Author: chogan@directresearch.com

Post #617: Slipstream, a followup on aerosol transmission of COVID-19

Four cigars (pr:  SEE-gars).  Source:  clipart-library.com

I have give David Patariu a cigar for this one.  He gave me the most apt analogy for what I’m about to bring to your attention.

If somebody smoked a cigar in your house, you’d still be able to smell it long after the visible smoke had cleared.  That’s because there would still be some tiny smoke particles floating in the air.  Not enough to see, but enough to smell.

And that’s pretty much how aerosol transmission works.  There are tiny (under 5 micron) droplets floating in the air, produced as a result of anything from breathing (relatively few) to singing (lots).  Not enough to see, but maybe enough to spread viral infections such as COVID-19.

I’ve already discussed this in detail in several posts, and it’s summarized on the front page of this website.  But the upshot is that you should think of this the same way you’d think of avoiding second-hand cigarette smoke.

If the person talking to you was a smoker, they’d be blowing smoke in your face.  If they were singing at full volume, they’d be putting out clouds of cigarette smoke.

And, unsurprisingly, if they are doing any exercise that makes them breath deeply, they’ll be putting out great big clouds of smoke.  And if you happen to be walking/running/biking behind somebody who is sick (and doesn’t know it yet), particularly if they are breathing hard, you need to be aware of the potential for “slipstream” transmission of aerosol virus.

The upshot is that, among all our social distancing rules, I want to add a new one.  If you’re on the W&OD say, you really don’t want to be running or biking or, really, even walking closely behind anyone else. For sure, not if it’s a still day.  And, for sure, not if the wind is coming from directly ahead of you.  The reason is the potential for virus in droplets and aerosols to hang up in a person’s slipstream.  Combine that with higher droplet/aerosol production when breathing heavily, and … you get the picture.

Even a slow walk (4 KPH, about 2.5 MPH) is enough to create such a slipstream effect.  If you want to, you can think of it as the person ahead of you walking out of his or her own cloud of droplets, and you walking into that cloud before they can all settle to the ground.

Here’s an easy way to think of it:  The 6′ social distance is for when you’re standing still.  The faster you are moving, the larger that distance needs to be between you and the person you are walking/biking/jogging behind.  For the simple reason that your movement carries you into the droplet stream of the person ahead of you.  Six feet only works when you’re stationary.  That’s obvious, really, when somebody points it out to you.  But I needed to have this pointed out to me, before I got it.

Or just think of it as the same as walking behind somebody who is smoking a cigarette.  Walk too close, or walk into the wind, and you’ll smell the smoke.  More-or-less the same effect here.

That’s courtesy of a new piece of research out of Belgium.  They concentrate on droplets (conventionally, larger than 5 microns) but the same rules apply.  Some of these droplets (and for sure, aerosols) can get hung up in the slipstream of a walker, runner, or bicyclist, and land on the person behind them.

In general, the slipstream effect is so large that racing bicyclists routinely take advantage of it.  As do runners.  That’s why bike teams travel in a straight line, one behind the other.  You just need to be aware, now, of the theoretical possibility that if the person ahead of you in the slipstream has COVID-19 (and presumably doesn’t know it yet), you can be exposing yourself to it.

The advice from Brussels is that if you go jogging or biking with others, side-by-side is safer than single file.  No proven cases of transmission yet, but it’s not clear how you would ever prove one anyway.

You can see a popular writeup of the research at this link.

Post #616: Aerosol spread, and taking stock of how vastly better the picture looks right now, than it did just one week ago.

Source:  Science, 4/2/2020, brief piece authored by Robert F. Service.

Panic gets a bad rap these days.  A lot of people push a meme of “Don’t Panic”.  Keep calm and carry on, and all that.

But my motto is: Panic Early and Often.  Panic can be a good thing when it gets you off your butt and doing something productive.  There’s a reason we have a fight-or-flight reflex.

