<http://schema.org/alternativeHeadline>
"Researchers found that for every 10-microgram increase of pollution particles per cubic meter of air, birth weight decreased by 8.9 grams."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/family/babies-pregnancy/stories/air-pollution-may-lower-birth-weight>