Flight delays, missed connections, stuffy cabins, narrow seats, screaming children. As if commercial air travel isn’t hard enough, now comes evidence that it could be harmful to your health.

In recent lawsuits and public complaints, dozens of passengers and airline personnel report inflight chemical exposures that triggered serious illnesses. The illnesses are similar to those associated with “Toxicant-induced Lack of Tolerance,” or TILT, a clinical condition that breaks down a person’s natural resistance to chemical compounds.

The Boeing Co. recently settled a suit out of court in Seattle with a former American Airlines flight attendant. She alleged that contaminated cabin air in an MD-82 jetliner caused her to have tremors, memory loss and severe headaches. US Airways pilots and flight attendants have filed a similar suit involving a Boeing 767. They reported headaches, sore throats, eye irritations, dizziness and nausea.

At issue are so-called “fume events” where petroleum smells enter the aircraft cabin. Commercial airliners routinely pump, or “bleed,” compressed air to the cabin from outside. Nearly all airliners use this “bleed-air” ventilation system. The airline industry and government regulators say the system is safe, and has been in use since the 1950s. The industry says the number of reports of illness is minuscule compared to the thousands of people who fly each day.

Critics say bleed-air systems draw a substantial amount of air past the engine, thus raising the risk that petroleum fumes can enter the cabin. Loose engine seals and poor aircraft maintenance raise the chances that air can become contaminated on its way to the cabin.

Air travel is difficult for people with chemical intolerances, but until recently no one suspected that taking a flight might trigger illnesses in otherwise healthy people. Finding solutions is urgent because the sheer volume of passenger traffic may leave hundreds of thousands of people exposed and vulnerable to a new sickness.

On any plane, the people most affected by a lack of fresh air usually have asthma, suffer migraines, or are already chemically intolerant. It’s fortunate that the largest amount of fresh air is sent to the flight deck, where the pilot and co-pilot fly the plane. But even pilots and co-pilots have reported illnesses and, in a few cases, even impaired cognitive function.

Even under normal conditions, an air traveler’s “breathing zone” is frequently violated on flights. Some examples:

• Boarding the plane, passengers sometimes enter a hot plane with little fresh air. Some of them get headaches or have difficulty breathing. Crews often turn off the PAC, or air-conditioning system, to save fuel. My advice: Ask the crew to turn it on.
• Once seated, passengers encounter unpleasant odors — from perhaps from a cigar smoker seated nearby, those wearing fragrances, or others using nail polish. Again, as a passenger, your breathing zone is violated, and you’re stuck for the duration of the flight.
• Waiting for takeoff, passengers sometimes breathe exhaust from other planes lined up ahead of them.
• Also, the fragrance from restroom deodorizers can cause problems. I was on a recent flight and the odor was intense. Putting potent deodorizers in tiny spaces can cause a very high concentration of fragrance. Passengers also carry the fragrance back to their seat. Recommendation: Sit in the middle of the plane. That way fewer passengers will drag their restroom fragrance vapor trails past your aisle.

Facts and narratives about airplane illnesses are becoming more widely known. MSNBC.com reporter Jim Gold has written an excellent article about the situation.

Passengers may have few defenses, but scientists are working to minimize exposures aboard airplanes. In his article, Gold describes efforts to develop a biomarker for TCPs, or tricresyl phosphates, one of the suspected contaminants in fume events. One key researcher, Dr. Clement Furlong of the University of Washington, said the goal is to better understand the chemistry of the incidents so refiners can develop less-toxic engine fluids. This might improve the bleed-air system, or at least minimize its potential risks to health.

TCP is the cause of numerous poisonings and is a neurotoxin, in part via organophosphate-induced delayed neuropathy. It has been responsible for many deaths. The most serious incidents occurred in the 1920s when TCP was used to adulterate Jamaica Ginger, and in Morocco in 1959 when cooking oil was adulterated with jet-engine lubricant containing TCP.

TCP’s mechanism of action is similar to other organophosphates in that it can inhibit the enzyme acetylcholinesterase, leading to a buildup of acetylcholine in the synaptic space. This can lead to hyperactivity in cholinergic neurons in the brain, and at neuromuscular junctions in the peripheral nervous system resulting in apoptosis of those cell types. This is the reason for paralysis and other irreversible neurological problems seen in the “Gingerjake” syndromes during Prohibition, when TCP was added to gingerjake moonshine.

Dr. Furlong is working to develop a blood test to prove with a biomarker that someone aboard an aircraft during a fume event was exposed to TCPs. A reliable test would dispel the uncertainty now in the air for air travelers.

TCP is one of many substances capable of initiating TILT. However chlorpyrifos, or Dursban, is one of the most common causes. Why has chlorpyrifos initiated so many illnesses? You may want to review a paper I co-authored in the Archives of Environmental Health about initiators. Note mention of TCP on page 121.

Symptoms and health effects of TILT often accumulate over time. People can gauge their sensitivities using the free QEESI questionnaire. It is a clinical tool to evaluate whether someone has TILT or is acquiring intolerances.

     
Illustrations depict chemical structures of TCP, left, and chlorpyrifos, or Dursban, which is one of the most commonly reported initiators of TILT.

