Fact Check-Sahara dust magnetism is not evidence of chemtrails

(Note language in paragraph 4 that some readers may find offensive)

Saharan dust contains naturally magnetic minerals and is not evidence of metals purposely released into the air, according to experts and contrary to online claims.

Dust blown by wind from the Sahara thinly coated parts of the United Kingdom on Sept. 7, leaving some cars smeared with red-hued flecks (here, here).

A video posted to Facebook on the same day and viewed more than 30,000 times shows someone using a magnet to pick up dust from a car.

“So if you all want to know what the shit was that came down last night, yeah get yourself a magnet, scrape it off your car… check this,” the person says, claiming that the substance is “metal, not sand” (here).

The social media post for the clip, as well as another video posted to Twitter here, also claims that the dust’s magnetism is evidence of “chemtrails”.

However, experts say magnetism is typical of Saharan dust.

“Windblown Saharan dust contains a mix of particles lifted from the [North] African ground surface, and additionally mixed with anthropogenic air pollution as the dust is blown northwest towards Europe and the UK,” said Professor Barbara Maher, director of the Centre for Environmental Magnetism & Palaeomagnetism, Lancaster University, in an email to Reuters.

Saharan dust’s characteristic red colour reflects the presence of small amounts of haematite, a weakly-magnetic mineral, she said.

The dust can also contain more strongly magnetic minerals, magnetite and maghemite, said Professor Richard Harrison, head of the University of Cambridge’s Department of Earth Sciences.

He said by email: “Magnetite and maghemite are more magnetic but less abundant.”

The aeolian, or wind-blown, dust’s magnetic properties are well-documented in scientific journals (here).

A review by Maher published in the Aeolian Research journal in 2011 said magnetic chemical compounds occur “ubiquitously” in aeolian dust (here and here.

Saharan dusts can also contain manmade magnetite particles and other pollution particles which mix with it as it travels northwards, said Maher.

However, air pollution-derived metals are usually present in much lower quantities than the naturally-sourced metal-bearing dust particles, she said.

Claims about chemtrails, toxic substances released deliberately into the atmosphere by aircraft, are part of a conspiracy theory Reuters previously addressed here , here and here .

VERDICT

Missing context. Saharan dust contains naturally magnetic particles, including haematite, which gives the dust its characteristic red colour. Its magnetism is not evidence supporting the chemtrails conspiracy theory.