03
Nov
Researchers Uncovering Patterns that Help to Explain Chemical Sensitivities
(Beyond Pesticides, November 3, 2021) With a significant and increasing share of the U.S. population reporting sensitivities to certain chemicals, a team of researchers at University of California (Irvine), University of Texas (San Antonio), and the Massachusetts Institute of Technology is working to better understand how these symptoms develop. Although referred to by several names over the years, including Multiple Chemical Sensitivity (MCS) and Idiopathic Environmental Illness, medical professionals are now referring to the disease as Chemical Intolerance, or Toxicant Induced Loss of Tolerance (TILT), to better represent the disease process and range of nervous system symptoms that individuals develop to low level chemical exposures. “We established evidence of this previously understudied disease process,” said Shahir Masri, Sc.D, at University of California, Irvine. “Our insights will help public health scientists, physicians and policymakers better understand how to minimize harmful exposures and prevent future disease.”
TILT is characterized by a two-step process. First, there is an “initiation exposure event,” whereby an individual is either repeatedly exposed to low levels of certain chemicals, or experiences a major exposure incident. In the second stage, affected individuals are “triggered” even by minute exposures, not only to the chemical that affected them in the first place, but also to other chemicals that didn’t affect them previously. Exposure to a trigger results in a range of debilitating symptoms, such as weakness, chronic fatigue, asthma, rash, and headache, that can sometimes leave exposed individuals incapacitated and unable to lead a normal life. This disease is not similar to pollen allergies that can be tested by immunoglobin antibodies. TILT sufferers are often bounced from doctor to doctor based on individual symptoms, have significant difficulties receiving a diagnosis, and must navigate a world filled with triggering compounds, ranging from pesticides, to fragrances, molds, and other indoor air contaminants, traffic exhaust, pharmaceutical drugs, certain food, or food and drug combinations, or other volatile compounds.
To better understand the processes at play with TILT, researchers reviewed 8 case studies that resulted in a certain proportion of exposed individuals developing TILT. Per the study, these included: (1) workers at U.S. Environmental Protection Agency (EPA) headquarters exposed to industrial chemicals after installation of new carpeting in 1988; (2) Gulf War veterans exposed to organophosphate nerve agents and burn pits; (3) casino workers chronically exposed to high levels of carbamate pesticides sprayed at their work; (4) pilots, cabin crew, and frequent flies chronically exposed to aircraft oil fumes; (5) the World Trade Center tragedy and range of chemical that were released from the wreckage; (6) patients exposed to silicon and Teflon (PFAS) laminated surgical implants; (7) a moldy home; and (8) workers exposed to solvents when excavating a former gas station.
Within each of these case studies, a percent of exposed individuals went on to develop TILT. With the EPA HQ renovation, for example, 2,000 individuals were exposed, 60 developed illness (13%) and eight (.4%) developed TILT. Gulf War Illness exposed roughly 700,000 veterans to nerve agents, pesticides, combustion pollution, and other VOCs, sickening 210,000 and resulting in 200,000 (29%) cases of Chemical Intolerance. Sixteen (11%) of 142 exposed casino workers developed TILT; of 142 pilots and fliers that have reported illness from fumes while flying 16 (11%) have developed TILT; eight (27%) of the 30 tunnel workers exposed to gas station vapors developed the disease. In the case of a family living in a moldy home, all nine family members became sick, but four started to experience TILT symptoms. Although firm numbers are not available for the WTC and implant aids, a number of individual case studies are available in the literature.
Researchers analyzed these disparate events for trends in exposures. They found that the most prevalent initial exposure was from chemicals considered to be Volatile Organic Compounds or Semi-Volatile Organic Compounds, with pesticides next, and combustion products the third most frequent exposure. The study notes, “As a broader category, synthetic organic chemicals and their combustion products were the primary exposures associated with chemical intolerance, including pesticides, peroxides, nerve agents, anti-nerve agent drugs, lubricants and additives, xylene, benzene, and acetone.”
Work initially conducted by one of the paper’s co-authors, Claudia Miller, MD of University of Texas, San Antonio, with Gulf War veterans led to the development of the Quick Environmental Exposure and Sensitivity Inventory, or QEESI test, an internationally recognized tool for quickly evaluating an individual for TILT, and can be used both by medical professionals and patients. This tool is increasingly important as reports of Chemically Intolerant individuals rise in the U.S. The study references a 2016 survey finding that up to 36% of Americans reports being “unusually” intolerant to certain chemicals, and roughly 5% indicating they have been diagnosed by a physician. These numbers are up significantly from assessments taken a decade before, which found only 11% of individuals self-reporting intolerance to specific chemicals.
The presence of TILT undermines classical toxicological concept that “the dose makes the poison.” The authors indicate that a better phrase may be that “dose plus host makes the poison,” with an understanding that past exposures and various genetic factors are likely at play in terms of individual tolerance to environmental pollutants. These factors play into why it is so difficult for affected individuals to receive treatment, let alone a diagnosis. Researchers suggest that new facilities are needed as part of efforts to diagnose and treat TILT. This includes Environmental Medical Units, where patients can be housed without problematic exposures to achieve a “clean” baseline, and then slowly observe introductions of new compounds to determine specific challenges. No such facilities exist in the U.S. today.
Authors of the study compare TILT to the development of cancer, which can be trigger by a mutagenic event, and go through multiple steps where a tumor develops and further mutates. It is indicated that mast cells, which are white blood cells that originate in bone barrow, may play a role in the development of TILT. However, the researchers note, “In a forthcoming paper, we propose a new, plausible biological mechanism for TILT.”
Beyond Pesticides regularly receives correspondence from individuals that have TILT, or TILT symptoms and have had a difficult time receiving diagnosis or receiving reasonable accommodation for their illness. Individuals with cancer and chemical sensitivity have had difficulty simply finding out what pesticides are being sprayed in and around at hospitals they visit for chemotherapy, let alone stopping the spray that debilitates them for days or weeks. Beyond Pesticides has resources published to assist individuals in receiving reasonable accommodations under the Americans with Disabilities Act, but recent court rulings have undermined protections for Chemical Intolerant individuals.
For more information on TILT, see read a transcript of a talk given by Doris Rapp, MD published in Beyond Pesticides’ Pesticides and You newsletter, and visit the University of Texas, San Antonio website on the Hoffman TILT program.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: University of California, Irvine press release, Environmental Science Europe
All this perfectly matches up with how mine started and progressed. I made a documentary on how mine started and progressed.
November 6th, 2021 at 6:52 amPlease contact me the makers or scientists of this study
https://youtube.com/channel/UCANXvhkTgKsfAyNz0_MoauA