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Can my indoor air quality affect the food I eat?

Can my indoor air quality affect the food I eat?

Do you ever look at the food on your countertop, whether it’s an apple pie or bowl of potatoes, and wonder, how did that food go bad so fast?  It’s a common problem, even more so in warmer climates, so we thought you’d like to know how your indoor air quality affects your food!

Admittedly, not all spoilage comes from your own air.  It’s been recognized that food processing plants need to have better air contamination control during the food production process.  “Primary  air  pollutants  in  the food  industry  are marked,  being,  in addition  to  microorganisms, suspended particles, combustion  products (nitrogen oxide,  carbon monoxide, carbon dioxide,  sulfur oxide) and volatile organic substances.” (2019 Meat Industry Conference Paper)  The contamination of food products is dependent on:

  • air’s microbial load, and 

  • on the duration of exposure to the air, whether during specific technological processing stages (e.g. cooling) or during storage (from book: Hygienic Design of Food Factories, chapter 14: Managing Airflow and Air Filtration to Improve hygiene in food factories).  

Air in slaughterhouses and sausage production facilities, for example, is more than 10 times more laden with yeasts and molds than dairy processing facilities, because of contamination that can come in on the product (animal feces).  The second point is that the product contact with air needs to be limited in order to limit its contamination.  Air  quality  is  particularly  important  in facilities for  production and packaging of butter, if this is manufactured in open-type mixers, since these devices can also incorporate up to 5% of the surrounding air into the product [Varnam  A  and Sutherland  J  P  1996 Milk  and  Milk  Products: Technology,  Chemistry  and Microbiology 1st ed, Chapman and Hall, London, p 451].

Another factor that causes spoilage during food processing is humidity.  There are three ways that humidity affects the food: 

  • Condensation on equipment and food can accelerate microorganism growth

  • Dry foods can absorb moisture that will lead to microorganism growth

  • Packaging like paper and metal start to degrade, leading to spoilage

These insights into how food gets contaminated in factories are good for application in the home because although we can’t much control how it gets packaged, we can certainly control how it’s stored and prepared at home.  So let’s dive in…

The three main biological pollutants that cause food spoilage are bacteria, yeasts and molds. (online course)  Bacteria, yeasts and molds, which are typically small in size, can hitch a ride on larger particles like water droplets or dust.  Where do these come from?

The bathroom.  It’s not pleasant to think about, but “Germs will more likely spread after you flush, when bits of fecal matter blast into the air in aerosol form, a phenomenon known as "toilet plume." From there, Kelly Reynolds (a public health researcher at the University of Arizona) said, the "bits of fecal matter settle on surfaces, contaminate hands and then get spread to the eyes, nose or mouth." (USAToday.com)  Here are some ways to limit the spread of germs from the bathroom to the kitchen: 

  • Close the toilet lid before you flush.

  • Wash and dry hands before leaving the bathroom

  • Use an ionizer like the Germ Defender in the bathroom, to kill germs in the air and on surfaces.

Pets.  Similar to the slaughterhouse scenario, many of us have furry animals (pets) walking around in our food-processing facilities (kitchens).  Where these pets have been and what they have on their fur and feet can be really disgusting!  Worse, homes with litterboxes in the kitchen, or allowing pets to walk on the counters, is like placing a toilet in the kitchen or even on the countertop!  It’s just not pleasant to think about.  If you have pets and you have a kitchen, think about these reforms:

  • Bathing pets regularly so that bacteria and mold are minimized

  • Not allowing pets to walk on countertops

  • Keeping litterboxes in another area of the home away from the kitchen if possible

  • Spraying pets’ fur regularly with a safe anti-microbial spray like Remedy Mold Treatment Spray by CitriSafe.

  • Always wash your hands after touching your pets and especially before food preparation!

The refrigerator.  What?  How can the refrigerator work against us when we’re talking about food spoilage?  Actually, I’m not talking about inside the refrigerator, although that can be a problem (more on that later).  Here, let’s talk about what happens in the “guts” of the refrigerator, where the heat is actually released through the coils.  The speaker is Jeff May, a renowned air quality inspector.  

