To Gulf Oil Spill Responders: What You and Your Doctors Need to Know About TILT

Gulf oil spill responders, like the cleanup workers for the Exxon Valdez 20 years ago, are already reporting chronic health problems associated with TILT,  including multi-system symptoms (fatigue, sleep problems, headaches, digestive difficulties, and problems with memory and concentration), as well as new intolerances for everyday exposures that never bothered them before. For example, they may feel dizzy or nauseated around engine exhaust, cleaning chemicals, fragrances, or ill after meals, certain foods or even drinking one can of beer or a glass of wine. These new intolerances are the hallmark symptom of a disease process called “TILT” or “Toxicant-Induced Loss of Tolerance.” We know that even so-called “safe” levels of exposure to toxic petroleum-based chemicals like those in the Gulf can initiate TILT.  Once TILT develops, it is hard to treat, but it can be prevented. To find out whether you may be susceptible to TILT or to track your symptoms, take the QEESI—a validated and published questionnaire developed by Dr. Claudia Miller, a physician and professor at the University of Texas. You can download the QEESI and the professionally acclaimed book Chemical Exposures: Low Levels and High Stakes at at no charge. These resources are provided free as a public service to help prevent others from becoming sick. The website answers questions you and your doctors may have concerning TILT:

Are Gulf oil spill responders and local residents at risk?

Regarding the new air sampling data for the Gulf spill responders, some levels are clearly elevated. What is being overlooked in this sea of data is the fact that even air levels that fall below so-called “allowable” or “safe” limits may lead to lifelong illness, resulting from Toxicant-Induced Loss of Tolerance or TILT. TILT has been the focus of two NIH meetings and multiple journal articles over the past decade. TILT develops in individuals following a single high-level (acute) exposure or repeated lower level (chronic) exposures to petrochemicals or their combustion products. Susceptible individuals who have prolonged exposures, as in the Gulf cleanup, are at greatest risk. As humans, our ability to detoxify and eliminate different kinds of chemicals can vary by as much as 10,000-fold.

Why is TILT called the “petrochemical problem”?

TILT occurred among many Exxon Valdez cleanup workers, Gulf War veterans, and 9-11 responders. Now the Gulf spill cleanup crews and those living nearby are at risk. TILT can also develop “at home” among individuals and families exposed to petrochemicals through hydraulic “fracturing” or “fracking” to release natural gas from tight rock formations in their neighborhoods, and in those exposed to solvents, cleaning agents, or pesticides in their homes, schools or workplaces. TILT is almost always caused by petrochemicals, which include most solvents, pesticides, and cleaning agents, but other exposures may be involved.  For example, the complex volatile organic chemicals released by molds, which give molds their characteristic musty odors, may also initiate TILT.

Petrochemicals are a relatively recent exposure in human history—they have only been around for the past 60 years, since WWII. Our bodies’ detoxification and elimination systems have evolved over thousands of generations in order to deal with certain substances in our foods and other natural exposures. These protective mechanisms may lack the capacity to detoxify and eliminate the myriad complex petrochemical products introduced into our environment over the past 60 years. Our own individual capacities to deal with these substances vary greatly from substance to substance and from person to person.

What exactly is TILT?

From a medical perspective, we are at the “germ theory” stage in terms of our understanding of TILT. TILT is based on observations by doctors and researchers across more than a dozen countries over the past few decades. It is clear that we are dealing with a new disease process involving petrochemical exposures, a process few doctors have heard about, even though TILT has appeared in the environmental health literature for over a decade. TILT follows an unmistakable pattern. Initially there may be flu-like symptoms. But, unlike regular flu, the symptoms may not go away. About the time you would expect to feel better, in as little as 2 weeks, you may instead notice new symptoms. Triggered in response to everyday exposures, or by repeating the initial exposure, these symptoms can involve any and every organ system—difficulty breathing, headaches, fatigue, sleep difficulties, confusion and memory and concentration problems, irritability and mood changes may occur. The hallmark symptom for TILT is the new-onset intolerances for everyday exposures that never bothered the person before. Examples include feeling ill after exposure to diesel or gas engine exhaust, fragrances, cleaning products, tobacco smoke, eating(an early symptom of food intolerances), experiencing inebriation or a hangover after just one can of beer, or one glass of wine or other alcoholic beverage that was formerly well-tolerated, adverse reactions to medications—often multiple medications, anesthetic agents, and other everyday exposures. In fact, people can develop symptoms in response to so many different “triggers” that they have trouble singling out problem exposures. This is called “masking.” Masking is one reason TILT can be hard to recognize.

