The Crowd & the CloudViral vs. Virus, Ep. 3 Special | 57m 1s Sensors on asthma inhalers generate real-time maps of environmental dangers to help patients in Louisville, KY. Street knowledge was crucial in a historic medical breakthrough: John Snow’s mapping of cholera in 19th c. London. In West Oakland, CA, citizens confront air pollution and rising asthma rates by collecting traffic data. Aired: 04/20/17 Expires: 03/31/20 Rating: TV-G Closed CaptioningVideo has closed captioning.checkmarkAdd to WatchlistProblems Playing Video?Report a ProblemClosed CaptioningShare:Share this video on FacebookFacebookShare this video on TwitterTwitterShare this video on Google PlusGoogleShare this video via EmailE-mailEmbedEmbed Code for this videoEmbed CodeThe Crowd & the CloudViral vs. Virus, Ep. 3Width in pixels px Height in pixels px Copied to your clipboardLabelCopy to ClipboardClick to copy embed code for videoCloseCloseReport a ProblemBefore you submit an error, please consult our Troubleshooting Guide.Type of ErrorVideo doesn't loadVideo loads, but doesn't playVideo jumps back/forwardOnly audio is streamingSponsorship playback errorOtherPlease add more detailsCancelSubmit ReportYour report has been successfully submitted. Thank you for helping us improve PBS Video.CloseCloseCloseDistributed nationally by American Public Television The Crowd & The Cloud is made possible by NSF, The National Science Foundation, "Where Discoveries Begin."