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Electronic nose for indoor mold detection and identification

201 points2 daysadvanced.onlinelibrary.wiley.com
alfonsodev1 day ago

At the risk of sounding stupid, I’ve noticed my mom’s house smell has changed a lot in the last year and is stronger in her room and bathroom, coincidentally or not, since she has started showing mild dementia symptoms and has been diagnosed with vascular dementia. She feels extremely tired despite standard blood test markers being OK.

The smell could have simple explanations, like she forgets to ventilate the room, or her hygiene is not as good as before, since she has become more avoidant of any discomfort, but we are helping her with the hygiene part at least, the ventilation is harder because she complains about cold, and refuses to leave the room. Also to me, it is a different smell from what would be poor ventilation and from what would be lack of hygiene, but I can’t point out what it is. I'm usually very good detecting when a room has not been ventilated, I just feel I breath worse and can't focus as well, I'm annoying to other people that doesn't want to open the window.

She spends most of the time in bed, her body is telling her to sleep much more than before, and she has become very stubborn about getting out of the house, going to the dentist, etc. Since she is very intelligent and still has the verbal ability to make you believe she will do it as soon as she feels better and that will be soon, the reality is that months are passing by and that is not happening.

I wonder if anyone could recommend an affordable but effective air quality device, mold testing kits (if such a thing exists), or what targeted blood tests can be done. Also, if there are tests to fine grain the diagnosis of vascular dementia, to know if there is accumulation of proteins in the brain, or what is the origin of the issue.

She is 79 years old, perhaps there is nothing to do, but somehow I feel the environment of the house has something toxic in it, I even thought about electromagnetic fields, but I really don’t know where to start.

Edit: We live in Spain, her doctor feedback is that her blood tests are great for her age, and we didn't have much info about the vascular dementia situation somehow has been implied that is normal in her age.

theIntuitionist21 hours ago

There is an easy and cheap test that is actually accurate. You place Petri dishes with a specific medium in them in the room, open, for an hour. Then you close them and put them in a dark spot for a week. When you next look at them, count the colonies that have formed. 3 or 4 or below is fine. 3 to 6 or 7 you need to wipe the walls with citrus oil cleaner or diluted bleach, deep clean carpets, remove old books and otherwise deep clean the space. More than that, you likely have mold issues in the walls or ceiling or floors. All mold issues come from water sources- small leaks in plumbing, old seals around the edges of bathtubs, ingress from clogged gutters backing up, etc. here’s where you can get the petri dishes- https://immunolytics.com/store/ Don’t bother with the kit or with paying them to interpret results, just count colonies like I outlined above.

We are going through this now. It’s no fun at all. We have the house ripped down to the studs. A couple times the plates saved us, showing there was more mold then we’d thought. We’d rip out some stuff we’d found, run the test, find too many colonies on the plate then dig some more only to find more issues. Finally, we are getting clear plates, and I feel much better.

If it does turn out to be mold and fatigue caused by the mold feel free to contact me as I have been through it and am now on the mend. It’s a long difficult process with only the vague signals you mentioned to guide you.

Aurornis20 hours ago

Please don't direct people to that website selling overpriced petri dishes, "expert consult" services, and using scare tactics to convince people to order their expensive tests.

> count the colonies that have formed. 3 or 4 or below is fine. 3 to 6 or 7 you need to wipe the walls with citrus oil cleaner or diluted bleach, deep clean carpets, remove old books and otherwise deep clean the space.

Mold spores are everywhere in the air. This is not an accurate test at all. It's a random number generator. The thresholds don't even make sense: 3-4 is fine but 3-6 means throw out your books and deep clean the house?

If you want professional mold testing services, please start by looking up your local health department and seeing who they recommend for testing.

Most importantly, don't buy anything or take any advice from websites that have long lists of non-specific health symptoms that they claim are caused by mold. The lists of symptoms on that website include everything under the sun from headaches to sleep problems to acid reflux - https://immunolytics.com/understand-mold/ - This is how alternative medicine (and testing) sellers make their sales funnel as large as possible, not real science.

theIntuitionist21 hours ago

In the US where I live, professional mold testing companies have big expensive machines which supposedly count spores in the air. The results always come back negative, unless the space is visibly super contaminated. This is because mold is usually in the walls and these services are called in after a water issues to absolve landlords of financial responsibility for the extensive work and expense it would take to actually solve mold problems. It’s a nasty business.