Medical researchers are finding that children with autism and their parents suffer in some of the same ways when they encounter certain chemicals in everyday products.

Recently, at the invitation of the Autism Society of America, I presented a national webinar describing how children with autism and their parents often share certain intolerances, and may react in similar ways. Why? I think it’s a case where “Genetics loads the gun, and the environment pulls the trigger.”

We know, for example, that in adults certain acute or chronic chemical exposures sometimes can initiate a process that has come to be known as “Toxicant-induced Loss of Tolerance,” or TILT. TILT may develop after a workplace exposure or remodeling of a home or exposure to petrochemicals or combustion products from a fire. Thereafter, everyday exposures to common chemicals, foods, medications, and even caffeine, can trigger cognitive and mood difficulties, as well as a host of baffling symptoms that can affect the nervous system, digestive tract, airways, and skin.

Notably, many of the same environmental exposures, e.g., certain pesticides, that initiate TILT in adults can also interfere with neurodevelopment in a fetus, starting as early as the first month of pregnancy when the neural tube forms and before the mother even knows she is pregnant!

And, as for chemically intolerant adults, we should make every effort to prevent suspected initiating exposures as well as minimize exposures that can continue to trigger autistic behaviors and other symptoms throughout the lifespan. This also means that continued avoidance of even low-level exposure triggers may be important for treating children and adults with autism.

These differences in susceptibility to environmental chemical exposures, which may predispose to TILT in adults and autism in children, are the consequence of normal human genetic diversity — a good thing! My concern, as we learn more about the important relationships between autism, genes and exposures, is that differences in our genetic susceptibility not be viewed as a defects, but rather normal individual differences. These differences are not new. What is new are our exposures. Since World War II, the petrochemical era has ushered in myriad chemical exposures, exposures unprecedented in human history. There can be as much as a 10,000-fold difference, from person to person, in our ability to detoxify and eliminate substances from our bodies. Currently we are unable predict which exposures can cause TILT or autism in which persons.

Other shared features of autism and chemical intolerance include food cravings (mimicking addiction) and intolerances including gluten (wheat) and milk. From our own studies, mothers of children with autism, compared to mothers of “neurotypical children’” were much more likely to report that common chemical exposures make them sick. These included household cleaners, fragrances and pesticides. We used the validated “Quick Environmental Exposure and Sensitivity Inventory” or QEESI, questionnaire to gauge chemical, food and other environmental intolerances in the mothers. You too can use the QEESI questionnaire to gauge sensitivities.

The underlying causes for autism and the reasons why it now affects a staggering 1 in 110 babies born in the United States — a national epidemic according to the Centers for Disease Control and Prevention (CDC) — continue to elude the medical and scientific communities. There are many clues, and theories. The webinar I presented on behalf of the Autism Society of America, which is available to you free of charge, focuses on the striking and often overlooked parallels between autism and chemical intolerance. The increased use of petrochemically based household products and recent emphasis on greener, more energy efficient homes with little fresh air to dilute contaminants in the United States parallels the rise in autism over the past few decades. Globally, autism has been on the rise in every industrialized nation.

During medical schoo l, my colleagues and I learned that children are not just little adults! There are obvious size and many metabolic differences between children and adults. At the same time, children with autism and chemically intolerant adults are strikingly similar in important ways: They share exposures to petrochemicals, indoor air pollutants and pesticides, and both experience chemical and food intolerances. A crucial difference in the case of autism is timing: Exposures that occur during pregnancy or early childhood have the potential to alter neurodevelopment. One tool that is urgently needed in medicine is an Environmental Medical Unit, or EMU, which would allow physicians and families to determine whether and to what extent autism might be reversible if chemical and food triggers could be avoided systematically for a few weeks. Here is a paper I wrote about EMUs.

Thanks to the Autism Society of America for allowing us to post the webinar presentation.

To follow the proceedings, you will need to install the Cisco Webex browser software. You will be prompted at the website. Adding the software only takes a few seconds.

Fragrances are among the most frequent and potent symptom triggers for people who report developing chemical intolerances following an acute or chronic exposure such as to pesticides or indoor air pollutants. Sometimes specific formulations (air fresheners, fabric softeners, etc.) or brands are especially problematic, with individuals reporting headaches, impaired concentration, confusion, sudden mood changes, fatigue, etc.

Anne Steinemann at the University of Washington and her colleagues recently analyzed 25 top-selling fragranced consumer products. The paper, which can be accessed here, is an eye-opener. Using GC/MS (gas chromatography/mass spectrometry), Steinemann found that these products contain an average of 17 chemicals each, almost all of which do not appear on any label, and many of which are known to be toxic. A single fragrance may contain 100 or more VOCs. This strongly suggests that we need to find unscented alternatives for cleaning our homes, our laundry and ourselves.

Q: Why don’t the names of these chemicals at least appear on the product labels? A: Manufacturers are not required to disclose fragrances in cleaning supplies, air fresheners or laundry products. These are regulated by the Consumer Product Safety Commission. Likewise, the Food and Drug Administration, which regulates personal care products, does not require listing of ingredients used in fragrances, “even though a single “fragrance” in a product can be a mixture of up to several hundred ingredients.” Ms. Emily Sohn, writer for Discovery News, asked me to comment on the significance of this new study. Read the article here.

