Monthly Archives: October 2023

How do water-based vacuums work and are they better than traditional vacuum cleaners?

How do water-based vacuums work and are they better than traditional vacuum cleaners?

Do you like how fresh the air seems after a rainstorm?  Well, that is the effect of the rain “washing” dust and microbes out of the air.  Sure, on a hot summer’s day it’s not long until these contaminants return, but it’s a welcome respite.  It’s nature’s air purifier!

This brings us to the topic of water-based vacuum cleaners.  Mechanically, the suction part of the vacuum (with or without a rotary brush to dislodge dirt) is the same as traditional vacuum cleaners.  However, using water to “filter” dust out of the air stream is the main difference. 

Let’s talk about how filtration using water as a filter is different from filtration using other mechanical means, such as a cyclonic separator or filter.  When a stream of dirty air is filtered by water, the dirt or dust in the air gets wet and heavy, and thus becomes entrained in the water, leaving the air “clean” on exit.  However, most water-based vacuums also use HEPA filters, in order to prevent any remaining dust or dust in water droplets from leaving the machine.   These HEPA filters are designed to get wet, whereas non-water-based vacuums do not have filters that can get wet.  

In traditional vacuums, the incoming dirty air stream usually first passes through a vacuum bag or cyclone, which filters out larger particles of dirt and hair.   In bagless systems, the cyclone uses centrifugal force to “spin” out these large particles so that the user only has to empty a cup of dirt, not replace the bag.  Single-stage or multi-stage cyclones can be employed, where a multi-stage cyclone allows the vacuum to operate longer without losing suction.  After the bag or cyclone, a final filter (this is where the HEPA filter is found if the vacuum has one) filters out any remaining dust in the air stream before exhaust.

The attraction and “wow” factor of water-based vacuums usually lies in the dirty water that you empty from the vacuum after cleaning.  If the floor is cleaned with a traditional vacuum and then with a water-based vacuum, being able to “see” the dirt that’s left behind drives enthusiasm for the water-based vacuum.  No one cuts open the bag from their traditional vacuum after cleaning, so the satisfaction of seeing that dirty water makes one think that water-based vacuums provide superior cleaning power. 

Although we haven’t tested them, we thought we’d share some insight on the most common water-based vacuum brands and what their customers like and dislike about them. 

Rainbow Vacuum Cleaners

You may have heard of or viewed a Rainbow Vacuum Cleaner, the first vacuum to remove dust from its vacuum stream using water.  The manufacturer, RexAir, was formed in the 1920’s and has been improving the Rainbow ever since it was introduced in the 1950’s. (The Original Water-Based Cleaning System)  It relies on a rotating brush to dislodge dirt, and the suction power of the vacuum motor to bring it into the machine, where the filters purify the air before exhaust.  According to product literature, its unique water filtration system captures typical household dirt, while remaining microscopic particles are caught by the HEPA Neutralizer Filtration System. This two-stage filtration combination removes nearly 100% of dirt and contaminants.  The company uses a network of Independent Authorized Rainbow Distributors which demonstrate the product in homes and businesses, so it’s not sold online.  Purchase prices for these units are not published either, however, customers seem to verify that these vacuums are the most expensive on the market.  Devoted Rainbow customers seem to keep their vacuums for 15-20 years, so the price per vacuum may be a very good value.  The units weigh in at about 20 pounds and rely on smooth casters to roll through your home.  Rainbow is “Certified Asthma & Allergy Friendly” and AHAM Certified: The Association of Home Appliance Manufacturers (AHAM) certifies that the Rainbow is a proven air cleaner designed to reduce air pollutants that contribute to poor indoor air quality.  The weight of the E2 model is approximately 40 lbs and comes with an 8 year warranty.

Sirena vacuums ($600-990) are designed and made in Canada.  They can pick up wet or dry messes, and come with an assortment of tools to get into nearly every crevice.  The motor is quite powerful, providing ample suction, and the water reservoir hold 3.5 liters of water maximum, which is quite a lot of water in which to filter out dust and dirt.  It weighs 40 lbs and comes with a 10 year warranty.

Quantum X ($439) is an upright vacuum, meaning you don’t have to drag a canister around with you while you clean.  The power head can extend up to 18”, making it a good competitor to most canister vacuums, and it has a hose for smaller cleaning attachments.  The upright style affords less room for the water compartment, but this also allows it to be more portable.  It weighs 27.1 lbs. 

Kalorik Water Filtration Canister Vacuum Cleaner ($120) is a good budget cleaner made by a Belgian company that has been in business since 1930. Termed the “poor man’s Rainbow” by one reviewer, it’s a great option for those with pets and/or allergies, and it’s a lot lighter at 14.3 lbs.  The suction head does not have a rotating brush, but it has a high/low adjustment, very powerful suction, and picks up wet and dry messes. Without the rotating brush, it’s best suited for hard floors and not carpets.  It has a 1 year warranty.  

These four vacuums all use water as a filter, but are different from cleaners that vacuum and mop at the same time.  I use the CrossWave floor and area rug cleaner by Bissell ($257), which uses water to clean AND filter out dust.  For homes that have no wall-to-wall carpet or a lot of area rugs, these types of upright vacuums are convenient and ideal because they perform two functions at one time–vacuuming and mopping, with good efficiency (check out our article on using these types of vacuums to tackle dust in your home).

In all, many customers (including myself) prefer water-based vacuums over traditional ones because:

  1. You can see the dirt they pull off your floors very readily when you empty the vacuum, which is both satisfying and disgusting.  Whether this is more than the dirt that is captured by traditional vacuums is not measured.

  2. There’s no bag to retain smelly dirt (especially pet hair).  With traditional vacuums, this smelly dirt stays in your home until you replace the bag, and it also expels smelly air every time you vacuum until you replace the bag.  (As a pet owner, I appreciate this!)

  3. There are no bags to purchase and replace! 

  4. They are very good at retaining suction (most work until the suction compartment is completely clogged with debris or pet hair), and restoring suction is very easy to do–empty the compartment!

  5. Many of these models remove wet or dry messes (traditional vacuums can only handle dry dirt). 

  6. Many of these models allow addition of essential oils to the filter water or cleaning water for a fresh scent of your choice, and some, like the Rainbow and Sirena, double as air purifiers.

The “cons” of water-based vacuums are that: 

  1. Of course, water is heavy and more quality construction can make the unit VERY heavy and bulky, to the point of not being mobile enough to clean separate floors in a home if you are physically challenged.  Most water-based models are “cannister” type instead of “upright” in order to more easily and stably move the water around.

  2. Water-based vacuums can be more costly than traditional vacuums.

  3. Some water-based vacuums (like the Bissell CrossWave) require a detergent to enhance cleaning of the floors.  This detergent is an added operating cost and can have toxic ingredients in it (unless you make your own, check out our recipe here). 

  4. If your vacuum uses water to “scrub” and then suck up dirt and debris, water that stays on your floor can temporarily increase humidity in your home, albeit less than regular mopping.  If water is used to clean carpeting, you must be careful that it’s thoroughly dried, and quickly, so that mold doesn’t have a chance to take root.

Do you prefer another type of vacuum that we haven’t discussed?  Let us know!

Photo by No Revisions on Unsplash

Which is a healthier home habitat: the forest or the desert?

Which is a healthier home habitat: the forest or the desert?

Is it more healthy to live in or near a forest or a desert?  Spoiler alert: we’re not going to call that decision.  Each habitat has its advantages and disadvantages, so we’ll explore them to see which one is best for you.

You might think that these two climes are extremely opposite, but they do have (at least) one thing in common: trees!  Granted, there are many more trees in forests, but trees in the desert can accomplish many of the same purposes.  In a 2020 study, one particular type of tree found in Qatar (desert region), Acacia tortilis, was found to be the most efficient tree species for reducing air pollution, having good capacity to intercept storm water runoff, reducing energy consumption and reducing air pollution levels through dry deposition, avoiding further pollution formation and CO2 removal.  Mature trees (with diameter greater than 45 inches) were much more efficient at accomplishing these goals than younger trees (diameter 10 inches). 