I didn’t really hit full panic mode until the morning of 4/2/2020.  I explain below how I know the exact date and time.  But, at that time, panic  was an entirely reasonable reaction in response to facts as they then existed.

But I went through that panic.  A panic based on my judgment of the facts.  And I’m not panicked now.  Again, for what I believe to be excellent reasons.

So I figured, all things considered, I might as well share those reasons.  Because my assessment of how things look today is vastly more upbeat than it was when I hit flat-out panic on 4/2/2020.  And it’s not that I’ve changed.  It’s that the facts have changed.

My wife tells me that I’m about three days ahead of the newspapers on this pandemic.  Sometimes more, sometimes less.  So, as the death tolls mount, and the case counts continue to march upward, I figured I should take the time to point out how vastly better things look now than they did one week ago.

This, from a guy who’s been a few days ahead since the start of this.  And one whom no one would call an optimist.  Skip down to “What a difference a week makes” if you just want the bottom lines of these topics.

 

Continue reading Post #616: Aerosol spread, and taking stock of how vastly better the picture looks right now, than it did just one week ago.

Post #615: Daily case increase to 4-8-2020

These charts show the day-to-day increase in COVID-19 cases in Fairfax County and in the Commonwealth, through about 6 PM today, courtesy of the Johns Hopkins coronavirus information website.

The black line is a seven-day moving average.  I’d have to say that, still, by eye, Fairfax does not look like it’s seeing exponential growth (like the side of a bowl).  Instead, this looks more like a hilltop.  And I’ll note that the break between concave-up (exponential growth) and concave-down (hilltop) seems to have occurred more-or-less at the right time for this to have been the result of the shutdowns and social distancing — a little more than 10 days after Fairfax shut the schools on March 13.

For the Commonwealth, by contrast, I’d say it’s still too soon to tell.

 

Post #614: The sky is blue

 

White Clouds in Blue Sky ca. 1996

Source:  Clipart-library.com

No, really.  Stick with me here.  What I mean is, have you noticed that the sky is unnaturally blue.

This is Virginia, for crying out loud.  The spring/summer sky should be, at best, pale blue, edging toward fish-belly white.  But day after day, it’s like we’re living at high altitude in the Rockies.  Perfect beautiful blue sky.

Did you know that if we shut down all industrial activity and fossil-fuel use, the impact would be to raise the earth’s temperature significantly?  In the short run.  And only in the short run.  True fact.  That’s because we release both C02 and particulates/aerosols.  C02 warms the earth, but aerosols cool it.  The C02 is very stable, remains in the air for a enormously long time.  Most particulates and aerosols would rain out/fall out in a matter of weeks to months.

Basically, the longer the shutdown, the better the sky should look.

But apparently this is perception of better air in the DC area is purely in my head.  Because empirically, somehow, the air quality index for DC is … no different than it normally is.  Per this web page.

So I’m a little perplexed.  You’d think, from the traffic reduction alone, you’d see better air quality.  But … no.  I think I’ll keep looking around to see if anyone can explain this.  Or maybe the Air Quality Index doesn’t quite measure what I think it measures.

CORRECTED AND CORRECTED AGAIN 613: Masks, rescinding post #608, getting a jump-start on my offer.

I have now been absolutely assured, by a Town Council member, that, in fact, there will be a distribution of masks of some sort, on Friday, for all Town of Vienna residents who want one.  All you have to do is show up at the offices of Nova Dentistry 307 Maple Ave W #F100, Vienna, VA 22180. 

So, the instruction are at this point:  Ignore what it says on the Nova Dentistry website.  Apparently, ignore what they tell you if you email them and ask.  Show up there — I’m not sure what time, but it looks like after noon on Friday — drive by, and they’ll drop a pair of masks through the open rear window of your car.

