Katsuko Saruhashi

Pioneering geochemist who advanced the study of ocean acidification and nuclear fallout, advocating for women in science.

Katsuko Saruhashi (1920–2007) was a Japanese geochemist whose research on carbon dioxide in seawater laid the foundation for understanding ocean acidification. She developed the Saruhashi’s Table, a method to measure carbonic acid in water, which became a global standard. Her work in the 1950s revealed the long-term environmental impact of nuclear testing, particularly the spread of radioactive fallout across oceans.

Saruhashi’s analysis of the Bikini Atoll hydrogen bomb tests demonstrated how radioactive isotopes traveled from the Marshall Islands to Japan, influencing international policies on nuclear disarmament. She co-founded the Society of Japanese Women Scientists in 1958 to combat gender discrimination, famously stating, “There is no border or gender in science.”

Her accolades include becoming the first woman elected to the Science Council of Japan and receiving the Miyake Prize for geochemistry. Saruhashi’s legacy endures through the Katsuko Saruhashi Award, which recognizes outstanding female researchers. By merging scientific rigor with social advocacy, she transformed both environmental science and gender equality in academia.