Katsuko Saruhashi

was a Japanese geochemist who created tools that let her take some of the first measurements of carbon dioxide (CO2) levels in seawater. She later showed evidence of the dangers of radioactive fallout and how far it can travel. Along with this focus on safety, she also researched peaceful uses of nuclear power.

Her other major area of significance involved raising the number and status of women scientists, especially in Japan. She established both the Society of Japanese Women Scientists and the Saruhashi Prize, which is awarded annually to a female scientist who serves as a role model for younger women scientists.

Among her other honors, she was the first woman elected to the Science Council of Japan, to earn a doctorate in chemistry from the prestigious University of Tokyo, and to win the Miyake Prize for Geochemistry.

Education Saruhashi was born in Tokyo in 1920. At a very young age, Saruhashi wanted to know what made it rain. This fascination was derived from watching raindrops slide down windows one day during primary school. Kuniharu and Kuno Saruhashi both saw the importance of education and supported their daughter after their shared experience during World War 2, where many women struggled to support themselves without husbands or fathers. Saruhashi and her mother understood that there was a lack of women with technical knowledge and figured that it could be useful to gain financial independence. At the age of 21, Saruhsashi quit her secure job at an insurance firm to attend the Imperial Women's College of Science, now known as Toho University, where she earned a degree in chemistry.

After graduating in 1943 with an undergraduate degree in chemistry, Saruhashi took a position at the Meteorological Research Institute where she worked with her mentor Miyake Yasuo,

Career Saruhashi conducted research with Teruko Kanzawa from 1973 to 1978. They began their research by measuring the pH of every rainfall event over the five-year period at the Meteorological Research Institute in Tokyo. her novel method for measuring the amounts of caesium-137 and strontium-90 in seawater, and her research concerning the environmental impact of the US bomb test site, Bikini Atoll, which ultimately provided justification for the prohibition of above-ground nuclear testing. She also made important contributions to the study of the carbon dioxide system in the oceans, finding that the Pacific Ocean emits more CO2 than it absorbs. Saruhashi's table provided oceanographers with a method for determining the composition of three carbonic acid substances based on water temperature, pH, and salinity. 1979 - named executive director of the Geochemical Laboratory. 1980 - first woman elected to the Science Council of Japan. 1981 - won the Avon Special Prize for Women, for researching peaceful uses of nuclear power and raising the status of women scientists. 1981 - established the Saruhashi Prize, given yearly to a female scientist who serves as a role model for younger women scientists.

On 22 March 2018, Google displayed a Google Doodle honoring Saruhashi on what would have been her 98th birthday.

In December 2021, a dramatization of Saruhashi's life as a scientist was broadcast in Japan, starring Kiko Mizuhara.

Influence over women in science Saruhashi spent much of her career actively fighting for equal opportunity in science and advocating for women. She acknowledged the reasons why women are under-represented in science, saying, “the lack of equal opportunity is one. There is also the attitude of society, of parents and teachers. And there is little recognition of the contributions of women scientists.” She worked to establish both funding opportunities and community for women scientists.

In 1958, Saruhashi established the Society of Japanese Women Scientists to promote Japanese women in science.

In 1981, she established the Saruhashi Prize, a $2400 cash award given to a Japanese woman fifty years old or younger who has made considerable contributions in the physical sciences. The award is also intended to help those wanting to pursue projects overseas. Saruhashi wanted to gift the award recipients larger amounts, contributing personally and with help from friends, but the funds are small compared to other prizes.

Selected publications Her publications include: