20,000 volunteers across the U.S. measure precipitation. When extreme weather hits, this data turns into life-saving alerts. Mappers worldwide update information used by first responders after the Nepal earthquake. A new project, EyesOnALZ, enlists the crowd to add research on Alzheimer's disease. D.I.Y. enthusiasts from Public Lab map the BP oil spill and watchdog pollution.
Citizen scientists track air and water pollution at fracking sites using techniques developed by the "Bucket Brigade." Volunteers monitor water quality regularly, generating baseline data. Community members connected with professional researchers to tackle Flint's drinking water crisis. In China, citizens use government data and a unique mobile app to report environmental crimes.
Sensors on asthma inhalers generate real-time maps of environmental dangers to help patients, physicians and disease detectives. Citizens confront air pollution and rising asthma rates by collecting traffic data. Citizens fight mosquito-borne diseases with apps. Medic Mobile develops software to give phones the capability to help community health workers improve maternal and child health.