Plus the vacuum cleaner one-liner that definitely doesn’t suck.
South African vacuum repair technician Gary Sheen has a fascination for collecting vacuum cleaners.
Some might say it borders on the obsessive.
You see, at last count he owned 204. He even named the family dog Dyson.
Most homes have fewer vacuum cleaners than the Sheen household, but almost everyone owns at least one, and there are some fascinating connections between these ubiquitous cleaning devices and (you knew it was coming) bacteria.
Consider, for example, the study done by British researchers in 2003 which showed that vacuum cleaners are both effective collectors and reservoirs of microbial contamination.
Scarily, the scientists dosed dust with salmonellae, sucked it up, and were then able to recover it more than a month later.
Makes you wonder what could be alive and kicking inside your vacuum, doesn’t it?
The same study showed that bacterial count inside vacuum cleaners correlated with the number of people in the household, and whether the house was in an urban or rural setting (there were significantly more bacteria in the country).
There was, though, no association between the amount of bacteria in vacuum cleaners and the number of children in the household, the presence of pets, or whether or not people wore shoes indoors.
We have Australian and Canadian scientists to thank for a couple of studies that suggest that vacuum cleaners can also be powerful spreaders of bacteria.
Studies in 2012 and 2013 showed that some devices can suck up bacteria, then immediately squirt them out again in their exhaust fumes, liberally distributing the microbes.
Surprisingly, even some cleaners fitted with so-called High-Efficiency Particulate Air (HEPA) filters released only slightly lower levels of dust and bacteria.
They even use vacuum cleaners up in space.
A good thing too, because astronauts in the International Space Station (ISS) on Expeditions 30 and 31 reported more visible dust on the walls than had been previously noticed.
Of course, NASA and its partner agencies go to enormous lengths to assemble payload materials in cleanrooms, but then they go and add half a dozen bacteria-laden humans to the mix.
Researchers at the Jet Propulsion Laboratory in Pasadena examined vacuum cleaner bags returned from the ISS.
I always knew rocket science was a glamorous profession.
Anyway, they found the bags contained no fewer than 62 different microbial genera, all presumably originating from the astronauts.
Remarkably, while we’re on the subject of NASA, in 2013 their scientists discovered a completely new bacterial life-form living in the cleanrooms at the Kennedy Space Center. They were then were astonished to learn that precisely the same species had been isolated thousands of miles away over at the European Space Agency.
It’s suggested that this new species is a less competitive bug which can only thrive without other bacteria around, and it has been called Tersicoccus phoenicis—“Terci” means clean in Latin, and the species name “phoenicis” is a tip of the hat to the Phoenix Lander.
Back in the real world, a Norwegian study in 2015 showed that high vacuuming frequency (twice or more a week) was associated with an altered gut microbiome composition in pregnant women.
The results are a little confusing, as the researchers found that frequent vacuum cleaning resulted in higher levels of one species and lower levels of another, although both were considered “good” bacteria.
When it comes to vacuum cleaner hygiene, experts recommend changing the filter regularly—and/or the bag if your model has one.
They also stress the importance of vacuuming under and behind furniture, where all kinds of microorganisms can linger.
Finally, the last word on vacuum cleaners must go to comedian Tim Vine, who won an award for the “funniest joke” for this one, at the Edinburgh Fringe Festival in 2004.
“I’ve decided to sell my Hoover,” he said. “Well, it was just gathering dust.”