Governments throughout the world employ scientists and technicians to operate and maintain networks of expensive and precise air quality instruments. The measurements from these networks is primarily used to determine whether pollution levels meet health-based ambient air quality standards. If pollution is higher than regulatory standards allow then strategies, technologies, and additional regulations may be developed and implemented to reduce pollution levels and improve public health.
AirCasting is now publishing PM2.5 and ozone measurements from thousands of government-run air quality monitoring stations located the world over. The data is coming from OpenAQ, a non-profit that operates an open-source platform dedicated to aggregating and publishing government-measured and research-grade data.