nuclear-news

Determining the measure of a great scientist is a challenge. Is it an enormous contribution to science, noted by awards and distinctions? Publications in peer-reviewed journals or keynotes at conferences? Serving as an expert to governments, effecting change on national and international policy? Or can this measure be more granular: beyond being a role model, to be present and provide sustaining mentorship, lifting up others?

No matter how you slice it, Katsuko Saruhashi is one such great scientist, and a woman who certainly lived up to her name, which translates to strong-minded or victorious in Japanese. Not only did she conduct groundbreaking research—developing the first method to measure carbon dioxide levels in seawater—but her work also made waves internationally, as she tracked and raised a global alarm on the dangers of nuclear testing. Throughout her 35-year career as a geochemist, she collected numerous awards and led the way for women to follow her in science……….

After graduating in 1943 with her undergraduate degree in chemistry, Saruhashi joined the Geochemistry Laboratory at the Meteorological Research Institute (now called the Japan Meteorological Agency). There, she studied not rain, but oceans, specifically carbon dioxide (CO) levels in seawater. Saruhashi developed the first method for measuring CO using temperature, pH, and chlorinity, called Saruhashi’s Table. This method became a global standard. Perhaps more importantly, she discovered that the Pacific Ocean releases more carbon dioxide than it absorbs: a concept with dire consequences today as the climate changes.

Saruhashi also led the way in studying ocean-borne nuclear contamination. Although World War II had ended years before, the United States continued to carry out nuclear tests, particularly in the Pacific Ocean near Bikini Atoll, 2,300 miles southwest of Japan. After several Japanese fishermen became mysteriously ill while out trawling downwind of the testing site in March of 1954, the Japanese government asked Saruhashi and her colleagues at the Geochemical Laboratory to investigate.

…….Saruhashi and her team ultimately found nuclear fallout didn’t travel evenly throughout the ocean. They tracked ocean circulation patterns using radionuclides, discovering that currents pushed radiation-contaminated waters clockwise, from Bikini Atoll northwest toward Japan. As a result, fallout levels were much higher in Japan than along the western U.S.

Their results were stunning: the radioactive fallout released in the testing had reached Japan in just 18 months. If testing continued, the entire Pacific Ocean would be contaminated by 1969, proving that nuclear tests even conducted out in the middle of the ocean, seemingly in isolation, could have dangerous consequences.

Even now, more than 60 years later, Bikini Atoll is still unlivable.

This data, unsurprisingly, sparked controversy, and the U.S. Atomic Energy Force ultimately funded a lab swap, bringing Saruhashi to the Scripps Institute of Oceanography to compare the Japanese technique for measuring fallout with the American method, developed by oceanographer Theodore Folsom. Her method turned out to be more accurate, settling the science and providing the critical evidence needed to bring the U.S. and Soviet Union in agreement to end above-ground nuclear testing in 1963: an amazing accomplishment at the height of the Cold War. Saruhashi returned to Japan and later became the executive director of the Geochemical Laboratory in 1979. …….

Saruhashi died in September of 2007 at the age of 87 …….https://psmag.com/environment/the-japanese-scientists-who-uncovered-nuclear-fallout