Vulnerable people across south Lincolnshire are being warned to stay indoors as air pollution levels rise.
The area, including South Holland, has been put on high alert over severe levels of air pollution.
Forecasters warn that one of the year’s worst smogs will worsen, with air pollution reaching the “very high” level across the district.
The unusually high levels of air pollution is a result of inland smog and powerful dust storms swept in from the Sahara by strong gales.
Chris Weston, public health consultant at Lincolnshire County Council, said: “Levels of air pollution in Lincolnshire are currently moderate to high and are expected to increase Thursday before beginning to drop on Friday.
“Residents should check the Defra website to view forecasts specific to their areas.
“The additional dust in the air, combined with normal emissions, could cause discomfort in some people, including sore throat, coughs, and sore eyes.
“Although this poses a low risk to healthy people, older people and those with heart or lung problems should avoid strenuous physical activity, especially outdoors.
“Asthmatics may find that they need to take their relief inhalers more often.”