PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • hydrogen sulfide is present at or near oil and gas facilities, including oil and gas wells, tank batteries, gas processing plants, flares, compressor stations and refineries. levels of hydrogen sulfide ranged from the relatively low concentration of 2 ppb (recorded in Louisiana) to concentrations in the 1,000 ppb range (observed in New Mexico).
http://www.w3.org/ns/prov#wasQuotedFrom
  • earthworksaction.org