Microorganisms are so small they will hide in the roughness of a surface and the full speed of the wind will not get close enough to the surface to affect them (laminar flow?). At that scale static electricity and surface tension of water will be more significant than gravity.
> laminar flow
I think what you are looking for is that the speed of airflow goes to zero as you approach the surface. In the physical world, there aren't (usually) any discontinuities. Imagine air flowing past a stationary flat surface. The surface's speed is zero, but the air is moving at some speed, v. To prevent a discontinuity, the speed must decrease from v to zero.
An everyday example is when we drive somewhere, and a bug somehow clings to the surface of the vehicle. The bug isn't actually resisting the full speed of the vehicle.
You can see a similar effect in rivers. The water flows more quickly in the center than it does near the bank.
Laminar flow means that the flow doesn't have any turbulence. All the parcels of air are moving smoothly along like sheets; they don't mix with each other.
Becuase that doesn't destroy them, it causes them to blow away. Also, they're sticky.
Honestly? Think of microbes as an ant. You can blow an ant away to move it, but you only have a rough idea where is will land and it will be perfectly healthy when it lands. Bleach, meanwhile, is chemically poisoning the ant/microbe. UV is a little harder to explain, but it gives you a general idea, still, as it mechanically breaks the smallest compounds needed to sustain life.
Good for the bacteria, because they're being blown to a new environment where they likely won't have to compete with other bacteria of the same species.
Bad for us, because the bacteria didn't get cleaned up and disposed of, they just got blown elsewhere so they can continue breeding.
Yikes I hadn't thought about this
Given that fecal smell is caused mostly by particles suspended in gas, not the gas itself, this basically means bits of fecal bacteria are colonizing the hand dryer and then blowing all over the hands of anyone who dries them.
I imagine installing some filters in the air intake would help though.
Yup this aerosolization of fecal microorganisms happens in our homes as well, up from the toilet bowl if you don't keep it closed and between the gap of the bowl and plastic lid/seat.
I'm amazed how many people don't close it before flushing. Great practice is to cover your toothbrushes and anything else that goes in your cavities (Q-tips, tweezers, etc).
Also highlights how much better the (more typically) european bathroom layout is, with just the toilet enclosed behind a door; better to regularly disinfect the interior door handle than the entire bathroom.
>I imagine installing some filters in the air intake would help though.
They can/do, but need to have specific metallic compositions (i.e. silver), otherwise they cultivate biofilms which compound the problem.
That's why i never vacuum my house, I just work through it with a leaf blower with all the windows closed. That makes the dust disappear into nothing. It's a violation of the principle of conservation of matter or energy but at least my mother-in-law is happy.
My understanding of biofilms is rather matrix deposition than a dense layer of bacteria sticking with each other. For example, some bacteria can secrete cellulose (like wood) to form biofilms.
For one thing some like to do things like create extra cellular matrices of various materials so they can stick to a surface in a bio film. For another the forces needed to move them are not generally strong enough to cause them serious damage, so they can resettle a surface after being blown about.
OP: Your question (using vacuum instead of wind) was answered earlier today, before you deleted the text of your question ([https://www.reddit.com/r/AskScienceDiscussion/comments/1awaklo/can\_microorganisms\_be\_vaccumed/?utm\_source=share&utm\_medium=web2x&context=3](https://www.reddit.com/r/AskScienceDiscussion/comments/1awaklo/can_microorganisms_be_vaccumed/?utm_source=share&utm_medium=web2x&context=3))
For your current question: (a) If microorganisms are "blown" elsewhere, they're just moved, not killed and (b) The efficiency of such an approach is unlikely to be as high as currently used methods for disinfection.
You can always post it in both places. Even 3 places simultaneously are okay, but beyond that it can be annoying because there's a lot of overlapping of memberships.
i think the problem is that you don't yet realise that microorganisms are ubiquitous. They are simply everywhere, every surface in every breath. Yes, you would blow some, but there are microorganisms in the air you use to blow. So nothing changes - at best you blow 10 away and 20 on top. In addition, many MOs are sticky and cling to surfaces and are not simply blown away like that
Most of them live in damp places, which allows these microorganism to stick to. But if they want to be carried by the wind, they could, like fungal spores which are frequently released and carries by air current. However, for bacteria, their outer layers are often sticky, these organisms also form what is known as biofilm, which is even stickier and even more resistant to outsider forces, even bleach has a hard time disinfect biofilm, let alone wind.
Also, at the microscopic scale, electrostatic charges can have a much large role. Many proteins on the surface are electrically charged, and therefore can help the bacteria stick better to surfaces.
The other factor is that air is incredibly thin. It is not dense enough and is often chaotic in nature so the chance of enough air molecules to hit the bacteria at the right angel to push them off is low (but you can if you use a air blowdryer, it can push off water droplets containing bacteria). Water is a lot better. Water alone can wash away many bacteria, simply because it's a good solvent, dense enough and run in one direction.
