Nuclear fallout doesn’t typically promote fertility, but it certainly spurred Mike Chessin’s growth as a scientific activist.

“I had kids growing up here,” the retired University of Montana botany professor recalled. “By the mid-1950s we were already detecting it. North Dakota was a hot spot.”

Chessin was studying how ultraviolet radiation affects plants when zoologist Bert Pfeiffer showed up with a pile of radioactive bones collected from milk cows downwind of early atmospheric nuclear bomb tests. Along with several colleagues, the professors soon organized the Western Montana Scientists Committee for Public Information to spread the discussion.

“It was one of 24 university-based committees around the country,” Chessin recalled. “We’d go around and talk to PTAs and service clubs on the biological effects of radiation. We’d always try to be as objective as possible. But at the end, everyone always wanted to know, as scientists, were we building fallout shelters?”

It was the time of the Cold War between the United States and the U.S.S.R., when Americans set off 210 above-ground nuclear bombs between 1945 and 1962. The U.S. military was funding what it called “environmental science” to catalog the effects of the forces it unleashed. One phenomenon it found was that clouds of radioactive cesium and strontium could travel for miles on the wind, from the testing fields of Nevada to the dairy fields of North Dakota.

“The Atomic Energy Commission was not too happy with what we were doing,” Chessin said. “But we started getting the government behind us. Eventually (President John) Kennedy was able to bring about a limited test ban treaty that ended atmospheric testing.”

Initially reluctant to get involved in public health issues, Chessin found the calling irresistible. He went on to challenge soldiers’ exposure to Agent Orange in Vietnam and Missoulians’ risk from pulp mill exhaust and wood smoke. He protested the placement of nuclear-tipped missiles in Montana silos, convinced that a geopolitical strategy that assumed the end of life on earth after a nuclear winter was not worth following.

Chessin said his Army Signal Corps duty in Germany after World War II ended helped form his ethical viewpoint.

“I wasn’t prepared for what I saw,” he said of Berlin’s post-war devastation. “It was completely flattened. It really convinced me there must be some other way to settle problems.”


Chessin retired from UM in 1990, but has kept active in progressive politics and letter-writing. Now 96 and still meeting friends for hamburgers and pool games at the Missoula Club, Chessin says he hears disturbing parallels in the way President Donald Trump talks about nuclear conflict.

“I don’t understand where Trump fits in the nuclear issue,” Chessin said. “He talks about getting together with Russia, when we’ve spent all this time saying of course nothing with Russia can be any good. The whole thread seems to be moving toward increased tension between the U.S. and Russia.”

Looking back over the decades of nuclear debate, Chessin said he also can’t fathom why science has become so distrusted in the public arena. Fresh off the Cuban Missile Crisis in 1963, Democrat Kennedy was able to get his test ban through Congress on an 80-14 vote. Republican President Ronald Reagan, who had warned that a nuclear winter “could just end up in no victory for anyone because we would wipe out the earth as we know it,” won Senate passage of his Intermediate Range Nuclear Forces Treaty, 93-5.

But in the next decade, Democratic President Bill Clinton failed to win Senate support for a comprehensive nuclear test ban in 1999, when 51 Republicans voted against 44 Democrats and four GOP dissenters to reject the treaty. Presidents George W. Bush and Barack Obama did more of their nuclear deals either unilaterally or through agreements that didn’t require a Senate supermajority.

“Life is full of ironies,” he said. “Reagan came within a hair’s breadth of getting a comprehensive test ban. Our military is as great as the rest of the world combined. But we say we don’t want an empire, so what do we need it for?”