Four-time world champion Sebastian Vettel has called on Formula One's governing body to protect drivers from breathing in harmful carbon brake dust during races.
The Aston Martin driver was asked about the dust on his face, after removing his helmet, as he spoke to Sky Sports television at Sunday's Austrian Grand Prix.
"That's something I think they need to work on because the design of the brake ducts this year, the front axle is blowing all the brake dust into our faces and it's not good," he replied.
"Carbon dust is not really something healthy to breathe in. I hope the FIA looks into this very soon because it's pointless and easy to change."
This year's rule changes mean more brake dust is directed directly at the driver than before when it went through the wheels, but the problem of drivers inhaling carbon has been known for years.
Former F1 driver Mika Salo told Finnish newspaper Ilta-Sanomat in 2005 that doctors had found large amounts of carbon fibre dust in his lungs after a routine operation.
"If I have this much of it, how much will Michael Schumacher have after driving for 10 years more than me?" the Finn asked at the time.
In 2019 then-Mercedes pairing Valtteri Bottas and Lewis Hamilton spoke in Singapore, where there was also a problem of poor air conditions caused by forest fires in Indonesia, of what they had experienced.
"Any time after the race when you sneeze it is black, so year after year, I am not sure what it does to your body. No idea," said Bottas.