Katsuko Saruhashi, Japanese geochemist (born 1920)

Katsuko Saruhashi (猿橋 勝子, Saruhashi Katsuko; March 22, 1920 – September 29, 2007) 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.

September 29 is the 272nd day of the year in the Gregorian calendar; 93 days remain until the end of the year.