Electronic nose for indoor mold detection and identification

https://advanced.onlinelibrary.wiley.com/doi/10.1002/adsr.202500124

by PaulHoule • 7 months ago

210 124 7 months ago

advanced.onlinelibrary.wiley.com

andsoitis2• 7 months 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?

joezydeco2• 7 months ago

Maybe check out AirAnswers.

https://www.airanswers.com/

bflesch19• 7 months 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.

Aurornis10• 7 months 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.

westurner4• 7 months ago

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

Ancapistani• 7 months 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.

Aurornis10• 7 months 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.

gerdesj• 7 months ago

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

bflesch19• 7 months 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.

z2• 7 months 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).

tdeck• 7 months 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.

taneq2• 7 months 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.

Aurornis10• 7 months 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.

DANmode5• 7 months ago

or unusually warm!

(When your shower is improperly installed, for instance)

_blk• 7 months ago

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

HPsquared• 7 months 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).

westurner4• 7 months 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.

westurner4• 7 months 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

bflesch19• 7 months 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.

HocusLocus• 7 months 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!

taneq2• 7 months 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.)?

DANmode5• 7 months 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.

adamddev12• 7 months ago

How do you "project negative ions" ?

jadamson2• 7 months ago

With an ionic air purifier.

m348e912• 7 months 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.

jadamson2• 7 months ago

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

DANmode5• 7 months 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.

ram_rattle2• 7 months ago

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

pedro_caetano• 7 months 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_rattle2• 7 months ago

interesting, thanks for sharing these!

sschueller2• 7 months 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".

lopis• 7 months 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.

throwaway198846• 7 months ago

Or Mass spectrometry

Razengan• 7 months 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"?

sschueller2• 7 months 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.

Terr_4• 7 months 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.

luz666• 7 months 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).

ptman• 7 months 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?"

williamdclt• 7 months 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.

praptak2• 7 months 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.

rcxdude• 7 months 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)

jeremyscanvic• 7 months ago

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

vjanma2• 7 months 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.

alansaber• 7 months 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.

tippa1232• 7 months 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.

npsomaratna• 7 months ago

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

tippa1232• 7 months 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.

alfonsodev6• 7 months 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.

adastra223• 7 months ago

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

alfonsodev6• 7 months 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

lobsterthief• 7 months 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.

snoopen• 7 months ago

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

ethersteeds• 7 months 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.

bflesch19• 7 months 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.

alfonsodev6• 7 months ago

Thank you! I think I'll start with the water supply and air humidity monitors, vitamin D (supplementing), iron and B12 shows normal in blood tests.

get her out of the damn house for one or two weeks Yes, this is my thinking too, I'm trying to solve the logistics of that as well, and hopefully we can do it soon enough.

meindnoch• 7 months ago

It's just old people smell.

https://en.wikipedia.org/wiki/Old_person_smell

jpster• 7 months ago

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

canadiantim• 7 months 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.

alfonsodev6• 7 months ago

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

bell-cot• 7 months 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);

alfonsodev6• 7 months 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.

Aurornis10• 7 months 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.

theIntuitionist2• 7 months 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.

theIntuitionist2• 7 months 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.

Aurornis10• 7 months 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.

alfonsodev6• 7 months 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 ?

asveikau2• 7 months 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.

asveikau2• 7 months 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 ...

NickNaraghi• 7 months 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.

crispyambulance• 7 months 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.

voxleone• 7 months 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.

vjanma2• 7 months 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.

xtiansimon• 7 months 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.

Electronic nose for indoor mold detection and identification

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