About: http://webisa.webdatacommons.org/38282633

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	The air quality in cities such as London, U.K., Donora, PA and other cities has improved from toxic levels only decades ago to tolerable.
http://www.w3.org/ns/prov#wasQuotedFrom	nonwovens-industry.com