About: http://webisa.webdatacommons.org/194879733

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	However, because many of the trace elements detected, including lead and mercury, may have been the result of sample contamination, additional data are needed to confirm that trace-element concentrations generally are low.
http://www.w3.org/ns/prov#wasQuotedFrom	usgs.gov