<http://schema.org/about>
"Indoor air can be toxic and cause respiratory irritation and illness \u2014 especially in the winter. Here are some simple and mostly free ways to clear the air."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/health/healthy-spaces/blogs/healthier-cleaner-air-for-you-and-your-family-in-2012>