I've been mulling over the amazing work @nshapiro and others have been doing on formaldehyde detection and remediation -- especially the plant-based remediation kit folks have been testing out -- and had a few ideas I wanted to share for input.
I was thinking about whether it'd be possible to set up a version of the plant based filter, as shown here, but with some tweaks, and I'll get to why in a moment:
In this prototype, it's hard to structure a blind test, where you aren't "primed" by knowing that the filter is running, and so you may be feeling a placebo effect (though really, any reduction in symptoms would be great). I wanted to think of a way around this, and was inspired by the NASAL RANGER blogged about by Nadya Peek:
The interesting part about the NASAL RANGER is that it lets you flip on and off the valve drawing in the smell you're pointing it at. That is, you can compare between the smell and the absence of the smell.
But I thought -- what if that were randomized when you pressed the button? If you could find out only after your ran the test whether you were smelling it? Or likewise, if you could be running the plant air filter OR NOT but could tell retrospectively afterwards? It could enable you to run a blind test, where you record your symptoms over a period of time, and then find out whether any change (for better or worse) correlated with whether the filter had been on.
So, I thought, maybe you could just run the pump but shut off the valve. But just to think a little further, I imagined a bell jar (like the one the Little Prince used to protect his rose, or the one in Beauty and the Beast) with a kind of black box as a base, which had two fans inside. One fan would pull air thorough the glass chamber, and the other would just bypass the chamber, but you couldn't tell which was actually running -- both would cause some air to flow out the exhaust vent.
So, you'd run it for a period of time -- I'm not sure what that'd be, a week? A month? I'm sure @nshapiro would know better. And you'd know that it might or might not be on. But when you're done, you turn it off, and it shows (with, say, a blinking light or something) whether it had been on for real or not. You add this to your journals, and you've conducted a self-study. You can repeat it, change things, etc etc, to modify the study.
Refining the study, not the sensor
One thing I really like about this is that instead of the kit being the sensing technique, it's the study design. You can change the period you observe over, you could run it in different sized rooms, or track different symptoms. You can choose to do a standardized test that many other people with this kit are doing, so you could compare, or you could branch off and try a different variation.
It also seems powerful that, should you choose to share your data, you're sharing a study you've run yourself, rather than a researcher knowing if it's a placebo or not (I'm reminded of Alan Irwin's 1995 case study on citizen science by AIDS activists who argued that placebo-based blind studies were unethical, and -- do I have this right? -- swapped pills to "take over" the studies). Of course, such a kit could also have a switch so that it's never a placebo -- that's in the hands of the individual. They could just run the study themselves and only compare it privately with others' published results, without posting their own. Or they could decide to post their data and co-create a broader study with others.
This is especially interesting to me because I think community environmental science tends to focus a lot on the sensor -- and very narrowly -- often just the electronics, to the neglect of things like study design, setup, and issues of privacy, control, and feedback:
One thing I like a lot about doing a remediation kit is that, unlike so many environmental testing projects, it involves a feedback loop. Instead of just putting a sensor or something in your window, and learning something about the presence of pollutants that you may not be able to substantively improve, you're actually changing the space you live in. And you're also measuring it to see if you've changed it.
The feedback loop is one reason I think folks can get really addicted to FitBits and the kind of self-tracking from the Quantified Self movement -- change something, and see its effects. So I wanted to think about how the remediation kit and a means of measuring formaldehyde could interact.
I didn't want to get to far ahead of myself, but I did look into some parts and prices. There are 1 gallon and 2.5 gallon glass fermentation jars with standard 4" lids available online:
They also, interestingly, often have holes in them for valves. I think a bigger hole would be needed, especially if I'm going to look at how airflow with small fans could work -- is it consistent enough? I do think it'd be a lot cheaper and more compact, as well as quieter. But it could work either way.
Anyhow, that's a lot -- I'd be glad to hear peoples' thoughts, and may want to try making some prototype "placebo jars" if anyone's interested in using them!