Federal regulators and company officials were aware of the dangers, but ignored them, the newspaper reported Wednesday, citing government and court documents, and internal company memos and reports.

Because of the transient nature of the workforce, it might never be known how many processing plant workers died from inhaling tremolite asbestos, a rare and extremely toxic form of asbestos released by mining for vermiculite, the paper said.

Vermiculite, a mineral that expands when wet, is used for insulation and gardening.

The Post-Intelligencer reported last month that asbestos-related illnesses linked to the now-closed vermiculite mine in Libby, Mont., killed at least 192 people in the past 40 years. Most developed asbestosis, lung cancer and mesothelioma, a cancer of the lung lining.

At least 375 others were diagnosed with ailments that were likely caused by the asbestos, the paper said.

Mine owner W.R. Grace & Co., and previous owner Zonolite Co. ignored the dangers, the newspaper reported.

The mine was closed in 1990, but health officials say asbestos-related contamination continues to affect people.

Workers in the vermiculite processing plants likely inhaled ``nuisance dust,'' as the company called it, without understanding its potentially harmful effects.

``It was so thick that you couldn't see your hands at times,'' said Arland Blanton, 82, who managed a vermiculite plant in North Little Rock, Ark., from 1951 until 1963.

``Nobody never told me nothing about this stuff being able to kill you,'' Blanton said. ``There's a lot of people dead today who would still be alive if we were told the truth about that ore.''

Grace's vice president of corporate communication, William Corcoran, did not respond to requests for information by the Post-Intelligencer, except to say that Grace personnel were too busy ``helping the people of Libby'' to address the questions.

In a 1991 deposition taken in a civil suit against the company, Robert Junker, treasurer and superintendent of the Grace processing plant in Dallas, said, ``To tell the public about a potential hazard - that's what this is, a potential hazard - is kind of asinine. ... It's bad for business.''

Sixty-seven of 187 asbestos-related lawsuits filed against Grace have been resolved with the company either settling out of court or found liable and ordered to pay damages.

Even though the company gave workers annual physicals and X-rays, Little Rock lawyer Edward Moody said none of the workers was ever given a report on what the tests indicated.

Respiratory problems among workers at The Scotts Co. - one of Grace's largest customers - prompted the National Institute of Occupational Safety and Health to lead a 1978 investigation into the impact of tremolite.

The study documented the hazards, but the agency did not inform workers there.

Grace, based in Columbia, Md., also was the focus of the book and movie ``A Civil Action,'' about a lawsuit concerning acute lymphocytic leukemia cases in Massachusetts that were linked to chemicals in drinking water.