About: http://webisa.webdatacommons.org/427238875

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	Indeed, those gasses all occur naturally in the atmosphere, but couldn???t a gas such as carbon dioxide also be a contaminant?
http://www.w3.org/ns/prov#wasQuotedFrom	kcpw.org