According to the US Department of Agriculture (USDA), trees provide many benefits, including the ability to clean our atmospheric environment both directly underneath their canopies, and at a larger, regional scale. Because leaves transpire large amounts of moisture, trees have a cooling effect on the surrounding environment—like air conditioning. By cooling and cleansing the atmosphere, trees help to make air safer for breathing by plants, animals, and humans and have positive benefits on habitat. In fact, air quality underneath a closed tree canopy is often significantly better than above that tree canopy, especially for ozone—a common air pollutant that forms downwind of urban air pollution sources. On a regional scale, forests also scrub ozone and other nitrogen and sulfur-containing air pollutants out of the prevailing winds, protecting more sensitive areas.  Healthy forests with large, widely-spaced trees also protect from wildfire smoke because pines and other fire-adapted trees with their thick, fire retardant bark better resist fire in all but the most extremely hot, dry, and windy conditions.

Interestingly, some trees contribute to ozone production, while others reduce it.  This is because species like black locust, European oak and poplar intensively emit isoprene, which results in higher ozone and PM10 concentrations, while tree species emitting primarily monoterpenes such as beech, magnolia and wayfaring trees yield less of both.  (Impact of vegetative emissions on urban ozone and biogenic secondary organic aerosol: Box model study for Berlin, Germany)

Another common denominator between forests and deserts is animals–whether they are domesticated or wild, contact with animals is more frequent in remote areas than in urban areas.  There is also much research that shows how exposure to animals benefits us.  In one study, the researchers recruited 2 groups of young men:  20 young men who were raised for the first 15 years of life on farms with farm animals, and a second group of 20 young men who were raised for the first 15 years of life in a city of over 100,000 people, without daily exposure to pets. Both groups were then given Trier Social Stress Test (TSST), a model of acute psychosocial stress in humans. The results revealed that those who grew up in cities without daily exposure to pets, and thus lacked exposure to diverse microbial environments during childhood, responded to psychosocial stress with exaggerated inflammation markers,  (Less immune activation following social stress in rural vs. urban participants raised with regular or no animal contact, respectively)

Now, let’s talk about some specifics of each habitat.


Although the stereotypical desert is hot, dry and sandy, only one of these words accurately describes every desert (dry).  Most experts agree that a desert is an area of land that receives no more than 25 centimeters (10 inches) of precipitation a year. The amount of evaporation in a desert often greatly exceeds the annual rainfall. Surprisingly, areas near water can actually be deserts, because humidity in the air doesn’t predict or cause rainfall.  The Atacama Desert, on the Pacific shores of Chile, is a coastal desert. Some areas of the Atacama are often covered by fog. But the region can go decades without rainfall. In fact, the Atacama Desert is the driest place on Earth, and some weather stations in the Atacama have never recorded a drop of rain.  (Desert)

Low humidity is obviously a benefit to keeping mold from growing on outdoor or indoor surfaces, if air conditioning is not needed.  Dryness would lead some to believe that mold could not be a problem in the desert.  However, mold spores are present everywhere, and lack of home maintenance can allow even a small amount of rainfall to turn into a mold disaster.  Mold can start growing undetected in attics, crawlspaces and walls during one of the infrequent rains, and can turn into a big problem whenever it is disturbed, such as during renovation or further deterioration.  If air conditioning is used, it can generate mold problems when moist air (like from cooking or showering) hits cold air, or around the surfaces where cold condensate is produced.   

Low humidity also means little to no mosquitoes and many other biting insects.  Low pollution (when the wind is not kicking up dust) and warm weather can also be a positive for those who suffer from breathing problems like asthma.  

One problem of low humidity is its effects on the human body (see our article).  Dehydration can become evident in dry skin, hair and nails, respiratory system and through your whole body, affecting every major system.  In addition, static electricity builds up in your clothing and furniture, which can hurt and damage electronics.  Finally, dry air allows pathogens to stay afloat in the air for longer periods of time.  

Most deserts have very little cloud cover and thus a lot of sunshine.  This, for sure has its benefits and drawbacks; it can be the cure for Seasonal Affective Disorder (SAD) but also present higher risk for skin and eye damage and cancer.  Exposure to UV sunlight was associated with lower systolic blood pressure (the first number in a blood pressure reading) regardless of the temperature. (Could sunshine lower blood pressure? Study offers enlightenment)  In addition, sunlight assists your body in making vitamin D, which strengthens bones, and sunlight promotes collagen production in your connective tissue, which helps you move quickly. (7 Health Benefits of Living in the Desert)

The purifying power of sunlight should not be underestimated.  Those who live in or near the desert can use the UV rays of sunlight to purify water, their laundry, and anything else they can bring outside for a good “freshening”. 

One important disadvantage to desert life is dust.  In fact, you don’t have to live in the desert to suffer from the effect of desert dust, because dust from deserts can be transported on the wind and even injected into the troposphere, allowing it to travel great distances (such as across the Atlantic Ocean in the case of Saharan dust).  Dust clouds at surface levels bring particulate matter, coarse and fine, worsening air quality and posing respiratory or even cardiovascular risks.(What is desert dust and how does it change atmosphere and the air we breathe?)  The danger of dust presents in two different ways: size of the particles and content of the particles.  Particles that are approximately between 2.5 to 10 microns (PM10) are inhalable, but can be trapped and cleared from the upper respiratory tract.  Particles less than 2.5 microns (PM2.5) can lung alveoli, entering the blood stream where they cause systemic harm to other organs in the human body. (A Retrospective Cohort Study of Military Deployment and Postdeployment Medical Encounters for Respiratory Conditions)  Especially concerning is the class of particles less than 1.0microns (PM1.0), which are sure to enter directly into the bloodstream and may also cross the blood-brain barrier.  The toxic content of dust can be pathogens such as bacteria, including some that carry respiratory diseases (Characterization of Bacteria on Aerosols From Dust Events in Dakar, Senegal, West Africa), and most importantly, a fungus Coccidioides which causes Valley Fever.  It can also be bioreactive metals such as copper, chromium, nickel, lead and zinc, as well as pesticides, herbicides, radioactive particulates and aerosolized sewage (yuck!!). (Desert dust storms carry human-made toxic pollutants, and the health risk extends indoors)

Increased heat and low humidity also tends to decrease the number of negative ions in the air.  Elevated negative air ion levels are widely reported to have beneficial effects on humans including enhanced feeling of relaxation, and reduced tiredness, stress levels, irritability, depression, and tenseness. Depleted ion levels and enhanced positive ion levels are reported to have no effect, or deleterious effects. (Air Ion Effects

The study of how gasses in the earth’s atmosphere react with each other is very complex.  For example, it’s been shown that desert soil releases nitrogen species gasses into the air.  The release of NOx from desert soil and subsequent effective oxidation in the atmosphere indicates that the desert ecosystem is an important area for ozone production. This has been manifested by higher ozone in the desert air than the regional background from many observations (Güsten et al., 1996; Hoffer et al., 1982).  (Active Nitrogen Cycle Driven by Solar Radiation in Clean Desert Air)  Thus, higher levels of ozone in the desert could make it unhealthy for sensitive individuals.  These could become particularly high after rains, when microbes in the soil emit N2O (nitrous oxide, also known as laughing gas).  (Following rain, desert microbes exhale potent greenhouse gas)  In addition, it’s been shown that “stratospheric intrusions” (ozone-rich air descending from the stratosphere during spring storms) can also capture ozone created by pollution from Asia as they descend and transport it to desert areas of the southwest.  Particularly in the area of Las Vegas, these can create short episodes of high ozone that exceed federal air quality standards without factoring in local pollution.  (Background ozone burdens Las Vegas’ air quality in spring)

The other side of the coin is that in some areas of the world (like Atacama and Sechura deserts in Chile and Peru), dust from deserts can contain significant iodine, which actually destroys ozone.  (Iodine in Desert Dust Destroys Ozone)  Therefore, the mineral makeup of the soil in deserts is very important in characterizing what’s in the air. 

Living in/near the Forest

Forest bathing” is a Japanese term that emerged during the 1980’s as an antidote to tech burnout: it’s being calm and quiet amongst the trees, observing nature around you whilst breathing deeply can help both adults and children de-stress and boost health and wellbeing in a natural way. (How to start forest bathing)  If you regularly spend quiet time in the outdoors, perhaps you are already aware of its benefits: lower blood pressure, heart rate, and levels of harmful hormones like cortisol.  (Forest bathing: What it is and why you should try it)

What is in the air of forests?

