More than 600 railroad workers, from Maryland to Kentucky to Montana, have been diagnosed with brain damage over the last 15 years from handling toxic degreasing solvents, reports the Louisville Courier-Journal after a 10-month investigation. Thousands more may be ill, but not know why. Railroad companies, particularly CSX Transportation, have paid tens of millions of dollars to settle workers’ solvent lawsuits, while denying any link between exposure and brain damage. Meanwhile, millions of Americans are exposed regularly to the same solvents and related chemicals at work and at home.