As an allergist, I know that individuals’ responses to exposures vary widely. The problem is, we can’t know a priori whether or in whom a scent is going to cause nasal congestion, a headache or impair the ability to concentrate-at home, at work, at school or while driving. We do know that a sizable percentage of the population responds adversely to various fragrances and other low-level exposures.

Fortunately, there is something we can do. We can stop buying fragranced products, instead choosing those that are clearly labeled “fragrance-free.” Tell the managers at places you and your family frequent, from the grocery store to restaurants to your child’s school, that you want fragrance-free products used because of the hazardous chemicals found in many fragranced products. There is no way to know how toxic a specific fragranced product may actually be, and as Steinemann found, simply choosing products that are “green” or “natural” is no guarantee of their safety. Fragranced “green” products, she reported, also emitted volatile organic compounds (VOCs) which can irritate the airways and cause multi-system symptoms in susceptible individuals.

Individuals with chemical intolerances can benefit greatly from fragrance-free policies at school or work and from eliminating fragrances at home. Unfortunately, while fragrance-free policies can help protect building occupants and custodial staff from harmful chemicals, one of the greatest sources of fragrances indoors is other people. Many people start off their day by applying a variety of fragranced products, which then volatilize into the air throughout the day. This personal “out-gassing” is worst in the morning, and it can be debilitating for chemically intolerant individuals if they must start their day sitting next to someone at a meeting or in class, inhaling complex mixtures from fabric softeners, personal care products, and cologne.

Fragrance intolerance may be an important sentinel symptom for Toxicant-induced Loss of Tolerance (TILT). There is a close anatomical relationship between the nose and the limbic (mood and memory) part of the brain. People tend to notice when a fragrance that was once loved now makes them feel ill. In my work with Gulf War I veterans, I met a soldier who sent his spouse their favorite fragrance while still he was overseas. After he returned from Iraq, she went to pick him up from the airport wearing that special scent. During the several-hour drive back home, he became so sick that he begged her never to wear it again.

I firmly believe that “Your right to wear fragrance ends at my nose,” a phrase adapted from the days when smoking indoors was still common. But, regardless of who is right, the best strategy when seated next to a heavily fragranced person is to move. It is tiresome to feel you are “on the run,” from invisible vapors of fragrance, but as more people gently explain that fragrance causes headaches, asthma, burning eyes, or nausea, perhaps both policies and personal choices will change.

One woman I know has recently been trying a new approach. When she sits next to individuals who aren’t wearing discernible fragrances, she thanks them, saying, “I want to thank you for not wearing fragrance. I often have to get up and move because other people’s perfume and laundry products can give me a headache.”

It’s a great conversation starter.

Remember: Fresh air is the best air freshener, and the best smell is no smell!

Sunday, September 12, 2010

Newswise — Swimming in indoor chlorinated pools may induce genotoxicity (DNA damage that may lead to cancer) as well as respiratory effects, but the positive health effects of swimming can be maintained by reducing pool levels of the chemicals behind these potential health risks, according to a new study published in a set of three articles online September 12 ahead of print in the peer-reviewed journal Environmental Health Perspectives (EHP). This study is the first to provide a comprehensive characterization of disinfection by-products (DBPs) in an indoor pool environment and the first to study the genotoxicity of exposure to these chemicals among swimmers in an indoor chlorinated pool.

DBPs form in pool water from reactions between disinfectants such as chlorine and organic matter that is either present naturally or is introduced by swimmers, such as sweat, skin cells, and urine. Previous epidemiologic studies have found an association between exposure to DBPs in drinking water and risk of bladder cancer, and one such study has found this association for dermal/inhalational exposure such as occurs during showering, bathing, or swimming.

Chemicals in Indoor Swimming Pools May Increase Cancer Risk

Share your story of chemical exposure and loss of tolerance by responding to this post. If we feel your story may be helpful to others learning about TILT, Dr. Miller will re-post your story with her comments. Be aware that you are posting your story in a public forum. Do not include identifying information unless you are comfortable with it being available to anyone on the web, and please do not post your story if you are pursing any legal action regarding your exposure or TILT-related illness. We also ask that you do not name any third parties including doctors, coworkers or family members. We will remove any postings that are not appropriate to this forum and the topics we address.

Following is a format you may wish to follow in describing your experiences. Specific information is most helpful.

Initiating exposure(s): What was it? Which year did it occur?

How many others were exposed and did they develop TILT?

Fill out the QEESI – what are your scores on the 5 scales, both now and when you were at your worst?

After the initial exposure, how soon did your intolerances begin? Which did you notice first? Which caused the most severe symptoms?

Please indicate if you have experienced the following types of intolerance, and describe your principal reactions/symptoms.
Chemical intolerances:
Food intolerances:
Caffeine intolerance:
Alcoholic beverage intolerance:
Adverse drug reactions or drug intolerance:

What medical diagnoses have you or other affected family members received since developing TILT?

How many doctors did you see before you figured out what had happened to you?