We had our place professionally tested, got negative results, then tore the place down to the studs anyway (eventually, after the Petri dish tests described above) and found all sorts of mold.

alfonsodev20 hours ago

Thanks a lot for sharing that.

Now that you say water sources, I just remembered she has a reverse osmosis water filter, and God knows the last time that filter was changed.

How would you go about testing the water or the filter with that method ?

lobsterthief1 day ago

My grandmother is currently dying from vascular dementia at 80. She sleeps all day. There’s really nothing you can do except keep them comfortable. There is no cure, only treatments for side effects unfortunately.

And yes, she smells weird ;) it’s mostly from change in normal hygiene. No matter how much you help clean them, they will smell different than they used to. And not good-different.

adastra221 day ago

I don’t have specific suggestions for your questions, but that does sound like mold, and the mold could be progressing those symptoms.

alfonsodev1 day ago

> but that does sound like mold, and the mold could be progressing those symptoms

That's both my fear and my hope, if you have any good resource that I could educate myself about this hypothetical type of mold that can accelerate the symptoms of dementia, please share, would be very useful.

Thank you

Aurornis23 hours ago

If you think there is a mold problem you could look for any sources of moisture or leaks and remediate those. The CDC has some guidance on where to start https://www.cdc.gov/mold-health/about/index.html

If moisture is a problem in areas like the bathroom you can install an automatic humidity controlled switch for the fan. It will regulate humidity automatically after showers.

If you feel like you must do something more, a HEPA air purifier would remove mold spores from the air. A carbon filter would remove odors and other compounds. A building-level solution is a heat recovery ventilator which brings in fresh air but captures most of the heat from the exhaust air.

I know you want to find a source of the health problem and identify something you can fix, but mold is probably not it. Mold is a popular topic in complementary and alternative medicine as an explanation for everything. If you ask the internet if any health condition could be caused by mold, someone will show up and tell you yes. I need to caution you that there are forums and subreddits where this is taken to extremes and anyone who disagrees has their comments deleted, creating an illusion of consensus. Some of these forums will tell you that the only solution is to move to a dry climate and only sleep outside. There are mold testing companies where your results will always come back positive followed by a recommendation that you buy their expensive consulting services. Please take some caution and a healthy dose of skepticism before getting involved with this subject.

adastra2221 hours ago

One addition to this excellent advice: removing the moisture is not enough. Now that there is a mold infestation, you will need to replace the drywall and other affected areas.

zDOx116 hours ago

Last year I found this YouTube channel, which you might find helpful. He mostly covers topics like how to deal with mold issues, improving air quality at home, as well as his experience with mold sickness. https://youtube.com/@healthyhomeguide

adastra2221 hours ago

I do not have a good link sorry. This is more of my general background knowledge that have accumulated over the years, as I have faced various similar situations. Persistent fungal infestation in the body can cause accumulating plaque from immune response, which compounds with other sources that are the root cause of the dementia.

NickNaraghi20 hours ago

Hi - this very much parallels my experience with significant mold exposure. We were able to identify mold using a laboratory test of air sample + swab completed by a certified specialist here in the US. Cost about $500. Highly recommend as the effects on our health have been drastic and long-lasting. Best of luck.

asveikau20 hours ago

I'm sorry about your mom.

The odor part may be nothing to worry about. When I was a child I noticed an "old lady smell" that many people have. I used to think they had terrible taste in perfume. As my mom got older and I observed her in life, I realized she was starting to smell that way without any effort, and did not before. I don't think she had particularly poor hygiene. I have no idea, but perhaps there is some biological reason for this, that older people produce distinct body odors from younger people.

asveikau14 hours ago

Too late to edit but I googled "old lady smell" and here is the ai summary:

> ... aging odor, is a real biological scent caused by the compound 2-nonenal, produced as skin's antioxidants decline with age, creating a greasy, musty, or grassy smell that starts around age 40. While natural and not always a hygiene issue, it can be managed with specialized soaps ...

meindnoch1 day ago
jpster1 day ago

Can be targeted by soaps containing persimmon extract. https://miraiclinical.com/pages/nonenal

snoopen1 day ago

It could be "old person smell"? https://en.wikipedia.org/wiki/Old_person_smell

bflesch1 day ago

I'm sorry, dementia is horrible and most likely the major reason for the symptoms. Just remember that dementia patients can also forget to turn off the water and cause a spillage they don't remember, or fall down in the shower and spray the whole room with water, or simply forget where the toilet is and urinate somewhere. But nevertheless if it smells weird you should check it, one can have both dementia and mold in the house.

