The various anthropogenic markers under consideration reflect different scientific specialties or ways of knowing the global environment.11John V. Pickstone, Ways of Knowing: A New History of Science, Technology and Medicine. Manchester: University of Manchester Press, 2000. Each offers a distinct view of how humans have, quite literally, changed the world. My contribution argues that the nuclear Anthropocene has guided how scientists and citizens understand the manifold residues of human activities in the world.22Soraya Boudia, Angela N. H. Creager, Scott Frickel, Emmanuel Henry, Nathalie Jas, Carsten Reinhardt, and Jody A. Roberts, Residues: Thinking Through Chemical Environments. New Brunswick, NJ: Rutgers University Press, 2021. Scientific investigations of the atomic nucleus, as well as of radioisotopes, go back to the early twentieth century, but the attempt to master nuclear fission for weapons during World War II and the Cold War took the science and technology of the atom to a new and more violent scale. (See below.) The recognition of Earth’s global environment nucleated from the anthropogenic conditions of the atomic age.33Toshihiro Higuchi, Political Fallout: Nuclear Weapons Testing and the Making of a Global Environmental Crisis. Stanford, CA: Stanford University Press, 2020; Jacob Hamblin, Arming Mother Nature: The Birth of Catastrophic Environmentalism. New York: Oxford University Press, 2013; and for a more direct statement of this argument via technologies of environmental monitoring, Néstor Herran, “Pour une histoire transnational des reseaux de surveillance de l’environnement: le case de la radioactivité,” Habilitation à diriger des recherches, Sorbonne Université, vol. 2 (2021).  Other scholars have traced the broader contours of this complex legacy.44E.g., Michael D. Gordin, Red Cloud at Dawn: Truman, Stalin, and the End of the Atomic Monopoly. New York: Farrar, Straus, and Giroux, 2009; Paul N. Edwards, Vast Machine: Computer Models, Climate Data, and the Politics of Global Warming. Cambridge, Mass.: MIT Press, 2010; Simone Turchetti and Peder Roberts, The Surveillance Imperative: Geosciences During the Cold War and Beyond. New York: Palgrave Macmillan, 2014. I will focus on how problems associated with artificial radioactivity led ecologists, geneticists, and biomedical researchers to understand environmental contamination and low-dose exposures.55Soraya Boudia, “From Threshold to Risk: Exposure to Low Doses of Radiation and its Effects on Toxicants Regulation,” in Soraya Boudia and Nathalie Jas, eds., Toxicants, Health and Regulation since 1945. New York: Routledge, 2013, pp. 71–87; Angela N. H. Creager, “The Political Life of Mutagens: A History of the Ames Test,” in Soraya Boudia and Nathalie Jas, eds., Powerless Science? Science and Politics in a Toxic World. New York: Berghahn Books, 2014, pp. 46–64. These concepts and tools subsequently shaped the science and regulation of toxic chemicals and other human-generated environmental contaminants.66Scott Frickel, Chemical Consequences: Environmental Mutagens, Scientist Activism, and the Rise of Genetic Toxicology. New Brunswick, NJ: Rutgers University Press, 2004; Boudia et al., Residues.

Radioecology

To start on familiar ground, the military development of atomic energy (first by the US) resulted in the generation of many long-lasting radioelements not naturally present on Earth, such as plutonium, as well as a wide variety of fission byproducts, most radioactive isotopes. Many of these radioisotopes were of toxic chemical elements, and their half-lives and biological effects were not well-understood. Even as the Manhattan Project began to do secret research on these radioisotopes, they were already contaminating the planet. Nuclear waste from the production of fissionable material and fallout from the above-ground detonation of hundreds of atomic weapons dispersed radioactive elements throughout the world from 1943 to 1963.77The first nuclear blast was not until 1945, but uranium separation and plutonium production began earlier. 1943 was the construction of the first nuclear reactor by the Manhattan Project. On radioactive fallout as a marker, see Andy Cundy, Colin Waters, Irka Hajdas, and Yoshiki Saito, “Radioactive fallout as a marker for the Anthropocene,” Nuclear Anthropocene: Anthropogenic Markers (2022). 

