Soaring levels of air pollution have triggered a health alert for the south-east, with the elderly and people with lung and heart condtions told to avoid strenuous physical activity.
The region's worst air pollution for many years has been caused by a combination of local emissions, light winds, pollution from the continent - and dust blown in from sandstorms in the Sahara Desert.
The red dust - which has covered thousands of cars across the region - is a potential health hazard for asthmatics and others sensitive to air pollution. Pollution levels remain high tonight but are expected to ease in most areas tomorrow.
David Johns reports, speaking to health expert Dr Rossa Brugha, Councillor Graham Gibbens (Con) of Kent County Council, and carwash owner David Charman.
The Met Office has released a video showing the dust cloud arriving from the Sahara Desert.
Crawley has been badly hit by today's pollution and smog, with visibility down to a few yards.
These were the scenes at Dartford this morning on the day that pollution and smog across the south east is predicted to hit dangerous levels. Experts have warned that anyone suffering the effects, including sore eyes, coughs and sore throats, should cut down the amount of activity they take outside.
There are further health warnings for the Anglia region as air pollution is forecast to hit high or very high levels for the third consecutive day. Vulnerable people are being advised not to take exercise outdoors.
The government warning from the Met Office and the Department for Environment, Food and Rural Affairs (Defra) says:
"For England and Wales, Moderate to High air pollution levels are forecast for central and southeast England, to the south and east of a line from around The Wash to Cheshire to east Devon, with local Very High levels expected in parts of East Anglia and the East Midlands.
"This is due to light easterly winds continuing to bring in pollutants and allow local pollutants to remain close to source. There may also be some component due to Saharan dust."