“I was sitting in my kitchen, and every once in a while, I’d start to wheeze, but just couldn’t understand why. One day, I realized every time the refrigerator turned on, I would have trouble breathing. Our refrigerator was only three years old, but in those days, the drip pan was accessible from the front. When I removed the grille and took it out, there was a pearl onion that somehow bounced into it. The onion had an inch and a half of Penicillium mold growing on it. So, every time the compressor turned on, it would blow mold spores out into the room. Every frost-free refrigerator has a heating cycle. The cooling coil gets full of ice, and you have to melt that ice in order for the refrigerator to cool. The water from that melt goes into a pan at the bottom. The heat from the compressor is supposed to evaporate the water, but very often, the water persists. There’s just not enough heat. So, if there’s any dust in that pan, mold growth ensues. And if you’re allergic to cats and dogs, and somebody had a pet in the house before you moved in, that refrigerator can be a perpetual source of allergens just from the dust that accumulated on the coils when the pets were there. We’ve had people who have just simply cleaned their refrigerator, and all of their allergies went away.” (Jeff May, during interview with author of moldfreeliving.com)

Now for the inside of the refrigerator: Ok, it seems like a no-brainer that you shouldn’t leave spilled food lying around in the fridge because it can contaminate other food by direct contact.  But using your fridge properly also prevents spoilage:

  • The real reason there is a Fruits and Veggies Drawer: it controls humidity in the drawer and prevents certain foods from ripening too fast.  If there is a vent or slot on the drawer, this is used to adjust the humidity and air flow (because ripening fruits also produce a gas called ethylene, which will cause other fruits exposed to it to ripen).  Closed vent or no vent = high humidity, and Open Vent = low humidity.  For a quick way to remember what to put in the “Crisper Drawers”, remember this rule of thumb: “rot-low, wilt-high.” Fruits that are prone to rot belong in the low-humidity drawer, while produce that's prone to wilting needs to be enclosed completely in the high-humidity drawer. (for a full explanation see article at epicurious.com)

  • Don’t put meat, cheese, milk and eggs in the door shelves!   The door of the refrigerator tends to stay at a higher temperature and these items will spoil more quickly (with nasty consequences) when stored there.  For more on where to store what food, this article helps a lot).

The FoodKeeper App from the FDA is a useful tool to determine how long to keep, and when to throw out specific foods.  It is also helpful to know why you need to preserve foods by refrigerating or freezing them right away (within  2 hours of cooking).  Bacteria are not killed by these colder temps, but their growth is slowed down or stopped.  Some bacteria and their endotoxins (toxins released by the bacteria through its life cycle and during death) are highly resistant to heat, so thoroughly re-heating them before eating does not kill the toxin! (check out our post on endo-and exotoxins here).  Staphylococcus aureus is one example of such a bacteria, and it can cause some serious food poisoning, even death.  

The dishwasher. Wait–the dishwasher is supposed to clean my dirty dishes, how can it be polluting my kitchen air?  If you have ever cleaned the vent on your dishwasher, you will know how absolutely filthy this spot can be.  Food residue, along with moist, steamy air will cause a thick slime to grow.  The rest of the dishwasher needs a deep clean too (not just using a bowl of vinegar and/or baking soda), but the vent especially is the area where escaping steam will carry bacteria into your kitchen air. 

Finally, keeping proper humidity in your home is super-important not only for your sinuses, but for food preservation too.  Some fruits and veggies should only be stored on the counter (check them out here), so the proper humidity will help them to stay fresh longer.  

Now you know how good air quality in your home means better food (especially in your kitchen).  By reducing the bacteria-load in the air, reducing exposure to the air, and keeping proper humidity in the air, you can waste your precious foods less, and enjoy them more!

How to equip your college student with better air quality

How to equip your college student with better air quality

If you’re a parent with a son or daughter in college, of course you want to see them succeed!  It can get costly, though.  From helping with tuition, room and board and everything else, it seems like “clean, fresh air” should be a free part of the package. Unfortunately, that may not be the case.  Many colleges and universities are housed in old buildings that did not give thorough consideration to air quality when they were designed, built, or renovated.  In many cases, you are paying for the privilege of  studying there, with living as only an afterthought!  

The problem with poor air quality in the university setting is that it affects the very thing young adults go there to do: learn.  Contaminants in the air work against their body in the following ways.