Why don’t doctors know about TILT?

Petrochemicals first entered our lives after World War II. Their production and use have grown exponentially over the past 60 years. In terms of our medical understanding, this is very recent. TILT is mentioned in only a few medical textbooks and not yet taught in most medical schools. The first symptoms of TILT are non-specific and are often diagnosed as the “flu.” Treatment is frequently directed toward symptoms like headache or cough, and exposures rarely enter the discussion unless the patient raises them. Even when patients do mention an exposure, few doctors today know how to take an exposure history or what to do with the information they obtain. With the flu, people generally spring back in a week or two. With TILT, illness may continue. This is because TILT is a two-stage disease process: those affected develop secondary intolerances for numerous common chemicals at very low levels as well as intolerances for foods and medications—hence the name “toxicant-induced loss of tolerance.” Once TILT becomes entrenched, the process can be very difficult to treat or reverse. Think of Humpty Dumpty. Prevention is the key. Those who develop TILT may continue to experience symptoms long after they are away from the initiating exposure. This is because everyday exposures that were never a problem for these patients before, and that don’t bother most people, now trigger symptoms, thus perpetuating illness. When doctors see patients in this stage, it is a bit like walking in on the second act of a play and having no clue as to what went on before.

This is why doctors need to ask about the key clue for TILT: new-onset intolerances. The validated, peer-reviewed and published Quick Environmental Exposure and Sensitivity Inventory or QEESI makes this easy to do. New intolerances are the hallmark symptoms for TILT, just as fever is the hallmark symptom for an infectious process.

How can you avoid developing TILT?

1.      If you feel ill, stay completely away from the suspect exposure for a weekend, or up to a week—long enough that you feel recovered. Then you can try to return and see whether your same symptoms come back. This practice of avoidance and very cautious re-exposure helps pinpoint the cause of your symptoms. Do not do this if you have ever experienced potentially life-threatening symptoms such as severe asthma. Continued, precautionary avoidance will be necessary in such a case.

2.      Wear all appropriate respirators and other protective equipment as the situation warrants. In order to protect you, respirators must fit your face snugly and have appropriate organic vapor or particulate cartridges for filtering out petrochemicals or smoke, respectively. A tight fit means that the respirator must seal up against your face when you block the cartridges off and inhale. Wearing a snug rubber face piece can be extremely uncomfortable, especially in hot weather, and may increase risk for heat stress, heat stroke, and overheating. The resistance to breathing can be very tiring, requiring more frequent breaks or a slower rate of work.  Your employer should provide a respiratory protection program that meets OSHA standards, with proper medical evaluation, fit-testing, cleaning, storage, and respirator/filter replacements. Fitting individuals who tend to have smaller faces (e.g., many women or certain ethnic groups) or different contours can be difficult unless appropriately sized face pieces are available. If a respirator doesn’t fit properly, then, when you inhale, air will follow the path of least resistance and go around the face piece directly to your nose instead of through the filter. Such a respirator would provide a false sense of security. For “nuisance” dust or odors, “paper” masks that remove low levels of relatively non-toxic particles or chemicals (charcoal filters) may or may not be sufficient. You need to have some idea of the level of exposure and what the exposure is—employers need to provide this information to you. Again, any respirator, disposable or not, must fit the face snugly in order to protect you.

