Indoor Air Pollution

indoor air pollutionIndoor air pollution is one of the most overlooked threats to human health. Households in developing countries might be the hardest hit. Because children spend almost eighty percent of their time indoors, they are the most likely victims. In the past several years it has been determined that conditions ranging from asthma, headaches and fatigue to allergic reactions, hormone imbalances and central nervous damage may be attributed to indoor air quality—or, rather, the lack of it. Most of us realize that outdoor air quality can affect health, but few pay attention to the indoor air…unless it smells bad.

In a paper supported by the University of Medicine and Dentistry of New Jersey and printed in the British Medical Bulletin in the early 2000’s, Junfeng (Jim) Zhang and Kirk Smith allowed that the ubiquitous character of indoor air pollution “…may contribute to increasing prevalence of asthma, autism, childhood cancer, medically unexplained symptoms, and perhaps other illnesses.”   Because the sources of indoor pollution are not expected to abate in the near future, particularly those associated with tobacco use, we can expect to voice concerns for a long time. The authors add that “…risks associated with solid fuel combustion coincide with risk associated with modern buildings.”

It is absurd that indoor air quality should be so poor that it causes sickness and disease, yet that appears to be more the rule than the exception in modern times.  Nobody would think of running a tractor-trailer or a tour bus in the living room, but the pollution effect is the same.  Most of us are unaware of the problem because a single major source of indoor pollution can’t be fingered. Despite this unrecognized threat, indoor pollution is twice as bad as outdoor, according to studies performed by the Bloomberg School of Public Health at Johns Hopkins.  Others put the rate at five times. There are so many sources of indoor pollution that have become part of our daily lives that we never question them. Have you thought about the unpronounceable ingredients in your cleaning products and other household chemicals, like the pesticides you use in the yard? How about your cosmetics and the smelly things you plug into the wall to hide other smelly things?  Got new carpet or upholstery? Oh, yeah, there are more, such as the aroma of hot tar being applied to the new roof at your children’s school…while school’s in session. The activity may be outdoors, but the sickening smell is certainly indoors.

The influx of biological pollutants is hard to manage.  Molds, bacteria, viruses, animal dander, skin particles (yes, even human), pollen and dust mites are everywhere.  You can see airborne particles in that beam of sunshine coming through the window, but you can’t identify any of them.  Some can breed in the stagnant water that sits in your humidifier, or where water has collected in your ceiling tiles, insulation or carpet.  These things can cause fever, chills, cough, and chest tightness, among other symptoms.  Even when we do what we think is good for the family, we may do the opposite.  Burning the woodstove or fireplace might save money on the heating bill (though the fireplace is suspect), but how about the junk it puts into the air?  You can’t win, eh?

In our attempts to conserve energy, we have sealed our houses so tightly that nothing can get in and less can get out.  Once we change the air pressure dynamics of our houses, we have allowed intruders to enter.  Radon and soil gases are most common, and they creep through the cellar floor.  Mechanical ventilation can help to get the junk out and bring at least some fresher air in.  Not only does insulation contribute to the tightness of our homes, but also it brings problems of its own in the form of irritating chemicals.

Increasing ventilation is one of the easiest steps to improving indoor air quality.  Even in the dead of winter it’s a good idea to open the front and back doors simultaneously once a day to let fresh cold air in and the stale reheated air out.  Pathogens grow in an environment that is warm, dark and damp.  Your hot-air heater is a prime breeding ground for colds and the like.  The American Lung Association and the Mayo Clinic have recognized air filters as being sufficiently effective to allay at least some of the problem.   Using a vacuum with a HEPA filter is another prudent intervention.

Concerning household cleaners, we all know that anything natural costs more than anything man-made, and that mindset is hard to figure out.  Why do we have to pay for things that are left out?  In the mean time, note that vinegar-water concoctions are just as good as many commercial products at cleaning our homes—even the commode.  Who cares if it smells like salad?

But what might just be the best air cleaner on the planet is a collection of house plants.  Formaldehyde is a major contaminant of indoor air, originating from particle board, carpets, window coverings, paper products, tobacco smoke, and other sources.  These can contribute to what has been called “sick building syndrome.”  The use of green plants to clean indoor air has been known for years.  This phytoremediation has been studied with great intensity in a few laboratories across the globe, where it was learned that ferns have the greatest capability of absorbing toxins.  (Kim, Kays. 2010)  As is the case with many endeavors, there is a hierarchy of plants that does the job.  After the ferns, the common spider plant (Chlorophytum comosum) was found best at removing gaseous pollutants, including formaldehyde.  Way back in 1984 NASA released information about how good the spider plant is at swallowing up indoor air pollution.  The heartleaf philodendron partners well with Chlorophytum.  Dr. Bill Wolverton, retired from NASA, has a list (  Areca and lady palms, Boston fern, golden pothos and the dracaenas are at the top.  Plants with fuzzy leaves are best at removing particulates from smoke and grease, and some are even maintenance-free (almost), including the aloes, cacti, and the aforementioned spider plants, pothos and dracaenas, the last sometimes called the corn plant.

For more information, try these resources:

Indoor Air Pollution Increases Asthma Symptoms (Johns Hopkins Bloomberg School of Public Health)

Pollution at Home Often Lurks Unrecognized (12/26/2008, Reuters Health) by Amy Norton

Air Purifiers and Air Filters Can Help the Health of Allergy and Asthmas Sufferers (S. A. Smith)

Indoor Air Pollution Fact Sheet (08/1999, American Lung Association)

An Introduction to Indoor Air Quality (Environmental Protection Agency)


Br Med Bull (2003) 68 (1): 209-225.
Indoor air pollution: a global health concern
Junfeng (Jim) Zhang and Kirk R Smith

Environmental and Occupational Health Sciences Institute & School of Public Health, University of Medicine and Dentistry of New Jersey, NJ

Indoor air pollution is ubiquitous, and takes many forms, ranging from smoke emitted from solid fuel combustion, especially in households in developing countries, to complex mixtures of volatile and semi-volatile organic compounds present in modern buildings. This paper reviews sources of, and health risks associated with, various indoor chemical pollutants, from a historical and global perspective. Health effects are presented for individual compounds or pollutant mixtures based on real-world exposure situations. Health risks from indoor air pollution are likely to be greatest in cities in developing countries, especially where risks associated with solid fuel combustion coincide with risk associated with modern buildings. Everyday exposure to multiple chemicals, most of which are present indoors, may contribute to increasing prevalence of asthma, autism, childhood cancer, medically unexplained symptoms, and perhaps other illnesses. Given that tobacco consumption and synthetic chemical usage will not be declining at least in the near future, concerns about indoor air pollution may be expected to remain.