High CO2 due to inadequate fresh-air ventilation decreases the ability of the brain to metabolize oxygen.  In other words, the brain becomes oxygen deprived!  This can affect learning in terrible ways.  In a Havard study in 2015, 24 participants spent 6 days in simulated offices to control for CO2 and VOCs.  Days were designated by the research team, but blinded to the participants and analysts, to be one “High CO2” day of 1400 ppm CO2, two “Conventional” days representing the average office building conditions of about 940 ppm CO2, one “Green” day representing better ventilation with conditions of approximately 740-750 ppm CO2, and two “Green +” days representing 100% outdoor ventilation (approximately 550 ppm CO2). Cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day. On average, a 400-ppm increase in CO2 was associated with a 21% decrease in a typical participant’s cognitive scores across all domains after adjusting for participant (data not shown), and a 20-cfm increase in outdoor air per person was associated with an 18% increase in these scores.  This shows that for lack of fresh air in their dorm room or classroom, your student could be missing out on their chance to absorb all the material presented, with lower test scores as a result!  Here are some ways to “open the windows”, so to speak:

  • Add a Window Ventilation Filter to their dorm room.  It’s easy to install and remove, and filters out pollution, pollen and dust. 

  • For more info on how to measure CO2 in your dorm or classroom, check out our post.  If the classroom or lecture halls turn out to be high in CO2, advise students to check with their student advisor on advocating for more ventilation.  

VOCs: Most dorm rooms come equipped strictly with the basics -- a bed, desk, chair, light and garbage can, plus a small amount of storage space in the form of a dresser and/or closet. (howstuffworks.com) Therefore, moving into a new dorm room usually means getting new bedding and new accessories like rugs, wall hangings, and more storage like dressers or bookshelves.  When these things are purchased new, VOCs from off gassing can increase dramatically if the doors and windows are kept closed for most of the day.  In the study discussed previously,  a 500-μg/m3 increase in TVOCs was associated with a 13% decrease in the cognitive scores.  Once again, fresh air ventilation is really important to keep VOC levels in check. 

  • Use a portable VOC sensor to check for levels in the dorm room or wherever it’s suspected that VOCs may be high (like a newly renovated area).  

  • Install a  Window Ventilation Filter in the dorm room to get fresh air dilution. 

  • The Air Angel neutralizes VOCs with the catalytic molecules emitted by its AHPCO cell. Being portable and requiring very little maintenance, it can travel anywhere they go: on weekend sports events, home, and on vacation.

  • The Germ Defender/Mold Guard's optional carbon filter adsorbs VOCs emitted by newer items as they off-gas.

Indoor humidity plays a major role in our health: when it’s too low, disease transmissions are more likely, and when it’s too high, mold growth occurs and different mold-related conditions spike.  We can think of many reasons to keep humidity in the recommended range of 40-60% so that your loved one’s health is not at risk!  Sadly, sometimes it takes severe illness and even death to prompt renovation of problem buildings (see this article about the University of Maryland).  Here’s how to equip your student against high humidity and the risk of bacteria, viruses, and mold-related illness.

  • It’s super inexpensive to put a portable humidity sensor in their suitcase or next care package.  Ask them to message you with a photo of the sensor when you’re talking with them in the dorm room, or whenever else it seems to be high.  

  • If the humidity remains high, you can speak to the dorm manager, but also equip your student with a dehumidifier.  Amazon and big box stores can even deliver one from an online purchase.  Since the average dorm room is only about 228 square feet, and larger dehumidifiers come with complaints of extra noise and heat, you’ll want to keep it small.  This economical one by Eva-Dry only covers about 150 square feet (1200 cubic feet), but two of them plugged into different areas will help keep moisture under control.  Here is a review of other models that work great for dorm rooms. 

  • The Germ Defender/Mold Guard is perfect for small, humid spaces, and does triple-duty in a dorm room: 1) Even though the bathroom is typically always humid, mold doesn’t have to grow there… I can testify that one Mold Guard stopped mold growth when I couldn’t get a leaky shower valve repaired right away.  2) This unit also deactivates viruses and bacteria in the air and on surfaces across the room with polarized ions. 3)  Finally, it has an option for a carbon filter to adsorb stinky odors like running shoes and sweaty clothing!

