Strontium and cesium accumulation in soil-rice system: Influencing factors and predictive modeling

Abstract

Strontium (Sr) and cesium (Cs) accumulation in rice grains poses significant dietary health risks, yet their nationwide distribution patterns and controlling mechanisms in soil-rice systems remain poorly quantified. This nationwide study analyzed 14 major rice-producing regions in China through multiple linear regression and positive matrix factorization source apportionment (PMF), exploring the source, distribution, and key factors influencing Sr and Cs. Random forest analysis showed that soil Sr was primarily influenced by total calcium, cation exchange capacity, clay, and pH, whereas grain Sr was mainly governed by organic matter, total calcium, and clay. For Cs, soil accumulation was predominantly affected by total potassium, while grain Cs was largely controlled by total potassium and total nitrogen. And we developed highly reliable models for predicting soil and grain concentrations of Sr and Cs (R² values of 0.97 for soil Sr, 0.93 for soil Cs, 0.86 for grain Sr and 0.65 for grain Cs), validated by field experiments. Spatial mapping showed high-concentration areas for soil Sr were in central China, Inner Mongolia, and Xinjiang. Soil Cs was mainly in the southeast of the Heihe-Tengchong Line and the Tibetan Plateau. Source analysis identified mining activities as the predominant Sr contributor (62.7%), while Cs exhibited balanced sources including traffic-related (20.2%) and nature source (25.7%). This study clarifies Sr and Cs distribution mechanisms and offers a scientific basis for regional pollution prevention and control strategies, stressing the need for targeted measures in high-risk areas to ensure food safety and public health.

Graphical abstract

Keywords

Sr and Cs accumulation / soil-rice system / paddy soil / prediction model / environmental risks

Highlight

	● Soil pH significantly affects strontium uptake in rice grains.
	● Cesium accumulation in rice is influenced more by organic matter and clay content.
	● Multiple linear regression models predict soil and rice Sr and Cs concentrations accurately.
	● Southeast China shows higher concentrations of strontium and cesium in rice and soil.

References

[1] Abdel-Sabour, M.F., 2022. Fate of cesium and strontium in soil-to-plant system (overview). Journal of Radiation and Nuclear Applications7, 87–93.

[2] Adams, E., Chaban, V., Khandelia, H., Shin, R., 2015. Selective chemical binding enhances cesium tolerance in plants through inhibition of cesium uptake. Scientific Reports5, 8842.

[3] Alharbi, A., El-Taher, A., 2013. A study on transfer factors of radionuclides from soil to plant. Life Science Journal10, 532–539.

[4] Ammar, A., Nouira, A., El Mouridi, Z., Boughribil, S., 2024. Recent trends in the phytoremediation of radionuclide contamination of soil by cesium and strontium: sources, mechanisms and methods: a comprehensive review. Chemosphere359, 142273.

[5] Bekelesi, W.C., Basuki, T., Higaki, S., Nakashima, S., 2022. Distinction of migration of strontium-90 and cesium-137 for Fukushima soil and sediment following the Fukushima accident. Radiation Safety Management21, 26–35.

[6] Bouzidi, A., Ararem, A., Imessaoudene, D., Yabrir, B., 2015. Sequential extraction of Cs and Sr from Ain Oussera soils around Es-Salam research reactor facility. Journal of Environmental Sciences36, 163–172.

[7] Bu, W.T., Zheng, J., Liu, X.M., Long, K.M., Hu, S., Uchida, S., 2016. Mass spectrometry for the determination of fission products ¹³⁵Cs, ¹³⁷Cs, and ⁹⁰Sr: a review of methodology and applications. Spectrochimica Acta Part B: Atomic Spectroscopy119, 65–75.

[8] Buesseler, K., Aoyama, M., Fukasawa, M., 2011. Impacts of the Fukushima nuclear power plants on marine radioactivity. Environmental Science & Technology45, 9931–9935.

[9] Buesseler, K., Dai, M.H., Aoyama, M., Benitez-Nelson, C., Charmasson, S., Higley, K., Maderich, V., Masqué, P., Morris, P.J., Oughton, D., Smith, J.N., 2017. Fukushima Daiichi–derived radionuclides in the ocean: transport, fate, and impacts. Annual Review of Marine Science9, 173–203.