Although the US bomb project was shrouded in secrecy, radioactivity from detonation of the first nuclear device and waste from the production of plutonium betrayed its existence. In New Mexico after the Trinity blast, livestock on nearby ranches suffered from radiation exposure, with skin burns, hair loss, and bleeding.88Barton C. Hacker, Dragon’s Tail: Radiation Safety in the Manhattan Project, 1942–1946. Berkeley: University of California Press, 1987, pp. 105–106. (Ranchers were also exposed though did not show immediate effects.) In August 1945, employees at a Kodak production plant noticed exposure spots on their photographic film, providing another kind of evidence of radioactivity from the top-secret nuclear test blast.99Joseph Masco, “Optics of Exposure,” in Bernadette Bensaude-Vincent, Soraya Boudia, and Kyoko Sato, eds., Living in a Nuclear World: From Fukishima to Hiroshima. Abington: Routledge, 2022, pp. 45–65.  The US government tried to prevent information breaches through its stringent national security apparatus, but the Army realized it could not censor the natural environment. Despite this, Manhattan Project officials often denied civilian observations of its activities and disclaimed any responsibility for their negative effects. In a few cases, such as with Kodak, the government brought civilians into its regime of secrecy to prevent further disclosure. For reasons related to both national security and human safety, studying the environmental movement and biological effects of radioactive materials being released by the atomic bomb project became vital (if secret) topics for investigation by the Manhattan Project and subsequently by its postwar successor, the Atomic Energy Commission.

In Hanford, Washington, the Manhattan Project contracted with fisheries researcher Laurel Donaldson of University of Washington to investigate the effects of radioactivity on aquatic life.1010Matthew W. Klingle, “Playing Atomic Waters: Lauren Donaldson and the ‘Fern Lake Concept’ of Fisheries Management,” Journal of the History of Biology 31 (1988): pp. 1–32. The salmon industry along the Columbia River, into which cooling water from the Hanford reactors would be dumped, was worth eight to ten million dollars per year.1111C. C. Gamertsfelder, “Effects on Surrounding Areas Caused by the Operations of the Hanford Engineer Works,” OpenNet Acc RL-1-374061 (March 11, 1947): p. 5. In addition, the river was a source of drinking water for local populations.1212Neal O. Hines, Proving Ground: An Account of the Radiobiological Studies in the Pacific, 1946–1961. Seattle: University of Washington Press, 1962, p. 8. Any impact on fish (or people) could alert locals to the nature of secret military activities on the Hanford Reservation.

Donaldson and his coworkers demonstrated that fish, like mammals, suffer from radiation sickness, and that exposure to sub-lethal doses of ionizing radiation caused birth defects in salmon. These studies were done in the Applied Fisheries Laboratory in Seattle, but Donaldson argued for the need for research on site at the Columbia River as well. An Aquatic Biology Laboratory was established at Hanford in June 1945 to study the effects of cooling water from the nuclear reactors (called effluent) on salmon and trout at various stages of development. Hanford scientists also studied the levels of radioactivity in the water, and in fresh water organisms. (See below.) In 1946, they found that fish concentrate radioactivity in their bodies (especially liver and kidneys) following ingestion; in the river this involved radioisotopes of naturally-occurring minerals and other elements that were irradiated as the water cooled the reactors. Follow-up studies showed a concentration of up to several thousand-fold of these radioelements in the fish bodies over levels in the river water.1313Karl E. Herde, “Radioactivity in Various Species of Fish from the Columbia and Yakima Rivers,” Hanford Health Instruments Section, OpenNet Acc NV0717089 (May 14, 1947); idem, “A One Year Study of Radioactivity in Columbia River Fish,” OpenNet Acc NV0717090 (October 25, 1948). 

The radioactivity was also moving between organisms. Already in 1947, a report circulating within the Atomic Energy Commission (AEC) mentioned the “transfer of radioactive material in ‘food chains’” from plankton to fish.1414Stafford L. Warren, Report of the Meeting of the Interim Medical Committee, Atomic Energy Commission, OpenNet Acc NV0727195 (January 23-24, 1947): p. 12. Hanford scientists did not publish these findings in the open literature until the mid-1950s, by which time ecologists elsewhere had begun documenting similar effects.1515Richard F. Foster and Royal E. Rostenbach, “Distribution of Radioisotopes in the Columbia River,” Journal of the American Water Works Association 46 (1954): pp. 633–40; Richard F. Foster and J. J. Davis, “The Accumulation of Radioactive Substances in Aquatic Form,” Proceedings of the International Conference on the Peaceful Uses of Atomic Energy, Held in Geneva 8–20 August 1955, vol. 13. New York: United Nations, 1956, pp. 364–67; W. C. Hanson and H. A. Kornberg, “Radioactivity in Terrestrial Animals near an Atomic Energy Site,” Proceedings of the International Conference on the Peaceful Uses of Atomic Energy, Held in Geneva 8–20 August 1955, vol. 13. New York: United Nations, 1956, pp. 385–88. By the 1960s, environmental scientists began considering the behavior of chemical contaminants as similar to that observed with radioisotopes. At the AEC’s Brookhaven National Laboratory, George Woodward and coworkers investigated how DDT moved through ecosystems and entered food webs, finding that it showed the same pattern of bioconcentration through the food web that had been observed earlier with certain radioactive elements.1616George M. Woodwell, Charles F. Wurster, Jr., and Peter A. Isaacson, “DDT Residues in an East Coast Estuary: A Case of Biological Concentration of a Persistent Insecticide,” Science 156 (1967): pp. 821–24.