Phytoncides are aromatic compounds from plants which can increase your number and activity of natural killer cells, a type of white blood cell that supports the immune system and is linked with a lower risk of cancer. These cells are also believed to be important in fighting infections and inflammation, a common marker of disease.  In one study, researchers found that people who took a long walk through a forest for two days in a row increased their natural killer cells by 50% and the activity of these cells by 56%. Those activity levels also remained 23% higher than usual for the month following those walks. (Why Spring Is the Perfect Time to Take Your Workout Outdoors)

Hinoki cypress, cedar, oak, pine and spruce are just some of the trees to release phytoncides (aromatic compounds), which include alpha-pinene and d-limonene.  Although these are actually VOCs, they are termed biogenic VOCs (BVOCs) because they are naturally made, unlike chemical VOCs that are manufactured.  Pinene and limonene are monoterpenes, which global annual emissions amount to 330–480 million tons. When visiting a forest, monoterpene VOCs such as limonene and pinene are mainly absorbed through inhalation, their blood levels rapidly rise after exposure, and they are mostly eliminated unchanged both in exhaled air and in the urine.  The tree composition can markedly influence the concentration of specific VOCs in the forest air.  Although essential oils do contain BVOCs, not all BVOCs are present in essential oils, and some molecules included in essential oils are not part of the BVOC molecular suite but are rather artifacts of distillation. (Forest Volatile Organic Compounds and Their Effects on Human Health: A State-of-the-Art Review)

Some other benefits of forest living are:

  • Humidity: in moderate amounts, humidity is good for the skin and respiratory system, 

  • Cooling effect: trees cool air through evapotranspiration. As trees transpire, they release water into the atmosphere through their leaves. As the water changes state from liquid to vapor, the surrounding air is cooled, similar to how we sweat.

  • Particulate matter capture: Forests can improve public health greatly by catching dust, ash, pollen and smoke on their leaves, keeping it out of our lungs.

  • Trees are sinks for other harmful pollutants, such as nitrogen oxides, ammonia and ozone, which can all cause respiratory problems from repeated exposure. (The Important Relationship between Forests and Air)

  • Healthy forest air includes bacteria, fungal spores, plant and animal particles and pollen, which may have good and bad effects.  Good effects of exposure to these include desensitization to allergies (exposure therapy), and certain bacteria, like Mycobacterium vaccae (a bacteria strain that lives in soil), which can stimulate serotonin production, and can make you feel relaxed and happier, as well as reduce inflammatory responses to stress. According to Dr. Christopher Lowry, “Surprisingly, when adults engage in soil-mixing activities for ten minutes with soil that is ‘spiked’ with M. vaccae ATCC 15483, there is a rapid alteration in brain activity within the occipital cortex and alteration in the plasma metabolome, relative to soil that is not spiked with M. vaccae ATCC 15483 [35]; this suggests that exposures to mycobacteria not only have long-term immunoregulatory effects but also alter physiology and neurophysiology within minutes. Perhaps we all really should spend more time playing in the dirt.” 

  • Ions: That “fresh air” feeling in the forest also comes from higher than normal presence of ions.  Negative air ions (NAIs) are an important indicator of air quality, and are significant for the evaluation of air conditions. In a 2020 study of a scenic area in China, negative air ions were present in forested areas  approximately 3.2-3.4 times over the numbers in open areas or the lake.  (For more information on the cleansing power of ions, read our post here!)

And the cons of forest living: 

  • Humidity: many forests are high in humidity, which can promote mold growth.  Without dehumidification in a home, it would be difficult to live in many forested areas because of mold growth. 

  • Radon: Trees are sources, sinks, and conduits for gas exchange between the atmosphere and soil, so radon, a product of uranium decay in the soil, is naturally expired by trees along with other gasses.  Although radon accumulation in homes through their foundation (the rocks and soil below the foundation) is most concerning, emission of radon by trees will cause a forest to have a higher level of radon than unforested areas, because radon is approximately 7.5 times heavier than air, so that living in or near the forest may increase the ambient level of radon outside the home depending on winds.  There are two units of measurement for radon, picocuries per liter, and becquerels per cubic meter.  According to a 2015 study in Brazil, radon concentrations as high as 40 kBq/m3 (40,000 Bq/m3) were found in a national forest.  The EPA recommends that homeowners take action to lower radon levels in their homes if there is a level above 2 pCi/L.  Since one pCi/L is equivalent to 37 Bq/m3, the measurement in the Brazilian forest showed 1,081 pCi/L, or 250 times the upper limit of radon recommended by the EPA!  Thus, the study rightly inferred that “the results indicated considerable radon hazard for human occupation in the neighborhood.”

Overall, the desert and the forest are two vastly different climates, yet each have potential for healthy lifestyles for those who can live further away from urban areas.   From forest bathing to hiking to biking, there are plenty of ways that each environment offers us to connect with nature and take in its natural health benefits. 

Enjoy Your Favorite Scents and (Effortlessly) Reap the Benefits!

Enjoy Your Favorite Scents and (Effortlessly) Reap the Benefits!

You might have said this of different tasks in your life, that you can “do it while sleeping”, meaning that you don’t have to use much conscious thought to do them.   Well, here’s a literally simple way to boost cognitive capacity and avoid dementia-related diseases: plug in an essential oil diffuser before you go to sleep!  

Previously, a 2009 study showed that olfactory enrichment (the daily exposure to multiple odorants) could improve both memory and neurogenesis (the formation of new neurons) in the mouse brain. In addition, novelty was the critical element in this kind of stimulation, as exposure to odorant mixtures did not produce these changes, while exposure to multiple odorants individually did.  

When some COVID-19 patients began to lose sense of smell, researchers tested subjects and found that MRI scans from individuals both pre-infection and post-infection have revealed neural deterioration that resembles a decade of aging in brain regions that receive olfactory-system projections.  Because olfactory loss precedes or accompanies cognitive decline in dementia-related diseases like Alzheimer’s and Parkinson’s diseases, researchers hypothesized that easy and affordable intervention to prevent cognitive decline could be using scents.

In a study, 20 participants (the Enriched Group) between ages 60 to 85 were given a diffuser and 7 essential oil odorants (rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender) in identical glass vials that each fit into the diffuser. They were asked to turn on the diffuser when they went to bed, and the odorant was released into the air during the night for 2 h when they first went to sleep. They rotated through the different odorants each night, continuing at home for 6 months. Twenty-three individuals in the control group also were provided with an odorant diffuser, and they followed the same regimen as the olfactory enrichment participants, however they were provided with bottles that contained distilled water with an undetectable amount of odorant added. 

The results showed a 226% difference between enriched and control older adults in performance on the Rey Auditory Verbal Learning Test (RAVLT). This test evaluates verbal learning and memory, including proactive interference, retroactive interference, delayed recall, retention, and recognition memory.  (Overnight olfactory enrichment using an odorant diffuser improves memory and modifies the uncinate fasciculus in older adults)

Before and after MRIs also showed that parts of the brain that receive input from the olfactory system, specifically the uncinate fasciculus, are modified by olfactory enrichment.  The researchers found a moderate increase in the mean diffusivity (MD) of the left uncinate fasciculus in the enriched group compared to controls, which correlates to increased integrity of that specific brain pathway.

What does this mean for the average senior?  Olfactory stimulation (smelling different scents) can be an important way to avoid dementia-causing diseases, and the cost of a programmable essential oil diffuser and a variety of different oils is not prohibitively expensive.  Here are a few options:

Best of all, this method is not hard to do; basically, with a little preparation, you can “do it while sleeping”! 

Photo by Kelly Sikkema on Unsplash

Keeping safe when using supplemental heat

Keeping safe when using supplemental heat

When the weather turns chilly, sometimes your main heat source doesn’t heat quickly or completely, or it’s expensive to run, and you may turn to supplemental heaters for a quick way to warm up.  Supplemental heating sources like radiators, space heaters, and fireplaces are alternative options to simply turning up the heat in your home or installing a new, main heating system.  However, they have limitations and safety considerations you should note!

Portable space heaters





  • Heats whole space, not limited to line-of-sight

  • Lightweight

  • Because it’s convection heat, it usually requires a fan to direct the heat

  • Can dry out the air excessively

  • Lose heat due to convection (heating air instead of objects)

  • May take longer to heat 

Infrared/ Quartz

  • Great for small, open spaces

  • Cost depends on which power source it uses: electric or gas (natural or propane).

  • Quickly heats due to direct transfer of radiant heat

  • More efficient than ceramic heaters (over 90% efficiency)

  • Must be in line-of-sight of the heater to feel warmth

  • Not good for large spaces

Oil-filled Radiator (electric)

  • Quiet!  Fans are not necessary in these models.  

  • Modern versions have features like programmable timers and adjustable thermostats. 

  • Radiant heat is very comfortable and continues even after the heater is turned off.

  • Surfaces become hot and may endanger children and pets.

  • These type of heaters may take longer to heat up a room initially.