If you can smell that the house is bad for you then it would be easiest to just get her out of the damn house for one or two weeks, maybe to somewhere on the ocean, and see if her symptoms improve significantly.

Check her Vitamin D / iron / B12 levels and supplement with relevant cofactors. Doctors often don't check it here in Germany.

If she drinks tap water do one of the online water tests which checks both for bateria and lead contamination - both for hot and cold water supply. Contamination can be by old pipes or in the water boiler. If lead in water is high also tell the doctor.

If you have access to thermal imaging camera it is a very quick way to figure out water leaks in the wall or places of bad insulation. Maybe a shingle on the roof has moved and rain has been dripping into the ceiling. I bought one for ~350€ and didn't regret it.

As you mention the bathroom check the silicone sealings around the bathtub and see if they are broken and/or moldy. Maybe water leaks behind the shower because the silicone has a defect. Silicone needs to be relaced every couple of years, just rip it out and apply new silicone it is a DIY job with many youtube videos. Wear mask while you are in the house.

You can DIY hack a around-the-clock humidity/temperature monitoring with esphome/homeassistant so you can compare outdoor air vs. indoor air in several rooms and also calculate dew point temperature to see where/if water condensation in the walls occur. It is quite cheap and wifi-based but a lot of fiddling.

Good luck in these stressful times.

bell-cot21 hours ago

> At the risk of ...

Any decent person would take that risk, for their mother's health.

At least in the US, there's a fairly large industry built around mold testing & remediation. Laboratories need to be inspected & certified, and you can do your own home air testing and receive the results directly from the lab.

Compared to a family member's health, testing is very cheap.

Vs. if you're testing to make sure the house isn't rotting - that's trickier. Many sorts of mold can be underachievers at releasing spores (which is what the common air tests look for). Or the spores could be released in a wall cavity or something, where air doesn't circulate and carry them to where you're taking samples.

I've no idea what the situation is in Spain.

Changing topic - my mother's mental health & vision were destroyed by an undiagnosed case of https://en.wikipedia.org/wiki/Giant_cell_arteritis . America's health care system burned through incredible amounts of money for fancy high-tech scans and tests. It did not bother with having a competent doctor sit down, and really think about what might be causing mom's slowly-worsening symptoms. That would not have been hard - mom was in the very highest-risk demographic for that disease. And after it was too late - my optician was able to diagnose her in seconds, sight unseen, from just my in-passing mention of her eye-related symptoms.

(Yes, I also got the clear feeling that the health care system did not care at all about an elderly woman's declining health);

Aurornis20 hours ago

> At least in the US, there's a fairly large industry built around mold testing & remediation

Be aware that's there's also a very large industry built around selling people unnecessary or non-standard mold tests (which always come back positive) along with "expert consultation services" and then refer you to local remediation companies for a very large kickback.

Mold scares are big business. If you visit a company's website and they have long lists of non-specific illnesses or make claims that nearly every disease could be caused by mold, don't engage with them. If you contact them at all or buy their services you're likely to end up in their leads database and be marketed to until the end of time. There is a lot of money in scaring people into unnecessary mold testing and remediation services.

alfonsodev20 hours ago

Thanks for sharing that experience, it means a lot.

Sometimes it feels like the health system is just about keeping you alive, and they don't dig enough in different posible root causes, they focus on treating the symptoms, specially with elderly.

> That would not have been hard

I understand the feeling, and it inspires me to look for a second opinion and someone more involved in finding a root cause. I'm sure in your case you did what you though it was best with the information you had, the reality is that the system does not invest in prevention and education of us patients and relatives. Knowing certain demographic is high risk should be somehow automated to raise flags when certain symptoms are mention even if they are in-passing mentioned as you said, because we as regular people are not educated to weight the importance of symptoms, and often doctors get defensive if you come with a theory.

The other day I was at the doctor, he was asking me many things, trying to figure out my stomach problems, I though I had a stomach flu, then really at the and by chance I mentioned I was at the dentist the week before and they gave me antibiotics for 7 days, it was only then with that small comment that I almost forget to say that the doctor could have the explanation, he said some antibiotics wipe out the gut microbiota, and it just gave me some probiotics and I was fine the day after, with a big improvement. I don't know how much time would have take me to recover if I would have forgotten about that detail.

When I think about it after the fact, duh! of course antibiotics kill gut bacteria, I heard that a million times in podcasts, but I did not make the connection.

