Is there any research in the effectiveness of face shields?

[lewelma]

My sister is a teacher in a bad state. She is willing to wear a mask and face shield if there is evidence that adding the face shield makes a difference if you are already wearing a mask. She did this all last year, but now with all the aerosol info rather than droplets, she is wondering if it makes any difference. Does anyone have any reputable sources one way or the other that I can give her? Thanks!

[gardenmom5]

Medical personal have always used face shields in conjunction with a mask - NEVER - in place of a mask.

I had a dentist/hygienist who started using them back in the 80s.

When I was in the hospital when covid broke, and was on droplet protocols (they wanted to be sure I did NOT have covid) - the medical personal attending me had face shields AND masks (in addition to gowns and gloves.)

face shields are more about protecting eyes, not what you breathe.

[lewelma]

Thanks for that. So she will definitely wear a mask, and she wears glasses. Is there evidence that a face shield in addition would in any way add more protection. It is a burden to wear it all day every day, so if it won't help, she would rather not do it again this year. But will, if there is evidence. 

[Drama Llama]

I looked into this last year, as we were planning on the return to school for my students, some of whom can't mask.  In the end, most of the kids didn't come back.

Anyway, at that point, a long time ago, what I understood is that a face shield can be protective in a 1:1 face to face interaction.  Someone checking your teeth, or swabbing you for covid, or having a 1:1 conversation, or providing speech therapy, would expect most of the droplets coming at them to come from a single direction, and stopping those droplets can reduce viral load, making it less likely to get the virus if exposed.  

But in a classroom, where there are kids in every direction, all talking and breathing, and you don't know where the threat is coming from, they aren't going to be helpful.

But I have nothing for you to read to back that up.  

[gardenmom5]

16 minutes ago, lewelma said:

Thanks for that. So she will definitely wear a mask, and she wears glasses. Is there evidence that a face shield in addition would in any way add more protection. It is a burden to wear it all day every day, so if it won't help, she would rather not do it again this year. But will, if there is evidence. 

For covid - I doubt it.  Unless she's got students sneezing in her face.   

I just flew - and they were clear you had to have a mask.  There are people who want to use shields in place of a mask - and that wasn't allowed.

[lewelma]

Thanks guys, this is very helpful. She is thinking not to bother but wants evidence. I wonder if anyone has done any studies? 

[mathnerd]

46 minutes ago, lewelma said:

Thanks guys, this is very helpful. She is thinking not to bother but wants evidence. I wonder if anyone has done any studies? 

If she is in the same room as her students and they happen to cough (which happens all too frequently in the flu-season in the Fall), the face shield will cut out 95%+ of the aerosols from their coughing. I am going to assume that not all students have on well fitting masks and that aerosol will escape through gaps if there is coughing or sneezing.

If she is in close contact with a student with covid for more than 15 minutes, she is potentially exposed to the virus. Wearing both face mask and face shield is essentially the best protection against aerosol for a vulnerable person. Both my doctor and the pediatrician we see wear both a face shield and a face mask for this reason.

Edited August 16, 2021 by mathnerd

[AmandaVT]

I didn't dive too deeply, but the website looks pretty decent and I skimmed the study - the AJIC looks legit.

"Wearing a surgical mask along with a face shield affords health care professionals only statistically insignificant better protection against aerosolized particles than wearing a surgical mask alone, according a study in the American Journal of Infection Control (AJIC)."

https://www.infectioncontroltoday.com/view/face-shields-called-flawed-protection-against-pathogens

[wathe]

Faceshields protect eyes and face against droplets.  They also decrease surface contamination of the mask.

Covid is spread by both droplets and aerosols.  It's true that face shields don't protect against aerosols, but protection from droplets remains important.

IPAC wisdom is that glasses are not adequate to protect against droplets and/or splash.  Standard safety glasses (with side shields) are also inadequate - they are meant to protect against impact.  To protect against droplets and splash, you really need either goggles with indirect vents,  or a faceshield.

Faces shield plus mask studies (both with simulators)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7922468/

https://pubmed.ncbi.nlm.nih.gov/24467190/

 

 

 

[lewelma]

I've shared the research with her and she is thinking that she lectures with only a mask, but then puts on the face shield with the mask when she is stopping at desks and leaning over to help students with their work. 

[lewelma]

Thanks everyone for helping her out. She is NOT happy to be back at this place again. 