  • They are heavy but most are equipped with casters for portability.


  • Kerosene stores well for long periods so it can be a good emergency heater for power outages.

  • Inexpensive

  • Quiet because no fans are needed

  • Can heat larger spaces like garages

  • Because it burns fuel liquid inside your home, you must take abundant safety precautions around flammable furnishings, children and pets.

  • Combustion byproducts mean that carbon monoxide monitors must ALWAYS be used, and room should be ventilated adequately (possibly losing heat).

  • They’re illegal to use indoors in MA and possibly other states

  • They produce water vapor, which can cause excess humidity

  • Kerosene can emit significant particulate pollutants, especially if burners/wicks are not kept clean

Sometimes the permanent heating system in your home is undersized and it can’t heat the whole home adequately.  In other cases, if you have a gas furnace, propane or natural gas can become relatively expensive!  In these cases, permanent supplemental heating (the installation of a heater in one part of the home) can help. 

Permanent Supplemental Heating




Electric Radiators or wall-mounted heaters

  • Provides steady heat with minimal safety issues

  • Unobtrusive because they are located on or near a wall

  • Can consume a lot of electricity during prolonged cold spells

Electric Heat Pump Mini-Split

  • Heat pumps are more efficient for larger spaces than portable electric heaters

  • Heater can be sized to the space very easily

  • Air handler portion is mounted on a wall, out of the way

  • Can be regulated with a programmable thermostat

  • Units typically heat and cool, making them very versatile

  • Long life

  • May also include an electric coil for emergency backup heating

  • More expensive initial investment than portable heaters

  • Requires exterior space for the heat pump

Wood heating systems

  • Wood burning fireplaces are attractive

  • Very economical if you have the ability to cut and haul wood

  • Fireplaces do not require power

  • Wood pellet stoves produce very little ash, burn cleanly and easy to operate

  • Long-lasting

  • Sealed fireplace inserts increase heat efficiency while decreasing emissions

  • Professional installation is recommended

  • Wood pellet stoves require electricity to operate the fan and feeder motor

  • Flues must be cleaned at least annually to prevent fire risk

  • Carbon monoxide monitors must ALWAYS be used and it’s a good idea to monitor for CO2 and NOx

  • Unsealed fireplaces always have risks of dangerous smoke and embers coming out of the firebox into your living space


Gas Fireplace or heater

  • Gas fireplaces are attractive and vented models are readily available

  • Can work when the power is off but are more efficient when using the fan to disperse heat

  • Environmentally friendly

  • Professional installation is recommended for any permanent combustion heater

  • Requires a nearby gas line

  • Carbon monoxide monitors must ALWAYS be used and it’s a good idea to monitor for CO2 and NOx


Propane or Natural Gas Heater

  • Very efficient and inexpensive

  • Available with safety features such as oxygen depletion sensor (ODS) that immediately shuts down the blue flame heater if carbon monoxide or lack of oxygen is detected

  • Can work when power is off but are more efficient when using the fan to disperse heat

  • Broad choice of unvented models; however read the precautions below

  • Professional installation is recommended for any permanent combustion heater

  • Requires a nearby gas line

  • Lack of venting required does not mean lack of air pollution.  NO2 and CO2 levels can become relatively high if ventilation is not used.

  • Combustion byproducts mean that carbon monoxide monitors must ALWAYS be used, and room should be ventilated adequately (possibly losing heat)

  • Should not be left burning when the room is unattended

We want you to be knowledgeable about and avoid air quality poisons that are created just by heating your home with a combustion unit!  According to a Japanese study of propane, kerosene and electric space heaters used in a non-ventilated, 215 ft2 room:

  • concentrations of NO2 and CO2 from all the heaters except the electric heater exceeded the 1-hr Environmental Quality Standards (NO2: 0.04-0.06 ppm) and the Building Sanitation Management Standards (BSMS, CO2: 1,000 ppm).  

  • The CO concentration emitted from reflection kerosene and natural gas heaters slightly exceeded the BSMS (10 ppm). 

  • The concentrations of suspended particulate matter and polynuclear aromatic hydrocarbons showed an increasing tendency during the use of kerosene-fueled heaters. 

In a study of kerosene heaters, NOx, CO2 and CO are the main gaseous pollutants emitted by kerosene space heaters. In addition, carbonyl compounds (formaldehyde, acetaldehyde, acetone) were identified, as well as ∼50 other VOCs, six of which presenting a risk for human health (1,3-butadiene, benzene, ethylene, propene, isobutene and acetylene). There is an accumulation of soot on wick heaters after a few hours of operation, which causes incomplete combustion that increases CO emissions, (CO poisonings are frequent with kerosene heater use). Therefore, the recommendation with any combustion gas heater is to ventilate profusely, or go with a vented heater model.  This article on concurs that we should avoid unvented gas heaters. 

Photo by Jessica Johnston on Unsplash

“Sleeper” bacteria spores are like mold spores

“Sleeper” bacteria spores are like mold spores

One of the unsavory facts about mold is its ability to lie dormant when food and moisture sources dry up, until conditions allow it to “bloom” again.  Scientists are finding out that there are other microbes that exhibit this same behavior, necessitating finding new ways to detect their presence.  

One of these is Acinetobacter Baumannii.  This superbug is usually present in wet environments, such as soil and mud, ponds, wetlands, wastewater, fish farms and seawater.  Healthy people can also carry the Acinetobacter bacteria on their skin, particularly if they work in a healthcare setting. It can survive for a long time on dry surfaces, making it difficult to eliminate. (Acinetobacter: What to know)  

Scientists have recently discovered a new state of “life” of this bacteria.  When living conditions become too stressful, many bacteria enter a dormant state that is almost death-like, showing no metabolic activity. These are known as spores. 

Acinetobacter baumannii can alternatively form special cells which are in a kind of deep sleep. Although these cells still show signs of life and breathe, it is no longer possible to cultivate them on culture media in Petri dishes. "We know this state from cholera bacteria, for example; it is referred to as the viable but non-culturable (VBNC) state," explains Professor Volker Müller of Goethe University Frankfurt.  (The deep slumber of a hospital pathogen: Why infections with Acinetobacter baumannii can flare up again and again)

As of the study date (September 2023), scientists have kept the acinetobacter in VBNC state for 11 months, and are still able to “wake them up” after 2 days of “rehab” with special nutrients and oxygen.  No end is in sight for the length of time these bacteria can hibernate.  

The danger is that courses of normal antibiotics and culture procedures (on a plate) can yield negative culture results, which would indicate that a patient is clear of such dangerous microbes.  However, VBNC cells can be hiding in nooks and crannies of the body, waiting to resurge when stress or antibiotics are removed  Tests like PCR (Polymerase Chain Reaction) can be used to detect VBNC cells because they identify specific genes that cause virulence and predict antibiotic resistance, but it’s probable that these are not used in smaller hospitals currently.

Acinetobacter Baumannii is not the only bacteria with “sleeper” capabilities; dormancy or persistence is just a “state” that many bacteria can occupy.  Mycobacterium smegmatis, which is related to the bacteria that causes pneumonia, was studied in 2013 and discovered that “persister” bacteria continued to divide and die even during antibiotic treatment so that the total number of bacteria stayed approximately the same.  The fact that the cells weren’t classically “dormant” but still continued to divide, makes them technically “dynamically resistant” to antibiotics, while other microbes use other techniques to evade death and can be labeled “tolerant, latent, indifferent, dormant and non-multiplying”.  (Sleeper cells – the secret lives of invincible bacteria) However, it all comes back to their ability to survive antibiotics, which is dangerous for us!

Here is some recent literature on other “sleeper cells”

Since persistent bacteria are difficult to kill with traditional antibiotics, scientists are pursuing several strategies to take them out.  One is to find ways to wake all of them up, so that they are easy to kill with accessible drugs.  The second is to discover what genes or proteins allow them to stay alive in sleep mode.  Some of these “upregulate” cell functions (like scavenging for iron), and some of them downregulate cell functions (like digestive functions).  A third tactic would be to look for drugs that kill the sleeper cells, not just active ones.  

To the layman, all this sounds like poking into a hibernating bear’s den with different sticks until you find one of the right length poking in the right place, and having the best gun or trap ready for when he wakes up!  The sad fact is that people regularly suffer from hosting these persistent bacteria in their bodies and we sincerely hope that scientists can find the right triggers in labs to find the combination of methods to help patients who need it.