My point is that we have enough in our plates and our profession is already quite complex, we deal with tons of complexities and it shouldn't be our job to know the right questions, or the right doctor to go for, but I wish there was a system that focused more on preventions, and finding the root cause with a more multidisciplinary approach rather that specialized niche knowledge doctors that ignore other causes, or symptoms if they are not present if their knowledge map.

ethersteeds1 day ago

As another top level comment describes, there are very inexpensive hardware store mold testing kits which are essentially just petri dishes you leave open and then mail in for testing.

Also if it is indeed mold, the source is typically some source of moisture. You want to rule out roof leaks and plumbing leaks, and bear in mind that water is incredibly non intuitive and creative in getting from point a to point b.

Another major source of humidity is the human body. Between sweat and respiration, we emit quite a bit of water. This goes into the air and into the bedding and requires ventilation to dissipate. Tightly sealed under-bed areas prevent the mattress from breathing. You might consider stripping the bedding and lifting up the mattress to see how things look.

Consider the rooms' ventilation system. Are the filters new, are the ducts clean? Hiring a professional to check the HVAC system is good routine maintenance.

A final source of moisture leading to mold to consider is condensation. Anywhere warm air meets a much colder surface leads to liquid water and mold. This can mean cracks and poor insulation in exterior walls during winter, or the air conditioning parts during summer. I've seen this combine with the bed-human moisture where under a bed against an exterior wall in a poorly insulated house was staying cold. The bottom of the mattress was moldy.

Mold is insidious. You often need to get into the mindset of a detective, or hire one, to find it. Good luck.

canadiantim23 hours ago

I would very strongly recommend you get her tested for mycotoxins. Vascular dementia / Alzheimer’s symptoms can come from mold exposure alone (type 3 Alzheimer’s). If you find signs of mold exposure, consider the shoemaker protocol or something like Cellcore to bind the mycotoxins or other similar endotoxins out of the gut using things like Cholestyramine, or other binders.

You can use the Mosaic mycotox test, order it directly to your home and then ship the sample to the lab.

alfonsodev20 hours ago

Thanks a lot! I'm going to look it up.

NedF24 hours ago

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sschueller1 day ago

I find it interesting that we seem to have mastered what the human eye can do and even go beyond it with like infrared but somehow we still can't build a chip that can "taste" or "smell".

vjanma21 hours ago

This is exactly the problem I've been obsessing over. The challenge is that olfaction isn't like vision. you're not detecting photons at discrete wavelengths, you're dealing with ~400 olfactory receptor types responding to millions of possible volatile molecules in combinatorial ways.

MOX sensors (like the SnO2 in this paper) have been around for decades but hit a fundamental ceiling—they require specific coatings to bind to specific VOCs. Want to detect a new substance? You're changing hardware.

The more promising path, IMO, is carbon nanotube (CNT) sensors that actually mimic how our nose works. Instead of measuring bulk resistance changes, you functionalize CNT arrays to respond to specific molecular binding events—much closer to how olfactory receptors operate. detection of new substances becomes a software/ML problem rather than a hardware redesign. That's how biology does it—your nose doesn't grow new receptors, your brain learns new patterns.

Full disclosure: I'm building in this space (https://nosy.network) Nosy is using CNT paired with transformer models to create what we call a "Large Essence Model" (LEM). LEM "GPT for smell" processes scent information similar to how LLMs process text.

lopis1 day ago

Makes total sense to me. Detecting and measuring photons seems much simpler than accurately detecting whole molecules. When we need to detect if a sample contains a certain kind of molecule, it usually requires expensive chemical processes.

throwaway1988461 day ago

Or Mass spectrometry

Terr_1 day ago

Pretty sure that relies on a lot of assumptions about how the pieces being detected originally fit together, or extremely pure samples.

Latitude79731 day ago

Mass spectrometry is a multi-faceted beast, and has many applications. One that comes to mind is ion mobility spectrometry. I am most familiar with FAIMS which is an extremely selective method and can detect trace amounts of specific molecules.

