Martin Kaplan, who has died aged 89, was a pioneering researcher in public health whose concerns about the environmental implications of chemical and biological weapons led him to become secretary-general of the Nobel peace prize-winning Pugwash conferences, while holding a top post with the World Health Organisation (WHO).
Martin, whose work was mainly in the field of rabies, influenza and tropical diseases, was trained in veterinary science. He worked on and off for more than 50 years for WHO, and was its director of science and technology.
He was born in Philadelphia, the youngest of eight children whose parents emigrated from Russia in the 1880s. From childhood he had a passion for music: at the age of 11 he joined Hoxie's Harmonica Band, and won the Philadelphia championship for harmonica excellence. He pursued this interest for the rest of his life in a string quartet - he played the cello - which used to meet weekly at his home in Geneva.
After college, and training as a veterinarian, Martin ran an animal practice in Philadelphia. During the second world war, he joined the United Nations Relief and Rehabilitation Administration (UNRRA). On VE Day he sailed from Greece, on a Swedish freighter escorting six prize bulls donated by the Brethren Society of Pennsylvania for the purpose of restocking the cattle population of Greece.
He then set about establishing new laboratories and refurbishing old ones, producing much needed animal vaccine, as well as teaching new methods to the local professionals. This involved travelling to Cyprus and Lebanon to purchase Arab stallions and mules. When UNRRA closed down, he joined the Food and Agriculture Organisation (FAO), doing similar work in several European countries, particularly Poland.
On returning home to the US, he was, for a brief period, dean of the school of veterinary medicine at what later became Brandeis University, Maryland. He was chosen for this post at the behest of Albert Einstein, who had the vision of creating an institution for learning in medical sciences, to countervail the practice of numerus clausus . This limited the access of Jewish students to universities in Europe and, from the 1920s, was a practice followed, unofficially, by some prestigious colleges in north-east America.
In 1949, Martin joined the nascent WHO in Geneva, where he set up a veterinary division. In collaboration with scientists at the University of Wisconsin and the Wistar Institute in Philadelphia, he carried out early investigations on the flu virus in animals and birds.
At WHO he became director of science and technology, and, later, head of the office of research and development. He worked at WHO in various capacities, mainly as adviser to the director-general, until his retirement.
Martin's decision to remain in Europe, and not to return permanently to the US, was to a large extent influenced by the dismal happenings in the US during the McCarthy period. Several of his friends fell victim to the McCarthyite witch-hunt.
Martin's fate would have been similar since he would not have been willing to denounce to the House Un-American Activities Committee colleagues suspected of communist leanings. He lived until the end of his life on the shore of Lac Léman, in the Bellerive suburb of Geneva.
One of his neighbours there was Prince Sadruddin Aga Khan (obituary, May 15 2003). Martin became friendly with him and collaborated in a number of colloquia held by the prince on the threats posed by weapons of mass destruction and environmental pollution.
My links with Martin go back to 1955, to the proclamation of the Russell-Einstein Manifesto which gave rise to the Pugwash movement.
A few days after the proclamation he unexpectedly walked into my office in London saying: "I have heard about the new organisation of scientists you are setting up, and I have come to offer my help in whatever form you may need." And he meant this literally. From that day onwards, he never refused any request for help - and there were plenty of them.
The first major assignment was to organise, in 1959, in the Pugwash village of Nova Scotia, a conference on biological and chemical warfare. This was the first time that eminent scientists, experts in the field, from both sides of the Iron Curtain, met to assess the dangers posed by the use of weapons of mass destruction, and to seek means to prevent such use.
One outcome of this conference was to set up a Pugwash study group on chemical warfare, whose main task was to facilitate the drafting of the Chemical Weapons Convention. When the CWC came into force, in 1993, the study group took up the task of its implementation. Most of the workshops were held in Geneva, and Martin was responsible for their organisation. As secretary-general of Pugwash, he set up and ran a study group on nuclear forces, which frequently met in Geneva between 1980 and 1997.
In total, Martin organised 52 Pugwash workshops. Much of the credit for the achievements of Pugwash, recognised by the award to it of the 1995 Nobel peace prize, must go to him.
Martin was a unique person; and in this increasingly selfish world of ours, he stood out as a beacon of friendship, generosity and, simply, goodness.
He is survived by Lenna, his wife of 60 years, a daughter and two sons.
· Martin Kaplan, public health researcher, administrator and peace campaigner, born June 23 1915; died October 16 2004