Bacteria, mold and other microbes also populate our homes in the form of spores, persisting for years until the right moisture AND nutrients come along.  Although there is no “silver bullet” like an antibiotic to remove them completely, we can use the same principles to keep the population under control so that our bodies don’t suffer!

  • Clean regularly with non-toxic ingredients.  The less dust and dirt we allow to accumulate in our homes, the less microbe spores are lying around.  Check out our article on Tackling Dust in Your Home.

  • The FDA states that over-the-counter antibacterial hand soaps don’t protect us from disease any better than regular soap and water.  The cleansing action happens in the thorough agitation of soap and water over hands, and a good rinse with water.  Many “antibacterial” soaps also contain ingredients, like triclosan, which can be harmful to us over time.  

  • Since you can’t easily scrub and rinse items like your countertop or toilet seat with soap and water, however, different solutions need to be employed there.  Sure, you can get antibacterial cleaning sprays, but the same concerns apply: are they safe long-term?  Instead, opt for cleaners that are non-toxic and are less likely to create antibiotic resistance.  We’ve recommended the following cleaners for these reasons:

    • Our all-purpose, non-toxic cleaner TotalClean combines both copper and iodine, and when they are combined, they produce peroxide!  In simple terms, the peroxide acts as an “oxidizing agent”, destroying the means for bacteria to take in oxygen and suffocating them.  

    • The Honest Company Disinfecting Spray also uses hydrogen peroxide to clean, disinfect, and deodorize while meeting EPA’s criteria for products effective against SARS-CoV-2 and a laundry list of other germs.

    • Because hypochlorous acid is an oxidant, it leaves nothing behind for bacteria and viruses to create resistance to and therefore does not contribute to the superbug (multidrug-resistant organisms) dilemma.(The Role of Hypochlorous Acid in Managing Wounds: Reduction in Antibiotic Usage)   Hypochlorous is not bleach; in fact, it’s superior to bleach.  Some hypochlorous cleaners include Force of Nature and Clean Republic’s All Purpose Cleaner.

  • Of course, change your HVAC filter regularly so that spores do not find their way to your air handler’s evaporator coil, where moisture can allow them to reactivate.  We’ve got some great filters with activated carbon and MERV 10-14 ratings (for more on MERV, check out our article HVAC filter changes are vital to your indoor air quality

  • The technology in our bipolar ionizers like our Germ Defender, Upgraded Air Angel Mobile and Whole Home Polar Ionizer has been tested against bacteria such as E. coli, MRSA and C. diff (see test results here), so why not add them to your non-toxic cleaning arsenal as a passive way to keep the spores under control? 

There’s a lot about the microscopic world of bacteria and mold that we don’t know, and obsessing over it doesn’t help much!  Thankfully, there are quite a few ways to keep safe using non-toxic products and methods that are tried and true. 

Photo by CDC on Unsplash

How do emergency shelters get fresh air?

How do emergency shelters get fresh air?

If you must go into an emergency shelter, then you can bet that conditions outside are not good, whether it’s a natural disaster, war or safety from criminal activity. You can store many supplies such as food and water for staying in a shelter, but without clean air, survival will only be minutes instead of days, weeks or months!  There are a number of things that air and ventilation systems need to accomplish for shelters:

  1. Providing a positive pressure at all times so that contaminated air from leaks or outside sources does not enter the shelter.

  2. Filtering out contaminants such as nuclear, biological, chemical (NBC) or smoke toxins. 

  3. When the shelter must be completely closed up due to bad air quality outside, two things must happen: 

    1. Removing carbon dioxide (CO2) byproducts of the people residing in the shelter.

    2. Providing supplemental oxygen to replace the oxygen depleted by residents

Let’s go through these in order.  When the shelter is not being used or only tested during good external conditions, then its ventilation system can operate like your home system: bring in outside air, send it through filter(s) to remove dust and normal microbes like mold and bacteria, and keep a slight “overpressure” of 0.3 inches of water so that leaks in the shelter’s walls and doors will only cause air to move out, never in.  The exhaust “vents” are really one-way valves that only let air go out, so that air coming in is controlled.  They also protect residents of the shelter from any explosive “blast” of pressure and debris.  For this reason, they are called overpressure blast valves.   

The flow of fresh air should be similar to what is required at home: according to US standards, that is 0.35 air changes per hour (ACH) or 5 cubic feet per minute per person, whichever is greater (5 cfm is the specified minimum required by the US military, whereas 15 cfm is the recommended supply for ventilation in residential and commercial buildings).  That said, 5 cfm is usually the design criteria to remove the moisture and carbon dioxide (CO2) that shelter residents exhale, and make them feel comfortable.  The air intake must be protected from water and animal intrusion and sufficiently distant from the exhaust (overpressure blast valve) so that used air is not recycled through the shelter.  Routing airflow through the shelter ensures that the exhaust is in the airlock (the chamber where residents enter and exit) so that any outdoor contamination is flushed out with the positive air pressure.

NBC filtration (or as the military defines it CBRN: Chemical, Biological, Radiological, and Nuclear) requires unique filter material.  Pre-filters are used to keep dust and particulates out of the airstream, and then activated carbon impregnated with specific minerals is used to adsorb gasses that may be emitted during disasters or wars.  For example, the activated carbon may be mixed or “doped” with potassium permanganate, potassium iodide, or magnesium dioxide or copper dioxide (see our article on what these materials remove from air). These are not typical systems used in home ventilation, as the activated carbon must be in sufficient purity and quantity to allow filtration for a number of days until outside air clears.

In the event that outside air is heavily contaminated, the ventilation system will need to be completely sealed off and the shelter will operate more like a submarine, where supplemental oxygen is added and CO2 is removed.  The atmosphere needs to be maintained close to ambient outdoor air, at 19.5% oxygen and less than 0.2% (2000 ppb) CO2, and that’s a complex task when humans are using oxygen and expelling CO2 every minute!  It’s good in this case to use the same two principals we introduced in our article on submarines: use good instruments to measure the air quality and have redundant systems to ensure that each function is maintained in case of system failure.  In well-planned shelters, it’s common to have the following instruments: thermometer, humidity meter, differential pressure gauge (to maintain 0.3” water overpressure), smoke alarm, low oxygen detector, carbon monoxide alarm, carbon dioxide alarm, and a radon meter. (NBC Air Filtration Systems)

Although NBC filtration systems can be expensive, systems for adding oxygen and removing CO2 are even more expensive and complex.  Here are some ways that military and professional systems do it (Air Supply Principles in Isolated Shelters & Chambers):

Supplemental Oxygen is available in three different methods:  

  1. Oxygen can be stored in a gas form under pressure or as liquid oxygen in cylinders, and released from these tanks when needed.

  2. Oxygen generators can separate oxygen from compressed air stored in the tanks, or even generate oxygen from electrolysis of water (passing an electric current through it).

  3. Oxygen “candles”, also called chlorate candles, are a very hot-burning cylindrical candle that actually puts out oxygen instead of consuming it.  

Removal of CO2 requires even more chemistry. On average, each person produces 1 kg of CO2 per day, and buildup of CO2 in the air is lethal (see our article on CO2 levels).  Therefore one or more of the following systems is needed:

  1. CO2 scrubbers use a soda lime or lithium hydroxide material to remove CO2 from the airstream, but they produce a lot of moisture and heat and require space for storage of filters and material, which could be prohibitive for smaller bunkers.

  2. Regenerative carbon-dioxide removal systems use a solid amine material and are advantageous in terms of space required, but have a high energy consumption and are costly to install.  

Since air supply is one of, if not the most, critical aspects of a shelter, these systems are best designed and installed by professionals who have experience.  In the survival shelter industry, NBC filter systems made by Israeli and European (Finnish and Swiss) companies differ significantly from those made in the US and UK.  The former systems are more robust, with significantly better materials, engineering and more generous carbon supply than others.  (NBC Air Filtration Systems)

Due to threats of war, disease and scarcity, many people are becoming interested in emergency shelters, but an improperly designed or constructed shelter can be more life-threatening than life-saving!  If you are interested in building or buying an emergency shelter, we recommend you check out this article and research first.  Having a place to retreat in emergency requires a lot of forethought and planning to truly make it "safe"!

Photo by Billy Freeman on Unsplash

What happens behind closed doors…

What happens behind closed doors…

What happens behind closed doors…is STAGNATION!  When you close the door to a room in your home, air is trapped in the room, resulting in the following:

  • If there is no fan operating, air will not circulate, and any humidity present in the air will saturate soft furnishings, increasing the likelihood that mold will grow (see our article on ventilation and one of our favorite tools,

  • If central air conditioning or heating is pushing air into the room, the closed door prevents proper cycling of air out of the room, causing the system to a create a negative pressure zone near the return grille and placing stress on the system’s mechanical parts like blower motors.

