October 22, 2021
In the late 19th Century, scientists discovered that humanity’s most intractable infectious diseases and the blight of staple crops were caused by microscopic pathogens. This discovery led scientists on an urgent mission to prevent pandemics and famine with chemicals. The discovery that many diseases are transmitted by insects and other animals presented a means to end misery: pesticides were quickly developed to kill these animal vectors. Inevitably, scientists discovered that many of these chemicals could be weaponized, and the world experienced waves of chaos as modern warfare swept over national boundaries. By the end of World War I, one-quarter of artillery shells contained chemicals. The complex, two-way relationship between pesticides and chemical weapons solidified, and chemical companies accumulated wealth and power. The use of chemicals in war led to a rush to harness the power of chemistry against pests during times of peace.
Advances in chemical weaponry and insecticides continued to feed into each other’s development prior to World War II, especially in Germany. In 1925, the German companies BASF, Bayer, Hoechst, Agfa, Cassella, Kalle, Ter Meer, and Greisham combined into the conglomerate I.G. Farben, the largest chemical company in the world. With Adolf Hitler’s ascent, I.G. Farben led corporate financial backing of the Nazi Party, and it provided the war materials that enabled Nazi expansionism. The company’s chemist Gerhard Schrader advanced Nazi capabilities when, in his search for new insecticides, he synthesized the nerve gases tabun and sarin, along with a plethora of organophosphate insecticides. As the war wound down, the US Chemical Warfare Service prioritized the importation of Hitler’s chemists and their organophosphate nerve agents in order to advance US chemical weaponry, and the US recruited Nazi scientists through “Operation Overcast” and “Operation Paperclip.”
The use of pesticides as a tool of warfare peaked with Operation Ranch Hand, in which the US sprayed 73,000,000 liters of herbicides and defoliants, such as Agent Orange, over the rainforest and mangrove forest canopies of Vietnam, Laos, and Cambodia. All the while, chemical discoveries ratcheted the world into ever-newer realities in which hunger and disease retreated into smaller geographic regions, the sophistication of chemical weapons became accessible to more belligerents, and persistent pollutants contaminated even the most remote habitats on the planet. Who were the scientists battling pests and opposing armies with chemistry? These scientists, embedded in national conflicts, and shaped by adulation and fame, took extraordinary risks on the path to extraordinary discoveries, which occurred in the context of our long and tumultuous relationship with lethal chemicals.
Frank A. von Hippel is a professor of environmental health sciences in the Mel & Enid Zuckerman College of Public Health and the lead of the One Health Research Initiative at the University of Arizona. Frank was born and raised in Alaska, received his A.B. in biology at Dartmouth College in 1989, and his Ph.D. in integrative biology at the University of California, Berkeley in 1996. He taught for Columbia University (1996-1999), the University of Alaska Anchorage (2000-2016), and Northern Arizona University (2016-2021) before moving to the University of Arizona in 2021. Frank has taught ecology field courses in over twenty countries, and conducted research in the Americas, Africa and Australia. He conducts research at the nexus of ecotoxicology, mechanisms of toxicity, and health disparities, with a focus on Indigenous and underserved communities. Frank’s research has been widely covered in the press, including The New York Times, National Public Radio, The Economist, the BBC, and many other media outlets. Frank is the author of The Chemical Age (University of Chicago Press, 2020; ) and he is the creator and host of the Science History Podcast ().