WHAT WAS CLAIMED
CDC advice on wildfire smoke shows masks are “totally useless” against COVID.
OUR VERDICT
Misleading. A graphic accompanying the claim misrepresents how COVID is spread.
AAP FACTCHECK - A misleading infographic is being used to suggest the Centers for Disease Control (CDC) in the US has "accidentally" admitted face masks are "totally useless" against COVID.
However, the graphic not only misrepresents the size of smoke particles but also misleads on how COVID particles are spread.
The CDC told AAP FactCheck masks are effective and that different types offer varying levels of protection.
The organisation's website notes efficacy between 10 and 99 per cent across 11 different masks.
How well a mask fits is a major factor in how effective it is: "Gaps can let air leak in and out," a CDC spokesperson said.
The claim first appeared in 2020 following a genuine CDC Facebook post, during California's August Complex Fire, advising cloth masks used to slow the spread of COVID shouldn't be relied on as protection against smoke.
Although previously debunked by AFP and Health Feedback, the claim has now resurfaced amid the latest wildfires.
One of the recent Facebook posts shows a diagram with a line-up of particles labelled in order of increasing size as "Coronavirus", "Bacillus Bacteria", "PM2.5", "Red blood cell" and "SMOKE".