Nippon Eiseigaku Zasshi. 2009 May;64(3):683-8.
[Indoor air pollution of volatile organic compounds: indoor/outdoor concentrations, sources and exposures]. [Article in Japanese]
Chikara H, Iwamoto S, Yoshimura T.
Fukuoka Institute of Health and Environmental Sciences, Mukaizano, Dazaifu, Fukuoka 818-0135, Japan. [email protected]

In this review, we discussed about volatile organic compounds (VOC) concentrations, sources of VOC, exposures, and effects of VOC in indoor air on health in Japan. Because the ratios of indoor concentration (I) to outdoor concentration (O) (I/O ratios) were larger than 1 for nearly all compounds, it is clear that indoor contaminations occur in Japan. However, the concentrations of basic compounds such as formaldehyde and toluene were decreased by regulation of guideline indoor values. Moreover, when the sources of indoor contaminations were investigated, we found that the sources were strongly affected by to outdoor air pollutions such as automobile exhaust gas. Since people live different lifestyles, individual exposures have been investigated in several studies. Individual exposures strongly depended on indoor concentrations in houses. However, outdoor air pollution cannot be disregarded as the sources of VOC. As an example of the effect of VOC on health, it has been indicated that there is a possibility of exceeding a permissible cancer risk level owing to exposure to VOC over a lifetime.

Environ Sci Technol. 2009 Nov 1;43(21):8338-43.
Uptake of aldehydes and ketones at typical indoor concentrations by houseplants.
Tani A, Hewitt CN.
Institute for Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan. [email protected]

The uptake rates of low-molecular weight aldehydes and ketones by peace lily (Spathiphyllum clevelandii) and golden pothos (Epipremnum aureum) leaves at typical indoor ambient concentrations (10(1)-10(2) ppbv) were determined. The C3-C6 aldehydes and C4-C6 ketones were taken up by the plant leaves, but the C3 ketone acetone was not. The uptake rate normalized to the ambient concentration C(a) ranged from 7 to 19 mmol m(-2) s(-1) and from 2 to 7 mmol m(-2) s(-1) for the aldehydes and ketones, respectively. Longer-term fumigation results revealed that the total uptake amounts were 30-100 times as much as the amounts dissolved in the leaf, suggesting that volatile organic carbons are metabolized in the leaf and/or translocated through the petiole. The ratio of the intercellular concentration to the external (ambient) concentration (C(i)/C(a)) was significantly lower for most aldehydes than for most ketones. In particular, a linear unsaturated aldehyde, crotonaldehyde, had a C(i)/C(a) ratio of approximately 0, probably because of its highest solubility in water.

Proc Am Thorac Soc. 2010 May;7(2):102-6.
Indoor air pollution and asthma in children.
Breysse PN, Diette GB, Matsui EC, Butz AM, Hansel NN, McCormack MC.
Department of Environmental Heath Sciences, Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA. [email protected]

The purpose of this article is to review indoor air pollution factors that can modify asthma severity, particularly in inner-city environments. While there is a large literature linking ambient air pollution and asthma morbidity, less is known about the impact of indoor air pollution on asthma. Concentrating on the indoor environments is particularly important for children, since they can spend as much as 90% of their time indoors. This review focuses on studies conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment as well as other relevant epidemiologic studies. Analysis of exposure outcome relationships in the published literature demonstrates the importance of evaluating indoor home environmental air pollution sources as risk factors for asthma morbidity. Important indoor air pollution determinants of asthma morbidity in urban environments include particulate matter (particularly the coarse fraction), nitrogen dioxide, and airborne mouse allergen exposure. Avoidance of harmful environmental exposures is a key component of national and international guideline recommendations for management of asthma. This literature suggests that modifying the indoor environment to reduce particulate matter, NO(2), and mouse allergen may be an important asthma management strategy. More research documenting effectiveness of interventions to reduce those exposures and improve asthma outcomes is needed.

HortScience 45: 1489-1495 (2010)
Variation in Formaldehyde Removal Efficiency among Indoor Plant Species
Kwang Jin Kim1, Myeong Il Jeong, Dong Woo Lee, Jeong Seob Song, Hyoung Deug Kim, Eun Ha Yoo, Sun Jin Jeong and Seung Won Han

The efficiency of volatile formaldehyde removal was assessed in 86 species of plants representing five general classes (ferns, woody foliage plants, herbaceous foliage plants, Korean native plants, and herbs). Phytoremediation potential was assessed by exposing the plants to gaseous formaldehyde (2.0 µL·L–1) in airtight chambers (1.0 m3) constructed of inert materials and measuring the rate of removal. Osmunda japonica, Selaginella tamariscina, Davallia mariesii, Polypodium formosanum, Psidium guajava, Lavandula spp., Pteris dispar, Pteris multifida, and Pelargonium spp. were the most effective species tested, removing more than 1.87 µg·m–3·cm–2 over 5 h. Ferns had the highest formaldehyde removal efficiency of the classes of plants tested with O. japonica the most effective of the 86 species (i.e., 6.64 µg·m–3·cm–2 leaf area over 5 h). The most effective species in individual classes were: ferns—Osmunda japonica, Selaginella tamariscina, and Davallia mariesii; woody foliage plants—Psidium guajava, Rhapis excels, and Zamia pumila; herbaceous foliage plants—Chlorophytum bichetii, Dieffenbachia ‘Marianne’, Tillandsia cyanea, and Anthurium andraeanum; Korean native plants—Nandina domestica; and herbs—Lavandula spp., Pelargonium spp., and Rosmarinus officinalis. The species were separated into three general groups based on their formaldehyde removal efficiency: excellent (greater than 1.2 µg·m–3 formaldehyde per cm2 of leaf area over 5 h), intermediate (1.2 or less to 0.6), and poor (less than 0.6). Species classified as excellent are considered viable phytoremediation candidates for homes and offices where volatile formaldehyde is a concern.