I would not mention this except that I have been told, in no uncertain terms, that this is going to happen, by a Vienna Town Council member, and I think everyone should be wearing the best mask they can get, when in public among other people.  I can make a mistake by announcing something will happen, that won’t.  I can make a mistake by announcing something won’t happen, that will.  In this case, if I’m making a mistake, it’s better to make the first one.  Based on an unambiguous statement from a Town Council member, if you want a pair of masks, show up there tomorrow.

So, below, where this says “patients”, apparently, just ignore that. Where it says 2 PM, question that.  But otherwise, what’s posted on that dentist’s own website is your guidance on this.  Less those changes.

Apparently there is a “press release”, somewhere, that fully explains this, but I have not yet been able to find it.

Source:  https://www.novadentalcareofvienna.com/  Used without permission, with a claim of fair use given the current pandemic and shutdown.

Correction:  I am now hearing yet a third story about a face mask distribution scheduled for this Friday at a Town of Vienna dental office.  The story I have now been told is that there will be two sets of hours for this, one for patients, one for the general public. 

But that story directly contradicts what is posted, right now, on the website for that practice.  And it contradicts the plain language of an email that a colleague got in response to an inquiry sent to that practice.

It’s possible they don’t know what they are going to do.  It’s possible that their plans are changing.  It’s possible that what I have been told is wrong.  Beats me.  I’m butting out of this one.  You can probably track this one down if you have the time to do so.  But the plain language of their website and their emails say what they say.

Caveat emptor.

Update to Post #608:  Not an offer to the general public

I think everyone should be masked when in public, around others.  I explain that succinctly on the front page of this website. Any mask is better than no mask.

Recall that I got an obscure notice that somebody in Vienna was going to be handing out masks this Friday, discussed in Post #608.  I finally tracked down the true information and that’s not a mask giveaway open to the general public.  That’s a dentist trying to help out his patients, and the masks are for his patients.

The status of my masks.

Not here yet, but should be coming soon.  I have about 500 adult and 150 child-sized “single-use” surgical-type masks on order, as of 4/2/2020, from a variety of sources.  These are NOT certified as to filtration and so CANNOT legally be used by hospitals.  First box should have shown up today, but everything shipped seems to be moving slowly.  Based on the rate at which my other orders are arriving, I should have some by the end of the week. 

No telling exactly what I’ll get, or when.  By the time I thought to order them, the ordering process was chaotic, to say the least.  FYI, there are a handful of offers for non-medical (“single use”) masks on Amazon that promise delivery times on order of two weeks now.  So if you’re of a mind to deal with this yourself, you can do so.

I’ll put up a sign-up page tomorrow, either here or on Google Forms.  I’m going to distribute these by dropping them off at your home, assuming that the order rate is slow.  I’ll arrange to mail them if not.   I’ll wash my hands first.  If that’s too risky for you, don’t ask for one.

As of last Friday, the CDC says we should all wear masks when in public.  My take on it is that everyone should be wearing the best mask they can get, every time there are in any indoor public space (like a store), or outdoors within “social distancing” distance of others (such as when waiting in line to get into a store).

My plans regarding masks are on the front page of this website.  The masks I bought are in no sense “medical supplies”.  I plan to improve them for better filtration of aerosol particles, as outlined on the front page of this website.  I’m making no guarantees of anything.  The only thing I’m guaranteeing is that I did, in fact, build them as described, with materials as described.

I’ll be giving them away to Town of Vienna residents.  If there’s no demand for them here, I’ll start start offering them to the highest-traffic Town of Vienna businesses that are not yet fully masked up.  If not, then I’ll expand the offer to the immediate vicinity.  If still no takers, I’ll be sending them to a contact in New York City.  Or I’ll just write this off as not a very bright idea.

Please read the front page of this website to see why you may or may not want a few of these masks.  Any mask will comply with the CDC’s direction to wear masks so that you don’t infect others.  These will, in addition, at least in theory, also provide some filtration ability against aerosol particles, due to the use of the Filtrete (R) 1900 or MERV-13 filter material.  But I make no guarantees.

