When concentrations of PM in the air are elevated and the individual particles are small enough, as they are in soot, these small particles penetrate deep into the lungs, causing serious respiratory and cardiovascular problems. In the winter, portions of Ulaanbaatar can reach daily average concentrations of a particular type of PM known as PM10--particles with a diameter of 10 microns or smaller--that are 70 to 85 times the maximum daily exposure recommended by the World Health Organization (WHO).
Despite comparatively less-polluted summers when indoor hearing is unnecessary, the intense winter pollution raises the annual average PM10 concentration so high that Ulaanbaatar ranks second out of over 1,000 cities in a list of the most PM10-polluted cities on the planet, according to a 2011 WHO survey--far worse than Beijing, Mexico City, or Bangkok. Only Ahwaz, Iran has a higher annual PM10 concentration.
While Ulaanbaatar represents an extreme case, it is not alone in having increasing difficulty balancing its growing need for energy with maintaining safe air. Since 2008, and for the first time in human history, we now live in a world where over half of the population resides in urban areas. The urbanization rate is highest in developing nations, where more than three-quarters of humanity live. While urban centers create the potential for efficient energy and resource disbursement, the reality is that many cities in developing countries are forced to produce more energy in inexpensive ways that compromise local air quality and their citizens' health.
Currently, the WHO estimates that indoor and outdoor pollution causes 3.3 million premature deaths per year--substantially higher than the annual death rate from malaria and AIDS combined. The health impacts of air pollution are felt most acutely in Asia, where over the last 30 years, the population has doubled and the need for cheap energy skyrocketed. A 2002 WHO report states, that of the total urban air pollution related-deaths in 2000, nearly two-thirds of them occurred in developing countries in Asia. Of the WHO's 10 most polluted cities, only Gaberone in Botswana is not a growing, impoverished city in Asia.
In Ulaanbaatar, the health impacts are already severe. A recent study from British Columbia's Simon Fraser University offers a conservative estimate that 10 percent of all deaths in Ulaanbaatar are traceable to PM pollution, while a December 2011 World Bank report estimates that approximately 1,600 deaths in Ulaanbaatar, or nearly 25 percent of all the city's deaths, can be attributed to PM every year. PM pollution has also been linked with a wide range of other negative health impacts including reproductive effects, respiratory infections, asthma irritation, impaired lung growth, cardiovascular disease, heart attacks, and strokes. The World Bank calculates that the adverse health impact of high PM levels results in nearly $500 million in losses each year--some 20 percent of Ulaanbaatar's 2008 GDP. In short, the air pollution in Ulaanbaatar is at tragically high levels with devastating health and economic consequences to the onethird of Mongolia's total population who live in the capital.
The health impact of...