PM2.5 will be monitored and the data published twice a day on Twitter via @CANalert and on Facebook at http://www.facebook.com/cleanairnetwork. 

Disclaimer: the PM2.5 data we release is measured by a portable PM2.5 monitor (TSI SidePak AM510) which is widely used by university researchers.  The location is outside of our CAN office (102-106 Queen’s Road West, Sheung Wan) at ~5m above ground.  The data is subjected to variation and uncertainty, and is for REFERENCE ONLY, NOT to be extracted to other locations in HK.  The goal of our PM2.5 reporting is solely to help our concerned citizens to get a rough idea of what the PM2.5 level is like and to raise awareness.