[10] Burger, A., Lichtscheidl, I., 2019. Strontium in the environment: review about reactions of plants towards stable and radioactive strontium isotopes. Science of the Total Environment653, 1458–1512.

[11] Cao, J.F., Li, C.F., Wu, Q.Y., Qiao, J.M., 2020. Improved mapping of soil heavy metals using a Vis-NIR spectroscopy index in an agricultural area of eastern China. IEEE Access8, 42584–42594.

[12] Chapagain, S.K., Shrestha, S., Du Laing, G., Verloo, M., Kazama, F., 2009. Spatial distribution of arsenic in the intertidal sediments of River Scheldt, Belgium. Environment International35, 461–465.

[13] Chen, H.L., Wu, D.D., Wang, Q., Fang, L.H., Wang, Y.N., Zhan, C.L., Zhang, J.Q., Zhang, S.C., Cao, J.J., Qi, S.H., Liu, S., 2022. The predominant sources of heavy metals in different types of fugitive dust determined by principal component analysis (PCA) and positive matrix factorization (PMF) modeling in southeast Hubei: a typical mining and metallurgy area in central China. International Journal of Environmental Research and Public Health19, 13227.

[14] Chen, S.C., Liang, Z.Z., Webster, R., Zhang, G.L., Zhou, Y., Teng, H.F., Hu, B.F., Arrouays, D., Shi, Z., 2019. A high-resolution map of soil pH in China made by hybrid modelling of sparse soil data and environmental covariates and its implications for pollution. Science of the Total Environment655, 273–283.

[15] Chen, Z.M., Wang, S.L., Xu, J., He, L., Liu, Q., Wang, Y.F., 2024. Assessment and machine learning prediction of heavy metals fate in mining farmland assisted by Positive Matrix Factorization. Journal of Environmental Management350, 119587.

[16] Deng, F.F., Lin, F., Yu, W., He, J.H., Wang, F.F., Chen, Z.H., 2020. The distributions of ¹³⁴Cs, ¹³⁷Cs, and ⁹⁰Sr in the northwest Pacific seawater in the winter of 2012. Marine Pollution Bulletin152, 110900.

[17] Ding, C., Du, S., Ma, Y., Li, X., Zhang, T., Wang, X., 2019. Changes in the pH of paddy soils after flooding and drainage: Modeling and validation. Geoderma337, 511–513.

[18] Froidevaux, P., Bochud, F., Haldimann, M., 2010. Retention half times in the skeleton of plutonium and ⁹⁰Sr from above-ground nuclear tests: a retrospective study of the Swiss population. Chemosphere80, 519–524.

[19] Giannakopoulou, F., Haidouti, C., Chronopoulou, A., Gasparatos, D., 2007. Sorption behavior of cesium on various soils under different pH levels. Journal of Hazardous Materials149, 553–556.

[20] Guan, Q.Y., Wang, F.F., Xu, C.Q., Pan, N.H., Lin, J.K., Zhao, R., Yang, Y.Y., Luo, H.P., 2018. Source apportionment of heavy metals in agricultural soil based on PMF: a case study in Hexi Corridor, northwest China. Chemosphere193, 189–197.

[21] Guan, Y.J., Guo, Z.C., Chen, W., Fan, K.D., He, H., Cui, L.J., Huang, C.P., He, X.W., Xu, Z.Y., Zhang, J.J., He, Y., Wang, H.J., 2024. Migration mechanisms of ⁹⁰Sr and ¹³⁷Cs on terraces. Journal of Environmental Radioactivity275, 107428.

[22] Guo, J.H., Liu, X.J., Zhang, Y., Shen, J.L., Han, W.X., Zhang, W.F., Christie, P., Goulding, K.W. T., Vitousek, P.M., Zhang, F.S., 2010. Significant acidification in major Chinese croplands. Science327, 1008–1010.

[23] Hampton, C.R., Broadley, M.R., White, P.J., 2005. Short review: the mechanisms of radiocaesium uptake by Arabidopsis roots. Nukleonika50, S3–S8.

[24] He, J.Y., Yang, Y., Christakos, G., Liu, Y.J., Yang, X., 2019. Assessment of soil heavy metal pollution using stochastic site indicators. Geoderma337, 359–367.

