isotope americium-241 decays (half-life 432 years) to neptunium-237 which has a much longer half-life, so in the long term, the issues discussed above for neptunium apply. Americium released into the environment tends to remain in soil and water at relatively shallow depths and may be taken up by animals and plants during growth; shellfish such as shrimp take up americium-241 in their shells, and parts of grain plants can become contaminated with exposure. In a 2021 paper, J.D. Chaplin et al. reported advances in the Diffusive gradients in thin films technique, which have provided a method to measure labile bioavailable Americium in soils, as well as in freshwater and seawater. Curium Atmospheric curium compounds are poorly soluble in common solvents and mostly adhere to soil particles. Soil analysis revealed about 4,000 times higher concentration of curium at the sandy soil particles than in water present in the soil pores. An even higher ratio of about 18,000 was measured in loam soils. Californium Californium is fairly insoluble in water, but it adheres well to ordinary soil, and concentrations of it in the soil can be 500 times higher than in the water surrounding the soil particles. See also Uranium in the environment Radium in the environment Background radiation Radioecology References Further reading Hala, Jiri, and James D. Navratil. Radioactivity, Ionizing Radiation and Nuclear Energy. Konvoj: Brno, Czech Republic, 2003. . External links "Why do mechanisms matter in radioactive waste management?" – Royal Society for Chemistry "Spectroscopies for Environmental Studies of Actinide Species" – Federation of American Scientists Nuclear materials Nuclear technology Nuclear chemistry Nuclear physics Inorganic chemistry Radiobiology Radioactive contamination Soil contamination