Hundreds of Google employees were exposed for months to the toxic chemical TCE, or trichloroethylene, at the search company’s offices in Mountain View, Calif.

No employees reported becoming sick but such exposures can take months or even years to cause problems.

Repeated chemical exposures can produce the condition called TILT, or Toxicant-induced Loss of Tolerance. People with TILT suffer from chemical intolerances that can impair cognitive abilities and cause multi-symptom illnesses.

Cases like Google’s are becoming common worldwide where industrial chemicals have been buried or released underground, and slowly seep up into structures built over them, affecting occupants of buildings.

Google’s buildings are near a known underground pool of contaminants. The EPA has monitored the site since 2003 and detected the high levels of TCE in December 2012. Several companies once manufactured silicon chips near the site.
TCE is usually used as an industrial solvent.

Google says employee health was never at risk and building improvements will prevent any future episode. But nonetheless health professionals and Google employees need to understand:

• No chemical exposure is minor. Repeated low-level exposures, such as in a “sick building,” or a one-time, high-level exposure such as at a chemical spill or pesticide accident, can initiate TILT. For many individuals who have been “TILTed,” life is no longer the same. It affects their health, their ability to work or go to school, and other activities in perpetuity. Thereafter even low levels of common cleaning chemicals, fragrances, gasoline at a gas station, diesel exhaust, outgassing from new furnishings, carpet, and other products can trigger symptoms that range from mild to disabling.
• Doctors need help in diagnosing chemical illnesses. Most physicians don’t understand chemical intolerance or test patients for it. A medical study in July 2012 found that chemical intolerance contributes to the illnesses of 1 in 5 patients but their condition seldom is diagnosed. Patients and physicians need to know about and use a widely accepted screening instrument for multiple chemical intolerance that’s called “QEESI,” short for Quick Environmental Exposure and Sensitivity Inventory. Download it here.