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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.”

COMMENTARY
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 (http://www.sti.nasa.gov/tto/Spinoff2007/ps_3.html).  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)
http://www.jhsph.edu/publichealthnews/press_releases/2009/breysse_indoor_asthma.html

Pollution at Home Often Lurks Unrecognized (12/26/2008, Reuters Health) by Amy Norton
http://www.reuters.com/article/2008/12/26/us-pollution-home-idUSTRE4BP1ZL20081226

Air Purifiers and Air Filters Can Help the Health of Allergy and Asthmas Sufferers (S. A. Smith)
http://ambafrance-do.org/alternative/11888.php

Indoor Air Pollution Fact Sheet (08/1999, American Lung Association)
http://www.lungusa.org/healthy-air/home/healthy-air-at-home/

An Introduction to Indoor Air Quality (Environmental Protection Agency)
http://www.epa.gov/iaq/ia-intro.html

References

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.

SUPPORTING ABSTRACTS
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.

Yoga

yogawomanIf there exists such a philosophical regime that can bring a person closer to Elysium in every aspect of life—balance, health, aging—its enthusiasts argue that it is yoga.  Investigations into the complexities of this physical / mental / spiritual discipline have focused on the almost inexplicable efficacy of its practice.  That it is conjectured to effect a return to normal following a physical or mental derangement deserves at least a little attention.

The cognitive behaviors of yoga entail calorie restriction, meditation, breathing techniques and additional practices that separate it from other holistic modalities, and have a distinct affect on the function of the human body.  Research at the Albert Einstein College of Medicine, in New York, has classified yoga’s influence on human physiology into four categories that encompass humoral factors (affecting immunity), CNS activity, cell trafficking, and bioelectromagnetism (the study of membrane and action potential).  The investigators allowed that, “…yogic practices might optimize health, delay aging, and ameliorate chronic illness and stress from disability.”  (Kuntsevich. 2010)  A reductionist approach tries to explain complex matters by using the simplest of its facets and nomenclature, but this cannot address the intricacy of yoga and its long-term benefits to the whole person.

From lower back pain, arthritis and carpal tunnel syndrome, all the way to functional development in children, yoga has been an oft-visited body of knowledge.  Practicing yoga increases flexibility, strength and stamina, and can do that in the gentlest of manners using Hatha techniques, or by employing the more explosive Ashtanga form, which relies on quick movements from one pose to another.

Because lower back pain cannot satisfactorily be treated with surgery and injections, other interventions have been pursued, yoga paramount among them.  Chronic back pain has a significant impact on a person’s ability to work and perform daily tasks.  The fact that pain is non-specific makes some therapies uncertain, but the physical motions of yoga meet the need for non-invasive remediation.  (Carter. 2011)  Perhaps it is such that synovial lubrication is enhanced, or that directed movements create healing substances at the cellular level.  Whatever the reason, it works.

If yoga intensifies a person’s awareness of his body and helps him to understand his relationship to a body in pain, with the expectation of attenuating discomfort, then the discipline has been effective, particularly in changing cognitions and behaviors towards nociception.  (Tul. 2011)  Modified forms of Hatha yoga have been tested on such patients with outcomes that were not surprising.  Not only were flexibility and reach improved, but also the emotional insults that accompany refractory pain, such as anxiety and mild depression, were reduced, as reported in a study performed at the Richard Stockton College of New Jersey, providing renewed interest in additional study on the salubrious nature of yoga.  (Galantino.  2004)

Recent work at Johns Hopkins examined prior studies on yoga’s application to arthritis, and found that evidence was strong for reduced disease symptoms and disability, especially the tender and swollen joints that characterize the condition.  (Haaz.  2011)  Noting that it can be tailored to the specific needs of the geriatric population, investigators at the University of Pittsburgh concluded that yoga is among the mind-body interventions associated with reduced pain perception.  (Morone.  2007)

Executive function in a human being is that capacity to make decisions in novel situations, outside the domain of normal automatic processes.  This is tantamount to thinking outside the box, and appears to be a desirable developmental milestone in children.  Yoga is just one of the activities that can help to develop such a trait, one that telegraphs creativity, flexibility, self-control, and self-discipline.  The physical benefits are the cherry on top.  (Diamond. 2011)

It is accepted that what enters a pregnant woman’s digestive system has an effect on the neonate, as well as on the mother.  Could mind-body processes do the same?  There is evidence that improvement in perceived stress, mood, and perinatal outcomes may be realized from practicing yoga.  Not only that, but also it was found that such practices resulted in higher birth weight, less time in labor, and fewer instrument-assisted births, accompanied by lower stress and anxiety levels in both mother and child.  (Beddoe. 2008)  Good news, eh?

