Biological Report 26 Contaminant Hazard Reviews December 1994 Report No. 29 RADIATION HAZARDS TO FISH, WILDLIFE, AND INVERTEBRATES: A SYNOPTIC REVIEW by Ronald Eisler Patuxent Environmental Science Center U.S. National Biological Service Laurel, MD 20708 Abstract Physical Properties of Radiation General Electromagnetic Spectrum Radionuclides Linear Energy Transfer New Units of Measurement Sources and Uses General Natural Radioactivity Anthropogenic Radioactivity Dispersion Radionuclide Concentrations in Field Collections General Abiotic Materials Aquatic Ecosystems Birds Mammals Case Histories Pacific Proving Grounds Chernobyl Effects: Nonionizing Radiations Effects: Ionizing Radiations General Terrestrial Plants and Invertebrates Aquatic Organisms Amphibians and Reptiles Birds Mammals Proposed Criteria and Recommendations Conclusions Acknowledgments Cited Literature Glossary TABLES Number 1 Selected radionuclides: symbol, mass number, atomic number, half-life, and decay mode 2 Radiation weighting factors for various types of ionizing radiations 3 New units for use with radiation and radioactivity 4 Annual effective dose equivalent to humans from natural sources of ionizing radiation 5 Annual-whole body radiation doses to humans from various sources 6 Sources and applications of atomic energy 7 Annual effective dose equivalent from nuclear-weapons testing to humans in the north temperate zone 8 Estimated fallout of 90Sr and 137Cs over the Great Lakes, 1954-83, in cumulative millions of Bq/km2 9 Fission products per kg 235U reactor charge at 100 days cooling 10 Radioactive waste disposal at sea 11 Theoretical peak dose, in microsieverts per year, received from plutonium and americium by three human populations 12 Time required to transport selected radionuclides added into marine waters at surface from the upper mixed layer by biological transport 13 Radionuclide concentrations in field collections of selected materials 2 14 Radionuclide concentrations in field collections of selected living organisms 15 Radionuclide concentrations in selected samples from the Pacific Proving Ground 16 Selected fission products in the Chernobyl reactor core and their estimated escape into the environment 17 Regional total effective human dose-equivalent commitment from the Chernobyl accident 18 Radionuclide concentrations in biotic and abiotic materials from various geographic locales before or after the Chernobyl nuclear accident on 26 April 1986 19 Radiation effects on selected terrestrial plants 20 Radiation effects on selected terrestrial invertebrates 21 Radiation effects on selected aquatic organisms 22 Concentration factors for cesium-137 and strontium-90 in aquatic organisms 23 Maximum concentration factors reported for selected elements in marine organisms at various trophic levels 24 Approximate maximum concentration factors for selected transuranics in marine sediments, macroalgae, and fishes 25 Radiation effects on selected amphibians and reptiles 26 Radiation effects on selected birds 27 Radiation effects on selected mammals 28 Recommended radiological criteria for the protection of human health FIGURES Number 1. The spectrum of electromagnetic waves, showing relation between wavelength, frequency, and energy 2. The principal uranium-238 decay series, indicating major decay mode and physical half-time of persistence 3. The three still existing natural decay series 4. Natural radiations in selected radiological domains 5. Plutonium-239 + 240 in environmental samples at Thule, Greenland, between 1970 and 1984, after a military accident in 1968 6. Chernobyl air plume behavior and reported initial arrival times of detectable radioactivity 7. Acute radiation dose range fatal to 50% (30 days postexposure) of various taxonomic groups 8. Relation between diet, metabolism, and body weight with half-time retention of longest-lived component of cesium-137 9. Survival time and associated mode of death of selected mammals after whole-body doses of gamma radiation 10. Relation between body weight and radiation-induced LD50 (30 days postexposure) for selected mammals 3 RADIATION HAZARDS TO FISH, WILDLIFE, AND INVERTEBRATES: A SYNOPTIC REVIEW by Ronald Eisler Patuxent Environmental Science Center U.S. National Biological Service Laurel, MD 20708 Abstract This account is a selective review and synthesis of the voluminous technical literature on radiation and radionuclides in the environment and their effects on notably fishes, wildlife, invertebrates, and other natural resources. The subtopics include the physical and biological properties of the electromagnetic spectrum and of charged particles; radiation sources and uses; concentrations of radionuclides in field collections of abiotic materials and living organisms; lethal and sublethal effects, including effects on survival, growth, reproduction, behavior, metabolism, carcinogenicity, and mutagenicity; a synopsis of two case histories of massive releases of radionuclides into the biosphere (military weapons tests at the Pacific Proving Grounds and the Chernobyl nuclear reactor accident); currently proposed radiological criteria for the protection of human health and natural resources; and recommendations for additional research. A glossary is included. Key words: Radioactivity, radionuclides, radioecology, Chernobyl, Pacific Proving Grounds, wildlife, aquatic organisms, invertebrates, flora, radiological protection criteria. 