[25] He, X.L., Yang, L., Li, A.Q., Zhang, L., Shen, F.X., Cai, Y.Y., Zhou, C.H., 2021. Soil organic carbon prediction using phenological parameters and remote sensing variables generated from Sentinel-2 images. CATENA205, 105442.

[26] Hu, Y.A., Cheng, H.F., Tao, S., 2016. The challenges and solutions for cadmium-contaminated rice in China: a critical review. Environment International92–93, 515–532.

[27] Huang, K.Y., Yang, Y., Lu, H.S., Hu, S.W., Chen, G.J., Du, Y.H., Liu, T.X., Li, X.M., Li, F.B., 2023. Transformation kinetics of exogenous nickel in a paddy soil during anoxic-oxic alteration: roles of organic matter and iron oxides. Journal of Hazardous Materials452, 131246.

[28] Igarashi, Y., Onda, Y., Matsushita, K., Sato, H., Wakiyama, Y., Lisovyi, H., Laptev, G., Protsak, V., Samoilov, D., Kirieiev, S., Konoplev, A., 2023. Hydrological setting controls ¹³⁷Cs and ⁹⁰Sr concentrations in a headwater catchment in the Chornobyl Exclusion Zone. Science of the Total Environment891, 164384.

[29] Ishikawa, S., Hayashi, S., Abe, T., Igura, M., Kuramata, M., Tanikawa, H., Iino, M., Saito, T., Ono, Y., Ishikawa, T., Fujimura, S., Goto, A., Takagi, H., 2017. Low-cesium rice: mutation in OsSOS2 reduces radiocesium in rice grains. Scientific Reports7, 2432.

[30] Karunakara, N., Rao, C., Ujwal, P., Yashodhara, I., Kumara, S., Ravi, P.M., 2013. Soil to rice transfer factors for ²²⁶Ra, ²²⁸Ra, ²¹⁰Pb, ⁴⁰K and ¹³⁷Cs: a study on rice grown in India. Journal of Environmental Radioactivity118, 80–92.

[31] Kasar, S., Mishra, S., Omori, Y., Sahoo, S.K., Kavasi, N., Arae, H., Sorimachi, A., Aono, T., 2020. Sorption and desorption studies of Cs and Sr in contaminated soil samples around Fukushima Daiichi Nuclear Power Plant. Journal of Soils and Sediments20, 392–403.

[32] Kenyon, J.A., Buesseler, K.O., Casacuberta, N., Castrillejo, M., Otosaka, S., Masqué, P., Drysdale, J.A., Pike, S.M., Sanial, V., 2020. Distribution and evolution of Fukushima Dai-ichi derived ¹³⁷Cs, ⁹⁰Sr, and ¹²⁹I in surface seawater off the coast of Japan. Environmental Science & Technology54, 15066–15075.

[33] Kondo, M., Maeda, H., Goto, A., Nakano, H., Kiho, N., Makino, T., Sato, M., Fujimura, S., Eguchi, T., Hachinohe, M., Hamamatsu, S., Ihara, H., Takai, T., Arai-Sanoh, Y., Kimura, T., 2015. Exchangeable Cs/K ratio in soil is an index to estimate accumulation of radioactive and stable Cs in rice plant. Soil Science and Plant Nutrition61, 133–143.

[34] Kumarathilaka, P., Seneweera, S., Meharg, A., Bundschuh, J., 2018. Arsenic speciation dynamics in paddy rice soil-water environment: sources, physico-chemical, and biological factors-a review. Water Research140, 403–414.

[35] Li, J.L., Gan, C.D., Du, X.Y., Yuan, X.Y., Zhong, W.L., Yang, M.Q., Liu, R., Li, X.Y., Wang, H., Liao, Y.L., Wang, Z., Xu, M.C., Yang, J.Y., 2024. Distribution, risk evaluation, and source allocation of cesium and strontium in surface soil in a mining city. Environmental Geochemistry and Health46, 270.

[36] Li, R., Zhou, Z., Zhang, Y., Xie, X., Li, Y., Shen, X., 2015. Uptake and Accumulation Characteristics of Arsenic and Iron Plaque in Rice at Different Growth Stages. Communications in Soil Science and Plant Analysis46, 2509–2522.

