Coronavirus - those in China, and general discussion

[889]

As to herd immunity, there's a very interesting question about the extent to which a part of the population already has some sort of immunity to Covid, perhaps as a result of SARS exposure in some instances.

 

There's a fascinating article on this in a recent issue of the British Medical Journal, but it's gotten little attention:

 

https://www.bmj.com/content/370/bmj.m3563

 

[Lu]

1 hour ago, Demonic_Duck said:

Herd immunity is only a realistic prospect once either a) an effective vaccine is discovered, b) treatments are discovered that make the death rate negligible, or c) many millions more people have died from the virus. Anything else is a pipe dream.

[Puts on amateur virologist hat] There have been several reports of people contracting covid-19 a second time. Seems to me that means that herd immunity will never happen, just like there is no herd immunity to the common cold or the seasonal flu.

[realmayo]

I have that hat too! But I'm more optimistic because of all the good news we're getting - including like what 889 linked to - about T-cells.

[Demonic_Duck]

25 minutes ago, realmayo said:

I'm more optimistic because of all the good news we're getting

 

Agree with this, albeit tempered with a hefty dose of caution. Bear in mind that "herd immunity" doesn't mean that every single person is immune; it means that the overall immunity of a population rises to a level where transmission of the virus fizzles out. This could be aided by one or more vaccines of varying efficacy. Think of it like how increasing atmospheric humidity gradually decreases the chance of a dropped match starting a forest fire — saturation point doesn't have to be reached before the risk is effectively nullified.

[Flickserve]

It's better to assume nothing about herd immunity. Assuming that herd immunity exists has just been an excuse for poor handling of the virus.

[realmayo]

... and it's possible that (a) a chunk of people have pre-existing immunity because of past exposures to othere coronaviruses. And (b), there seem to be lots of people who had Covid-19, have no antibodies detectable, but have T-cell response - which implies that more of the population may already have had (and are now immune to) Covid-19 than you'd expect just by looking at antibody tests.

Put those two together, pair a very optimistic pair of best-case sunglasses with the amateur virologist hat, and the bar to herd immunity might already be a lot lower than we think. Throw in a half-decent vaccine and we can all start licking door handles again.

[Demonic_Duck]

30 minutes ago, Flickserve said:

It's better to assume nothing about herd immunity. Assuming that herd immunity exists has just been an excuse for poor handling of the virus.

 

I don't think there's any doubt it exists, the question is how close it is to being achieved (probably not very IMO, but vaccines will change this equation). I agree the concept has become tarnished due to its misuse by political opportunists, but that doesn't mean it's worthless, any more than quantum entanglement is a worthless concept due to its misuse by charlatans who explain their wacko theories with "a quantum did it".

[Lu]

1 hour ago, realmayo said:

pair a very optimistic pair of best-case sunglasses with the amateur virologist hat

Halloween costume for next year.

[realmayo]

Also worth pointing out in the context of the slightly earlier discussion: China got very angry in February with countries that closed or imposed quarantine on transport links between China and themselves. (Some of the liberal left in the West was also of course very opposed to closing borders to people from coronavirus hotspots.)

[roddy]

Strong contender for the November least necessary forcing in of left/right politics award there, but the month is young...

[大块头]

15 hours ago, mungouk said:

Yesterday's drama was "how to clean up a mercury spillage". They gave us all mercury thermometers to report our temperatures twice a day, and I dropped mine. It broke and the bulb totally vanished. When I asked the medical team for help they said "you clean it up". A couple of hours of learning new life skills there, hunting for tiny silver balls and chasing them around the floor.  (Since my case arrived I now have my digital thermometer with me.)

 

Oh dear... I hope the floor is tile and not carpet? I'm surprised mercury thermometers are still in use over there!

[icebear]

1 hour ago, realmayo said:

China got very angry in February with countries that closed or imposed quarantine on transport links between China and themselves.

I suspect this is the reason they haven't explicitly banned incoming travel by foreigners, when their policy since April has been close to equivalent. Them brow beating Italy to stay open in late January would look even worse if they 100% closed now.

[mungouk]

1 hour ago, 大块头 said:

[Mercury spillage] Oh dear... I hope the floor is tile and not carpet?

 

Yes, it's a hard floor. Then again, if it had landed on carpet then the thermometer wouldn't have broken.

 

(ESL teachers, feel free to use that in your next lesson on third conditionals...)

 

China is apparently one of the world's biggest producers of Mercury, but Hg thermometers have been banned in most of Europe for years.

