One in eight deaths worldwide can be attributed at least in part to air pollution exposure, according to a March 25 report by the World Health Organization. In 2012, the WHO linked 7 million deaths worldwide to air pollution—making it the “world’s largest single environmental health risk.”
Smog in Beijing—like the thick blanket of gray that descended on the city Thursday—often makes international headlines. But China is hardly the only country whose cities are plagued by poor urban air quality. For example, India’s large cities are often smog-besieged, in part because of cheap but highly polluting diesel, as my colleagues at Businessweek/Bloomberg News wrote earlier this month. A June World Bank report estimated that air pollution cost India $18 billion annually.
Urban smog isn’t the only worrisome form of air pollution. The WHO report also considered the impact of coal and wood-burning stoves in unventilated homes, known as “indoor air pollution.” In low- and middle-income countries in Southeast Asia and the Pacific Rim, the WHO calculated that 3.3 million people died prematurely in 2012 due to long-term exposure to indoor air pollution, and 2.6 million people in the region died that year due in part to outdoor air pollution.
Women in these countries, who tend to spend more time indoors, were also disproportionately affected. “Poor women and children pay a heavy price from indoor air pollution,” says Dr. Flavia Bustreo, WHO’s assistant director-general for family, women, and children’s health, “since they spend more time at home breathing in smoke and soot from leaky coal and wood cook stoves.”
Indoor and outdoor pollution have somewhat different health impacts. According to the WHO, the No. 1 indoor-pollution-related killer was stroke. For outdoor air pollution, it was ischaemic heart disease. Both kinds of air pollution are also linked to lung cancer, chronic obstructive pulmonary disease, and in children, acute lower respiratory infections.