  • Use an Air Angel to prevent transmission of germs and mold growth. This unit is portable and requires very little maintenance, in fact only a replacement AHPCO cell once a year.

Finally, if your college student has not adopted good cleaning habits by now, we can’t help you! (just kidding, but we can supply you with the right goods, read on!)  Statistics on bacteria in dorm rooms are pretty gross: the average women’s dorm rooms had over 1.5 million colony-forming units (CFU)/sq. in. of bacteria, while men’s dorm rooms had an average of over 6 million CFU/sq. in. (collegestats.org).  The same article breaks down the types of bacteria and where they are most concentrated, and while not all of them were bad, most of them were.  It’s time to clean up, because it’s hard to know which is worse: being sick in college or having a sick roommate who will soon infect you.  For those who do clean, equip them: 

  • Once again, Germ Defenders and Air Angels are passive sanitizers that help in activate germs between active cleaning.

  • A bottle of TotalClean goes a long way!  Since dorm rooms are small, heavy-scented chemical cleaners can be super-irritating and not always welcome to their roommates’ sense of smell.  TotalClean is unscented, non-toxic and very effective against dust, dirt, and germs on many different surfaces, even windows and mirrors. 

  • Small pump bottles of non-toxic hand sanitizer and sanitizing wipes stationed around the room and on desks help between hand-washings. 

Of course, similar to sending them off to grade school, you can’t be there 24/7 to help your college student make smart choices, but at least by this point you can give them tools to monitor and correct their own air quality for the healthiest and most productive school year.  Viva la college!

Wall covering products that resist mold and mildew

Wall covering products that resist mold and mildew

When my kitchen faucet caused a leak under the sink and mold spotted the drywall behind it, I thought, with what material can I replace the drywall to make it less mold-friendly?  Under the sink is a dark, damp area where water can intrude again.   Searching my local big hardware store, all I came up with was fiberboard that had a melamine coating on one side.

Doing some more research online, however, uncovered several more options.   These are not only for under sinks, but garages, basements, utility closets, porches, and anywhere that moisture can be an issue.  

Using large panels instead of smaller cladding units (tiles, boards, etc.) minimizes labor, opportunities for water ingress, and also dust, which is always an inhalation hazard for the installers and anyone else in the area.  

Interior Cladding

Trusscore is a new PVC product that not only resists moisture, it reduces installation time, labor and cost when compared with drywall.  Trusscore panels are ½” thick, so that they are the same thickness as drywall.  They are so named because of the truss-like structure inside to give them strength with flexibility (they bend enough to facilitate installation inside channels without creasing).  Once you see this product being installed, who would ever want to go back to the labor intensive, dusty, mold-prone drywall process again?  I really like the clean simplicity of this product.  My major concerns with having it in residential spaces were:

  • VOCs and off-gassing: how much harmful pollutants will it pass into your indoor air?
  • Penetrations, because inevitably, someone will want to hang a picture or shelf on it, and then you have visible, difficult to patch holes in it.  
  • What about changing the color? 

However, the company has integrated solutions into each of these problems.  

  • Trusscore addresses IAQ here: “Trusscore Wall&CeilingBoard, RibCore, and NorLock products are all low-VOC compliant, including low formaldehyde, meaning it won’t off-gas and ensure a safe and healthy space for occupants. In addition, the installation of Trusscore products does not require potential VOC sources like glue or paint for a finished installation.  Each product has been tested according to the California Department of Public Health (CDPH) Standard Method v1.2 testing standard. This is the leading VOC standard used to evaluate VOC emissions from building products such as flooring, suspended ceilings, insulation, wall panels, paints and coatings, and wall coverings. The CDPH standard is referenced by some of the most widely used green building rating systems and green construction codes including USGBC LEED, CalGreen, and more.”  Still, in a fire, I would RUN out of any area that was covered in PVC...I’d say this is definitely not the material to cover any space where welding or high heat hobbies occur.  Also, I would hesitate install to it in high ambient heat places like Las Vegas or the southwest US (it’s plastic, after all)!  
  • Trusscore makes slatwall, which makes it easy to hang things (especially useful in garages and utility rooms)
  • All the panels come pre-finished in a durable white or gray coating, and painting guidelines can be found here (Painting requires special primers so that the paint will stick).  The benefit of painting: if you can paint it, you can also patch it!