 

And now, back to your scheduled geopolitics discussions...

[Flickserve]

3 hours ago, realmayo said:

Also worth pointing out in the context of the slightly earlier discussion: China got very angry in February with countries that closed or imposed quarantine on transport links between China and themselves. (Some of the liberal left in the West was also of course very opposed to closing borders to people from coronavirus hotspots.)

 

Also worth pointing out we knew far less more about the disease in February.

 

[Dawei3]

4 hours ago, mungouk said:

one of the world's biggest producers of Mercury, but Hg thermometers have been banned in most of Europe for years.

If it's any consolation, mercury exposure now is far less than it once was and your temporary exposure to a small amount of metallic mercury is unlikely to pose any health risks.  The risks from mercury derive from cumulative exposure.

 

If you've heard of "calomel", it was mercury-based teething cream applied to the gums of teething babies.  Mercury-based diaper powders were often used.  Mercury over-exposure was common in babies in the UK & US until the 1950s.  It was called the "pink disease" (Acrodynia) because the babies turned pink.  Also, environmental exposure to mercury was far higher because it is by product of coal burning and at that time, coal emissions were uncontrolled and it was the primary fuel for power stations.  However, starting in the 1960s in the US, coal plants had to remove mercury from their emissions (I don't know about Europe...).  Other sources of mercury exposure were also eliminated.  

 

Also, metallic mercury is poorly absorbed, unless you heat it up and inhale it (which I know you won't).  ~100 years ago, they used to feed liquid mercury to patients with the mistaken idea it would clean their digestive tracks.  People lived thru this because metallic mercury is relatively poorly absorbed.  Organic mercury is far more dangerous because it can be absorbed via any route, including the skin.  

 

 

 

 

[mungouk]

Thanks @Dawei3

 

I followed the guidelines at https://www.epa.gov/mercury/what-do-if-mercury-thermometer-breaks and the medical team here sent me some rubber gloves. I picked up the droplets using a couple of pieces of paper with a crease in, and put them in an empty water bottle which was then plastered with danger signs and disposed of in a hazardous waste bag.

 

I did read quite a few official-looking things online suggesting that very small droplets of mercury would evaporate/vaporise (whatever) in the room and become harmful gases, so I vented it best I could.  Sounds like you wouldn't be worried about that.

 

I remember at school the teacher rolling around droplets of mercury in the palm of his hand, and we played with it on the desk.  Wouldn't get away with that now, I suspect!

 

 

 

[abcdefg]

Is mercury, like the mercury in a thermometer bulb, 汞 or 水银 or something else entirely? I don't think I ever had the occasion to use that particular word. 

 

(Random useless information department: Didn't Qin Shi Huang 秦始皇 drink mercury in his quest for eternal life? Seems like I remember mention of that, along with talk of its use by certain Taoist Mystic Alchemists 道教。)

 

Quote

 

When ingested, these compounds did not always result in the desired outcome. Many individuals died or had psychological difficulties after taking certain elixirs. However, the loss of life may not have seemed a large risk, when compared with the promise of the afterlife. Although these elixirs were lethal or dangerous, there is some contention that these individuals were not ignorant of the fatality of some of the materials they were ingesting.

There were certain grades of immortality, so if the practiced alchemist died, the level of immortality they achieved was determined by their corpse. If their corpse was sweet-smelling, it was said that they had achieved immortality in an ephemeral state. Likewise, if their corpse disappeared, leaving behind only the clothes, such as in the death of an adept named Ko Hung, this was another form of immortality known as shih chieh hsien (corpse-free immortals) (Cooper, 14). -- Wikipedia

 

 

[889]

It's more than possible that that thermometer didn't contain mercury but galinstan, a non-toxic metallic substitute, instead.

 

https://m.alibaba.com/product/60086877702/Galinstan-Clinical-hospital-or-family-use.html

 

Easy to test: Galinstan will wet glass while mercury won't.

[mungouk]

Interesting, I hadn't head of Galinstan.

 

The medical team seemed to think it was Mercury though.

 

 

It certainly behaved like it, but then again maybe Galinstan behaves the same way...

 

 

  

 

 

 

 

[889]

As I said, the test is how it behaves on glass. If it balls up like that on glass, it's probably mercury. You can spread Galinstan on glass, but not mercury.

 

Also, Galinstan quickly forms a surface oxide, so it looks duller than shiny mercury.

 

(Note that while Galinstan is not toxic, it can nonetheless damage aluminium and other metals, so still take care.)