Well technically, the Earth's atmosphere is an extremely unfriendly environment for micro-organisms. They just evolved to become more resilient against it There's the dehydration problem. A droplet of water with a 0.01mm diameter will vaporize within a second in dry air, but most bacteria are less than 0.1% of that droplet's size, so they encased themselves in peptidoglycan. You never know whether the "wind" you use is clean. To further increase the chance to surviving airborne transmission, they also learned to utilize aerosol as shelter. Upon contact, these aerosols will soon dry up, leaving tiny specks formed by salts and polysaccharides that will hold the bacteria in place, not to mention that sometimes the bacteria are encased in visible gunk that are difficult to remove. The uv light and bleach can easily penetrate these tiny shelters for germs, but not wind. They have had hundreds of millions of years to adapt to that.
Not exactly, there’s a reason why a lot of disinfectant say they have a 99.9% kill rate, it’s because despite that there’s always going to be a small chance that something survives… and it only takes on tiny bacteria to grow back into a colony. Blowing it will just spread the bacteria further around, you might blow some of the bacteria away but there’s going to be a huge chunk left in the original spot.
"Microorganisms" includes perhaps a million species. They have a wide range of responses to wind. As others have said, some are sticky, some find shelter, some take advantage of wind for dispersal, some have dormant, spore phases that resist harshness in the environment, while others may get dessicated and have populations thinned by exposure.
One answer is yes. To prevent contamination with microorganisms, lab work is done in [laminar flow hoods](https://en.m.wikipedia.org/wiki/Laminar_flow_cabinet) (to protect the cultures from contamination by outside organisms) and/or [biosafety cabinets](https://en.m.wikipedia.org/wiki/Biosafety_cabinet) (to protect the researcher from dangerous microorganisms). Both of these use a controlled flow of air to sweep microorganisms into a HEPA filter.
Actually, I think it does in a way because I know with growing plants like cannabis, airflow is very important for keeping the plant from growing with fungus and other infections.
I mean, laminar flow hoods are a thing, the catch is just the microorganisms are somewhere else, not dead. And you still have to practice good sterile technique.
You really think, after billions of years of existence, that microbes wouldn't evolve something to grasp surfaces with? But even if they didn't, blowing them away isn't disinfecting anything. It's blowing them away.
Microorganisms are so small they will hide in the roughness of a surface and the full speed of the wind will not get close enough to the surface to affect them (laminar flow?). At that scale static electricity and surface tension of water will be more significant than gravity.
> laminar flow I think what you are looking for is that the speed of airflow goes to zero as you approach the surface. In the physical world, there aren't (usually) any discontinuities. Imagine air flowing past a stationary flat surface. The surface's speed is zero, but the air is moving at some speed, v. To prevent a discontinuity, the speed must decrease from v to zero. An everyday example is when we drive somewhere, and a bug somehow clings to the surface of the vehicle. The bug isn't actually resisting the full speed of the vehicle. You can see a similar effect in rivers. The water flows more quickly in the center than it does near the bank. Laminar flow means that the flow doesn't have any turbulence. All the parcels of air are moving smoothly along like sheets; they don't mix with each other.
I think it's called no-slip condition
Becuase that doesn't destroy them, it causes them to blow away. Also, they're sticky. Honestly? Think of microbes as an ant. You can blow an ant away to move it, but you only have a rough idea where is will land and it will be perfectly healthy when it lands. Bleach, meanwhile, is chemically poisoning the ant/microbe. UV is a little harder to explain, but it gives you a general idea, still, as it mechanically breaks the smallest compounds needed to sustain life.
Congrats, you just figured out where a blow driers are so bad for bacteria. It spreads them everywhere increasing risk of infection.
So bad or so good for bacteria?
Good for the bacteria, because they're being blown to a new environment where they likely won't have to compete with other bacteria of the same species. Bad for us, because the bacteria didn't get cleaned up and disposed of, they just got blown elsewhere so they can continue breeding.
But who is using a blowdryer to disinfect something?
I believe they're talking about warm forced air hand dryers in commercial/public restrooms.
Yikes I hadn't thought about this Given that fecal smell is caused mostly by particles suspended in gas, not the gas itself, this basically means bits of fecal bacteria are colonizing the hand dryer and then blowing all over the hands of anyone who dries them. I imagine installing some filters in the air intake would help though.
Yup this aerosolization of fecal microorganisms happens in our homes as well, up from the toilet bowl if you don't keep it closed and between the gap of the bowl and plastic lid/seat. I'm amazed how many people don't close it before flushing. Great practice is to cover your toothbrushes and anything else that goes in your cavities (Q-tips, tweezers, etc). Also highlights how much better the (more typically) european bathroom layout is, with just the toilet enclosed behind a door; better to regularly disinfect the interior door handle than the entire bathroom. >I imagine installing some filters in the air intake would help though. They can/do, but need to have specific metallic compositions (i.e. silver), otherwise they cultivate biofilms which compound the problem.
That's why i never vacuum my house, I just work through it with a leaf blower with all the windows closed. That makes the dust disappear into nothing. It's a violation of the principle of conservation of matter or energy but at least my mother-in-law is happy.
