Saharan dust

Clapham's cars are showing signs of this week's visitation to London of Saharan dust.

'A freak combination of weather conditions has left parts of the country covered in a smog haze made up of high levels of particles, including dust from the Sahara.'

We can see the dust on the cars. It looks like vehicular measles. We can't see it in other places it has settled - such as our lungs.