*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.

Mold In Your Cellar?

water-damaged-basement-wallThere are wet clothes on the line downstairs. Last night’s rain storm left a few puddles on the floor near the cellar windows. It feels a few degrees warmer in the cellar than in the kitchen because it’s more humid. Situations like this create a breeding ground for mold, one of the fungus kingdom. Molds are everywhere, and are a common component of dust. Large quantities of mold can become a health hazard, causing allergic reactions and respiratory problems. Those few that produce mycotoxins can pose a serious risk to human health, and are the “toxic molds” of conversation. One of the most infamous is called Stachybotrys chartarum, more commonly found outside than in, but an occasional resident of flooded buildings. Molds can live on plants, foods, dry leaves, and other organic matter, but can also grow on hard surfaces.

Molds are produced by spores, which can be carried by air currents because they are tiny and lightweight. Fungi in general are necessary to the food chain as decomposers. But as molds inside your house they can cause a myriad of problems. For significant mold growth to happen there needs to be a source of dampness, a source of food, and a substrate capable of sustaining growth. Building supplies, including carpets, plywood, sheetrock, and other porous materials, are ideal places for molds to live and grow. Cellulose is one of their favorites. A single incident of water damage can encourage mold to live inside a wall, later to be resurrected from near dormancy by high humidity. Identifying the source of humidity is an important step in resolution. Even the steam from a stovetop or the shower, the watering of houseplants or the use of a central humidifier can exacerbate—or even initiate—a mold problem.

The health effects of mold exposure include allergic reactions, eye and respiratory irritation, infection, and toxicity. About five percent of individuals are predicted to have some airway symptom from molds over their lifetimes. Wherever and whenever mold infestation is identified it needs to be remediated.

If the cellar is where the kids play when the outdoors is uninviting, paying attention to the presence of mold is important. If enough is there, you’ll be able to smell it, even if you can’t see it. If the mold is growing in black streaks and looks slimy, it could be Stachybotrys chartarum, and is usually indicative of poor indoor air quality. If the texture is fuzzy or matte, it’s likely another strain, such as Aspergillus or Fusarium. Regardless of what it is, it is advisable not to touch it or to inhale deeply when you examine it.

Sometimes you’ll see condensation on your (cellar) windows or walls. This might mean there’s a combustion problem with an appliance. Is the dryer properly vented?  How about the furnace and water heater?  Too little air to the furnace can cause back drafting, which is also a carbon monoxide threat. Using a de-humidifier in the cellar, especially if it’s unheated, is sound practice. If your dryer is vented into a bucket of water to trap lint because outdoor venting is difficult or impossible, and if the cellar lacks heat, the damp air from the dryer can condense once it contacts the cold walls. Hence the rationale for a dehumidifier. A fan can desiccate the air enough to deny mold a happy home.

The dryness of indoor wintertime air can cause static electricity, shrinking and warping of furniture, skin irritation, and even bloody noses. At 40% humidity, most of us are reasonably comfortable. Increasing indoor humidity to prevent problems is O.K. as long as there is no condensation inside the living room windows. Cold air cannot hold much moisture, and a heater dries it out even more. Being overzealous with humidification can create conditions favorable to mold, which prefers temperatures between 77° F. and 85° F, but can survive anywhere between 32° and 95°.   Unless there are symptoms of mold sensitivity, testing is unnecessary. If it is done, it should be performed by a trained professional. In a baseline home, mold spore counts may range from 300 to 1200 spores per cubic meter. Counts above 1000 suggest a mold problem. (Rockwell, 2005)  On the other hand, there are no regulations that outline acceptable mold counts

Simple steps to remedy a small occurrence start with sunshine, improved ventilation, additional insulation in the walls, and dehumidification. But these do not get rid of what’s already present; they only make it non-viable. Simply killing mold is not enough. It has to be removed because the chemicals and proteins that evoke a reaction are still present in dead mold. Using bleach will only make it lighter in color and fail to kill the roots. Why?  Because bleach is mostly water, and water is what mold needs to thrive.  The active ingredient in bleach, often sodium hypochlorite, is weakened. A stronger product than what we get from a store is dangerous. Not only that, bleach will only work on non-porous surfaces, like tubs and tiles. It does not penetrate porous materials, even concrete, so it can’t get to the roots, and the mold will return. It does, however, change the color. Some people think that if they can’t see any mold, all is well.

Borax and straight white vinegar can kill mold, but you have to be patient. Borax has to be mixed with water, but is strong enough and safe enough to do the job. Neither product needs to be rinsed. If you don’t care about spending money, tea tree oil is a great antifungal, using a teaspoon per cup of water in a spray bottle. It’s safe to humans and animals, and is one of the best mold slayers. People use it on cuts and scrapes because it’s also antibacterial. Any residue will prevent recurrence of mold. A novel product in the fight against mold is grapefruit seed extract, used to fight bacterial, yeast and viral infections. The citric acid seems to be the active component. Ten drops of this go into a cup of water in a spray bottle. It’ll kill the mold down to its roots. If a mold problem is severe, get a professional to do the job, but make sure he’s qualified.


Hardin BD, Kelman BJ, Saxon A.
Adverse human health effects associated with molds in the indoor environment.
J Occup Environ Med. 2003 May;45(5):470-8.

