In case the OP can't see them....
http://twitter.com/#!/cgshanghaiair
Tweets 27m Con Gen ShanghaiAir ?@CGShanghaiAir
06-05-2012 23:00; PM2.5; 3.0; 10; Good (at 24-hour exposure at this level)
06-05-2012 22:00; PM2.5; 18.0; 57; Moderate (at 24-hour exposure at this level)
06-05-2012 21:00; PM2.5; 18.0; 57; Moderate (at 24-hour exposure at this level)
06-05-2012 20:00; PM2.5; 13.0; 42; Good (at 24-hour exposure at this level)
06-05-2012 19:00; PM2.5; 14.0; 45; Good (at 24-hour exposure at this level)
06-05-2012 18:00; PM2.5; 17.0; 55; Moderate (at 24-hour exposure at this level)
06-05-2012 17:00; PM2.5; 20.0; 62; Moderate (at 24-hour exposure at this level)
06-05-2012 16:00; PM2.5; 27.0; 79; Moderate (at 24-hour exposure at this level)
06-05-2012 15:00; PM2.5; 10.0; 32; Good (at 24-hour exposure at this level)
06-05-2012 14:00; PM2.5; 13.0; 42; Good (at 24-hour exposure at this level)
06-05-2012 13:00; PM2.5; 17.0; 55; Moderate (at 24-hour exposure at this level)
06-04-2012 12:00 to 06-05-2012 11:59; PM2.5 24hr avg; 20.1; 62; Moderate
06-05-2012 12:00; PM2.5; 22.0; 67; Moderate (at 24-hour exposure at this level)
06-05-2012 11:00; PM2.5; 25.0; 74; Moderate (at 24-hour exposure at this level)
06-05-2012 10:00; PM2.5; 10.0; 32; Good (at 24-hour exposure at this level)
06-05-2012 09:00; PM2.5; 9.0; 29; Good (at 24-hour exposure at this level)
06-05-2012 08:00; PM2.5; 8.0; 26; Good (at 24-hour exposure at this level)
06-05-2012 07:00; PM2.5; 8.0; 26; Good (at 24-hour exposure at this level)
06-05-2012 06:00; PM2.5; 9.0; 29; Good (at 24-hour exposure at this level)
06-05-2012 05:00; PM2.5; 18.0; 57; Moderate (at 24-hour exposure at this level)
Looking back a bit there are some Unhealthy readings. Inbetween these it was Moderate.
06-04-2012 20:00; PM2.5; 40.0; 108; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-04-2012 18:00; PM2.5; 38.0; 105; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-04-2012 14:00; PM2.5; 37.0; 103; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-04-2012 12:00; PM2.5; 37.0; 103; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-04-2012 11:00; PM2.5; 41.0; 110; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-03-2012 22:00; PM2.5; 37.0; 103; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-03-2012 21:00; PM2.5; 42.0; 112; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-03-2012 20:00; PM2.5; 41.0; 110; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
06-03-2012 19:00; PM2.5; 44.0; 115; Unhealthy for Sensitive Groups (at 24-hour exposure at this level)
Air Quality Index (AQI) PM2.5 Health Advisory
---------------------
Good (0-50) None
Moderate (51-100) Unusually sensitive people should consider reducing prolonged or heavy exertion.
Unhealthy for Sensitive Groups (101-150) People with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion.
Unhealthy (151-200) People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion; everyone else should reduce prolonged or heavy exertion.
Very Unhealthy (201-300) People with heart or lung disease, older adults, and children should avoid all physical activity outdoors. Everyone else should avoid prolonged or heavy exertion.
Hazardous (301-500) Everyone should avoid all physical activity outdoors; people with heart or lung disease, older adults, and children should remain indoors and keep activity levels low.