Other health issues that benefit from yogic practices include metabolic syndrome (Anderson.  2011), chronic obstructive pulmonary disease (Fulambarker.  2010), and essential hypertension (Anand.  1999).  Each deserves additional attention.

References

Kuntsevich V, Bushell WC, Theise ND.
Mechanisms of yogic practices in health, aging, and disease.
Mt Sinai J Med. 2010 Sep-Oct;77(5):559-69.

Carter C, Stratton C, Mallory D.
Yoga to treat nonspecific low back pain.
AAOHN J. 2011 Aug;59(8):355-61; quiz 362.

Tul Y, Unruh A, Dick BD.
Yoga for chronic pain management: a qualitative exploration.
Scand J Caring Sci. 2011 Sep;25(3):435-43. doi: 10.1111/j.1471-6712.2010.00842.x.

Galantino ML, Bzdewka TM, Eissler-Russo JL, Holbrook ML, Mogck EP, Geigle P, Farrar JT.
The impact of modified Hatha yoga on chronic low back pain: a pilot study.
Altern Ther Health Med. 2004 Mar-Apr;10(2):56-9.

Haaz S, Bartlett SJ.
Yoga for arthritis: a scoping review.
Rheum Dis Clin North Am. 2011 Feb;37(1):33-46.

Morone NE, Greco CM.
Mind-body interventions for chronic pain in older adults: a structured review.
Pain Med. 2007 May-Jun;8(4):359-75.

Diamond A, Lee K.
Interventions shown to aid executive function development in children 4 to 12 years old.
Science. 2011 Aug 19;333(6045):959-64.

Beddoe AE, Lee KA.
Mind-body interventions during pregnancy.
J Obstet Gynecol Neonatal Nurs. 2008 Mar-Apr;37(2):165-75.

Anderson JG, Taylor AG.
The metabolic syndrome and mind-body therapies: a systematic review.
J Nutr Metab. 2011;2011:276419.

Fulambarker A, Farooki B, Kheir F, Copur AS, Srinivasan L, Schultz S.
Effect of Yoga in Chronic Obstructive Pulmonary Disease
Am J Ther. 2010 Oct 22.

Anand MP.
Non-pharmacological management of essential hypertension.
J Indian Med Assoc. 1999 Jun;97(6):220-5.

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

Solvents In The Home And Workplace

kitchen-cleanersThere are too many things we take for granted.  When it comes to health, if it doesn’t hurt, we don’t pay attention to it.  This is the case with the solvents we use around the house, including the apparently harmless cleaners and the more aggressive degreasers and thinners.  The solvents used at the workplace are considerably more powerful.  In general, quite a few of the products we use at home fit the definition of toxic.

The term solvent refers to liquid (usually organic) chemicals used to dissolve solids.  Some, like turpentine and the citrus solvents, are naturally derived.  Others are made from petroleum or other synthetic sources.  None is “safe,” although there are degrees of “un-safeness.”   (CDC. 2010)  Skin contact and inhalation are both means of entry into the body, and may be categorized by duration as long or short, and by intensity as low or high.  Acute effects occur after short-term exposure; chronic effects after a longer period of time.  Health consequences may be subclinical, meaning that symptoms are not yet manifest.

Some solvents—this includes pesticides—are fat-soluble and allow metabolites access to the central and peripheral nervous systems (CNS and PNS).  While narcosis (stupor) may be reversible, demyelination and cell death often are not.  Researchers in France looked at the relation between Parkinson’s disease and exposure to pesticides in a population whose exposure to these chemicals is prevalent (exterminators), and found that relation to be positive, especially for organochlorine insecticides.  (Elbaz. 2009)  Prior studies on the epidemiology of Parkinson’s by the same team came to a similar conclusion.  (Elbaz. 2008)

All solvents can dissolve the skin’s protective barrier of oils, causing the skin to dry and chap and leading to some form of dermatitis.  Some of the natural ones, like turpentine, may cause allergic reactions.  Some cause no overt damage but penetrate the skin, enter the bloodstream, and damage other organs, particularly the liver.  (Nachman. 2002)  Most of us connect toxicity to physical contact, never thinking that the vapors alone can cause damage, but scientists in Messina, Italy found depletion of reduced glutathione, decreased antioxidant activity, and oxidative damage in subjects exposed to the vapors of organic solvents.  (Costa. 2006)  All studies agree that early detection of toxicity is important to resolution.