Koburger T, Below H, Dornquast T, Kramer A.
Decontamination of room air and adjoining wall surfaces by nebulizing hydrogen peroxide.
GMS Krankenhhyg Interdiszip. 2011;6(1):Doc09.

Kuhn DM, Ghannoum MA.
Indoor mold, toxigenic fungi, and Stachybotrys chartarum: infectious disease perspective.
Clin Microbiol Rev. 2003 Jan;16(1):144-72.

Mudarri D, Fisk WJ.
Public health and economic impact of dampness and mold.
Indoor Air. 2007 Jun;17(3):226-35.

Robbins CA, Swenson LJ, Nealley ML, Gots RE, Kelman BJ
Health effects of mycotoxins in indoor air: a critical review.
Appl Occup Environ Hyg. 2000 Oct;15(10):773-84.

Rockwell W.
Prompt remediation of water intrusion corrects the resultant mold contamination in a home.
Allergy Asthma Proc. 2005 Jul-Aug;26(4):316-8.

Terr AI.
Are indoor molds causing a new disease?
J Allergy Clin Immunol. 2004 Feb;113(2):221-6.

U.S. Environmental Protection Agency
“A Brief Guide to Mold. Moisture, and Your Home”

*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.

Exposure To Motor Lubricants & Solvents

car-engineMuscle car plus motor head does not equal muscle head, although it could. The first pair evokes positive images for those who remember Holley carburetors, dual exhausts, Hurst shifters and four on the floor (gears, that is). The muscle cars of the 60’s were exciting to drive and fun to work on. That was an era when there was enough room in the engine compartment to swing a socket wrench. Of course, without air conditioning there was plenty of space to climb inside and yank a Champion or two. Considering that engine oil is to a car what blood is to the human body, you can bet that oil changes were dutifully timed events. Unlike blood, oil has changed over the years. Modern engine oils have viscosity-index improvers, antioxidants, dispersants, corrosion and foam inhibitors, and anti-wear agents that were absent half a century ago. Also some oil formulations vary from state to state. In the past, wearing oil and grease on hands and clothes was a badge of honor, an announcement that proclaimed mastery over a demanding technology. Today, protective gloves need to be the order of the day.

Mechanics and other auto workers who are exposed to used crankcase oil have experienced skin rashes, blood effects similar to anemia, headaches and tremors. Along with used oil, they are exposed to other chemicals/toxins common to the auto industry, including fluids, metal particles and fumes. Used oil may contain chemical constituents that result from the internal combustion process, such as the polycyclic aromatic hydrocarbons (PAH) associated with benzene and related suspect carcinogenic compounds. Systemic effects of exposure to used oils and automotive fluids may include elevated blood pressure, aberrant red blood cell values (caused by lead exposure), stress to the liver (as indicated by irregularities in enzyme markers), and skin rashes (Clausen and Rastogi, 1977). In mechanics who work with new cars, interior cabin materials present no less a threat to health. Exposures to high concentrations of the aliphatic hydrocarbons that render the appealing “new car smell” are found to accumulate in the body (Yoshida, Jan 2010 and Aug 2010).

What’s the big deal?

There is more than one route to internal toxicity. You can swallow almost anything, inhale too many other things, and absorb more than a handful of the remaining damaging substances available to the environment. Compounds that contain only hydrogen and carbon are called hydrocarbons. The number of atoms of either element can change to make a different substance, one of the simplest being CH4, known as methane. During the refining of petroleum, one kind of hydrocarbon can be converted to another, giving us gasoline, naphtha, kerosene, lubricating oils and more. Adding chlorine to the C-H backbone reduces flammability and increases stability, resulting in chlorinated hydrocarbon solvents that can be used to clean, degrease and thin almost anything. At high temperatures that vary according to the compound, they give off seriously toxic gases and can enter the body through the skin.

Most foreign substances are unable to penetrate skin, the outer layer of which is an effective barrier to most inorganic particles. But damage to the stratum corneum, whether by abrasion, exposure to U-V light, or by chemical insult, can allow penetration. Lubricating oils, some waxes, and greases can induce primary irritations and photosensitivity to skin. The severity depends on the nature of the oil, the integrity of the skin, the frequency and length of contact, and individual susceptibility. Certain size molecules of chlorinated and simpler hydrocarbons, and of those with a greater number of carbon atoms than hydrogens, are more apt to enter skin than others (Riihimaki and Pfaffli, 1978) (Babu et al, 2004).

Among the riskier materials are automotive and industrial solvents made with trichloroethylene or tetrachloroethylene, known to penetrate the skin and suspected of being carcinogenic. Up to the 1970’s, trichloroethylene was used directly on humans as a general anesthetic and as a wound disinfectant. Believe it or not, it was also used as a flavoring agent for coffee. This nonsense was halted in 1977. Today it’s being used as a degreaser, as a cleaner for textiles, as an additive to inks and paints, and as an ingredient in PVC (the polyvinyl chloride in plastic plumbing). At least it won’t catch fire. Strangely, the metabolites of trichloroethylene are identical to those that follow the chlorination of municipal water supplies, namely chloral, chloral hydrate, monochloroacetic acid, and di- and trichloroacetic acids (Simon, 2005).

Tetrachloroethylene is also known as perchloroethylene, most commonly used in dry cleaning.  Exposure, either respiratory or dermal, may cause depression of the CNS, liver and kidney damage, impaired memory and headaches (DHHS, 1991). Like trichloroethylene, it is non-flammable and stable. Earlier in its history it was used in commercial refrigerants and auto air conditioners. But it’s an excellent solvent for organic materials such as the greases and lubricants used in the automotive industry…and it dissolves fats from skin, resulting in skin irritation.

Does It Hurt?

