Arie Jan Haagen-Smit was a Dutch chemist. He is best known for linking the smog in Southern California to automobiles and is therefore known by many as the "father" of air pollution control. After serving as an original board member of the Motor Vehicle Pollution Control Board, formed in 1960 to combat the smog, Dr. Haagen-Smit became the California Air Resources Board's first chairman in 1968. He was born on December 22, 1900 in Utrecht, Netherlands. He graduated from the University of Utrecht in 1922 with a major in organic chemistry. He earned his M.A. degree in 1926 and Ph.D. in 1929. His work was on terpenes, a hydrocarbon found in plants. He stayed at the University of Utrecht from 1929 to 1935 as chief assistant. He became an expert in plant derived chemicals, particularly Auxins, a hormone. He was invited to lecture at Harvard University in 1936 by Kenneth Thimann. He was appointed as associate professor by California Institute of Technology in 1937 by Thomas Hunt Morgan, and professor in 1940, becoming one of the "Dutch Mafia" at Caltech. He published a paper jointly with two other scientists on traumatic acid, a wound healing hormone, in Science in 1939. He was the director of the Plant Environmental Laboratory at the California Institute of Technology from 1965 to 1971. He received the National Medal Of Science in 1973.