Barbara Quimby says she has found a measure of peace in federal chromosome studies that suggest her daughters may have birth defects because of where she has lived, not because of the way she has lived.

Barbara and Jim Quimby have spent their lives within a few blocks of the Love Canal chemical waste dump, and so have their daughters: Brandy, 8, who is mentally retarded and has has eye and tooth problems from birth; and Courtney, who has been hospitalized three times in her three years because of breathing difficulties.

The Quimbys were two of 11 Love Canal residents who have been found in one controversial study to have alarming genetic defects in their blood cells. While scientists wrangled in Texas yesterday over who would review that study, and while bureaucrats agonized in Washington over what to do about it, Barbara Quimby thought about a conversation she will one day have.

"Some day I'm going to have to sit my daughter down and explain to her that her mother brought up two children in this area, and that she may have suffered because of it," Mrs. Quimby said. "We didn't know, of course . . .

"My daughter will then have to explain it to the man she loves and decide whether having children is worth the risk." The Quimbys have decided to have no more children.

The Quimbys know that the chromosome damage may be reversible, because it has been found only in blood and blood cells so far. The Environmental Protection Agency, briefing them and the other families this weekend, also cautioned that the study may not be conclusive.

But the Quimbys are praying, they said, that the federal government will declare the Love Canal zone a disaster area to free relocation money that would enable 710 families to abandon the small homes in which they had invested their life savings.

Other residents went further. They held two EPA officials hostage for nearly five hours Monday afternoon to draw attention to their plight, and said that was only the beginning.

"We mean business," said Lois Gibbs, president of the Love Canal Homeowners Association. As 200 residents cheered her near the leaking waste dump site, she continued, "If we don't have a disaster declaration by noon Wednesday, then what they have seen today is going to seem like just a Sesame Street picnic."

The two officials were fed hamburgers and raisin bread, treated well and released unruffled, but EPA ordered them out of the area yesterday just the same. "I never felt threatened," said Frank Napal, a public affairs official from EPA's New York office. "I understand what these people have gone through."

The demand for a disaster declaration has registered in Washington, and EPA Deputy Administrator Barbara Blum promised a decision by Friday at the latest. Her problem yesterday, she said, was that scientists had first questioned the validity of the chromosome study and then could not agree with the study's authors on how best to review it.

"It's obvious we can't wait on making a decision and let the people up there dangle while the scientific community gets together," Blum said in an interview. "We will make a decision . . . a policy decision more than a scientific one at this point, although certainly there is accumulating scientific evidence to support this."

That remark and others from EPA sources indicated that the verdict is likely to favor a disaster declaration so that the people can be moved. The Federal Emergency Management Agency (FEMA) estimated the cost of 120 days' temporary relocation at $3 million to $5 million, which Blum said probably would be split 50-50 between FEMA and New York state.

A White House official noted that no formal request from New York Gov. Hugh Carey for a broader disaster declaration had been received as of late yesterday afternoon. An interim declaration by the state health department in 1978 allowed 235 families to be relocated, but President Carter needs a formal request before he can act.

Federal hesitation, according to sources within EPA and the White House, has two bases. First, the study that found genetic problems in 11 Love Canal residents has been strongly criticized. Secondly, although area residents are undeniably outraged and upset, evacuating them on the strength of questionable scientific evidence could set a precendent that any worried group might invoke in some future case, whether its fears were justified or not.

The chromosome study was submitted to EPA last Wednesday by the Biogenics Corp. of Houston. Its author, Dr. Dante Picciano, a genetic toxicologist, had completed the work by May 5 for the Department of Justice in connection with EPA's $124 million lawsuit against the Hooker Chemical Co., which created the Love Canal dump.

Checking the blood of 36 persons chosen for their relatively certain exposure to Love Canal wastes, Picciano's group found "significant chromosomal aberrations" in 11 of them. Although such problems also can be caused by virus infections and X-ray exposure, a normal group of 200 persons ordinarily would have only one case of such damage.

Picciano's study was immediately made public by EPA and the test subjects were informed of the results. Dr. David Rall, head of the National Institute of Environmental Health Sciences, was asked to form a committee to review the study on an urgent basis. His group of eight hand-picked scientists flew to Biogenics' headquarters in Houston yesterday, but Picciano objected to the group's composition.

According to both Picciano and EPA sources, Picciano wanted to remove one panel member and Rall refused, offering instead to name two other persons to the group. After prolonged negotiations, Picciano insisted that any additional persons had to include one individual that Rall's group thought had a conflict of interest in the case.

Talks consumed much of Monday night and all of yesterday and finally broke down, causing Blum to disband the review effort. Picciano said by telephone from Houston that he was happy with EPA's mediating effort but "upset and disturbed by the bureaucratic process." He said he would form an independent review group to report to EPA on the study this week.

The EPA sources said their problems with Picciano's study included some he mentioned himself in his initial report, such as the lack of a control group not exposed to the wastes with which the 36 subjects could be compared. Other problems, the sources said, involved the fact that one of the subjects appparently had undergone chemotherapy for cancer, and no case histories had been collected on others to determine prior chemical exposure. "It's just a wrong study for this kind of action to be based on," one medical expert said.

Picciano urged that fuller studies be done and noted that his report was never intended to be definitive, but only to guage the extent of the problem. Justice Department officials said further studies would be made whether or not area residents are evacuated.

Still, expensive evacuations have traditionally been based on something more concrete than a lot or firghtened people, according to an EPA official. "We're trying to be as judicial as possible," the official said. "We may have to declare this a unique situation . . . but we know there are lots of these abandoned dumps out there, and what will happen the next time?'