Duramax PVC Wall Panels are very similar to Trusscore, but they come in 16” widths instead of 48” widths.  They also do not have any slatwall systems, recommending instead to use hangers similar to drywall hangers to permanently hang anything.  The cost of Duramax is less than Trusscore ($2.70/sf vs. $3.60/sf). They do not have any VOC emissions information on their website or MSDS other than protection guidelines against dust generated while installing it.

MSD panels have a variety of natural and futuristic textures (brick, tile, wood, stone, etc.) for a moisture-resistant cladding for interior walls.  The video on this page contains a little bit construction, a little bit artistry as the installers hang the panels and patch the seams to make the brick wall look completely congruent. As an artist, I do like these for the realistic looks they form.  Unfortunately, they are in Spain!

EverBlock and EverWall products are like giant Legos (with these why would you want to “grow up”?).  Everblocks are made of High-Impact Polypropylene Co-Polymer (“no-break”) with UV Inhibitors added for outdoor use.  EverBlocks are recyclable. They don’t offer much insulative quality (R-2 equivalent), but they are hollow and internally reinforced.

Formica lives on!  Formica HardStop has the great variety of colors and patterns of traditional Formica, but instead of the traditional fiberboard backing that is susceptible to moisture ingress, HardStop has a fiberglass backing that makes it more durable and water-resistant. It can be applied to drywall, plywood, and particle board (which are susceptible to water) or to cement or cement board. HardStop panels are thin and flexible like the original Formica, so they do need a structural element for reinforcement behind them.  They also require adhesive (looks messy to me!).

DriCore Smartwall is a similar system that incorporates an insulated layer on the back of the panel.  Very genius, however, the system uses drywall in the panels, and wood cleats to install it and has wood interlocking sections within the panels.  Here is a video on the installation of DriCore Smartwall, which also uses patch material to make a seamless wall.

Exterior cladding

The more I read about building science, the more I see imperfections in “the way we always did it”.  There are many traditional finishes for commercial and residential buildings, but the gold standard calls for a “rainscreen” type structure that applies the cladding to a hidden track system, so that air can reach behind the rainscreen and dry things out.  Think about a rain fly for a tent, or a double roof system.  The air buffer separates water and extreme heat or cold from the exterior of the house, making for a longer-lasting house!  In his article “The Perfect Wall”, building scientist Joe Lstiburek defines the elements of this wall and how they are constructed to resist rain, snow, humidity, air intrusion, mold, heat and cold, etc.

Here are some products that work as rainscreens:

  • Nichiha: this company was founded in 1956 in Japan but now has an office and factory in Georgia.  Their cement fiberboard siding comes in architectural panels or premium planks and uses a hidden track system.  It is an upgrade to “Hardy Board” and the many imitations of it, because it “floats” on the track system with that air buffer behind it.
  • Ceraclad is a triple-coated ceramic and cement rainscreen with its own installation system. The panels are self-cleaning, with a photocatalytic coating that actually purifies the air!  The coating decomposes car exhaust and other pollutants in the air (NOx and SOx) and turns them into NO3 harmless polyatomic ions leaving the air cleaner.  According to the website, a building with 10,000 sf of external Ceraclad coating is the equivalent of 68 poplar trees!  10 Ceraclad panels are the equivalent purification to 1 poplar tree.  The coating also inactivates viruses and bacteria at its surface. 
  • Knight Wall Systems provide the hidden tracks to install your rainscreen.  They have three different types of attachment to accommodate many different types of cladding.  Although mainly commercial, this system could be used for high-end residential homes as well.
  • Monarch Metal offers cladding systems with all kinds of finishes including HPL Phenolic, stone, fiber concrete and more.  Their hanging system contains high quality “Z-clips” which are similar to french cleats that allow you to hang the facade without screwing into the face of it, also interlocking panels as you install them.

These are just a sample of ways to get less mold growth in damp areas, relying on 1) materials that don’t sustain mold and 2) siding that incorporates ventilation.  It’s building science at its best!

Photo by Phil Hearing on Unsplash