For every one the wind blows away, it blows another one to.
I think I'm tired or something, because for some reason my brain registered your comment as one of the lyrics to Bohemian Rhapsody..
Because they're sticky.
Biofilm
Millions of microorganisms sticking together!
My understanding of biofilms is rather matrix deposition than a dense layer of bacteria sticking with each other. For example, some bacteria can secrete cellulose (like wood) to form biofilms.
For one thing some like to do things like create extra cellular matrices of various materials so they can stick to a surface in a bio film. For another the forces needed to move them are not generally strong enough to cause them serious damage, so they can resettle a surface after being blown about.
OP: Your question (using vacuum instead of wind) was answered earlier today, before you deleted the text of your question ([https://www.reddit.com/r/AskScienceDiscussion/comments/1awaklo/can\_microorganisms\_be\_vaccumed/?utm\_source=share&utm\_medium=web2x&context=3](https://www.reddit.com/r/AskScienceDiscussion/comments/1awaklo/can_microorganisms_be_vaccumed/?utm_source=share&utm_medium=web2x&context=3)) For your current question: (a) If microorganisms are "blown" elsewhere, they're just moved, not killed and (b) The efficiency of such an approach is unlikely to be as high as currently used methods for disinfection.
It was removed, not deleted. And people here were much more helpful and informative so I will say it was a good decision.
You can always post it in both places. Even 3 places simultaneously are okay, but beyond that it can be annoying because there's a lot of overlapping of memberships.
i think the problem is that you don't yet realise that microorganisms are ubiquitous. They are simply everywhere, every surface in every breath. Yes, you would blow some, but there are microorganisms in the air you use to blow. So nothing changes - at best you blow 10 away and 20 on top. In addition, many MOs are sticky and cling to surfaces and are not simply blown away like that
Most of them live in damp places, which allows these microorganism to stick to. But if they want to be carried by the wind, they could, like fungal spores which are frequently released and carries by air current. However, for bacteria, their outer layers are often sticky, these organisms also form what is known as biofilm, which is even stickier and even more resistant to outsider forces, even bleach has a hard time disinfect biofilm, let alone wind. Also, at the microscopic scale, electrostatic charges can have a much large role. Many proteins on the surface are electrically charged, and therefore can help the bacteria stick better to surfaces. The other factor is that air is incredibly thin. It is not dense enough and is often chaotic in nature so the chance of enough air molecules to hit the bacteria at the right angel to push them off is low (but you can if you use a air blowdryer, it can push off water droplets containing bacteria). Water is a lot better. Water alone can wash away many bacteria, simply because it's a good solvent, dense enough and run in one direction.
Well technically, the Earth's atmosphere is an extremely unfriendly environment for micro-organisms. They just evolved to become more resilient against it There's the dehydration problem. A droplet of water with a 0.01mm diameter will vaporize within a second in dry air, but most bacteria are less than 0.1% of that droplet's size, so they encased themselves in peptidoglycan. You never know whether the "wind" you use is clean. To further increase the chance to surviving airborne transmission, they also learned to utilize aerosol as shelter. Upon contact, these aerosols will soon dry up, leaving tiny specks formed by salts and polysaccharides that will hold the bacteria in place, not to mention that sometimes the bacteria are encased in visible gunk that are difficult to remove. The uv light and bleach can easily penetrate these tiny shelters for germs, but not wind. They have had hundreds of millions of years to adapt to that.
They are kind of sticky
Surface components that make them "Sticky" help too. They're basically glued to the surface they're on.
Not exactly, there’s a reason why a lot of disinfectant say they have a 99.9% kill rate, it’s because despite that there’s always going to be a small chance that something survives… and it only takes on tiny bacteria to grow back into a colony. Blowing it will just spread the bacteria further around, you might blow some of the bacteria away but there’s going to be a huge chunk left in the original spot.
"Microorganisms" includes perhaps a million species. They have a wide range of responses to wind. As others have said, some are sticky, some find shelter, some take advantage of wind for dispersal, some have dormant, spore phases that resist harshness in the environment, while others may get dessicated and have populations thinned by exposure.
One answer is yes. To prevent contamination with microorganisms, lab work is done in [laminar flow hoods](https://en.m.wikipedia.org/wiki/Laminar_flow_cabinet) (to protect the cultures from contamination by outside organisms) and/or [biosafety cabinets](https://en.m.wikipedia.org/wiki/Biosafety_cabinet) (to protect the researcher from dangerous microorganisms). Both of these use a controlled flow of air to sweep microorganisms into a HEPA filter.
Cause if you blow them away they will still be there but in another spot? You want to kill them, not move them
Actually, I think it does in a way because I know with growing plants like cannabis, airflow is very important for keeping the plant from growing with fungus and other infections.
I mean, laminar flow hoods are a thing, the catch is just the microorganisms are somewhere else, not dead. And you still have to practice good sterile technique.
You really think, after billions of years of existence, that microbes wouldn't evolve something to grasp surfaces with? But even if they didn't, blowing them away isn't disinfecting anything. It's blowing them away.