Upper Hunter Air Quality Monitoring Map screenshot from Wednesday 10th April, 5:50pm
Dust and "local sources" are the most likely cause of PM10 levels exceeding national standards in the Upper Hunter this week.
The coarse particle pollution exceeded standards at locations including Muswellbrook, Singleton, Mount Thorley, and Camberwell a number of times. Levels also exceeded standards at Mason Dieu once this week.
An Office of Environment and Heritage (OEH) spokesperson has said that gusty winds were experienced in the area on Monday with particle levels increasing overnight under calm and variable winds, when dust levels can become trapped in the valley.
The spokesperson also said that elevated dust on these days was most likely due to local sources, although there may have been some influence of broader scale dust on Tuesday afternoon following reports of dust haze under fresh winds at Gunnedah on the same day.
Image credit: https://www.environment.nsw.gov.au/aqms/uhunteraqmap.htm