  • Again, central air conditioning or heating with closed doors causes imbalances in the temperature of the home, because conditioned air is prevented from mixing, which in turn affects the thermostat and causes the system to run longer to reach the temperature set point.

Keeping doors closed, in other words, is just not good for proper ventilation in your home!  This makes sense to us…until the question of privacy is brought up.  Of course, not everyone wants their door to be open at all times, even if it’s just cracked open.  Don’t worry, there are ways to get good ventilation even with closed doors!

The best solutions are brought in during the design phase of the home, before construction begins.  This is where our first idea is best incorporated.  Transfer grilles offset high/low in a wall cavity use the cavity to muffle sound, so that this design affords  the maximum privacy.  However, in order to avoid entraining dust and other building toxins from surrounding spaces, the cavity needs to be sealed by gluing the drywall to the studs and plates…meaning that this solution needs to be built in during construction.

Source: Building America Solution Center

If you’re realizing you need better air circulation after construction, then there are still more solutions to consider.  You can use a back-to-back grille over a door (or any high space on a shared wall), which have sheet metal baffles to block sound and light while still allowing the passage of air through the wall.  Here are some diagrams to show back-to-back grilles:

Source: Building America Solution Center

Thirdly, if wall space is an issue and you have attic space above the rooms, you could install a jump duct using flexible duct, two ceiling grilles, and foam sealant (to make sure air from the attic does not leak into your home).  Theoretically, a jump duct could also be placed through/under the floor to bridge two spaces, but in either place, take care to make sure the flexible duct is not crimped, and do not cut any structural beams like rafters or joists to install it.

Source: Building America Solution Center

Lastly, there’s a solution which I consider to be the easiest of all of these.  In-Door Return Air Pathways by Tamarack Technology are easily installed in the bottom of your hollow-core or solid wood interior doors (door must be 1-3/8” thick to fit).  Simply remove the door from the frame (I find that tapping the hinge pins out is easiest), lay it down, trace the provided template on the bottom of the door, cut it with a jigsaw, install the grille with two screws (provided) and re-install the door.  They do provide less privacy than the previous two options, but are quick to install (less than 30 minutes in my experience) and can be left white or spray painted to match any door color with paint suitable for plastic. 

In-Door Return Air Pathway installed in a solid wood door.

When you have the door closed with any of these three solutions, air is free to mix with the rest of the home, rooms do not become positively or negatively pressured, and you definitely have an advantage in keeping mold from forming in that room.  Additionally, the continuous use of the following in the closed room costs very little energy, but boosts your mold protection even more: 

Sure, we get it…everyone needs their privacy, but for health’s sake, make sure the air is flowing freely!  

Photo by Storiès on Unsplash

Excuse me but your fireplace is open!

Excuse me but your window fireplace is open!

Heading into the winter heating season, many of us are thinking of cozy nights snuggled inside our homes, not the cold drafts that spoil the atmosphere in more ways than one–ahem, even our heating bills!  Drafts are invisible sucks on our budget, like “phantom” power leeches that use electricity.  The drafts coming from the fireplace are comparable to leaving a window cracked open.  In our article about how to keep the fireplace from polluting the house, we noted that the average household can save 14% on their heating bill by weatherstripping the fireplace.   It’s time to prepare for maximum coziness!

Working fireplaces have dampers, and these should work well.   Dampers are like “valves” that should be closed when the fireplace is not in use, to prevent outside air (and smoke particles from the flue) from coming back into our homes when we’re not using the fireplace.  However, dampers are not air-tight; they just don’t have the ability to block drafts.  Here are several other places to really air-seal your fireplace:

1) At the chimney cap: this requires you to get up on the roof or hire someone to do that.

2) Inside the flue with a balloon: the balloon, however, can shrink as temperatures get colder, or get punctured on a rough surface and leak.

3) At the hearth (bottom): this is the most physically convenient place, and can be easily removable for those times you want to use your fireplace.

Although the first two can accomplish air sealing well with the right products, #3 is actually the healthiest because the chimney and firebox (with smoke particles on their surfaces) stays separated from your house air.  

Here are some ways we’ve found to seal out those drafts all year long: 

If your fireplace is a bare opening in the bricks, like mine, this is the most difficult to seal but worth the effort.  Here is are two ways to do it:

Method 1: You’ll need: 

  • 4 pieces of wood (at least 1” square, larger is better) or metal tubing cut to fit the length and width of the opening (see diagram below)
  • Foam insulation tape to go around the frame in the opening
  • Glue gun and glue if adhesive on insulation doesn’t work well
  • Magnetic tape or velcro tape
  • Optional: 1-2  tension rods will help stabilize the frame if the wood doesn’t fit snugly.
  • An insulated blanket or piece of plywood cut fit over the frame.

You’ll want to thoroughly plan out how the frame will fit together before cutting your wood or metal to length!  Here’s how I cut mine:

Then, add insulation to the perimeter of the pieces using the adhesive on them, or a glue gun, and fit the wood snugly back into the opening–you may need to re-cut the pieces to accommodate the increased thickness due to the insulation.  

You can add 1-2 adjustable tension rods across the opening or up and down for added stability.

Next, add magnetic tape or velcro to the front of the wood pieces in order to attach the insulation.  You can use all kinds of materials to cover the opening and get creative!  Just remember that there will be a temperature differential in winter or summer, so adding some insulation to the back of the material makes it even more energy efficient.

  • Foam board or cardboard (if cut to fit snugly, no tape is needed to secure it in the opening)

  • Bed blanket with extra insulation glued or stitched to back or inside

  • Old electric blanket with wire removed and extra insulation added inside (stitched in place)

  • Plywood

  • Drywall

Of course, if you decide to use the fireplace, remove ALL of these materials and store them away for re-installing later. 

Method 2 involves taking a baby or pet gate and setting it to firmly span the opening, then cutting a foam board or cardboard to fit exactly over it (you can cover the foam board with wallpaper or fabric).  While this method can be sturdier and quicker to do, it does involve finding an unused gate and cutting the foam very carefully so that it seals the opening. Alternatively, you could cut a used foam mattress topper slightly larger than the opening, and squeeze it into place to cover the gate (again, covering the foam with any decorative material). 

Here’s how my fireplace draft blocker turned out with a fleece blanket, 2 sheets of cardboard glued together, and a staple gun (admittedly I could have stretched the fleece a bit more or made a border for more visual interest):

Voila!  Just sticking my head into my fireplace one time during this project and smelling the lingering smoke smell made me think, why didn’t I do this sooner?  Drafts and smoke be gone all year long!

Glowing under blacklight

Glowing under blacklight

I’ve heard that in the 1960’s, blacklight posters were all the rage.  Glowing things are cool!  How does blacklight actually cause things to glow?  

“Blacklight” is an invisible form of light that operates in the ultraviolet range.  Because light takes on a wave form, the frequency of the peaks and troughs in the wave are known as wavelengths.  In the visible spectrum, reds and oranges have the longest wavelengths, and at the other end of the spectrum, blues and violets have the shortest wavelengths, meaning they have higher frequency.   Ultraviolet light is not visible to us, yet exists beyond the violet shade.  The wavelengths of ultraviolet light are grouped into 3 bands: A, B and C.   

UV-A, with wavelengths ranging from 320-400 nanometers (nm), is the safest form of UV light and often referred to as Longwave UV.  This kind of UV light is generated by Blacklight units (the dark purple fluorescent tubes) as well as UV LED flashlights.  Black lights are considered safe for use in the home as well as theatres and night clubs etc.  Most quality sunglasses will protect eyes against UV-A.  

UV-B, at 280-320nm wavelength, is the one that can cause sunburn when over-exposed. It can also be used in the medical treatment of certain skin conditions.  Most quality sunglasses will protect eyes against UV-B.

UV-C, at 200-280nm wavelength, is totally absorbed by the Earth's atmosphere, but also widely used as a germicidal sterilizer in hospitals. 

Obviously, UV light has had good and bad press.  As you may know, certain types of UV light are known to cause eye and skin damage and cancer.   And certain types of UV light are used to kill microbes, making the air you breathe (or surfaces you touch) safer.  We have a whole article on some of the ways researchers are using UV light to sanitize.  In this article, however, we’re going to look at some of the more useful ways to use blacklight (UV-A) in your life–to literally “see” the invisible!