Once in the body, either through the skin or the nose, these hydrocarbons attack the cell membrane and the proteins that prevent entry of toxic compounds. A bodyguard enzyme called ATP-ase directs cell traffic by letting food and energy in, and by escorting wastes and toxins to the door. Another of its jobs is to control the balance of sodium and potassium. Sodium tells a cell to contract so you can pick up a tool, and potassium tells it to relax so you can put it down again. Chlorinated solvents, though, attack the fats from which the membrane is made and cause it to lose its shape and to resemble a half deflated basketball. Now, it can’t do its job and you get tired quickly and your thinking becomes foggy. Once ATP-ase gets dissolved by chlorinated hydrocarbons, any work that requires muscle power becomes more and more difficult. There are no alternatives to crankcase oil, but there are optional solvents and degreasers. Read the labels, wear gloves, and protect your eyes. No matter how thick-skinned we think we are, we really aren’t.


Armstrong SR, Green LC.
Chlorinated hydrocarbon solvents.
Clin Occup Environ Med. 2004 Aug;4(3):481-96

Babu RJ, Chatterjee A, Ahaghotu E, Singh M.
Percutaneous absorption and skin irritation upon low-level prolonged dermal exposure to nonane, dodecane and tetradecane in hairless rats.
Toxicol Ind Health. 2004 Sep;20(6-10):109-18.

Clausen J, Rastogi S.
Heavy metal pollution among autoworkers:I Lead.
Br J Ind Med. 1977; 34(3):208-215.

Clayton GD, Clayton FE, eds. 1981.
Patty’s industrial hygiene and toxicology. Volume 2B: Toxicology. 3rd ed.
New York, NY: John Wiley and Sons, 3373, 3397-3398.

Clonfero E, Zordan M, Cottica D, et al.
Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of humans exposed to therapeutic coal tar. Carcinogenesis. 1986; 7:819-823.

DHHS 1991.  (NIOSH) Publication Number 97-155
Control of Exposure to Perchloroethylene in Commercial Dry Cleaning

Duprat P, Gradiski D.
Percutaneous toxicity of hexachlorobutadiene.
Acta Pharmacol Toxicol (Copenh). 1978 Nov;43(5):346-53.

Edelfors S, Ravn-Jonsen A.
Effect of organic solvents on nervous cell membrane as measured by changes in the (Ca2+/Mg2+) ATPase activity and fluidity of synaptosomal membrane.
Pharmacol Toxicol. 1992 Mar;70(3):181-7.

Filon FL, Boeniger M, Maina G, Adami G, Spinelli P, Damian A.
Skin absorption of inorganic lead (PbO) and the effect of skin cleansers.
J Occup Environ Med. 2006 Jul;48(7):692-9.

Jorgensen PL, Hakansson KO, Karlish SJ.
Structure and mechanism of Na,K-ATPase: functional sites and their interactions.
Annu Rev Physiol. 2003;65:817-49. Epub 2002 May 1.

Korpela M, Tähti H.
Effects of industrial organic solvents on human erythrocyte membrane adenosine triphosphatase activities in vitro.
Scand J Work Environ Health. 1987 Dec;13(6):513-7.

Francis J. Koschier
Toxicity of Middle Distillates from Dermal Exposure
Drug and Chemical Toxicology. 1999, Vol. 22, No. 1 , Pages 155-164

McDougal JN, Pollard DL, Weisman W, Garrett CM, Miller TE.
Assessment of skin absorption and penetration of JP-8 jet fuel and its components.
Toxicol Sci. 2000 Jun;55(2):247-55.

Monteiro-Riviere NA, Inman AO, Riviere JE.
Skin toxicity of jet fuels: ultrastructural studies and the effects of substance P.
Toxicol Appl Pharmacol. 2004 Mar 15;195(3):339-47.

Naskali L, Oksanen H, Tähti H.
Astrocytes as targets for CNS effects of organic solvents in vitro.
Neurotoxicology. 1994 Fall;15(3):609-12.

E Reese and R D Kimbrough
Acute toxicity of gasoline and some additives.
Environ Health Perspect. 1993 December; 101(Suppl 6): 115–131.

Riihimäki V, Pfäffli P.
Percutaneous absorption of solvent vapors in man.
Scand J Work Environ Health. 1978 Mar;4(1):73-85.

Skou JC, Esmann M.
The Na,K-ATPase.
J Bioenerg Biomembr. 1992 Jun;24(3):249-61.

Suzanne E. Simon
Editor’s perspective: The prevalence of trichloroethylene metabolites in public drinking-water supplies
Remediation Journal. Summer 2005; 15(3): 1-4

Vaalavirta L, Tähti H.
Astrocyte membrane Na+, K(+)-ATPase and Mg(2+)-ATPase as targets of organic solvent impact.
Life Sci. 1995;57(24):2223-30.

Vaalavirta L, Tähti H.
Effects of selected organic solvents on the astrocyte membrane ATPase in vitro.
Clin Exp Pharmacol Physiol. 1995 Apr;22(4):293-4.

Yoshida T.
Approach to estimation of absorption of aliphatic hydrocarbons diffusing from interior materials in an automobile cabin by inhalation toxicokinetic analysis in rats.
J Appl Toxicol. 2010 Jan;30(1):42-52.

Yoshida T.
Estimation of absorption of aromatic hydrocarbons diffusing from interior materials in automobile cabins by inhalation toxicokinetic analysis in rats.
J Appl Toxicol. 2010 Aug;30(6):525-35.

*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.

Microwave Safety

microwave-ovenIn the United States, food grade containers are known not to leach harmful substances into the foods they hold, whether for storage or for microwave cooking. In most homes in the country, you’ll find a range of containers in the refrigerator, from plastics of known and unknown origin to paper to glass to metals to ceramics. Although many of us probably don’t, maybe we should care whether or not a container is safe for microwave use.

How does a microwave work?  

The oscillating waves produced by a microwave oven are similar to radio waves but much faster. They act mainly by energizing the water molecules present in a food, causing them to vibrate and to make heat. Because of the speed involved, food cooks faster than with conventional means, where heat is transferred from an external source to the material, working from the outside in by way of thermal conduction. Only substances that absorb microwaves can be heated by a microwave oven, with the food itself becoming the heat source for cooking. Heating metals in a microwave produces different, and sometimes unexpected, results. Low penetration depth results in reflection of the waves, setting up high voltage between the metal and the magnetron that is the heart of the system. When this voltage surpasses a threshold, sparks fly. Powdered metal probably would react differently. But we suggest you refrain from trying this unless you work in a science laboratory.

