This is kind of my hobby horse: you don't need to subject people to harm to test causuality. You can do the opposite: Remove harm and see what happens. Maybe give people free HVAC upgrades to filter more particles.
People don't wait to determine whether school district performance is caused by the staff or the selection effect of eager parents, they just move to good school districts.
Chase those good effects AND attempt to understand them. Understanding the mechanism is not necessary to select for good results.
(All ethics is utilitarian in effect. Kantians stop pretending.)
So perhaps the asthma numbers are influenced by an increased willingness to diagnose it. Just a thought.
https://www.cdc.gov/asthma/asthma_stats/asthma_underlying_de...
Do you have any intuition for how to identify an increased willingness to over-diagnose? It may be true, but how do we test this hypothesis?
It will be interesting to see the driving environmental causalities behind these autoimmune disease increases if pollution is not a key variable.
Of course this would be irresponsible so I'm hoping that by combining data from multiple studies and getting a better grip on how to control the test environment to selectively adjust (remove) only the studied parameters (pollutants) we can still get a good idea of what's happening.
On the one hand, the machine is specifically administering the pollutant to humans; on the other, without the device they'd be getting the exact same and worse.. I'd say yes if offered that for my house and it could help research.
But using a filter that selectively removes just that pollutant and changes nothing[0] else would probably be the cleanest way to do it.
[0] another thing that's very hard to achieve.
Seems kind of like saying (although this example is certainly less ethical to those of us who oppose murder and death penalties) that there's a difference ethically between killing someone by putting poison into their body vs. killing them by preventing food/water to go into their body.
But as to achieving it, sure I wasn't proposing it as necessarily a good or feasible option - other the little bit of research I did when choosing which air purifier for my bedroom I don't know much about the technology.
I was more just thinking about the ethical question if it were possible, since I can appreciate the argument against it but like I said, I personally would be completely happy for a research team to offer me the hypothetical machine.
I guess it's the difference between a surgeon operating and taking out 90% of a tumor, and a surgeon taking out the whole tumor then putting a bit back in. But again, I am not an ethics expert, this is just me bouncing ideas.
By definition, it is a concentration of things small and solid. Whether they are ground tires, engine soot, rock/dirt, pollen, mold spores or powdered cyanides, they are counted the same.
If you wish to replicate pollutants, then consider ethical implications of: Looks the same to me, my colleagues and everyone I know, yet it's not, or is it?
https://ehp.niehs.nih.gov/doi/10.1289/ehp.1408795
Personally, I'm down with harm reduction even if it doesn't teach us anything. As a goal it seems pretty good on its own.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119479/
I wish I had as many advocates as the devil did.
I'm not suggesting that the things in a room cause depression. Correlation tells you more than strict causation ever could.
An example: Income is higher among vim users than eclipse users. Does that suggest anything to you?
It does to me, but that's because I'm willing to let the evidence shape my decisions. If I waited for strictly-causal proof then I'm leaving money on the table.
Another tip: When will it stop being the case that vim users make more money than eclipse users? When evidence mounts and marginally push the lazy-about-evidence-people toward vim. By the time the last eclipse user switches away there won't be any more money on the table to take. Also eclipse will be dead by then.
Be greedy with evidence and lazy with your attachments, not the reverse.
HVAC and indoor air quality (IAQ) is a fascinating topic and it takes good design to get it right. In most HVAC systems you can't just stick a higher MERV filter in and expect good results because they are designed for specific amounts of air flow. Thicker filters cause more air resistance which reduces air flow and fan efficiency which means less comfort and greater energy use.
Often a better strategy in a retrofit is to increase air sealing (a good energy recommendation anyway) and install an E/HRV to exchange indoor for outdoor air with a good filter in it. PM2.5 comes from outside so this should take care of it.
https://www.energyvanguard.com/blog/unintended-consequences-...
https://www.energyvanguard.com/blog/7-reasons-your-filter-is...
Or just reduce pollution in the first place! AFAIK, manufacturing and running HVAC would add more pollution and cost more than switching (for instance) from internal combustion engines to electric vehicles. Or even better, cycling within cities. etc.
Plus unfiltered air is elsewhere, as a confounder.
1. Does adding an air filter in peoples home improve health outcomes? 2. Does pumping a suspected noxious element into a room in lab harm some small group of people in some limited testable way?
Question 1 is better than 2. Why? Because there are more people like those in question 1. Answers to question 1 inform my future choices, answers to question 2 do not. I prefer answers that improve health to those that harm health.
Always prefer observational studies done in the field (in situ). Demanding experimental studies done in a lab will give you less bang for your buck. Let's all do our part to drive down health care costs, please.