Saharan sand and fumes from the UK and mainland Europe mean Gloucestershire has a moderately high level of smog today according to the Defra pollution forecast.
Nationally Public Health England is advising people experiencing sore throat or eyes and coughs should consider reducing their activities outdoor.
The Defra pollution forecast for Gloucestershire today puts the area at a level five or six which is a moderately high level.
Gloucester and Stroud are generally at five while Gloucestershire Airport and Cheltenham are at a six.
The advice from Defra with levels at 5-6 on the piollution index is: "Adults and children with lung problems, and adults with heart problems, who experience symptoms, should consider reducing strenuous physical activity, particularly outdoors."
Tuffley astronomer and amateur micrioscopy expert John Fletecher has taken some up cloe pictures which breveal the exact composition of the Saharan sand pollution.
Taking samples from his car roof Mr Fletcher has blown up the picture to x45 to x90 their original size.
He said: "One can see that some are silicones whilst others are sheer dirty pollution."