<http://schema.org/alternativeHeadline>
"Toxic metals like lead, zinc and cadmium are commonly found in soil, particularly in urban areas, and lead is neurotoxic, especially to babies and young children."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/your-home/organic-farming-gardening/stories/produce-from-urban-gardens-could-contain-lead>