3.      Determine whether you may be more susceptible to chemical exposures before you ever enter an exposure area. If you go to the website,, you will find the Quick Environmental Exposure and Sensitivity Inventory (QEESI). The QEESI’s 50 questions will help you gauge your own sensitivity and enable you to chart your symptoms over time. You may download and print the QEESI for free. Save this information and take it to your doctor. Over time, if you experience worsening of your symptoms, fill out another QEESI, put the date on it, and save it too. By taking copies to your doctors, they will be able to learn about TILT and perhaps use the QEESI with other patients who have had environmental exposures.

4.      On a calendar or daily log, record when and where you have been each day. Note what you were doing and record any odors and how strong they were, on a 0-10 scale (0= none at all; 5 = moderate; 10 = overpowering). Note: not all petrochemicals have odors, but many do. Nor are all odors harmful.

5.      Complete references for the QEESI and the professionally acclaimed book that first described TILT, Chemical Exposures: Low Levels and High Stakes by Drs. Nicholas Ashford and Claudia Miller, are available at The book may be viewed there and downloaded free of charge.

If you think you have TILT, what should you do?

In its earliest stage, TILT may be reversible with avoidance of exposure. This is why early identification and avoidance of initiating exposures and symptom triggers are crucial. If you suspect TILT, then take the QEESI to your doctors and ask them to read about TILT. Refer them to the scientific papers and book that are on the website. The information is free and provided as a public service.  Your doctors should be good listeners and take your concerns seriously. If they do not, then you need to find a different doctor. They should perform a complete medical history and an exposure history, plus a physical examination as well as any relevant laboratory testing. There is no laboratory test that is diagnostic for TILT, just as there is no laboratory test for migraine headaches. Your symptoms and history tell the story. You will need to learn more about specific triggers for TILT and how avoid them. Feeling ill after meals or particular foods or beverages (like a can of beer or glass of wine), and even food cravings, can be signs of food intolerance. Among people with TILT, 90% have food intolerances. These can make you feel very ill. Symptoms vary from person to person and from exposure to exposure, making TILT difficult to diagnose. Medications and certain procedures requiring drugs, such as anesthetics, may trigger symptoms too. It is important for you and your doctor to watch out for potential adverse reactions to medications, including those you may have been taking for years.

Background for Claudia S. Miller, MD, MS

Dr. Miller serves as assistant dean for a dual degree MD/MPH (masters of public health) program, and is a tenured full professor of occupational and environmental medicine at the UT School of Medicine in San Antonio. In addition, she is an industrial hygienist, allergist/immunologist, and co-author of the professionally acclaimed book Chemical Exposures: Low Levels and High Stakes. Her work has been recognized by the World Health Organization’s prestigious Macedo Award. She has worked or consulted for several federal agencies including the EPA, CDC/ATSDR, OSHA, NIOSH and NIEHS/NIH, as well as for the governments of Japan, Germany, Canada and Thailand. Currently, Dr. Miller chairs a subgroup on Individual Susceptibility for the CDC’s National Conversation on Public Health and the Environment.


Additional Information on the Gulf Oil Spill

Q: How is the Oil Spill similar to 9-11 and the Gulf War?

A: These events all resulted in protracted exposures to petrochemicals, their byproducts or combustion products—exposures that have been linked to TILT. Sick Buildings, pesticides, fracking, the Exxon Valdez clean-up, and formaldehyde in trailers have also associated with TILT. Even the complex mixture of volatile organic compounds (VOCs) produced by molds (the smell you associate with mold) appear to contribute to TILT. Mold exposures can occur in sick buildings, and after hurricanes and floods.

Click here to read the article and watch the video of Dr. Miller being interviewed on San Antonio’s KENS 5 News.

Click here to read the article and watch the video of Dr. Miller being interviewed on San Antonio’s KSAT 12 News.