I refer to these as a “shopper’s mask”.  They are not heavy-duty, and not intended for every-day day-long wear.  That doesn’t mean they can’t be used for that.  I’m going to do my best to beef up the weakest piece, which is the elastic, as I modify them.  For sure, they will not lose their filtration ability for some months to years, if you use them sparingly and take care of them as I suggest.  To disinfect, do what hospitals currently do for N95 masks:  Drop it in an open paper bag and leave it for a few days.

My target group is people who might benefit from a mask for (say) one-hour-a-week of necessary grocery shopping, or something like that.  They are certainly not an excuse to get out more.  But they might be handy if (e.g.) you need to take an elderly relative to the doctor, go grocery shopping, and so on.

If you don’t want my “upgraded” masks, but do want a simple “single-use” surgical-type mask (not rated for medical use), exactly as they come out of the box, I’ll accommodate you if I can.  In fact, if I have misjudged, and for whatever reason, I can’t upgrade these to Filtrete-based masks, that’s all that will be available.   In that case, these will be plain, cheap three-ply disposable masks.  They will fulfill the CDC mandate to wear a mask in public to protect others.  They will not do much to protect you.

I’m going to withdraw this offer to provide “factory-stock” masks in about two weeks, because that’s the back-order time of the earliest available disposable masks of this type on Amazon.  If that’s what you want, you can have those off Amazon in two weeks. (Most of their disposable masks are back-ordered to the end of May.  But some are available earlier).

Aren’t I worried about people inhaling fibers?  Well, yes and no.  The materials for the furnace-filter cloth are inert plastics, and the factory-made mask will be between you and the filter cloth.  If they do shed fibers, those should be caught by the factory-made face mask that is the basis for this design.  That is, in part, why I’m building these on top of sonically-welded factory-made (i.e., no-internal-leaks) masks.. So, yes I worried about it.  Past tense.  I have done my best to make sure that’s not an issue.  If it still bothers you, don’t order a mask.

I look at this whole project as a purely temporary gap-fill.  Give it another month or two, and you should be able to get a proper high-filtration mask again.  At which time, you should throw mine away.

I’ve decided to distribute these by the simple expedient of delivering them to Town of Vienna addresses.  If the demand is light, I’ll do that by hand.  If the demand is heavy, I’ll end up mailing them.  I’m going to put up the order page tomorrow, one way or the other, even though the masks have still not yet arrived.  (I have some of all the other materials now).

I’ll also give away the filter material:  Filtrete (R) 1900 or MERV-13 or higher furnace filter material, if you are making your own mask  You can still buy these furnace filters in the stores, but a) you only need a small piece, b) you shouldn’t make a trip just to buy these and mostly c) I bet there’s a lot of people out there who don’t really believe this works well, and so won’t buy this on their own, but would incorporate it into a sewn mask if it were free.  It really is a leap of faith that this little bit of fluff can protect you.  But that’s the story.

Please ask for furnace-filter material only if you are trying to sew a mask for yourself or your neighbors, and want to give yourself a bit more protection that a cloth mask would.  Please don’t ask for that if you are planning to give your mask to some anonymous hospital worker.  You can see my discussion on the front page of this website.  Unless you literally know your mask recipient personally, and they claim that they will wear this mask on the job, please don’t waste this stuff on mask destined for hospitals.  Because, right now, it would be illegal for a hospital to allow home-made masks to be used, and I suspect that hospitals will never again be so desperate that they would use home-made masks as masks of last resort.

If you know a public-facing retail worker in the Town of Vienna who does not have access to a mask, but would wear one.  Or Town employee whose job brings them routinely within 6′ of others, or into public indoor spaces of any sort.   Then do them a favor and get them one of these, or some other mask.  I’ve done the calculation on this website, and (e.g.) workers at our large grocery stores are probably being exposed to COVID-19, to some degree, on a daily basis.  For them, they should be wearing the best mask they can get.