The challenge is piecing together what you have detected to draw conclusions about the sample - in this instance you might detect a specific molecule, but to definitively conclude that it's caused by a particular fungus requires lots of prior testing.

rcxdude1 day ago

The human eye is still pretty difficult to beat on some metrics, especially dynamic range (I think top-of-the-line sensors are now competitive, but for a while there was not really any options)

jeremyscanvic1 day ago

Any reference you can share on this? I'm genuinely curious speaking as a PhD student in image processing for computer vision

williamdclt1 day ago

I think at least _part_ of the reason why is that it's just a whole lot less useful? There's tons and tons of applications for image and video and the automated analysis of it (for art, documentation or business purposes), whereas taste/smell capture and the analysis of it doesn't have that many useful use-cases (the article points at one of course, I'm not saying there's no use-case but much fewer). So we put a whole lot of effort and money into developing it, which didn't happen for smell.

praptak1 day ago

Dog level smell is pretty useful, as evidenced, well, by actual dog usage.

OTOH maybe dogs are cheap enough not to create strong incentive for automation.

red-iron-pine19 hours ago

can't cuddle my laptop the same way I can a goofy-but-well-trained golden retriever

praptak19 hours ago

Maybe programmers should become cuddly to avoid being replaced by AI.

ptman1 day ago

- "quantum mechanics are so hard to reason about since I have no senses where that plays a part"

- "oh, so you have no sense of smell?"

Razengan1 day ago

If you just want a histogram of all the chemicals that are present, that would probably be doable if not already done. But how would you even quantify/qualify the "sensations" of those senses?

Vision is "easy": What I see is what you see is what the machine sees.

A machine shows us what it sees and we can verify that it is working correctly, with a glance.

How would we verify that a machine smells or tastes "correctly"?

Terr_1 day ago

> a histogram of all the chemicals that are present, that would probably be doable if not already done.

I'm no olfactory biochemist, but that sounds like science-fiction to me. The, er, reference implementation we're talking about is advanced nanotechnology we don't fully understand.

While we can do stuff like mass-spectrography, that involves destroying complex chemicals and converting them to smaller fragments we can tally, and then guessing at possible configurations they might have originally had.

If someone had a device that could simply tell you the exact chemical formulas of all molecules of any kind in a sample, it would be used everywhere and they would be very rich.

sumea1 day ago

You are right that such device does not exist, but in theory you could combine many analytical techniques to a single black box that could analyze practically all of molecules and particles in the air or even in more complicated samples. It would contain at least some sort of chromatography, nmr, mass spectrometer, infrared spectrometer and various special analytical techniques for some compounds. Also some kind of sample preparation system would be needed.

This would be a very large machine and you would need to provide a sample to it in a test tube or similar manner. Automated blood analyzers in hospitals are maybe the closest thing to a such device.

luz6661 day ago

The machine smells correctly, when the same numbers (or similar when using some norm, e.g. the L2) appear for the same smell (reproducibility) and therefore a mapping (numbers -> smell) can be created. When this starts to exist (practically usable), there can be a database to store the mappings, allowing classification. E.g., the machine says "this tastes like banana". The machines/algorithms/products could itself be rated for precision.

I dont say such machines don't exist, but for my taste (pun intended) the solutions all lack something, either long term stability or having a second source supplier or being able to classify a reasonable amount of tastes or being able to distinguish between two tastes (or lacking all those things together).

sschueller1 day ago

The machine would need to reproduce the smell just like it reproduces what it sees on a screen. What the sensor "sees" isn't what our eye sees either.

crispyambulance1 day ago

I’ve used hardware store “mold kits” where you tack some tape onto a surface and then send it to a service that will analyze it for you. My understanding is that these services simply look at the tape through a microscope, or apply it to a growth media that’s been prepped to “prefer” the specific types of fungus they’re looking for.

One would think there are PCR-based services that do this? That would be the gold standard for this stuff, and it could easily scale enough to become economical, but to my knowledge there are no commercial mold testers that do this.

tippa1231 day ago

This would be very interesting for industrial applications that rely on clean rooms. What comes to mind is environmental monitoring for microbes, which is tedious but important and currently has significant lag time (≈2 weeks).

What I couldn’t determine is whether there is any information about concentration. I mean so what if something is present, you have a lot of ubiquitous organisms out there.

Nevertheless, if the technology matures, it could help identify a problem earlier before it becomes visually obvious. You would still need to determine the root cause. Or it could help with a better decision making before buying a house?

All in all a lot to think about.

npsomaratna1 day ago

Why is there a significant time lag? Is it because monitoring is done via cultures?

tippa1231 day ago

Correct, the workflow is something like this usually.

You would take contact, settle and active air sample plates within the cleanroom, followed by approximately one day before culturing is initiated in QC. Incubation then typically takes around seven days to cover both bacteria and fungi. You then get the colony forming units value which is the key parameter. Some companies take this further and perform organism identification, which adds additional days to the timeline but great for reactive investigations.