4 Life on earth has evolved under the ubiquitous presence of environmental solar, X-ray, gamma, and charged-particle radiation. On a global basis, radiation from natural sources is a far more important contributor to radiation dose to living organisms than radiation from anthropogenic sources (Aarkrog 1990). However, ionizing radiation can harm biological systems (Aarkrog 1990; Nozaki 1991; Severa. and Bar 1991), and this harm can be expressed (1) in a range of syndromes from prompt lethality to reduced vigor, shortened life span, and diminished reproductive rate by the irradiated organism and (2) by the genetic transmission of radiation- altered genes that are most commonly recessive and almost always disadvantageous to their carriers (Bowen et al. 1971). Direct effects of radiation were documented in lampreys in 1896-soon after H. Becquerel discovered radioactivity-and in brine shrimp (Artemia sp.) in 1923 (Whicker and Schultz 1982a). Genetic effects of ionizing radiation and thus X-rays as a mutagenic agent were first documented in 1927 in fruit flies, Drosophila melanogaster (Evans 1990). The discovery of radioactivity of nuclear particles and the discovery of uranium fission resulted in a great upsurge of nuclear research. During and shortly after World War II, nuclear reactors, nuclear weapons, and radionuclides as tracers in almost all scientific and technical fields were developed rapidly (Severa and Bar 1991). In the early 1940’s when fission of uranium and transuranic nuclei became possible in reactors and in explosions of nuclear weapons, environmental radiation from anthropogenic sources began to cause serious concerns (Aarkrog 1990). The first nuclear explosion resulted from a 19-kiloton (TNT-equivalent) source in New Mexico in July 1945 (Whicker and Schultz 1982a). On 6 August 1945, about 75,000 people were killed when the United States Army Air Corps dropped a uranium nuclear bomb on Hiroshima, Japan; on 9 August 1945, about 78,000 Japanese were killed and more than 100,000 injured when a plutonium nuclear bomb was detonated at Nagasaki (Kudo et al. 1991). The former Soviet Union detonated its first nuclear device in August 1949, and in 1952 the United Kingdom exploded a device in Australia (Whicker and Schultz 1982a). Since 1960, nuclear devices have also been detonated by France, India, and The People’s Republic of China. Nuclear devices have been developed that can release energy in the megaton range. The first such device was detonated by the United States in 1954 at Bikini Atoll and accidentally contaminated Japanese fishermen and Marshall Island natives. Between 1945 and 1973, an estimated 963 nuclear tests were conducted by The People’s Republic of China, France, the former Soviet Union, the United Kingdom, and the United States; 47% of them were atmospheric, and 53% subterraneous (Whicker and Schultz 1982a). Today, the most important environmentally damaging anthropogenic radiation comes from atmospheric testing of nuclear weapons that was conducted 20 to 30 years ago, authorized discharges to the sea from nuclear reprocessing plants, and the Chernobyl accident in 1986 (Aarkrog 1990). By the year 2000, the United States will have an estimated 40,000 tons of spent nuclear fuel that will be stored at some 70 sites and await disposal; by 2035, after all existing nuclear plants have completed 40 years of operation, about 85,000 metric tons will be awaiting disposal (Slovic et al. 1991). This report was initiated in response to a request for information on radiation from environmental contaminant specialists of the U.S. Fish and Wildlife Service. Specifically, general information was requested on radiation nomenclature, sources and uses, fate, effects, concentrations in field collections, and protection criteria. More detailed information was requested on radiation hazards to living organisms, especially fishes and wildlife. The report is an introduction to the broader fields of radioecology and radiation risk assessment and is intended primarily for use by service personnel, I emphasize that the published literature in these subject areas is particularly