It is speculated that particles mainly come from transport and ground dust.

推测颗粒物的主要来源为交通运输和地面扬尘。

youdao

A strong wind of dust storms can carry heavy objects, so you should try to stay low, and close to the ground, and protect your head with your arms or a backpack.

强劲的沙尘暴可以卷起重物，所以你应该尽量保持低姿态，靠近地面，并用你的手臂或背包保护你的头部。

youdao

That happens when heavier particles are lifted by the wind and then fall back to the ground, hammering and shattering the dust-clumps as they do so.

这种状况在较重的颗粒被风吹起再落回地面，从而对块状物进行敲击和摔打后发生。

youdao

The "size matters" myth has been ground to dust in other sports in recent years.

CNN: SHARE THIS

But modern would-be immortals know that old-fashioned cure-alls, like the ground mummy dust to which hopeful aristocrats turned in medieval times, were only so much quackery.

FORBES

Entire homes have been ground to dust.

BBC: Syrians hide underground to escape struggle for control