There is also a lag until the data becomes available in a digital format.

This of course differs between companies. Some companies may opt for shorter or longer incubation times, but in general, the key takeaway is that the process takes time.

ram_rattle1 day ago

This e-nose in general interesting, do anyone know any sensors that are currently commercially available to prototype these things?

pedro_caetano1 day ago

KIT had a project on this (Project KAMINA) which looks like it is also cited in the linked paper.

They had a spin off SMELLDECT GmbH which sells a kit but not exactly a order from DigiKey thing. I imagine you will need to send an RFQ and go through the motions with their sales team.

ram_rattle1 day ago

interesting, thanks for sharing these!

voxleone1 day ago

The inevitable AI angle: researchers are increasingly exploring perception, self-modeling, and grounded interaction as the foundation for the next wave of AI systems, ones that behave in ways more aligned with human-like awareness than LLMs alone can provide (see work like MUSE or situational awareness in vision-language reasoning).

Systems like the electronic nose described here highlight what many think is missing in current AI approaches: continuous physical sensing combined with explicit novelty detection and decision boundaries that let a system say “this is real”, “this is happening now”, or “this is outside what I know”. Human-like behavior is unlikely to emerge from language models in isolation; it appears to come from closed perception-reasoning loops that are causally coupled to the environment. Without sensory grounding, AI tends to optimize for plausibility rather than correctness, and scaling or prompting alone doesn’t seem to address that gap.

vjanma21 hours ago

LLMs are trained on text about the world, not the world itself. Olfaction is an interesting test case because it's one of the most ancient and direct sensory modalities. no symbolic abstraction layer, just molecular binding triggering pattern recognition.

What's compelling about pairing e-nose hardware with transformer architectures is you get that grounded perception loop you're describing. The sensor array produces high-dimensional response patterns from real physical interactions, and the model learns to classify and reason over patterns it's never been explicitly trained on—genuine novelty detection rather than interpolation over training data.

The "this is outside what I know" capability is critical for real-world deployment. A model that hallucinates a scent classification is potentially dangerous (think: fentanyl detection in law enforcement). You need calibrated uncertainty, not just a softmax score.

andsoitis2 days ago

Usually you have to spend thousands of dollars for an expert with the right equipment to focus on select areas of your home (areas that are suspect).

Are there ways to do a full-house scan yourself?

z22 days ago

I've had success using my nose and a cheap $15 moisture meter against walls and ceilings. In my case I was already pretty sure the moisture came from the roof when it rained so went looking right after rainstorms. This was after also running a dehumidifier in a formerly damp basement.

If a home has an active mold problem, it probably has an active water or moisture problem. What mold remediation people sometimes do as well is use an IR camera to try to find unusually cold (thus damp areas).

Aurornis1 day ago

> If a home has an active mold problem, it probably has an active water or moisture problem.

Mold can't grow or spread without moisture, so a moisture problem is a necessary prerequisite for a mold problem.

So focusing on fixing any moisture problems is a great place to start. Feeling around walls and baseboards or climbing up into the attic in the hours and days after a big rainstorm is one way to get started without any equipment investment. Air circulation also helps dry things out, so make sure every space has some openings for air exchange.

DANmode1 day ago

> or spread

Not explicitly true - dry spores get anywhere dust does.

Whether they become active growth or not is a different question.

+2
Terr_1 day ago
HPsquared1 day ago

Infrared thermometer is also good to survey a room and look for cold spots which are associated with moisture (condensation and/or structural dampness increasing thermal transfer). A thermal camera even moreso (but more expensive).

tdeck1 day ago

I've seen situations where experts put different colored water soluble dye on different spots outside the house, so that when it leaks through you can determine the source. Presumably that's within reach for an individual as well.

_blk1 day ago

Yup, look at anything with temps below the dew point and badly vented areas below (condensation follows gravity)

DANmode1 day ago

or unusually warm!

(When your shower is improperly installed, for instance)

taneq1 day ago

The IR camera idea is clever, usually we use them to find hot spots. Gonna try this next time I suspect we have a leak.

gerdesj2 days ago

Swabs and a microscope. Oh and a degree in biology might help!

bflesch2 days ago

That's what I had to do to figure out source of my asthma and allergies.