Finally, it goes without saying, but if you already have a mask with any rated level of filtration, please don’t ask for one of these.  A proper N95 is best, a filtration-rated surgical mask is next, and then everything else comes third.  If you have a proper medical mask, wear it and leave these alone.

More details tomorrow.  I’m about to spend a pleasant evening stripping down furnace filters.  Not something I would ever have imagined I would say.

Finally, if you’re of a mind to disparage me on social media for buying these masks, please be aware that I now know far more about this than you do.  At least read my posts explaining why I’m doing this, learn about the various types of masks, and read the CDC guidance on what masks hospitals may and may not use at present.  I don’t mind the fact that you’d be mistakenly calling me a jerk.  Much.  I do mind if you discourage people people from accepting and using these masks, based on your mistaken understanding of the masks that citizens should and should not buy at present.

If you don’t believe me, at least take 60 seconds to look on Amazon.  Anything of any medical value has been withdrawn from sale.  What left — the blue  “surgical-type” masks — that’s what these are.  With high-end furnace filter cloth taped to the front.

Post #612: Election confusion on two fronts

First, it looks like the Governor is trying to get all May elections postponed until November.  I think that’s the correct thing to do, all things considered.

Second, there still seems to be considerable confusion in Town over campaign finance laws.   Twice in the past two days I’ve seen or hear of things that lead me to believe that many people in Town still either don’t understand what the law is, or are deliberately misrepresenting what the law is.

I heard that, sometime in the past couple of days, somebody claimed that a sign was illegal because it had some candidates names, but no “Paid by …”  line noting the source of funding.  That’s wrong.  And we all know that’s wrong, because we’ve never had “paid by” lines on the yard signs before.  And I also see that, this year, one candidate actually does have a “paid by” line on her signs.  That’s also wrong, if she’s trying to convince people she’s complying with the CFDA.  But as long as we all recognize that’s just a bit of let’s-pretend, I think that’s harmless.

If you actually want to comply with the CFDA, you have to have duly-constituted and registered Virginia Political Action Committee.  I know because I did that last year, to make sure I understood the process.  And detailed what the CFDA does and does not do, on this website.

Looks like it’s time for a refresher course on the Virginia CFDA.

In a nutshell, no campaign finance disclosure laws apply to Town of Vienna elections.  That’s the way it has always been, ever since Virginia pass the Campaign Finance Disclosure Act.  (CFDA).  The only change this year is that they’ve added a clause that says, if you spend $25,000 or more, as a candidate, in a Town election, then yeah, in that case, you have to obey the CFDA.

So, briefly, with citations as to source:

Campaign finance law for Virginia Towns with under 25,000 population.

There are none.  So let’s start with the basics.  No campaign finance laws apply to Town of Vienna elections.  I wish they did (Post #272, from May of last year.)  Not unless the Town Council slipped in a piece of last-minute legislation. Or a candidate is planning to spend more than $25 grand, which I think is way beyond unlikely.

So if somebody tells you that (e.g.) some sign is illegal because it doesn’t comply with Virginia law, they just haven’t read the law.  Or they are trying to pull a fast one on you.  If somebody puts a “paid for” line on their signs, they’re either trying to convince you of something that’s not so, or they’re planning to shell out more than $25,000 in their election bid.

But that last one is easy enough to check.   If somebody’s complying the the CFDA, and that “paid by” line has any legal meaning, they have to have a Virginia PAC.  No PAC?  Then a “paid for” line is just an additional bit of election-year nonsense.  It’s easy enough to search all the active Virginia-registered PACs, right at this link.  Have a look for yourself, if you care.

It’s a simple test.   Got a PAC?  No?  Then any “paid for” line you see is the politician’s variant on “guaranteed not to turn pink in the can“.

So let’s all go read the law, because boy am I tired of having to explain this.  And, interestingly, it changed since the last time I looked at it:

This is § 24.2-945. Elections to which chapter applicable; chapter exclusive.

