A small chemical company began an unusual and potentially far-reaching to collect $2.1 million in damages from a scientist who publicly and persistently pointed to an abnormally high cancer rate in the northeastern Maryland community surrounding the company's plant.

An array of environmental health experts is expected to testify at the trial in which the familiar roles are being reversed. The Galaxy Chemical company, once the accused, has become the accuser in charging Dr. Pietro U. Capurro, the pathologist who for years waged a well publicized war against Galaxy's plant, with defaming the firm by linking its emissions to cancer in the area.

"I can't think of any greater calumny than saying that somebody's killing people," George W. Constable, the company's lawyer, told the jury today, Capurro "destroyed a good, small, successful company," he said.

In Capurro's research, Constable said, "He ignored facts which contradicted his theory . . . He showed an obsessive desire to get Galaxy."

By contrast, Dr. Capurro was described by his own attorney, Wilbur C. Preston Jr., as a "learned, brilliant scientist and physician," who came to the little Elk Valley in central Cecil County in 1967, and soon thereafter learned "that there was a strange plague on that neighborhood and valley - that this (plague) was a strange smell."

After doing some of his own investigation, Preston said, his client sough "the best advice and the best help he could get" before writing articles in medical journals about health problems in the valley.

Some of these articles claimed that the death rate in the Little Elk Valley, where about 400 people live, was more than twice the national average. The cancer death rate, according to Capurro's studies, was seven times the national average.

In one article, Capurro wrote of the "excessive rate of cancer deaths in the vicinity of Galaxy." His attorney told the jury, however, that "(Capurro) cannot say absolutely that the emissions caused the cancers . . . It needs more study."

A key piece of evidence will be a recently completed study by the Maryland State Department of Health and Mental Hygiene, which found that "there was a statistically significant increase in overall cancer deaths" in the Little Elk Valley near the plant between 1967 and 1968.

The scientists making the study were "not able to make any link to that firm," said D. Kathleen Acree, one of the study's authoris.

Acre said that the total sample of people studied was so small that "chance could still be an operative factor" in making the cancer death rate in the area much higher than the national average.

There will also be testimony from three nationally known scientists who have speciallized in the study of environmental health problems caused by toxic substances.

Dr. Samuel Epstein, of the University of Illinois, and Dr. Barry Friedlander, who was on the State Health Department task force, will testify for Capurro, his lawyer told the jury today.

Dr. Edward P. Radford, a former Johns Hopkins researcher who has done controversial studies on the cancer rate among steelworkers at Bethlehem Steel plant, is expected to testify for Galaxy and Mraz.

The trial is being held here on the Eastern Shore under a change of venue because of all the publicity in the area where the plant was located.

In his suit, which originally was filed in Cecil County, Galaxy owner Paul Mraz claimed that many national chemical firms refused to do business with Galaxy after the avalanche of bad publicity about the firm's emissions.

On the witness stand yesterday Mrax choked up briefly when he began to speak about the troubles that beset his firm. He said that Galaxy's revenues went from $35,000 annually in the early 1960s to a peak of $438,000 in 1974 - then dropped to $22,000 in 1976, the year the firm's creditors foreclosed.

Neither Marz nor his attorneys would say yesterday whether the firm has reopened and is still in operation. However, Carl York, a member of the health department task force, said after the court session that the firm is still operating under name of Solvent Distillers.

Mraz, a former Chemical engineer for DuPont in Wilmington, Del., founded the small company in 1961, with the intention of taking the liquid waste products of large firms like DuPont and recycling them.

Galaxy would first distill the original pure chemicals from the contaminated mix of chemicals discarded by the larger firms, then sell the recycled chemicals back to chemical firms around the East Coast. At its peak of operations, Mraz said, Galaxy employed about 20 people.

The name of Galaxy first began to appear in the headlines in the Washington area in 1970, shortly after a Cecil County Circuit Court Judge declared the plant a nuisance and gave it six months to clean up the fumes it was emitting.

In early 1970, the state ordered the plant to shut down the open waste pit where it dumped much of its solid waste. Shortly thereafter, the whole plant was ordered shut by a judge.

Less than a month later, the judge allowed it to reopen, instructing the State Health Department to monitor Galaxy's emissions and report on its findings.

A year later, a judge in Caroline County - where the present case is being heard - awarded five couples who lived near Galaxy $34,932 in total damages after they compalined in a suit that the plant's fumes had made them ill.

Dr. Capurro and his wife were among the people who shared in tha award.

Mraz's lawyer, Constable, claimed today that since Capurro started to complain about Galaxy, ". . . an avalanche of investigators (has) decended on the firm" and morale became so low that several employees quit.

The law suit filed by Mraz also charges that Galaxy received bomb threats, abusive letters and irate phone calls as a result of the publicity generated by Capurro and his articles in such publications as "Medical World News."

Several representatives of Washington based environmental activist groups said recently that the Capurro case is the first instance in their experience of a manufacturing firm suing a researcher because the researcher's studies indicated that the firm caused environmental or health damage.