It was not just this disturbing behavior of bioconcentration, but also the broader attention to the hazards of invisible, low-level contaminants that was part of the nuclear legacy. As Woodwell put it, the attention to one part per billion in the environment “in itself was a revolution,” and the realization that biotic studies required measurement in the “range of nanograms and picograms, nanocuries and picocuries” became a defining feature of environmental science.1717George W. Woodwell, “BRAVO plus 25 Years,” in Environmental Sciences Laboratory Dedication: Daniel J. Nelson Auditorium, Feb. 26–27, 1979, ed. S. I. Auerbach and N. T. Milleman. Oak Ridge, TN: Oak Ridge National Laboratory, 1980, pp. 61–64, on p. 62. As ecologists F. Ward Whicker and Vincent Schultz observed, when it came to studying processes involved in the spread of “smog, pesticides, and other chemical substances that may threaten the environment,” radioisotopes were a “model pollutant.”1818F. Ward Whicker and Vincent Schultz, “Introduction and Historical Perspective,” in Radioecology: Nuclear Energy and the Environment. Boca Raton, FL: CRC Press, 1982, p. 2.

Ionizing radiation as a health hazard

At the same time, studies of the biological effects of radioactivity shed light on the health consequences of low-dose, long-term exposure. During and after the Manhattan Project, radiological safety drew on a toxicological framework that assumed the existence of an exposure dose below which health hazards would be low to negligible.1919Soraya Boudia, “Gouvenor les risques, gouvernor par le risque: Pour une histoire du risque de la société du risqué,” Habilitation à diriger des researches, Université de Strasbourg, vol. 2 (2010). (See below.) Admittedly, some experiments, particularly on the genetic effects of radiation, suggested that such a threshold did not exist. In 1946, the National Committee on Radiological Protection changed the term “tolerance dose” to “permissible dose” in recognition that the limits specified by its recommendations might not be certifiably safe.2020J. Samuel Walker, Permissible Dose: A History of Radiation Protection in the Twentieth Century. Berkeley: University of California Press, 2000, p. 10. Nonetheless, health physicists and government officials operated on the assumption that hazards from radiation exposure could be safely managed. At the Oak Ridge Institute of Nuclear Studies, the US government offered researchers training courses in handling and measuring radioactivity. In 1955, as part of the Atoms for Peace initiative, these were opened up to foreign workers as well (though generally not to those from Soviet-aligned countries).2121Néstor Herran, “The Bounties of Our New Servant: Health, Science, Waste and the Industry of Radioisotopes after Atoms for Peace,” forthcoming, Cold War History. This was one of many international initiatives aimed at promoting the use of nuclear technologies, as well as the trust that they could be safe.2222Angela N. H. Creager and Maria Rentetzi, “Sharing the ‘Safe’ Atom? The International Atomic Energy Agency and Nuclear Regulation through Standardization,” in Bernadette Bensaude-Vincent, Soraya Boudia, and Kyoko Sato, eds., Living in a Nuclear World: From Fukushima to Hiroshima. Abington: Routledge, 2022, pp. 111–131. 

Most feared among radiation’s dangers was cancer, for which there could be a long latent period after exposure. In the 1950s a group of geneticists, drawing largely on studies in radiation biology and medicine, argued that human cancers typically arose from mutations to somatic cells.2323A. H. Sturtevant, “Social Implications of the Genetics of Man,” Science 120 (1954): pp. 405–7; J. Christopher Jolly, Thresholds of Uncertainty: Radiation and Responsibility in the Fallout Controversy. PhD dissertation, Oregon State University, 2003.  This conception subverted the longstanding distinction among health physicists between so-called somatic effects of radiation (particularly cancer), for which a safety threshold was thought to operate, and genetic effects, which were known to exist at low exposure levels. Geneticists instead connected the mutagenizing ability of an agent such as radiation to its role in cancer. Because there appeared to be no threshold for genetic damage, even low-level exposures might induce cancer-producing somatic mutations.2424Angela N. H. Creager, “Radiation, Cancer, and Mutation in the Atomic Age,” Historical Studies in the Natural Sciences 45 (2014): pp. 46–64.  In addition, the “multi-stage model” of carcinogenesis proposed by Peter Armitage and Richard Doll in 1954 treated cancer as the result of not just one, but several, cellular events.2525P. Armitage and R. Doll, “The Age Distribution of Cancer and a Multi-Stage Theory of Carcinogenesis,” British Journal of Cancer 8 (1954): pp. 1–12. These events could be mutations, such as those induced by radiation. In the 1960s, biochemists and biophysicists showed mutational damage by ionizing radiation to occur through specific kinds of DNA damage, giving the somatic mutation theory a clear mechanistic basis.2626Doogab Yi, “The Coming of Reversibility: The Discovery of DNA Repair Between the Atomic Age and the Information Age,” Historical Studies in the Physical and Biological Sciences 37, Suppl. 1 (2007): pp. 35–72. In 1972, the National Academy of Science’s report on Biological Effects of Ionizing Radiation advised that the carcinogenic effects of ionizing radiation should be regarded as linearly dose-dependent, with no threshold below which damage did not occur.2727National Research Council Advisory Committee on the Biological Effects of Ionizing Radiation, The Effects on Populations of Exposure to Low Levels of Ionizing Radiation. Washington, DC: National Academy of Science, 1972.