The provisions of this chapter shall apply to all elections held in Virginia, ... except nominations and elections for ... (iii) town office in a town with a population of less than 25,000, ....

Emphasis mine. But they’ve added a new exception since last year.  If you spend in excess of $25,000 on the election, you’ve got to abide by the CFDA:

The provisions of this chapter shall be applicable to a candidate for a town office in a town with a population of less than 25,000 if (a) such candidate accepts contributions or makes expenditures in excess of $25,000 within the candidate's election cycle

And then it goes on to say, or if the Town votes to put itself under the CFDA.  Herndon actually did that about 7 years ago.  But not, to my knowledge, the Town of Vienna.  Last time my wife brought this up at a Town Council meeting (Post #507).  That was met with roughly the same reaction as a fart in an elevator:  Dead silence and dirty looks.

Why do I know the law?  Because I bothered to go through all the steps to form a legally-registered Virginia PAC (Post #272).  I needed to know, first hand, exactly how burdensome it was, before I suggested that the Town vote to put itself under the CFDA.  I even wrote up a guide to doing all the steps required to form a legally-registered Virginia PAC.  I offered to make that guide freely available to anyone who wanted it if the Town ever voted to put itself under the CFDA,.  My wife got up in (one, several, I forget) Town Council meetings and pleaded with the Town to put itself, for reals, under the CFDA.

Which is also why I find people who don’t know the law, but throw it around to intimidate people, or mimic it to impress the gullible, I find that irksome.

Actually complying with the CDFA requires some significant effort.  There are a lot of legally-required reports that must be filed, for example.  I went through that, myself, forming a PAC, because I did not want to recommend that the Town put itself under the CFDA if that process was impossible to comply with.

But the short and simple answer is, the CFDA simply does not apply to Town of Vienna elections.   This year.  Just the same as it didn’t apply in any prior Town election.

Unless you plan to spend $25,000 or more.  That’s the only change for this year.

Post #610: An observation on masks

Source:  CNBC

CNBC has a long article about the end of the lockdown in Wuhan province, China.  Lots of pictures.

I challenge you to find a single individual not wearing a mask, in any of the pictures in that article.

And, I’m pretty sure that the entire flight crew pictured above is wearing KN95 masks, the Chinese-made equivalent of the N95 that is (for now) in such short supply in the US.

Not only is everybody wearing some kind of mask, I infer from this that critical personnel are wearing masks capable of filtering out aerosol particles.  The same masks we’d give to medical workers here.

And back in the USA, we still don’t have a mandatory mask ordinance in any state.  In fact, so far, I’ve only heard of one, for one Texas city.  We need to wake up and get with the program.

Post #609: What goes around comes around, in a good way

https://www.gofundme.com/f/pay-it-back-to-vienna-business

About a dozen Vienna businesses made large donations when this young man was trying to raise money for a cancer charity, a year ago.

Now he’s decided to try to raise money to pay them back, via GoFundMe

Even if you don’t donate, at least go read the story.

Post #608: Somebody in Vienna steps up on the mask issue

The US CDC wants us all to wear some sort of mask when in public, around others.  That was last Friday’s change in guidance to the public.
Some people don’t have a mask.  And, there’s a cultural (racial) barrier to wearing home-made masks in public .  And, frankly, I think most of us would prefer any commercially-produced mask to ginning one up at home.
I have been informed that one Vienna dental practice will be giving away two free masks per family, for a limited time period.  I don’t want to post the location until I am sure this is a general offer to the public, and not merely an offer to patients of that dentist that has somehow become more broadly known.  If it is a general offer to the public, I will post it.
Either way, I’m glad to see somebody stepping up.
I think, all things considered, we need an indoor public area mask ordinance here in the Town of Vienna.  Every employee in a public-facing position should wear a mask.  Every shopper should wear a mask.  If social distancing alone were enough, we would not have the CDC and the Governor of Virginia telling us to wear masks in public.