The effects of solvent exposure upon the eyes and respiratory tract are realized quickly if concentrations are high enough, but workers are commonly unaware of a solvent’s effects at low concentrations.  Often the only indication of exposure is an increased frequency of colds and respiratory infections.  Over time, chronic bronchitis may develop.   However, the instigating factor(s) may be out of mind and the relationship is never made.  The ubiquity of certain solvents, especially formaldehyde, takes a toll on unsuspecting consumers.  (Schenker. 1996)   Wall finishes, carpeting, cabinetry, plywood, insulation, timber paneling, and even some shampoos, lotions, baby wipes, and body washes may contain formaldehyde.  Some manufacturers will use unfamiliar synonyms to mask the presence of this proven carcinogen.  Formalin, methanol, urea, methylaldehyde, and formic aldehyde are but a few.  Tightness in the chest, breathing difficulty, unexplained rash, and swelling of the mouth and tongue are the more-common signs of exposure to formaldehyde.  Changes in heart rate are not uncommon with over-exposure to any organic solvent, with “over-exposure” being the key modifier, however subjective that may be.  (Morrowa.  1995)

An area lacking in study is reproductive health, but the little research already done points to solvents’ culpability.   Small studies indicate that subjection to solvents that are particular to specific industries may induce decline in sperm motility.  The painting and sheet metal trades and others that use naphtha, methyl ethyl ketone, xylene, toluene and the like are most likely to experience detrimental reproductive consequences.  (Lemasters.  1999)   Although tests in females are not nearly so definitive, infertility, spontaneous abortion, and reproductive cancers have been reported in some studies after chemical exposures.  The ambiguity of testing in females may be due to multiple confounders that include poor methodology and small sample size.  (Sharara. 1998)

Alternatives to harmful solvents are available, but, because they might demand more physical labor, are not the most popular items on the shelf.  Baking soda can kill foul odors.  Vinegar in water or cream of tartar in water can clean aluminum.  Borax cleans the bathroom, and bleach + water will remove mildew from grout.  TSP and water can clean almost anything.  Dismissing solvents is not only a matter of “going green,” but also a matter of personal and family health.  Thinking that your hobby is great fun, you might be surprised to hear that exposure to the solvents used in building models and in artwork during the year preceding childbirth has been associated with elevated risk of childhood leukemia.  (Freedman.  2001)

References

CDC, 2010
Workplace Safety & Health Topics
ORGANIC SOLVENTS
Page last updated:July 20,2010
http://www.cdc.gov/niosh/topics/organsolv/

Elbaz A, Clavel J, Rathouz PJ, Moisan F, Galanaud JP, Delemotte B, Alpérovitch A, Tzourio C.
Professional exposure to pesticides and Parkinson disease.
Ann Neurol. 2009 Oct;66(4):494-504.

Elbaz A, Moisan F.
Update in the epidemiology of Parkinson’s disease.
Curr Opin Neurol. 2008 Aug;21(4):454-60.

Nachman Brautbar, John Williams II
Industrial solvents and liver toxicity: Risk assessment, risk factors and mechanisms
International Journal of Hygiene and Environmental Health. Vol 205, Iss 6, 2002, Pp 479-491

Chiara Costa, Rita De Pasquale, Virginia Silvari, Mario Barbaro, Stefania Catania
In vitro evaluation of oxidative damage from organic solvent vapours on human skin
Toxicology in Vitro  Volume 20, Issue 3, April 2006, Pages 324-331

M.B. Schenker , J.A. Jacobs
Respiratory effects of organic solvent exposure
Tubercle and Lung Disease. Volume 77, Issue 1, February 1996, Pages 4-18

Lisa A. Morrowa, , Stuart R. Steinhauerb
Alterations in heart rate and pupillary response in persons with organic solvent exposure
Biological Psychiatry.  Volume 37, Issue 10, 15 May 1995, Pages 721-730

Grace Kawas Lemasters, Donna M Olsen, James H Yiin, James E Lockey, Rakesh Shukla, et al
Male reproductive effects of solvent and fuel exposure during aircraft maintenance
Reproductive Toxicology.  Volume 13, Issue 3, May-June 1999, Pages 155-166

Fady I Sharara M.D., David B Seifer M.D., Jodi A Flaws Ph.D.
Environmental toxicants and female reproduction
Fertility and Sterility.  Volume 70, Issue 4, October 1998, Pages 613-622

D M Freedman, P Stewart, R A Kleinerman, S Wacholder, E E Hatch, R E Tarone, L L Robison, and M S Linet
Household solvent exposures and childhood acute lymphoblastic leukemia
Am J Public Health. 2001 April; 91(4): 564–567.

Seaton A, Jellinek EH, Kennedy P.
Major neurological disease and occupational exposure to organic solvents.
Q J Med. 1992 Sep;84(305):707-12.

Ng TP, Lim LC, Win KK.
An investigation of solvent-induced neuro-psychiatric disorders in spray painters.
Ann Acad Med Singapore. 1992 Nov;21(6):797-803.

Y. Lolin
Chronic Neurological Toxicity Associated with Exposure to Volatile Substances
Hum Exp Toxicol July 1989 vol. 8 no. 4 293-300

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