Blacklight makes some of the invisible, visible, because it illuminates items that fluoresce.  These items contain exposed phosphorus atoms that reflect short wavelength UV light back to our eyes. For instance, paper shines under a blacklight because of the fluorescent chemicals added as a whitener. (Using Blacklights to Find Pet Urine)

Urine glows under UV light because it contains phosphorus. 

Pet Urine:  Unlike the synthetic fluorescents added to white paper, natural fluorescent substances such as dog and cat urine etc, do not glow brightly under UV. In fact, they are generally quite dim, so do not expect a supernova!  You will be looking for patches a little brighter than their background; you’ll know them when you see them.  Cat urine glows particularly well under a black light, as it contains high levels of phosphorus, but the intensity of the glow can vary depending on the animal’s diet and health.  When examining soft surfaces like carpet and fabrics, remember that liquids can quickly soak down into them, so that not a lot of urine remains on the surface to “glow”. It’s also easier to find it:

  • When fully dried, because liquid or damp urine will not glow.
  • When new–the “glow” slowly fades over time as the urine ages.

If you do find “accidents”, try a cleanser that uses enzymes.   You can read all about enzyme cleansers in our article.  (Stain Detective Pro)

Rodent Urine: Rats and mice are incontinent and will urinate and defecate on the move, up to 80 times a day! This means you will be looking for a trail of urine droplets or streaks leading in the direction of travel. Urine and droppings are deposited where the rodents spend most of their time and where they travel.  Amino acids in rodent urine will fluoresce, or emit light of a different color, when exposed to ultraviolet light. This makes it possible to see rodent, rat, mouse, hamster, guinea-pig or squirrel urine even in dark places. (Rodent Detector Pro)

Mold often glows under blacklight.  In this video, mold stains that are not visible in normal light are shown on the ceiling under blacklight.  If you are not seeing stains in an area that has leaked before, or has a high level of humidity, the key may be to shine the light at an angle against the wall.  You should shine the ultraviolet light closely along the sides of the suspected surface or walls. The angle of illumination will show the presence of fungus, however, some cleaning products also leave a glow, so be careful not to mistake cleaning residues for mold. (How To Detect Mold With A Blacklight)

Hand Washing: Blacklights make it possible to see if you are washing your hands effectively and make training on hand-washing easy!  If you apply some UV Germ Grease (which simulates the way germs cover your hands; it’s just a clingy grease with glowing particles), wash according to this video and check them under blacklight to see if any of the grease remains, you’re more likely to get your hands cleaner after this training.

Here are some other interesting items you can get to “glow” in your home: (Got a new UV torch? Here are some things to shine it on

  • Tonic water – the quinine in tonic water glows blue
  • Honey – the aromatic molecules in honey can glow green
  • Turmeric root – the curcumin in turmeric glows yellow
  • Eggs – a compound in eggshells called protoporphyrin IX can glow red
  • Rocks, jewels and gemstones – lots of minerals glow under UV light
  • Cash – banknotes have added photoluminescent details to prevent fraud
  • Cleaning materials – detergents (including laundry detergents) often have photoluminescent molecules to make them easy to see
  • Highlighters and dyes – fluorescence is a type of photoluminescence, so fluorescent markers and dyes will often glow under UV light
  • Vitamins: Vitamin A and the B vitamins thiamine, niacin, and riboflavin are strongly fluorescent. Try crushing a vitamin B-12 tablet and dissolving it in vinegar. The solution will glow bright yellow under a black light. (16 Things That Glow Under Black Light)
  • Antiques that have been repaired or touched up will glow or fluoresce differently in the area where the repair has been made.
  • Insects such as scorpions glow bright green, and Harvestman (Opiliones, also sometimes called Daddy Long Legs) glow blue, as do certain other spiders.

Here are some tips about selecting UV blacklights: 

  • Although many people associate blacklight with a purple light, if you can see the light, it’s not blacklight, and the contribution of visible light diminishes the ability to “see” any hidden markings. 
  • The frequency of UV light emitted determines the quality of results obtained.  There is a sweet-spot for UV which is between 365nm and 385nm.  However, to manufacture LEDs capable of emitting in this frequency range is far more expensive.
  • There are different types of lamps that are used to make UV light:
    • Mercury vapor lamps are used in theaters and large spaces where it’s needed to project UV light over a distance
    • UV fluorescent tubes or bulbs are smaller and more portable, with decent quality
    • UV LED lights: these come in a wide spectrum of quality (wavelengths), but they are very portable and consume little energy.

So....I went sleuthing one night with a small, inexpensive blacklight borrowed from a friend, and it works!  First I looked around some registers I knew had sweated when I had an older, less efficient HVAC system, and there they were--old stains and mold that was not even visible in the daylight (I have some popcorn ceilings so shining the light at an angle really accentuates the stain).  Next, I looked and saw a white patch where stains had been "touched up"--proof that not everything was stained or mold.  Then, I found a pet stain in a small rug that had absorbed and was unnoticeable in daylight. 

A small blacklight flashlight could be a cool science project for you and your kids, by not only finding things that glow, but eliminating the yucky animal pee and poo as well with enzyme cleansers.  Remember that the wavelength (365-385nm) is important to get quality black light, and many cheap flashlights don’t fall in that range. Here are some lights that will give the best results for your detective work:

Photo by h heyerlein on Unsplash

Mold in the Toilet

Mold in the Toilet

The bathroom is a room that’s very susceptible to mold growth, and once you understand what mold needs to grow, it’s easy to understand why. Basically, it just needs moisture (shower=check, sink=check, toilet=check), and food (dust=check, organic matter=check), so the bathroom sometimes becomes a petri dish that’s hard to keep up with.  Fortunately for you, we’re tackling this problem by appliance, so check out our other articles here:

Now, back to mold in the toilet.  Mold can be mistaken for those stubborn mineral toilet rings, until it starts to turn weird colors, like black, brown or pink. 

What type of mold is the black mold in the toilet?

Although you may know that Stachybotrys chartarum is the most commonly termed “black” mold, another mold that appears black is Aspergillus Niger, as shown in Figure 2 of this 2017 study from India.  Aspergillus Niger can be a cause of some forms of pneumonia, so it’s definitely not something you want in your bathroom!  The study identified five types of mold in public toilets, resulting from airborne spread of spores and improper or infrequent cleaning procedures.

Alternaria and Cladosporium are two other types of mold that can produce black growths. (10 Types of Mold Colors Commonly Found in the House)  The most important thing to know is that these molds can produce mycotoxins and mVOCs every time they are disturbed!  Stachybotrys has been demonstrated to produce a number of Macrocyclic Trichothecene mycotoxins.  (Black Mold and Stachybotrys Exposure Guide)  Aspergillus niger can produce Ochratoxin A, Cladosporium produces mVOCs which can be irritating, and Alternaria species produce more than 70 mycotoxins! (Alternaria host-specific (HSTs) toxins: An overview of chemical characterization, target sites, regulation and their toxic effects)

Brown stains in the toilet are another problem–they could be caused by a number of molds, such as Pithomyces chartarum, Aureobasidium pullulans, Stemonitis, Taeoniella, Cladosporium or Mucor.  Arguably the most harmful mold of these is Mucor, which can cause a life-threatening blood infection called mucormycosis. However, it’s not always brownt any point during its life cycle it can be brown, yellow, black, white, or gray.  (10 Types of Mold Colors Commonly Found in the House)

Pink slime in the toilet is actually not mold.  As we mentioned in our article about the shower, that pink slime that can also form around drains and at the bottom of the shower curtain is caused by the bacteria Serratia marcescens, and can cause urinary and respiratory tract infections, which are especially problematic for people with immune problems. 

If you decide to try to find out what type of mold is growing, you can test it with a lab, but in any case it’s wise to treat it as a dangerous air pollutant.  Don’t disturb it unless you spray a cleaner on it first (to immobilize the spores), or are using a mask!

What is the cause of mold in the toilet bowl?

There are several possible causes for mold in the toilet bowl, some of which can be easily resolved and some need more effort!  