Without any microbiology degree and while suffering from delibitating disease it was very hurtful that reddit posts with requests for help identifying objects were regularly deleted from the major microscopy communities. They simply refused any discussion or assistance with DIY microscopy related to any human disease while in other subreddits people post their poop for analyis.

In tune with the saying of "it can't be what mustn't be" ("Weil nicht sein kann, was nicht sein darf") a lot of medical professionals outright dispute mold-caused sicknesses. Their imaging can detect late stage fungal infections in the lungs and head of elderly people wholly consumed by the fungus, but they have no methods to detect early stage infections. And instead of realizing they're lacking appropriate analytical methods for mold detection they outright deny that it could be the cause of the problem.

Luckily the microscopy helped me to figure out which samples to send to a professional in order to pin down and remediate the cause of my sickness.

Aurornis1 day ago

> it was very hurtful that reddit posts with requests for help identifying objects were regularly deleted from the major microscopy communities. They simply refused any discussion or assistance with DIY microscopy related to any human disease

Unfortunately, this is the only way to keep a hobby subreddit on topic. Once a subreddit becomes known as an outlet for non-hobbyists looking for one time assistance, the same requests get posted over and over again until the people who want to discuss the topic get fed up and leave.

Mold topics are particularly sensitive on Reddit because mold exposure is a huge red herring theme on TikTok and social media. People with difficult to diagnose medical conditions will often go through a phase thinking that mold exposure must explain everything and there are thousands of TikTok accounts and Facebook groups that will tell them it's the only explanation.

bflesch1 day ago

I understand that one cannot expect a reddit hobbyist community to compensate for a medical system that has already "failed" the patients. But if you feel your disease is progressing despite the medications the doctors give you, you will desperately try every single thing that people post on social media.

The cycle of "long covid > mold > lyme > candida > parasites" can only be broken by clever people building better, cheaper analytical methods for detection of these diseases.

Doctors really should show some humility and remember that 200 years ago it was an innovation for them to wash and disinfect their hands, and the guy who told them, Ignaz Semmelweis, was "red herring" chased into psychiatric asylum.

kulahan1 day ago

Fungus in general is not well-understood at all. We didn't even realize until a few decades ago that it's pretty much the backbone of life on Earth. All of our research into it is highly specific (using fungi as chemical factories in pharmacology, for instance), but besides that, it's largely a very mysterious branch of life. In medical school, you learn about fungus as it pertains to a few common infections and some classes of drugs, but otherwise you don't hear much.

I wouldn't be surprised if it's just not something they're willing to speak on professionally because it's a huge blind-spot for science.

quesejoe1 day ago

Wie Ghets. Hope youre condition has improved. I went through something similar 10 years ago. I eventually isolated the cause of my illness. Its a general allergy to fungus probably. It is believed that after being infected with a virus, your mastocytes encode to react to fungus. As such, vast numbers of mastocytes are constantly firing off when you encounter mold or fungus. Here's the thing that took me a while to figure out. Traces of these protiens are common in food. Effectively, any food that isn't alive or microbe free, will cause a mild to moderate reaction. Foods that didn't cause problems, where things like, fresh meat, eggs, fresh leafy green (still alive). Anything that might have been stored in bulk, or might have had microbial activity, would cause a mild reaction. The good news is that with dietary restrictions and a clean dush and mold free home, you can live a comfortable life. Also, I think it may be the case that the encoded mastocytes eventually die out after 24 months and with it, the allergy. Not sure, but eventuntually i returned to normal and no longer am sensitive. Hope you are getting better.

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bflesch1 day ago
adamddev11 day ago

This is really interesting. I haven't been the same since I stayed in an extremely moldy place and have wondered about fungal infections/candida infection.

What was the remediation, some kind of anti fungal course/Nystatin?

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Aurornis1 day ago
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bflesch1 day ago
schiffern2 days ago

I gather that airborne mycotoxins also play a role in inflammation, in addition to actual fungal infections.

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bflesch1 day ago
joezydeco2 days ago

Maybe check out AirAnswers.

https://www.airanswers.com/

Aurornis1 day ago

Everything about this website screams alternative medicine scam. "Integrative medicine" and "book a consultation" is not what you want to see on your mold testing lab's website. It means they're out to sell you things. I can almost guarantee that everybody who gets one of their test kits will get, surprise, a positive result that requires more expensive consultations and treatments from them.

joezydeco1 day ago

One of the founders is a friend of mine that has been an IVD researcher for decades. I don't smell any scam. They are just looking for traction in the consumer and real estate sectors. They already have customers in agriculture, especially with cannabis farms looking for molds. They don't sell treatments. It's more like a radon sampler you leave in a house for a day to get a reading.

bflesch2 days ago

The AirAnswers website blocks visitors from the EU.