This understanding of the carcinogenicity of radiation, even at low dose, informed a parallel concern with exposure to synthetic chemicals in pollutants, pesticide residues, consumer products, and drugs. Chemicals, like radiation, were presumed to act at the level of DNA in causing mutations and potentially cancer.2828Claes Ramel, “Advantages of and Problems with Short-Term Mutagenicity Tests for the Assessment of Mutagenic and Carcinogenic Risk,” Environmental Health Perspectives 47 (1983): pp. 153–9. Many scientists turned their attention to harnessing their knowledge and techniques to detect carcinogens, with an eye towards regulatory testing. As Scott Frickel has shown, by the early 1970s genetic toxicology brought radiation and chemicals under the same umbrella of environmental mutagens, and this new field generated the research and expertise critical to new government regulation of these substances.2929Frickel, Chemical Consesquences.

In the US, federal agencies responded to the widespread belief that environmental agents were responsible for the majority of human cancers. In 1968, the National Cancer Institute launched a “Plan for Chemical Carcinogenesis and the Prevention of Cancers.” During the subsequent years the agency publicized an estimate that as much as 90 percent of human cancer was attributable to environmental agents.3030Library of Congress Environment and Natural Resources Policy Division, Legislative History of the Toxic Substances Control Act. Washington, D.C.: U.S. Government Printing Office, 1976, pp. 532, 539. As Soraya Boudia has observed, radiation protection law, which in the US first provided a population-level exposure limit in 1958, put forth a risk-based framework for conceptualizing and controlling the health effects of low-level toxic chemicals.3131Boudia, “From Threshold to Risk.”

A life-threatening marker

Rachel Carson’s Silent Spring began with a comparison of toxic chemicals to radioactivity, extending the widespread alarm about exposure to hazardous radioactive fallout from weapons testing to include pollution from the petrochemical industry: “In this now universal contamination of the environment, chemicals are the sinister and little-recognized partners of radiation in changing the very nature of the world—the very nature of life.”3232Rachel Carson, Silent Spring. Boston: Houghton Mifflin, 1962, p. 6. In this sketch I have tried to illustrate how the related concerns about radiation and chemicals underlay the growth of environmental life science, even as it also informed social movements and political demands for action.

Historians have previously demonstrated the ways in which the atomic age ushered in global monitoring systems and computer modelling of the environment.3333E.g., Turchetti and Roberts, Surveillance Imperative. Yet the catastrophic cost of anthropogenic change, as exemplified by climate change, is its terrible toll on living organisms.3434Elizabeth Kolbert, The Sixth Extinction: An Unnatural History. New York: Simon & Schuster, 2014. In this respect, an anthropogenic marker associated with the changing knowledge of life and how it is threatened by human activities seems especially suitable. The accumulation of human-made nuclear contamination has shaped not only our earthly environment, but also our epistemological reckoning with the ghastly aftereffects of our radioactive and chemical creations.

Angela N. H. Creager is the Thomas M. Siebel Professor in the History of Science at Princeton University. Her current book project, “Making Mutations Matter,” examines science and regulation in the 1960s through the 1980s, focusing attention on how researchers conceptualized and developed techniques for detecting environmental carcinogens.

Please cite as: Creager, A N H (2022) The Radioactive Footprint of the Anthropocene. In: Rosol C and Rispoli G (eds) Anthropogenic Markers: Stratigraphy and Context, Anthropocene Curriculum. Berlin: Max Planck Institute for the History of Science. DOI: 10.58049/zrb1-6e54