[SoCal_Bear]

I would say that wearing glasses to protect her eyes and from touching her eyes would help. A face shield would solve this problem as well as preven you from touching your face

Edited August 17, 2021 by calbear

[lewelma]

She wears glasses. And she is very very careful. As in peeing in a cup in her office to avoid the bathrooms and drinking her lunch through a straw to make sure she doesn't remove her mask. I think her decision to wear the shield when close to.possible droplets makes sense. Only wearing her mask and glasses when lecturing will just give her a small break. 

[SoCal_Bear]

Can she get anything like a a Travel Jane to make this easier on her to urinate?

 

 

Edited August 17, 2021 by calbear

[SoCal_Bear]

there are folding camp toilet seats as well.

[wathe]

42 minutes ago, lewelma said:

I've shared the research with her and she is thinking that she lectures with only a mask, but then puts on the face shield with the mask when she is stopping at desks and leaning over to help students with their work. 

This seems a reasonable strategy.

[Not_a_Number]

1 hour ago, lewelma said:

Thanks everyone for helping her out. She is NOT happy to be back at this place again. 

Your poor sister 😞 . 

[lewelma]

56 minutes ago, calbear said:

Can she get anything like a a Travel Jane to make this easier on her to urinate?

 

 

She has a cup and a sink. And did it for nine months last year. I'm not recommending she change strategy. She just told me today that she had a panic attack at a staff meeting where 80 staff/teachers removed their masks to eat, and she has gone home to have some booze.

[lewelma]

She very much appreciated the research articles you guys dug up for her. I told her I knew some people online that could help. And she said 'yes please'.

[Tanaqui]

Well... it won't hurt in conjunction with a double mask (cloth over disposable). However, she'll do better to crack the windows.

[lewelma]

31 minutes ago, Tanaqui said:

Well... it won't hurt in conjunction with a double mask (cloth over disposable). However, she'll do better to crack the windows.

I know that the school put in UV lights in the air ducts. But summer with cracked windows is probably a no go. 

I also think that double masking for 7 hours per day is incredibly hard on her. She already uses a microphone, but breathing is an issue since she has had a 2 year long sinus infection where they had to break her nose twice (Once with balloons blown up inside to crack open all the sinus cavities). So there are a lot of things that she just can't do for so many hours each day. I have sent her wool masks from NZ because they have a much smaller wetness problem than cotton. 

[Matryoshka]

6 hours ago, lewelma said:

I know that the school put in UV lights in the air ducts. But summer with cracked windows is probably a no go. 

I also think that double masking for 7 hours per day is incredibly hard on her. She already uses a microphone, but breathing is an issue since she has had a 2 year long sinus infection where they had to break her nose twice (Once with balloons blown up inside to crack open all the sinus cavities). So there are a lot of things that she just can't do for so many hours each day. I have sent her wool masks from NZ because they have a much smaller wetness problem than cotton. 

Has she tried Happy Masks? With N99 filtration, just alone that's likely higher than cotton or wool w/ surgical, they're lighter and thinner, and they're not cotton and don't absorb sweat. They also much easier to wear when talking than other masks I've tried - they sit away from your mouth so you aren't feeling like you're eating it, and are tall enough that they don't pull down your nose when your chin moves. I taught in them last year, but it was only for an hour to an hour and a half at a time.  My brother is a high school teacher, though, and also reports that he likes them.

Your poor sister. 😕

[kbutton]

7 hours ago, lewelma said:

I know that the school put in UV lights in the air ducts. But summer with cracked windows is probably a no go. 

I also think that double masking for 7 hours per day is incredibly hard on her. She already uses a microphone, but breathing is an issue since she has had a 2 year long sinus infection where they had to break her nose twice (Once with balloons blown up inside to crack open all the sinus cavities). So there are a lot of things that she just can't do for so many hours each day. I have sent her wool masks from NZ because they have a much smaller wetness problem than cotton. 

The masking thread has many recommendations for masks that stand away from your face. I like my Happy Mask, but I will likely try a boat style KF mask as well. We bought some for my son with a small chin, and he can adjust them several different ways to fit very well. Bluna FaceFit is what we got. He says it's the least hot mask he's used of all the masks that have come close to fitting him. 

https://behealthyusa.net/products/facefit-kf94-black-large?variant=36887298441380  You can order different amounts--not sure why it's defaulting to huge numbers in this link. Amazon also has them. 

[Hilltopmom]

Teacher here too- I’d suggest she wear the protective safety goggles over her glasses (or get prescription goggles) instead of the face shield.

This is what they are doing at our hospital again now (upstate NY, very low cases, hoping to stay that way)- my brother works in the ER & said they went back to mandatory goggle last week for all hospital staff.