Dangerous Dust

I close my eyes
Only for a moment, and the moment’s gone
All my dreams
Pass before my eyes, a curiosity

Dust in the wind
All they are is dust in the wind

Kerry Livgren – Kansas

Did you need one more reason to clean your store, practice, and home? DUST! That’s right, that age-old nemesis of every desk, showcase, countertop, and white-gloved mother-in-law…dust. The fight against dust is taking on a new villain in 2020, the coronavirus.

By now, you know that the coronavirus we are all looking over our shoulders at is a highly contagious respiratory disease. At the same time, we are learning the COVID-19 not only attacks the lungs, but has long-lasting effects on patient hearts, brains, and central nervous systems.

COVID-19 is spread from person to person mostly through droplets released when an infected person coughs, sneezes, or talks. Hence our current attachment to masks and the debate that has arisen around them. It may also be spread by touching a surface with the virus on it and then touching one’s mouth, nose, or eyes. We published a story on August 12, 2020, about how many experts predict a rise in transmission of the coronavirus as we move back indoors over the next several months as summer turns to fall.

Now we read of another way the virus is spread, through dust. According to an article in the journal Nature Communications, researchers are suggesting that COVID-19 can be spread through the air transmission of the virus on dust particles. Again, viruses don’t travel through the air by their teeny-tiny selves. They are carried most often in aerosols and water droplets that we expel; when we breathe, when we talk, and when we laugh. Even when we yell our side of the mask debate, alone in our cars that is. It shouldn’t come as too much of a surprise that dust is a carrier of pathogens. The EPA has rules surrounding dust lead levels and how children’s blood levels of lead are directly tied to lead dust in homes.

In a rather extensive test with guinea pigs, William Ristenpart, a professor of chemical engineering at the University of California, Davis and his colleagues showed how viruses can hitch a ride on more than just aerosolized water droplets, but the dust we shuffle with us as well. Their tests measured the aerosolization of non-respiratory particles, or in simpler English, the airborne virus concentration of viruses not exhaled.

courtesy of nature communications

a Schematic for aerodynamic particle sizer (APS) experiments to quantify the airborne particulates generated by awake, unrestrained (mobile) guinea pigs (GP) (Supplementary Fig. 1). b Representative instantaneous particle emission rate (left axis) and instantaneous guinea pig movement velocity (right axis) vs. time for a mobile guinea pig in a cage with granular dried corncob (CC) bedding. c Time-averaged particle emission rate over 1 min (N¯(1))(N¯(1)) vs. time-averaged guinea pig movement velocity over 1 min (V¯(1))(V¯(1)). Solid line is the power law fit with exponent 0.93, correlation coefficient 0.80, and p-value 9.6 × 10−15d Schematic for APS experiments to measure the particulates produced by anesthetized or euthanized (stationary) guinea pigs (Supplementary Fig. 4). e Particle emission rates, time-averaged over 15 min (N¯(15))(N¯(15)), for three mobile guinea pigs (GP1, GP2, and GP3). Gray markers denote background particle counts without a guinea pig in the cage with different beddings (dried corncob granulas (CC), polar fleece-covered absorbent pads (PF), or no bedding (No) on the plastic cage floor). f Measurements of the particle emission rates, time-averaged over 15 min (N¯(15))(N¯(15)), for stationary guinea pigs, performed prior to inoculation (day 0) and on days 1, 2, and 3 post-inoculation with influenza A/Panama/2007/1999 (H3N2) (Pan99) virus, and after euthanasia. Horizontal gray dashed line denotes background particle counts of empty cage. Particle emission rates are the total of all particles detected in the size range of 0.3–20 μm in diameter (Supplementary Figs. 2 and 3). Source data are provided as a Source Data file.

Dust is composed of sloughed-off skin cells, hair, clothing fibers, bacteria, dust mites, bits of dead bugs, poop, paper fibers, hair, soil particles, pollen, and in modern times, microscopic specks of plastic. Humans generate their own personal cloud of aerosols, which funny enough has been called the ‘Pigpen effect’ after the famous Charles Shultz Peanuts character.

The fact that the dust we breathe in or the dust we touch and then later our mouths, noses, or eyes, makes the transmission of any virus, whether an influenza virus or the coronavirus, should make us all take another look at cleaning. So, if your employees are bored and disgusted about dusting, you can now impress upon them how they are not only making the store look good, but are helping to stem the spread of COVID-19.

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