<http://schema.org/alternativeHeadline>
"A new study by WHO finds that air pollution has worsened since 2011, signaling increased health risks for city dwellers."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/climate-weather/stories/the-10-cities-with-the-worst-air-pollution-in-the-world>