Coal is everywhere in Mongolia’s frigid capital. It sits beneath the towering smokestacks of power plants in piles as big as football fields. Drivers haul it through town in the open beds of pickup trucks. Vendors stack yellow bags of the stuff along roadsides, and jagged pieces spill from metal buckets in the round felt yurts where the poorest families burn it to keep out the bitter cold. The smoke in Ulaanbaatar is at times so thick that people and buildings are visible only in outline. Its smell is acrid and inescapable. The sooty air stings throats and wafts into the gleaming modern office buildings in the center of town and into the blocky, Soviet-style apartment towers that sprawl toward the mountains on the city’s edges. On bad days, handheld pollution monitors max out, as readings soar dozens of times beyond recommended limits. Levels of the tiniest and most dangerous airborne particles, known as PM-2.5, once hit 133 times the World Health Organization’s suggested maximum. The pollution is worst in Ulaanbaatar's harsh winters, when people heat their homes—including the circular tents known as gers—with coal. Here the morning sun cuts through the haze of smoke and diesel fumes in the Bayankhoshuu neighborhood. Mongolia’s pollution problem is a more severe version of one playing out around the world. From the United States and Germany to India and China, air pollution cuts short an estimated 7 million lives globally every year. Coal is one of the major causes of dirty air—and of climate change. In Mongolia, at least for now, coal is essential to surviving the brutal winters. But the toll it takes is steep. “I no longer know what a healthy lung sounds like” Picture of a lone man walking in a smoggy street scene Ulaanbaatar has grown rapidly and in an unplanned way in recent years, as nomadic herders have left the countryside and settled on the city's outskirts, in districts such as Dari Ekh. Living in gers or simple houses, they use coal stoves for both heating and cooking. Evening air pollution, mostly due to coal-fired stoves, hangs in the streets of Bayankhoshuu, one of the heaviest-polluted neighborhoods of Ulaanbaatar. Picture of a mother dressing up her two children with air pollution masks Left: The evening air is thick over Bayankhoshuu, one of the city's most heavily polluted neighborhoods. Right: Parents do what they can to protect their children from the smog. Here a mother… Read More This winter authorities closed the capital’s schools for two full months, from mid-December to mid-February, in a desperate attempt to shield children from the toxic air. It’s unclear how effective that measure is. Hospitals are stretched far beyond capacity, as pneumonia cases, particularly among the youngest, spike every winter. “I no longer know what a healthy lung sounds like,” says Ganjargal Demberel, a doctor who makes house calls in a neighborhood of yurts—known in Mongolia as gers—tucked into the jagged brown hills in the city’s northeastern corner. “Everybody has bronchitis or some other problem, especially during winter.” One of Dr. Ganjargal’s patients is Gal-Erdene Sumiya, a shaggy-haired seven-month-old who, when I meet him, is just getting over pneumonia. “I can’t bring him outside to get any air, because it’s so polluted,” says his mother, Selengesaikhan Oyundelger. She keeps her older children inside almost all the time too. In Ulaanbaatar coal is also burned in power plants, like this one on the edge of the city. A patterned pink cloth covers the walls of the family’s ger, and the wooden poles that support its round roof are brightly painted, creating a living space that’s cozy and intimate. A small stove keeps it warm as Selengesaikhan rolls out dough for mutton dumplings. She says the other mothers she met when her son was hospitalized talked about pollution incessantly: “They were saying they had no confidence in the future of this country.” Ger districts like hers, a mix of the traditional round tents and simple wood or brick houses, are home mostly to migrants from the countryside, former herders who have come to the capital seeking jobs and education. Because they lack the infrastructure available to apartment dwellers—reliable electricity and district heating systems, as well as water and sanitation—residents shovel coal into small stoves for warmth. A single family easily burns two tons or more each winter. Smoke floats from the metal chimneys that poke up from every tent and house, and the ger districts are among the city’s most polluted. But bigger polluters darken Ulaanbaatar’s air as well. Huge black plumes waft from power plants, and smoke drifts too from the chimneys of apartment buildings, supermarkets, and schools where maintenance men heap coal into big boilers. Mongolian students nap in front of air purifier to combat effects of pollution An air purifier stands watch over napping children at a kindergarten in the Bayanzurkh District. Young children are especially vulnerable to air pollution; the school has a purifier in every room. The blanket of foul air that engulfs this city for half the year is both a profound threat to its people’s health and a symptom of a much wider set of failures. Almost 30 years after it ended decades of isolation, rejected communism, and became a democracy, Mongolia remains a nation in transition. It has opened its rich mineral wealth to foreign mining companies that extract gold, copper—and, of course, coal—from the Gobi Desert. Cold Place, Deadly Smog Nestled in a narrow valley, Ulaanbaatar, Mongolia’s capital, is home to nearly 1.5 million people and has some of the worst air pollution in the world—especially in winter, when many homes are heated by coal stoves. Levels of fine soot particles (PM2.5)—the most dangerous type of air pollution—can rise to more than 20 times the World Health Organization’s safe limit. Mountains trap air pollution In winter, cold, polluted air is trapped near the ground by an inversion: a layer of warmer air above that prevents the dispersion of pollutants. The 10 most polluted capitals in 2018 Annual average levels of PM2.5, in micrograms per cubic meter (µg/m³) Monthly PM2.5 in Ulaanbaatar Death rate from air pollution (per 100,000 people) 200 µg/m³ 200 WHO target (10) 1. New Delhi, India 2. Dhaka, Bangladesh 3. Kabul, Afghanistan 4. Manama, Bahrain 5. Ulaanbaatar, Mongolia 6. Kuwait City, Kuwait 7. Kathmandu, Nepal 8. Beijing, China 9. Abu Dhabi, U.A.E. 10. Jakarta, Indonesia