GARFIELD, N.J. -- The neighborhood looks exceedingly normal: single-family homes and apartment buildings packed together, dogs barking from postage-stamp-size lawns, parents hustling down narrow sidewalks to fetch children from school. But something with very dangerous potential lies below the surface, officials say.

The residents' toenails will provide confirmation.

A plume of hexavalent chromium, a metal used in industrial production that the Centers for Disease Control and Prevention calls a "well-established carcinogen," has spread under Garfield, putting about one-tenth of the city's homes -- about 600 structures and 3,600 residents -- at risk.

The Environmental Protection Agency is to start drilling to determine how much chromium is pooled beneath and remove tainted soil. Scientists from New York University will assess how much chromium residents may have been exposed to.

Researchers will collect toenail clippings, to be tested for traces of chromium. Toenails grow slowly, so it is possible to see how much chromium has accumulated in the body over the past 18 months or so, said Judith Zelikoff, an NYU professor of environmental medicine.

"Our major goal is to try to relieve their fears," she said. "With the economy, they can't sell their homes. They don't know if they got exposed."

The contamination started 30 years ago, when thousands of pounds of hexavalent chromium-- the same stuff that sickened Californians whose story was told in the film "Erin Brockovich" -- leaked from a tank at the EC Electroplating Co.

The EPA designated it a Superfund site, one of the nation's most toxic uncontrolled hazardous waste sites, in 2011.

Latest videos