I heard that microwaves destroy the nutrient value of food.

Yeah, we heard that, too. The fact is that any cooking method destroys some character of a food. Using too much water in a pot to cook frozen vegetables, for example, will render water-soluble nutrients to the water, which often goes down the drain. Several studies have shown that microwave cooking, if used the right way, has no more adverse effect on food nutrition than conventional heating methods. In fact, probably because of shorter cooking time, there might even be a tendency for greater nutrient retention (Lassen, 1995). If there be a fault, it would be uneven heating. Moisture loss is more noticeable (Cross, 1982) (Quan, 1985), though, and that makes sense, since all those water molecules bumping against each other create friction, and friction creates heat.

Some studies examined the effects of microwaves on human milk. Besides the usual nutrients a baby needs, breast milk contains immunity factors, such as IgA. Microwaving to temperatures between 161°F and 208°F caused a marked decrease in anti-infective factors (Quan, 1992). We have questions about this. Who heats jarred or bottled baby food or formula hotter than the human wrist can tolerate, which is far lower than the temperature of your water heater? Doesn’t milk come from mom at about 98.6°? At temperatures up to 149°F, fatty acids, most vitamins and immunoglobin are safe (Ovesen, 1996). The hydroxo- form of Vitamin B12, which predominates in foods, appears to be degraded by microwave heating as evidenced in tests on B12-dependent organisms fed a microwaved diet (Watanabe, 1998). But this is only one such test. And most of us don’t put all our eggs into one basket. Because adults cannot metabolize the vitamin B12 from food sources anyway (we lack the gastric intrinsic factor required), we mention this study as a courtesy to the young readers. To overcome poor absorption, sublingual or injectable forms of B12 are available.

So, what should not go into the microwave?

There are some things to keep in mind when using the microwave. Most containers from the takeout place, water bottles, plastic tubs from margarine, yogurt, cream cheese, mustard and mayonnaise, and whipped toppings are not safe for microwave use. Some microwavable trays, such as those from frozen dinners, are designed for one-time use. It should say that on the package. Plastic bags of any kind belong in the trash. If the plastic containers you just bought at the dollar store do not say “Microwave Safe,” don’t use them. Choosing to microwave with a plastic lacking such a declaration doesn’t necessarily mean it’s unsafe, but it is missing the assurance of safety. The symbol on the bottom of the container means nothing in this case.

Plastic wrap—saran—helps to retain moisture but it should not touch the food. The wrap itself is not heated by microwaves, but it will conduct heat from warmed food, and it could melt. The result would have to be an acquired taste that may present toxicity issues. The box of wrap will tell you if it’s microwave safe. Don’t even think about Styrofoam cups and dishware unless it says otherwise.

How about paper?

Paper coffee cups are occasionally lined with wax, and sometimes plastic. Overheating is the worry here. Learn to control the microwave. Many papers are manufactured with chemicals you don’t want in your mouth. You have to read the label. The dyes from printed paper towels can contain toxins. White paper towels are usually safe, but reading that affirmation on the package lets you know for sure. Paper grocery bags—or paper bags of any kind, for that matter—may contain unwanted metals or be recycled from who knows what. Waxed paper and parchment are safe in the microwave. Except for those coated with wax or a plastic film, paper plates should not be a problem. The wrapping will tell you. But plain paper plates are flimsy. The big-name companies have microwavable dinnerware. There is always a bottom line, right? Here it is: the preferred options are glass and ceramic. Still, the best habit to cultivate is to become a label reader. We said that already, didn’t we?


Anna Angela Barba, Antonella Calabretti, Matteo d’Amore, Anna Lisa Piccinelli, Luca Rastrelli
Phenolic constituents levels in cv. Agria potato under microwave processing
Food Science & Techniology. Dec 2008; 41(10): 1919-1926

Cross GA, Fung DY.
The effect of microwaves on nutrient value of foods.
Crit Rev Food Sci Nutr. 1982;16(4):355-81.

Anne Lassen, Lars Ovesen
Nutritional effects of microwave cooking
Nutrition & Food Science, 1995;  Vol. 95 Iss: 4:  pp.8 – 10

López-Berenguer C, Carvajal M, Moreno DA, García-Viguera C.
Effects of microwave cooking conditions on bioactive compounds present in broccoli inflorescences.
J Agric Food Chem. 2007 Nov 28;55(24):10001-7.

Ovesen L, Jakobsen J, Leth T, Reinholdt J.
The effect of microwave heating on vitamins B1 and E, and linoleic and linolenic acids, and immunoglobulins in human milk.
Int J Food Sci Nutr. 1996 Sep;47(5):427-36.

Quan R, Yang C, Rubinstein S, Lewiston NJ, Sunshine P, Stevenson DK, Kerner JA Jr.
Effects of microwave radiation on anti-infective factors in human milk.
Pediatrics. 1992 Apr;89(4 Pt 1):667-9.

Fumio Watanabe, Katsuo Abe, Tomoyuki Fujita, Mashahiro Goto, Miki Hiemori, and Yoshihisa Nakano
Effects of Microwave Heating on the Loss of Vitamin B12 in Foods
J. Agric. Food Chem., 1998, 46 (1), pp 206–210

*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.

Toxins In Baby Wipes

baby-wipes-boxThe populace has become so self-assured that it trusts people and products to be what they want them to be, which could genuinely be opposite of their expectations. In the case of personal hygiene products, we are satisfied if they remove the smudge, erase the stain and kill the germ. Few consider the trade-off. Well, folks, it’s about time we did…consider the trade-offs, that is. As is the case with our food, if you can’t pronounce the name of the ingredient, it doesn’t belong in or on your body. We’re told that we consume too little of this or that chemical to be concerned about cancer but have you wondered if a little bit here and there adds up to a lot? Such it is with baby wipes.

