You're right. From 2007:
Area 51 burning revealed
"But last week he went on the record about the nine years he spent as a security officer at the classified Air Force installation, 90 miles north of Las Vegas, telling a Department of Labor hearing representative how he supervised burning of poisonous stealth coatings in large open pits. 2007"
From 2013:
Area 51: The real cover-up
"Area 51, as the newly declassified material makes clear, was a test site for Cold War technology, including the U-2 spy plane. But it was also, according to people who worked there, a hazardous waste site, at which classified equipment and materials were disposed of in an illegal and extremely dangerous manner."
IIRC, Jonathan Gurley represented some of the workers claiming health problems. I think it was all settled quietly back during the Clinton years.