  • One of the easiest methods is just flushing the toilet more often. Toilets that are not used every day can allow mold and bacteria to attach to the bowl.  After cleaning the toilet, try to remind yourself to swing by and flush the toilet at least every other day so that these microbes don’t have a chance to proliferate.
  • Next, if the toilet does get used or flushed often, more frequent cleaning is often needed.  However, you need to skip traditional bleach based toilet cleaners, as they are toxic for you!  The following are some non-toxic cleaners that are very effective for bacteria and germs, however note that citric acid is not always effective on mold (read below on citric acid** and get a few more recommendations from Zero-Waste Memoirs):
    • Force of Nature is hypochlorous acid, a safe alternative to bleach that is a hospital-grade, EPA-registered disinfectant that kills 99.9% of germs including Staph, MRSA, Norovirus, Influenza A, Salmonella, and Listeria when used as directed.  You can spray Force of Nature in the toilet as a final disinfectant, but it should not be mixed with essential oils or cleaners that contain essential oils, as this can reduce its disinfecting power. 
    • Fragrance-free powder: Seventh Generation Zero Plastic Toilet Bowl Cleaner ($22) has citric acid as its main cleaning agent.  This non-toxic ingredient is registered with the FDA in products certified to kill feline calicivirus (a testing substitute for norovirus), so we know that it works.  If you or anyone in your household is exhibiting symptoms of this illness or a similar one, we would suggest cleaning toilets full-strength and often with a product like this!   If you like a little lemony fragrance, try the Probiotic Toilet Bowl Cleaner by Etee ($45), which also uses citric acid.  It may seem expensive, but it’s not bad on a per-use basis ($1.50), and some customers find that using less than the prescribed amount (1 TBSP) works just fine.  Added probiotics help to keep your septic system functioning optimally.
    • Dissolving strips:  Nature Clean Natural Toilet Bowl Cleaners Strips ($17) are highly rated too.  They use sodium coco sulfate as the main ingredient, which is a blend of the fatty acids in coconut oil. (Sodium Coco Sulfate: Is It Natural?)  It is a synthetic detergent with one of its ingredients being sodium lauryl sulfate (SLS), however it is less irritating should you immerse your skin in the soapy water (highly unlikely for a toilet bowl cleaner!) Lastly, the essential oils including Australian tea tree oil, provide a pleasant scent and antiseptic properties.
    • Liquid: Mrs. Meyer’s Liquid Toilet Bowl Cleaner, $6, uses citric acid and essential oils like lemon verbena to get a fresh-smelling clean, all in a bottle made from at least 30% post-consumer plastic (recycled).  

Safe descaling of your toilet bowl:  mineral stains and some molds may be removed by simply using the concentrated citric acid** (as you’ve read, a non-toxic ingredient in many toilet bowl cleaners), which comes in a granule or powder form.  Granules are safer to use because they are mostly dust-free (they’ve been formed into little clumps that don’t kick up dust when you handle them).  

The following is adapted from a post on Moral Fibres.  Their method did not work without scrubbing but I learned a few things working on my own toilets:

  • Gather your supplies: a large pitcher for clean water, ½ cup of citric acid powder or granules, latex or plastic gloves, an abrasive scrub sponge that’s safe for porcelain, Bar-Keeper’s Friend Cleanser (optional), several paper towels, small disposable cup, tape for closing the lid (optional), about ¼ cup baking soda. 

  • Turn off/close the water valve on the wall completely.

  • Flush the toilet.  The tank and the bowl won’t refill this time. 

  • Fill a large pitcher full of hot water from your sink and pour it into the toilet bowl. The water should not be boiling hot as it could crack your toilet.  Also, make sure to add it slowly so that the water doesn’t drain completely from the bowl; you’ll want the water at or above the water ring stain.

  • Put on gloves and add about ½ cup of citric acid powder or granules to your toilet bowl. (use a mask if your citric acid comes in powder form)

  • Swish the water in the bowl gently with your toilet brush to dissolve it, but don’t swirl too vigorously because it will cause water to drain from the bowl.  After you add the citric acid to the bowl, don’t add more water, because this will dilute the acid. Add paper towels around the bowl to cover all the stained porcelain, and use the disposable cup to wet them with liquid from the bowl.  The bowl should be lined with paper towels stuck to the inside wherever there are stains.

  • Close the lid and put tape and a sign to prevent people from using it! 

  • Leave the citric acid in the toilet bowl, without flushing, for at least one hour, or preferably before going to bed, so it can soak the scale overnight.

  • After leaving the solution to soak, use the bowl brush or gloved hands to remove the paper towels, and try using your toilet brush to remove scale deposits. If it doesn’t move, use gloved hands, the scrub sponge, and Bar-Keeper’s Friend or another agent safe for porcelain.  Scrub away!

  • Finish by adding the baking soda to neutralize the acid, swish with the bowl brush, open the water valve, wait for the tank to fill, and flush!

  • If your toilet is particularly stained, then it may need a second application to remove stubborn deposits.

Citric acid**: The interesting thing about this chemical is that it is commercially produced by the mold Aspergillus Niger, which may be the same type of mold you’re trying to eliminate.  Manufactured Citric Acid (MCA) is one of the most common food additives in the world, and has received the status of “generally recognized as safe” (GRAS) with the FDA.  However, there have been isolated cases of inflammation due to ingestion of foods with MCA, due to its great tolerance to heat and large potential that byproducts of A. niger remain in the final MCA product. (Potential role of the common food additive manufactured citric acid in eliciting significant inflammatory reactions contributing to serious disease states: A series of four case reports)  Unfortunately, we weren’t able to determine whether MCA actually kills Aspergillus Niger growing in your toilet, but it does a great job with all the other molds 

The atmosphere of the bathroom is also very important in preventing mold.  Here are two ways to keep the air in the bathroom less hospitable to mold: 

  • Bathroom exhaust fans are a must for any bathroom with an actual shower or bath.  If you have a fan but not sure if it’s large enough, check the cubic feet of air per minute rating (cfm) on the fan (you may have to remove the cover) and this article to see if it’s large enough for your bathroom.  In addition, go outside and see if you can see the little flapper lifting to show that air is indeed being exhausted.  If you can't find the exhaust of this fan, it's possible that the moisture is being exhausted in the attic, which needs to be fixed.  If your kids or guests are not switching on the exhaust fan during their showers, get an electrician to tie the fan and light switch together so that the fan MUST come on when the light is on.  Finally, if you don't have an exhaust fan, get a window fan like this one and make sure the kids use it!
  • Bipolar ionization units like our Germ Defenders, Mobile Air Angels and Whole Home Ionizers are a great way to keep mold away too.  At the very least, plugging a Germ Defender into the bathroom will send out ions to kill mold spores in this small space where air circulation can be a challenge.

If the mold keeps coming back despite flushing and cleaning, then there are several possible causes for this:

  • Older toilets commonly have pitting in the ceramic which can harbor mold. This video shows that no matter how hard a toilet is scrubbed with different products, pits in the ceramic are microscopic reservoirs that shelter bits of the mold, allowing it to come back again.  The safest solution in this case is to replace the old toilet with a new one.  The radical (but toxic) solution to keep your old toilet but lose the mold is to use diluted muriatic acid (also known as hydrochloric acid) to clean the pits.  However, the mold will eventually come back and inhabit those pits again unless you take another step to renew the enamel on your toilet bowl (a bit extreme to save an old toilet). 
  • Improper venting.  You may not know it, but all drains in your home require a vent to work properly.  We’re not talking about the air vents in ceilings and walls, but a gas vent for the drain line.  These are hidden in your walls.  According to the uniform plumbing code, vents must be located within six feet of the P-trap (that snake-like part under the sink and the S-curve under the back of the toilet); otherwise, the drain may not work properly and gasses can build up, supporting mold and microbe growth.  If this seems to be the case, it’s best to have a good plumber check out the location and condition of the toilet and sink vents and see if there are other drain problems.   
  • This next one is a difficult truth: there may be a cache of mold hidden in your home that is “seeding” spores into your air, causing mold to grow wherever there’s a water source (sinks, showers, and of course your toilet).  According to a respected mold inspection and remediation company, Mold hotspots include the basement, attic, windowsills and door frames, crawlspaces, appliances, and underneath the sinks. Do you feel worse in some rooms of your home and better after leaving them?  This gives a clue to where the mold contamination may be originating.  If you don’t see anything obvious, you could have a hidden leak somewhere, like in the walls or flooring, that’s allowing mold to grow. There are two things you can do in this case: 
    • Order some spore traps from GotMold or even just a set of EC3 test plates ($36 for 6-pack) by MicroBalance Health Products to check the relative mold level in rooms to narrow it down!
    • If you suspect a problem or are having chronic symptoms, it’s best to hire a qualified mold inspector.

There are many non-toxic ways to clean and keep clean nowadays, and with a little research and effort the toilet can be as clean and healthy as the rest of your bathroom and home!

Photo by Jas Min on Unsplash