Methylisothiazolinone (MIT) is one of those barely pronounceable words that may or may not find its way to the label of your baby wipes. It’s sort of like MSG, which has so many aliases you can’t tell if it’s in a food or not. Autolyzed this or that and hydrolyzed that or this are but two examples of MSG stage names. However, cosmetics and baby products do NOT fall under FDA regulations. A few things, such as soaps, require no label at all, but some makers include one to protect themselves legally. At the same time, proprietary ingredients can be secret and need not be listed at all. You see, if a product does not claim to have medicinal properties, its label can be vacant. MIT is a powerful biocide used in personal care products because it works well in solutions that contain water, which is a medium in which bacteria like to grow. Human occupational exposure to this chemical has resulted in contact dermatitis, chemical burns and allergic sensitization (Goncalo, 2013) (Urwin, 2013). Inhalation is also a common route of exposure (Aerts, 2013).  That means your baby gets a double whammy during a diaper change. The danger?  Neurotoxicity. Even brief exposure damages nerve cells (Du, 2002). One drop in a 55-gallon drum of water is all it takes. And that’s considered a safe level. Isn’t contact dermatitis enough insult (Lundov, 2011) (Monroe, 2010)?

A preservative originally meant for the paint industry has found its way into personal care products, including baby wipes. Iodopropynyl butylcarbamate (IPBC) is a biocide whose use is restricted in some countries, but not in the U.S.  Initially deemed safe, IPBC has been reported to be a potent contact allergen (Badreshia, 2002) (Bryld, 1997). Some things are put on the market without ever being checked out for safety. And that means long-term safety, not just for this week. Carbamate biocides inhibit acetylcholine at nerve synapses and neuromuscular junctions. Fortunately, this is reversible, but it might take a few weeks. Not all babies will react to all things in like manner, but there are signs to watch for. Hypersalivation, hypermotility of the GI system (stuff moves faster through the gut than normal), constriction of the pupil of the eye, vomiting, diarrhea, sweating, cyanosis, respiratory distress, muscle twitching and weakness, and convulsions are major reactions to carbamates (Merck Manual, 2013). This chemical has such potential for harm that the healthcare profession is prepared to handle its deployment as a terrorist weapon of mass casualties (Rosman, 2009). Sounds safe, eh?  If you don’t see it on the label, you have to call and ask…unless you have a guaranteed baby-safe product in your hand. This is serious business.

We’re not done yet. There’s one more. Actually, there are a few more, but time and space prevent their inclusion right now. If a disposable wipe is made from paper, it probably contains dioxins, which are not intentionally produced, but which are the by-products of several industrial processes, including bleaching of paper pulp, chemical and pesticide manufacture, and combustion activity. If there is waste incineration or a forest fire, there is combustion (Shibamoto, 2007) (Environment Australia, 1999). Anything termed “polychlorinated” is in the dioxin family. Notice that chlorine, a bleaching agent, is in the term. The toxicity of the various dioxin compounds varies, but it’s still there. Endocrine disruption is one action; altered gene expression is another. Reproduction problems, developmental delay, hormone dysfunction and immune damage add to the array. A more pressing matter with dioxins is their use in disposable diapers, where baby’ skin is exposed for a large part of the day.

Dioxins are persistent organic pollutants (POP’s) that exist ubiquitously—they’re everywhere, including the food supply, though because of strict emission controls are now on the wane. Because they accumulate in body fat, effects may not be realized for a long time, making it hard to pinpoint the blame for changes in liver function, heme metabolism, thyroid function and even diabetes and immunological disorders (Sweeney, 2000). Disturbances in tooth and sexual development have been observed (Alaluusua, 2004) (Mocarelli, 2000, 2008), as well as in bone resorption and formation (Koskela, 2012), where interference with the differentiation of osteoblasts and osteoclasts is a targeted effect (Korkalainen, 2009).

It’s important to purchase baby products that are safe. Adult products are no less contaminated with unpronounceable materials. Wipes made with organic fruit and vegetable extracts are much preferred, though paper may still be the substrate, in which case you night opt for cotton or flannel, which may be flushable, as hemorrhoid pads are. Considering the size of a baby’s gluteus, how big does a wipe need to be?  By the way, breast milk will contain dioxins that the mother has ingested from meats, poultry and fish that absorbed them from aerial transport of the chemical and consequent deposition on vegetables, pastures and roughages. Trimming fat from meat is the best first step to avoidance.


Aerts O, Cattaert N, Lambert J, Goossens A.
Airborne and systemic dermatitis, mimicking atopic dermatitis, caused by methylisothiazolinone in a young child.
Contact Dermatitis. 2013 Apr;68(4):250-1.

Alaluusua S, Calderara P, Gerthoux PM, Lukinmaa PL, Kovero O, Needham L, Patterson DG Jr, et al
Developmental dental aberrations after the dioxin accident in Seveso.
Environ Health Perspect. 2004 Sep;112(13):1313-8.

Badreshia S, Marks JG Jr.
Iodopropynyl butylcarbamate.
Am J Contact Dermat. 2002 Jun;13(2):77-9.

Bryld LE, Agner T, Rastogi SC, Menné T.
Iodopropynyl butylcarbamate: a new contact allergen.
Contact Dermatitis. 1997 Mar;36(3):156-8.

Castanedo-Tardana MP, Zug KA.
Dermatitis. 2013 Jan-Feb;24(1):2-6.

Coloe J, Zirwas MJ.
Allergens in corticosteroid vehicles.
Dermatitis. 2008 Jan-Feb;19(1):38-42.

Davies RF, Johnston GA.
New and emerging cosmetic allergens.
Clin Dermatol. 2011 May-Jun;29(3):311-5.

