Harold Elford Johns
1915 - 1998

Harold Johns was born in Szechuan, China, in 1915, son of Presbyterian and Methodist missionaries from Toronto and Exeter (Ont).   His family stayed there until 1926 when they had to leave due to the internal turmoil in China.    Upon returning to North America, the family moved to Tacoma (Washington), Brandon (Manitoba) and eventually Hamilton (Ontario).   Harold attended McMaster University (Hamilton) and obtained a BSc in Mathematics and Physics in 1936.   He then attended the University of Toronto to get a MA and PhD in Physics by 1939.   During WWII, he taught air force pilots physics, math and the practical aspects of radar and radio navigation, for the Commonwealth Air Training Plan.   He also became chief radiographer for western Canada, performing tests on aircraft castings using an obsolete x-ray tube obtained from Ottawa.

After the war, he was invited by Dr E.L. Harrington to join the physics department of the University of Saskatchewan in Saskatoon, and to spend half his time starting the medical physics group at the new Saskatchewan Cancer Commission in Regina.   He developed one of the "cobalt bomb" cancer treatment units (the other was created by Eldorado Mining & Refining Ltd.'s commercial products division), using Co-60 from Atomic Energy of Canada Ltd.'s NRX reactor at Chalk River.   The first patients were treated in Canada in the fall of 1951, at the University of Saskatchewan and in London (Ontario).

In 1956 Dr. Johns moved to Toronto to become head of the Physics Division, Ontario Cancer Institute, and created the Graduate Department of Medical Biophysics at the University of Toronto in 1958.

In April 1978, Dr. Johns was appointed an Officer of the Order of Canada, in recognition of his lifetime of devotion to cancer research and improvements in diagnosis and treatment.   He retired in 1980, having supervised 68 grad students and authored (or co-authored) 220+ papers in peer-reviewed journals.   He obtained several patents, including that for the cobalt bomb (the phrase was coined in 1952 by Maclean's magazine).   It is estimated that, to 1995, more than 7 million patients have benefitted from treatments from the 3000+ Co-60 teletherapy units in operation worldwide.   The majority of these units were designed and built by AECL and Theratronics (spun off from AECL and now a division of MDS Nordion).

The above was condensed from "A Profile of H E Johns and the Story of the Development of the Cobalt Bomb", written by Clive L. Greenstock of AECL Chalk River, for A New Kind of Ray: The Radiological Sciences in Canada 1895-1995, eds. J.A. Aldrich and B.C. Lentle, The Canadian Association of Radiologists, Montreal 1995.

Dr. Johns died on August 23 1998 - here is his obituary

JOHNS, Harold Elford - Officer of the Order of Canada, Ph.D., LL.D., D.Sc., Emeritus University Professor and Professor Emeritus in the Departments of Medical Biophysics and Radiology, University of Toronto. Harold was born of missionary parents, Alfred and Myrtle Johns, on July 4, 1915 in Chengtu, West China, while his father was Professor of Mathematics at the West China Union University.   He died peacefully, in his sleep, on Sunday, August 23, 1998, at St. Mary's of the Lake Continuing Care Hospital, Kingston, Ontario, after a thirty year battle with Parkinson's disease, fought with the same courage and determination with which he lived his life. Remembering him with love are his wife of 58 years Sybil (Hawkins); daughters Gwen Greenstock (Clive) of Petawawa, Ontario, Claire Shragge (Peter) of Kingston, Ontario, and Marilyn Duplacey (Harold) of Rockwood, Ontario; grandchildren Erica Charette (Glenn), Andrea Patrick (Tom), Jeffrey and Steven Shragge, Alan and Amy Duplacey; brothers Martin (Elsie), Paul (Fern), Edward (Naomi); sister Ruth Vogt (Arthur); and many nieces, nephews, friends and colleagues around the world. During his professional career he served with distinction as Professor in the Physics Department at the University of Alberta, 1939-1945; jointly with the University of Saskatchewan and the Saskatchewan Cancer Commission, 1945-1956; and at the University of Toronto in the Departments of Medical Biophysics, Radiology, and Physics, 1956-1980.   During his scientific career, he published over 200 peer-reviewed papers, trained over 100 graduate students, many of whom hold key positions in the field in Canada and around the world, won many prestigious awards, and published four editions of "The Physics of Radiology", the premier textbook in its field.   His development in the late 1940's of the Cobalt Therapy Unit led to a new career in the pioneering field of Medical Biophysics.   This in turn led to a national and international reputation among scientists.   His many awards and accolades reflect the respect and admiration in which he was held by the academic and scientific world.   His greatest public award was his appointment as an Officer of the Order of Canada in 1976 and his final professional honour will be his induction into the Canadian Medical Hall of Fame in October, 1998.   He retired in 1980 but remained active in his professional field until the demands of his disease took their toll. A Memorial Service celebrating his life will be held at the James Reid Funeral Home, Cataraqui Chapel (Counter Street and Highway # 2), Kingston, Ontario, on Thursday, August 27, 1998 at 1 p.m.   The family will receive relatives and friends one hour prior to the service.   A Reception will follow at the James Reid Reception Centre. As expressions of sympathy, the family would appreciate memorial donations to the Ontario Cancer Institute, 610 University Avenue, Toronto, Ontario M5G 2M9, for the Harold E. Johns Research Prize in Medical Biophysics.