Donald Gibson Crosby

The campus recently lost a founding member of the Department of Environmental Toxicology, and a long-time supporter of UC Davis, Professor Emeritus Donald Gibson Crosby.

Fascinated with chemicals early on, Professor Crosby majored in chemistry at Pomona College, followed by a doctorate in both chemistry and biology from CalTech. After eight years as a pesticide chemist for Union Carbide, he was recruited to UC Davis in 1961 to lead the recently established Agricultural Toxicology and Residue Research Laboratory (ATRRL) in measuring DDT residues in milk for the dairy industry. Under Professor Crosby’s direction, the ATRRL provided analytical services for the Agricultural Experiment Station and focused on the fate and effects of pesticides in the environment. This area of expertise soon became recognized as critical for agriculture and society with UC Davis recognized nationally as a major information source.

With the publication of Silent Spring by Rachel Carson, and in concert with Chancellor Emil Mrak, Professor Crosby recognized the need for pesticide regulation and the role of UC Davis’ research as its foundation. Thus, he initiated a teaching program, offering both graduate and undergraduate courses. With Professor Crosby leading the way, the ATRRL began attracting extramural research support and mentoring graduate students. In effect, the ATRRL began functioning as a de facto academic department – the first in the world focused on the new field of environmental toxicology.

Later faced with demolition of ATRRL space, Professor Crosby parlayed relocation funds to obtain matching support from both NSF and UC Regent Norton Simon to construct a new building that Professor Crosby himself designed (now Sprocket Hall). In 1968, he worked with retiring Chancellor Mrak to formally establish the Department of Environmental Toxicology. The following year, Professor Crosby helped to attract one of the first of two NIEHS graduate training grants in toxicology, which remains in the department today. The escalating demand for trained personnel to conduct research on chemicals and the risks they pose led to establishment of the Environmental Toxicology undergraduate major in 1974 – also the first in the world.

Professor Crosby’s career had a major impact on the regulatory system. Early on, he realized that little was known about pesticide degradation in the environment and focused his research on the chemical mechanisms by which it occurs. From his initial studies on the actions of sunlight, he pioneered research on pesticide photo-degradation in the environment. His many studies in flooded rice fields helped achieve the California rice industry’s goal of reducing the risks of pesticide residues. These pioneering results convinced regulators to require environmental fate studies in the formal pesticide registration process, and more recently for the evaluation of new pharmaceuticals.

In 1968, Professor Crosby organized what is now the Division of Agrochemicals of the American Chemical Society, serving as its first chair. He also authored more than 200 peer-reviewed scientific publications, including two books. Environmental Toxicology and Chemistry, published in 1998, aligned his pioneering insight into the new field of environmental toxicology with his many years of experience for college students at all levels. In 2001, ACS presented Professor Crosby with their International Award for Research in Agrochemicals for his pioneering work on the environmental fate of pesticides.

Professor Crosby had a major impact as an educator. He contributed to numerous graduate programs, including serving two terms as chair of the Agricultural and Environmental Chemistry Graduate Group. He was also influential in committee work to strengthen laboratory-related infrastructure for both graduate and undergraduate courses. In 1985, Professor Crosby initiated planning for what became the Department of Microbiology and Environmental Toxicology at UC Santa Cruz.

Professor Crosby was highly respected as a lecturer, impressively rewriting his materials annually. His courses in environmental chemistry were models for new faculty as well as students, as he enjoyed discovering new information and sharing it with others. His lectures were clear, unhurried and with frequent humorous cartoons to illustrate important concepts; he often commented he relished being a “bit of an entertainer” through his story telling. His graduate course on toxic chemicals featured weekly student presentations, chosen during each class. Thus, students had to be prepared each week to speak on a topic of their choice. He was dismayed that doctoral students spent months studying coursework in preparation for the qualifying exam when the best preparation was to work hard in the lab. Thus, his proposal to change the culture by emphasizing thinking experimentally during the exam was enthusiastically implemented.

Professor Crosby also catalyzed the connection between the fields of environmental toxicology and environmental studies, leading to establishment of the Ecotoxicology Graduate Training Program through the UC Toxic Substances Research and Teaching Program (TSRTP); he designed both graduate and undergraduate courses in this new area. Because of his love of marine chemistry, he was also a founder of the six-campus Coastal Toxicology Graduate Training Program (also through the TSRTP), where he taught environmental fate and chemistry in the interdisciplinary ecotoxicology research course at Bodega Marine Laboratory. He similarly brought an appreciation of marine toxicology, through his studies of pesticide degradation in marine organisms, to the Hawaii Institute of Marine Biology during his many summers in Honolulu.

Professor Crosby was personally generous in providing gift support to the campus, most notably to improve infrastructure at Bodega Marine Laboratory. Both he and wife Nancy also devoted countless hours to the UC Davis Arboretum. Probably his greatest legacy is the many students, graduate and undergraduate, trained in environmental toxicology at UC Davis. Many have assumed leadership positions in academia, industry and government, where they provide advice on the management of toxic chemicals to reduce their risk to humans and the environment. Establishment of both the Donald G. Crosby Endowed Chair in Environmental Chemistry and the Donald G. Crosby Graduate Fellowship in Environmental Chemistry by a former student testifies to his tremendous impact and legacy. Professor Crosby played a pivotal role in the rise of UC Davis as a global leader in environmental toxicology, and more broadly the environmental sciences.

Ronald S. Tjeerdema
Robert H. Rice
Gary N. Cherr
Spencer S. Walse