Thomas Cahill

Headshot of Thomas Cahill

Professor Emeritus

One Shields Avenue
Physics Department
Davis, CA 95616

Office: 301 Physics Building
Phone: +1 (530) 756-6146

Personal Website:

Research Interests:

Professor Tom Cahill joined the faculty at UC Davis in 1967, coming from a NATO Fellowship in France 1966-1967. In France, he was studying inner stellar nuclear processes, including the first measurement and phase shift analysis of polarized non-identical spin ½ nucleons, protons on He3. The work continued and expanded into few nucleon and neutron physics at Davis 1967 – 1976, with about 35 publications.

Beginning in 1970, Professor Cahill began applying nuclear and atomic techniques for environmental problems, especially in air pollution. He founded the Crocker Nuclear Laboratory Air Quality group and became Director of the Institute of Ecology, 1972-1976. His work was instrumental in the removal of lead from gasoline and introduction of the catalytic converter, the reduction of sulfur in fuel, and the new air basin for Lake Tahoe with more stringent environmental limits. In 1977, he designed and initiated for the US EPA the first measurements of atmospheric aerosols and visibility at national parks, which in 20 years expanded into the national IMPROVE network which he ran until 1997. In this regard, he repeatedly became involved in Congressional testimony and EPA hearings to demand controls on polluters throughout the west. These programs also resulted in roughly 70 publications.

In 1980, he became Director of the Crocker Nuclear Laboratory, and started a new program in analysis of ancient documents, the Crocker Historical and Archaeological Projects (CHAPs). This resulted in pioneering analyses of the Gutenberg Bible, Dead Sea Scrolls, and the Vinland Map, among others. CHAPS had projects with about 2 dozen faculty associates, resulting in 25 publications, many fellowships for his colleagues and a key role in establish a nuclear laboratory to do this work at the Louvre Museum, Paris.

After officially retiring in 1994, Prof. Cahill formed the DELTA Group (Detection and Evaluation of Long-range Transport of Aerosols) to study aerosol impacts on global climate. This program had major NSF programs in Asia and the Arctic, including the continuing aerosol sampling program under NSF Polar Programs on the Greenland Ice Cap, recently extended to 2021. This work has resulted in numerous grants and about 25 publications.

Prof Cahill continues to be involved in the health impacts of aerosols most notably during unique work on the threat of aerosols from the World Trade Center, railroads, and freeways. Working with local NGOs, he has been instrumental in a number of California laws in the past decade. Three of his papers on the health impacts of ultra-fine metals were chosen to be part of a EPA – sponsored special issue of Aerosol Science and Technology. Much of his work since 1997 has been based on his modification of x-ray beam lines at based at the Lawrence Berkeley Laboratory Advanced Light Source and the Stanford Synchrotron Radiation Lightsource. This work has resulted in over 50 publications in this area since retirement, including one in Science Magazine.

Professor Cahill’s most unusual achievement is that the for the 30 or so Ph.D. students mentored in his career, he was major professor and advisor in 6 separate departments – mostly in Physics, but including Chemistry, Geology, Ecology, Atmospheric Sciences, and Geography.

Since retirement in 1994, he has also published 5 science fiction novels and has in press a major book on air pollution, “I can breathe clearly, now. Protecting yourself from air pollution”.

Research Areas

Career History

  • Ph.D., UCLA 1965
  • Adjunct Professor, UCLA 1965 – 1966
  • NATO Fellow, Centre de’Etudes Nuclearies, Saclay France, 1966-1967
  • Assistant Professor, University of California Davis, 1967-1972
  • Associate Professor, University of California Davis 1972-1976
  • Director, Institute of Ecology, UC Davis 1972 - 1975
  • Professor, University of California Davis 1976 – 1994
  • Co-Director, Crocker Historical and Archaeological Programs, 1978 - 1994
  • Director, Crocker Nuclear Laboratory 1980 - 1989
  • Professor, Atmospheric Sciences 1992 – 1994
  • Visiting Professor and Fellow, U. Kyoto, Japan, 1992
  • Professor, Emeritus, Physics and Atmospheric Sciences 1994 – present
  • Founder and Head, UC Davis DELTA Group, (Detection and Evaluation of Long-range Transport of Aerosols 1997 - present
  • Appointed by the Speaker of the Assembly to the California Inspection and Maintenance Review Committee 2006- 2011


  • National Defense Fellow, UCLA, 1959- 1962
  • NATO Fellow, France, 1966-1967
  • OAS Fellow, Chile, 1968
  • Outstanding Educator of America, 1973
  • U. Kyoto Research Fellow, 1992
  • UC Davis Public Service Award 1994
  • American Lung Association Outstanding Scientist Volunteer, 2002
  • Who’s Who in the World 2003-present
  • Appointed by the Speaker of the Assembly to the California Inspection and Maintenance Review Committee 2006- present
  • UC Davis Distinguished Emeritus Professor Award 2013-2014