Dr. Liane B. Russell, a pioneer in the study of the dangers of radiation on developing embryos, whose findings are the reason doctors today ask women if they are pregnant before giving them X-rays, died on July 20 in a hospital in Oak Ridge, Tenn. She was 95.
The cause was pneumonia following treatment for lung cancer, her son, David Russell, said.
Dr. Russell spent more than a half-century at the Oak Ridge National Laboratory in eastern Tennessee, starting in 1947. The lab had a history; it had been the headquarters for the Manhattan Project, the secret World War II program that developed the atomic bomb.
Dr. Russell arrived just two years after the United States dropped atomic bombs on Hiroshima and Nagasaki, killing an estimated quarter of a million people instantly while tens of thousands more eventually died of radiation poisoning.
The effects of radiation were of intense interest in the postwar period. Scientists everywhere were exploring the peaceful uses of nuclear capability while also studying its dangers, including the effects of atmospheric fallout from atomic bomb tests and the effects on those who worked with radioactive materials.
It was against this backdrop that Dr. Russell, a geneticist, undertook her studies, which included the field of teratology — the study of congenital deformities and abnormal formations.
Shortly after their arrival, she and her husband, William L. Russell, established the storied “mouse house” at Oak Ridge, an extensive colony of mutant mice bred to show the effects of radiation exposure. There she helped identify the harmful effects of radiation and chemicals on mice embryos and the genetic implications of such damage.
In time, the “mouse house” would hold more than 200,000 mice and help to drive discovery in mammalian genetics research for decades. In 2001, Oak Ridge dedicated a new lab to mouse research, naming it the William L. and Liane B. Russell Laboratory for Comparative and Functional Genomics.
In studying embryos, Lee Russell, as she was known, identified the stages at which specific body parts develop. She also found a pattern of when deformities would occur.
For example, the embryos of mice that had been impregnated at the same time and then irradiated at the same time all developed the same foot deformity. The embryos that were radiated a day later all had a different foot deformity. A third group of mice, radiated on a different day, all had short tails.
Through extrapolation, Dr. Russell determined that in humans, developing fetuses were most vulnerable to radiation during the mother’s first seven weeks of pregnancy. Because women generally don’t know right away whether they are pregnant, Dr. Russell recommended that non-urgent diagnostic X-rays be taken in the 14 days after the onset of a woman’s menstrual period. Women don’t ovulate for those two weeks, so Dr. Russell reasoned that they could not become pregnant and doctors could avoid potentially causing harm to a fetus by using radiation.
That recommendation was adopted around the world and is the reason doctors, before taking X-rays, ask women of childbearing age if they are pregnant or if they think they might be pregnant.
In her experiments with mutated mice, Dr. Russell made another important discovery — that the presence of the Y chromosome meant a mammalian embryo was male.
Other scientists had discovered decades earlier that chromosomes determined sex, but had done so in lower-level organisms, like mealworms. Dr. Russell was the first to find that the Y chromosome determines maleness in mammals, setting off a scramble among scientists to see if this was the case in humans too, which it was. The discovery quickly opened up new avenues of research in genetics and genetic abnormalities.
“It seems an obvious and simple matter from today’s perspective,” said Dabney Johnson, a retired geneticist from Oak Ridge. “In 1959, it was quite a discovery — brand-new knowledge relevant to every one of us.”
So significant were Dr. Russell’s findings that in 1994 she received the prestigious Enrico Fermi Award from the Department of Energy, the department’s highest research honor.
The department’s announcement of the award noted her “outstanding contributions to genetics and radiation biology including her discovery of the chromosomal basis for sex determination in mammals and her contributions to our knowledge of the effects of radiation on the developing embryo and fetus.”
Her findings, the announcement said, “have been the benchmark for the study of mutations in mammals and genetic risk assessment worldwide.”
Liane Brauch was born on Aug. 27, 1923, in Vienna, the oldest of three children. Her father, Arthur, was a chemical engineer and her mother, Clara (Starer) Brauch, was a singing teacher.
Lee was 14 when Germany invaded Austria in 1938. The family, which was Jewish, was able to escape by surrendering their home and Mr. Brauch’s business and leaving behind all their belongings.
They fled to London, survived the Blitz and in 1941 moved to New York, where Lee studied chemistry at Hunter College, graduating in 1945.
She had planned to go to medical school. But after a summer job at the Jackson Laboratory, an independent biomedical research institution in Bar Harbor, Me., she changed her mind.
Her mentor there was Dr. Russell, a prominent geneticist who pioneered the study of mutagenesis in mice and the man who would become her husband in 1947. He encouraged her to attend graduate school at the University of Chicago, his alma mater, which she did. She graduated in 1949 with a Ph.D. in zoology.
Her husband died in 2003. In addition to her son, Dr. Russell’s survivors include her daughter, Evelyn Russell; two stepsons, Jack and Jim Russell; a stepdaughter, Ellen Gilmore, and four stepgrandchildren.
In addition to their scientific work, Dr. Russell and her husband were deeply involved in environmental causes in Tennessee. In 1966 they helped start Tennessee Citizens for Wilderness Planning, a conservation organization.
Her involvement in numerous environmental efforts — from letter-writing campaigns to purchasing fragile lands and donating them to land conservation groups — led to the permanent protection of more than 150,000 acres and 120 miles of river.
She and her husband were both elected to the National Academy of Sciences, one of only a handful of couples so honored.