Most likely because they are in violation of GDPR and have no plan to care about data privacy. This is a really big red flag for all AirAnswers customers.

andsoitis1 day ago

> Most likely because they are in violation of GDPR

Why do you say that’s the most likely reason? You can’t imagine other plausible reasons?

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bflesch1 day ago
westurner2 days ago

What sort of an indoor drone could this sensor be most usefully added to?

Aurornis1 day ago

Attaching an air sensor to a giant high-speed fan is not going to help you pinpoint anything, it's just going to blow the air around.

Getting accurate room-based location requires even turning the HVAC off and avoiding a lot of walking through a building.

Ancapistani2 days ago

UAS move a lot of air - I can't imagine this would be practical. At the very least, you'd need to put the sensor on a boom long enough to make it unwieldy.

westurner2 days ago

Many of the described robots in the mujoco_menagerie gallery could probably do the job: https://github.com/google-deepmind/mujoco_menagerie

The sensor recovery time limits the sampling time. A 28 second sensor recovery time with SnO2-Gr (graphene oxide) would be more useful for sampling larger volumes than minutes with just SnO2 FWIU; https://news.ycombinator.com/context?id=46521695

xtiansimon22 hours ago

And electronic mouth to taste water.

Residents in Bethpage, NY are dealing with Grumman water contamination or “plume”.

https://youtu.be/vgezHCoqiUo?si=1wn7Grt8vpAnzJ_Z

I live on Long Island and drink well water. I’d sure like a home monitor.

alansaber1 day ago

I was surprised to see surface acoustic wave sensing for bio mentioned, since my lecturer researched it in the 80s. I guess mechanical sensing is hard to innovate.

westurner2 days ago

Looks like adding Graphene to SnO2 (Tin Oxide) sensors increases sensitivity and battery life and reduces operating temperature to room temperature, for an increase in manufacturing complexity and cost.

westurner2 days ago

"Extraordinary Improvement of Gas-Sensing Performances in SnO2 Nanofibers Due to Creation of Local p–n Heterojunctions by Loading Reduced Graphene Oxide Nanosheets" (2015) https://pubs.acs.org/doi/10.1021/am5071656

"Highly Sensitive and Selective SnO2-Gr Sensor Photoactivated for Detection of Low NO2 Concentrations at Room Temperature" (2024) https://www.mdpi.com/2079-4991/14/24/1994 ; UV photo activation of SnO2-Gr sensors

"Engineering of SnO2–Graphene Oxide Nanoheterojunctions for Selective Room-Temperature Chemical Sensing and Optoelectronic Devices" (2020) https://pubs.acs.org/doi/10.1021/acsami.0c09178

"Humidity-sensing Performance of Graphene/SnO 2 Nanocomposites" (2025) https://sensors.myu-group.co.jp/sm_pdf/SM4049.pdf ; 28s recovery time instead of minutes

bflesch2 days ago

This is significant, especially if it can be productized. Thanks for working on such an important topic. One day in the future technologies like this will keep vulnerable, sick people from being gaslit by other humans about the cause of their disease.

HocusLocus1 day ago

Or just project negative ions into your working and sleeping places and breathe easy, wipe the mold spores off the walls every couple months or so. Test their effectiveness by shining a bright flashlight in the dark. You can't see the beam!

m348e9121 day ago

Ozone (the source of those negative ions) comes with its own issues. If you are going to use ionize with ozone, it's best to do it when you're not going to be home for a while.

jadamson1 day ago

Ozone doesn't generate ions, ionizers produce ozone, and how much will depend on the device.

taneq1 day ago

Are you saying that all particulates in the air inside a house are mold spores? Surely the vast majority is just normal dust (dander, microplastics, silicates, etc.)?

DANmode1 day ago

Dust becomes mold rapidly.

Way more rapidly than anyone’s comfortable.

Ambient air has mold spores.

Add a single humid breeze through the space, game over.

If you don’t have a humidity range being recorded day to day in your home, you may be surprised the excursions.

adamddev11 day ago

How do you "project negative ions" ?

jadamson1 day ago

With an ionic air purifier.

DANmode1 day ago

If you can see the mold, that’s too much mold for anywhere sharing air with the inside of your living and sleeping space.