the chemical solvent trichloroethylene (TCE)—common in soil and groundwater—increases the risk of developing Parkinson’s disease. The movement disorder afflicts about 1 million Americans, and is likely the fastest growing neurodegenerative disease in the world; its global prevalence has doubled in the past 25 years.
It’s used today mainly in producing refrigerants and as a degreaser in heavy industry.
But in the 20th century, TCE was used for many purposes, including making decaffeinated coffee, dry cleaning, carpet cleaning, and as an inhaled surgical anesthetic for children and women in labor. TCE is highly persistent in soil and groundwater; inhalation through vapor from these hidden sources is likely the prime route of exposure today. However, it’s detectable in many foods, in up to one-third of U.S. drinking water, and in breast milk, blood, and urine.