Air pollution worsening in U.S. cities
More than 40 percent of Americans are breathing heavily polluted air, increasing their risk for lung cancer, asthma, heart problems, and other health issues. That’s the worrisome conclusion of the American Lung Association’s latest annual “State of the Air” report, which has been tracking air quality across the U.S. for 19 years. The report concluded that 133.9 million Americans lived in areas that get an F for air pollution in 2016, up from 125 million in 2015. Researchers focused on the two most common outdoor air pollutants: ozone and particles. Ozone is an odorless toxic gas that occurs naturally in the upper atmosphere, but it can also form at ground level when industrial pollutants react with heat and sunlight. Particle pollution includes dust, fumes, soot, smoke, and aerosols. The report found that although particle pollution levels are still falling—a long-term trend attributed to the 1970 Clean Air Act—ozone levels are increasing, likely thanks to rising temperatures. In 2016, the second-hottest year on record, there was a sharp spike in the number of days with high ozone levels, reports CSMonitor.com. “Even with the continued improvements [in particle levels],” says the ALA’s Janice Nolen, “we’re seeing the evidence of the challenge of climate change.” Ozone exposure increases the risk of lung cancer, cardiovascular damage, asthma attacks, and developmental harm. Los Angeles has the highest ozone levels in the country; other cities with high levels include Sacramento, Phoenix, and New York City.