How do you run a fit-test for a mask at home when you don't have fancy equipment?

My answer links to a paper claiming that aroma diffusers can work well but humifiers, spray bottles, and spray bottles did less well. 

How do you run a fit-test for a mask at home when you don't have fancy equipment?

This paper from engineers at Cambridge University claims that a standard aroma diffuser and plastic bag is close to the performance of commercial equipment. That said, I'm not sure how much the total cost and prep time would compare to the nebulizer approach that jimrandomh suggests.

Paper Link



Qualitative fit testing is a popular method of ensuring the fit of sealing face masks such as N95 and FFP3 masks. Increased demand due to the coronavirus disease 2019 (COVID-19) pandemic has led to shortages in testing equipment and has forced many institutions to abandon fit testing. Three key materials are required for qualitative fit testing: the test solution, nebulizer, and testing hood. Accessible alternatives to the testing solution have been studied. This exploratory qualitative study evaluates alternatives to the nebulizer and hoods for performing qualitative fit testing.


Four devices were trialed to replace the test kit nebulizer. Two enclosures were tested for their ability to replace the test hood. Three researchers evaluated promising replacements under multiple mask fit conditions to assess functionality and accuracy.


The aroma diffuser and smaller enclosures allowed participants to perform qualitative fit tests quickly and with high accuracy.


Aroma diffusers show significant promise in their ability to allow individuals to quickly, easily, and inexpensively perform qualitative fit testing. Our findings indicate that aroma diffusers and homemade testing hoods may allow for qualitative fit testing when conventional apparatus is unavailable. Additional research is needed to evaluate the safety and reliability of these devices.

How do you run a fit-test for a mask at home when you don't have fancy equipment?

Do you have tips on how to not fail without having one of these test kits? Which N95s work best? Do rubber P100s tend to fit better?

Anna and Oliver discuss Children and X-Risk

Ability to succeed in building organizations or movements will correlate with ability to organize childcare (either through family, friends or paid help).

Anna and Oliver discuss Children and X-Risk

Clintons? Obamas? There are many examples from academia. Nobel Laureates Banerjee and Duflo, or these two economists:

During the pregnancy, they employed a doula, or birth companion; after the birth, they hired a nanny named Ellen, who had a BA and was finishing her master's degree in education policy, and whom they paid $US50,000 (about $65,000) a year. "We didn't just want a warm body," Wolfers says, over his second beer. "Some people just want someone who'll keep their kids safe, but we wanted more than that."

Anna and Oliver discuss Children and X-Risk

I haven't re-read the paper, although IIRC there are critiques online of this paper and the author's other statistical analyses. How strong do you think the evidence is for the counterfactual "If person has chooses to have kids, their chance of major achievement will drop substantially" (for a range of different people)? Ideally there'd be natural experiments (due to infertility or someone who didn't want kids raising their sibling's children etc). 

These graphs aren't that different and (I'd guess) it wouldn't be hard to p-hack to get the intended result. Rate of being unmarried will vary over time and with country and this will correlate with age of achievements (e.g. if people in biology peak later than math/physics, if there's more biologists in UK and math/physics people in Germany and Italy). And there's the causal / counterfactual inference.. 

Anna and Oliver discuss Children and X-Risk

I'd like to see discussion of data rather than mostly a priori argument ("I have a sense" ... "I suspect desire"). For aggregate data, there's SSC survey and there are studies of "ambitious" groups (e.g. the Harvard Men study, Benbow on precious math talent). There are also anecdata of the exceptionally ambitious. E.g. Musk had first child age ~30 and has many kids, Hassabis had first child aged ~29. It seems Jaan Tallinn had kids starting in his 20s before founding Skype (Wikipedia). Bezos has 4 kids (started age 37). Gates has 3 kids (started age ~40). Turing award-winners David Patterson and Judea Pearl had kids in their 20s before their biggest contributions. Yoshua Bengio in his 30s. etc

Second Citizenships, Residencies, and/or Temporary Relocation

I don't know of instances. But I'm also interested to know if people have good sources on this. 

My understanding is that people entering the UK by air (e.g. from the US) now enter via ePassport gates and so don't need to talk to a border/immigration official. This might make it easier to enter than before. At the same time, I would be wary (based on what little I know) of entering without a clear explanation and evidence you are not working in the UK (e.g. epic holiday in UK, clear family reasons). 

Second Citizenships, Residencies, and/or Temporary Relocation

I believe you can spend 6 months in the UK visa free and there's no rule against more than 6 months out of the year. My understanding is that visitors will be vaccinated and treated for Covid by the NHS -- you may need to pay some modest fee. 



Chinese History

China was somewhat unified and had a big chunk of the world's population and was more likely to record population levels -- though I'd guess there are huge error bars around the Three Kingdoms War and An Lushan Rebellion. If you control for political unity and population, were Chinese death rates in armed conflict higher than other regions?

The three historical figures I can think of who built giant institutions lasting thousands of years

Why draw the cutoff at thousands of years? And I'd guess recent institution building is much more relevant to EAs than ancient.

China does capitalism well without conflating capitalism with democracy

There were already the examples of Taiwan, South Korea, Hong Kong and Singapore. (One could also consider European and South American states that were right-wing dictatorships). 

Nor does China entangle religion with politics to the same extent you find in the Christian and Islamic worlds.

Christian worlds? Secularism has been important in France since the French Revolution. What about India or Japan? What about Hellenistic culture or Rome?

Robust models of a region usually depend on knowing the region's history.

The question is how much "memory" or "persistence" the time series has. Mostly history is screened off by the present and recent past. You wouldn't predict North vs South Korea by looking at Korean history for any time period up to 1930s. 

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