Du S, McLaughlin B, Pal S, Aizenman E.
In vitro neurotoxicity of methylisothiazolinone, a commonly used industrial and household biocide, proceeds via a zinc and extracellular signal-regulated kinase mitogen-activated protein kinase-dependent pathway.
J Neurosci. 2002 Sep 1;22(17):7408-16.

Environment Australia (1999),
Incineration and Dioxins: Review of Formation Processes
Department of the Environment and Heritage, Canberra.

Environmental Protection Agency
Mechanism of Formation of Dioxin-Like Compounds During combustion of Organic Materials
March, 4, 2005

European Commission
Brussels, 20 July 2001
Fact Sheet on dioxin in feed and food

Fewings J, Menné T.
An update of the risk assessment for methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) with focus on rinse-off products.
Contact Dermatitis. 1999 Jul;41(1):1-13.

Gonçalo M, Goossens A.
Whilst rome burns: the epidemic of contact allergy to methylisothiazolinone.
Contact Dermatitis. 2013 May;68(5):257-8.

Korkalainen M, Kallio E, Olkku A, Nelo K, Ilvesaro J, Tuukkanen J, Mahonen A, Viluksela M.
Dioxins interfere with differentiation of osteoblasts and osteoclasts.
Bone. 2009 Jun;44(6):1134-42.

Koskela A, Viluksela M, Keinänen M, Tuukkanen J, Korkalainen M.
Synergistic effects of tributyltin and 2,3,7,8-tetrachlorodibenzo-p-dioxin on differentiating osteoblasts and osteoclasts.
Toxicol Appl Pharmacol. 2012 Sep 1;263(2):210-7.

Lundov MD, Krongaard T, Menné TL, Johansen JD.
Methylisothiazolinone contact allergy: a review.
Br J Dermatol. 2011 Dec;165(6):1178-82

Lundov MD, Zachariae C, Menné T, Johansen JD.
Airborne exposure to preservative methylisothiazolinone causes severe allergic reactions.
BMJ. 2012 Dec 4;345:e8221.

Macias VC, Fernandes S, Amaro C, Santos R, Cardoso J.
Sensitization to methylisothiazolinone in a group of methylchloroisothiazolinone/methylisothiazolinone allergic patients.
Cutan Ocul Toxicol. 2013 Jun;32(2):99-101.

Merck Manual. Feb 2013
Organophosphate and Carbamate Poisoning
Reviewed by Gerald O’Malley, DO and Rika O’Malley MD

Mocarelli P, Gerthoux PM, Ferrari E, Patterson DG Jr, Kieszak SM, Brambilla P, et al
Paternal concentrations of dioxin and sex ratio of offspring.
Lancet. 2000 May 27;355(9218):1858-63.
Mocarelli P, Gerthoux PM, Patterson DG Jr, Milani S, Limonta G, Bertona M, Signorini S, et al
Dioxin exposure, from infancy through puberty, produces endocrine disruption and affects human semen quality
Environ Health Perspect. 2008 Jan;116(1):70-7.

Monroe HR, Hu JC, Chiu MW.
Methylchloroisothiazolinone / methylisothiazolinone and moist wipe dermatitis.
Dermatol Online J. 2010 May 15;16(5):14.

National Library of Medicine
Toxicology Data Network

Natkunarajah J, Osborne V, Holden C.
Allergic contact dermatitis to iodopropynyl butylcarbamate found in a cosmetic cleansing wipe.
Contact Dermatitis. 2008 May;58(5):316-7.

Rosman Y, Makarovsky I, Bentur Y, Shrot S, Dushnistky T, Krivoy A.
Carbamate poisoning: treatment recommendations in the setting of a mass casualties event.
Am J Emerg Med. 2009 Nov;27(9):1117-24.

Sato S, Shirakawa H, Tomita S, Ohsaki Y, Haketa K, Tooi O, Santo N, Tohkin M, Furukawa Y, Gonzalez FJ, Komai M.
Low-dose dioxins alter gene expression related to cholesterol biosynthesis, lipogenesis, and glucose metabolism through the aryl hydrocarbon receptor-mediated pathway in mouse liver.
Toxicol Appl Pharmacol. 2008 May 15;229(1):10-9.

Schöllnast R, Kränke B, Aberer W.
Anal and palmar contact dermatitis caused by iodopropynyl butylcarbamate in moist sanitary wipes
Hautarzt. 2003 Oct;54(10):970-4.

Shibamoto T, Yasuhara A, Katami T.
Dioxin formation from waste incineration.
Rev Environ Contam Toxicol. 2007;190:1-41.

Siebert J.
The sensitizing potential of iodopropynyl butylcarbamate in the local lymph node assay.
Contact Dermatitis. 2004 Nov-Dec;51(5-6):318-9.

M.H. Sweeney, P. Mocarelli
Human health effects after exposure to 2,3,7,8- TCDD,
Food Addit. Contam. 17 (2000) 303–316.

U.S. Department of Health and Human Services
Household Products Database
Health and Safety Information on Household Products

Urwin R, Wilkinson M.
Methylchloroisothiazolinone and methylisothiazolinone contact allergy: a new ‘epidemic’.
Contact Dermatitis. 2013 Apr;68(4):253-5. doi: 10.1111/cod.12064.

Uter W, Gefeller O, Geier J, Schnuch A.
Methylchloroisothiazolinone/methylisothiazolinone contact sensitization: diverging trends in subgroups of IVDK patients in a period of 19 years.
Contact Dermatitis. 2012 Sep;67(3):125-9.

Warshaw EM, Belsito DV, Taylor JS, Sasseville D, DeKoven JG, Zirwas MJ, Fransway AF, Mathias CG, Zug KA, DeLeo VA, Fowler JF Jr, Marks JG, Pratt MD, Storrs FJ, Maibach HI.
North American Contact Dermatitis Group patch test results: 2009 to 2010.
Dermatitis. 2013 Mar-Apr;24(2):50-9.

Zirwas M, Moennich J.
Dermatitis. 2009 Mar-Apr;20(2):106-10.

*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.