[37] Liu, S., Zhan, C.L., Zhang, J.Q., Guo, J.L., Liu, H.X., Liu, T., Zheng, J.R., Yao, R.Z., Liu, X.L., Xing, X.L., Cao, J.J., Qi, S.H., 2022. Source-specific health risk assessment of PM_2.5 bound heavy metal in re-suspended fugitive dust: a case study in Wuhan metropolitan area, central China. Journal of Cleaner Production379, 134480.

[38] Mao, G.Z., Zhao, Y.S., Zhang, F.R., Liu, J.J., Huang, X., 2019. Spatiotemporal variability of heavy metals and identification of potential source tracers in the surface water of the Lhasa River basin. Environmental Science and Pollution Research26, 7442–7452.

[39] Merz, S., Shozugawa, K., Steinhauser, G., 2015. Analysis of Japanese radionuclide monitoring data of food before and after the Fukushima nuclear accident. Environmental Science & Technology49, 2875–2885.

[40] Merz, S., Shozugawa, K., Steinhauser, G., 2016. Effective and ecological half-lives of ⁹⁰Sr and ¹³⁷Cs observed in wheat and rice in Japan. Journal of Radioanalytical and Nuclear Chemistry307, 1807–1810.

[41] Mishra, S., Kasar, S., Takamasa, A., Veerasamy, N., Sahoo, S.K., 2019. Measurement of uranium distribution coefficient and ²³⁵U/²³⁸U ratio in soils affected by Fukushima dai-ichi nuclear power plant accident. Journal of Environmental Radioactivity198, 36–42.

[42] Mollah, A.S., Begum, A., Ullah, S.M., 1998. Determination of soil-to-plant transfer factors of ¹³⁷Cs and ⁹⁰Sr in the tropical environment of Bangladesh. Radiation and Environmental Biophysics37, 125–128.

[43] Morita, T., Fujimoto, K., Kasai, H., Yamada, H., Nishiuchi, K., 2010. Temporal variations of ⁹⁰Sr and ¹³⁷Cs concentrations and the ¹³⁷Cs/⁹⁰Sr activity ratio in marine brown algae, Undaria pinnatifida and Laminaria longissima, collected in coastal areas of Japan. Journal of Environmental Monitoring12, 1179–1186.

[44] Nisbet, A.F., Woodman, R.F.M., 2000. Soil-to-plant transfer factors for radiocesium and radiostrontium in agricultural systems. Health Physics78, 279–288.

[45] Outola, I., Pehrman, R., Jaakkola, T., 2003. Effect of industrial pollution on the distribution of ¹³⁷Cs in soil and the soil-to-plant transfer in a pine forest in SW Finland. Science of the Total Environment303, 221–230.

[46] Pipíška, M., Horník, M., Koèiová, M., Augustín, J., Lesný, J., 2005. Radiostrontium uptake by lichen Hypogymnia physodes. Nukleonika50, S39–S44.

[47] Pu, S.Y., Duan, W., Zhu, Z.D., Wang, W., Zhang, C., Li, N., Jiang, P., Wu, Z.H., 2022. Environmental behavior and engineering performance of self-developed silico-aluminophosphate geopolymer binder stabilized lead contaminated soil. Journal of Cleaner Production379, 134808.

[48] Ray, D.K., Ramankutty, N., Mueller, N.D., West, P.C., Foley, J.A., 2012. Recent patterns of crop yield growth and stagnation. Nature Communications3, 1293.

[49] Rediske, J.H., Selders, A.A., 1953. The absorption and translocation of strontium by plants. Plant Physiology28, 594–605.

[50] Sahoo, S.K., Kavasi, N., Sorimachi, A., Arae, H., Tokonami, S., Mietelski, J.W., Łokas, E., Yoshida, S., 2016. Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima Daiichi nuclear power plant. Scientific Reports6, 23925.

[51] Sanchez, A. L., Wright, S. M., Smolders, E., Naylor, C., Stevens, P. A., Kennedy, V. H., Dodd, B. A., Singleton, D. L., Barnett, C. L., 1999. High plant uptake of radiocesium from organic soils due to Cs mobility and low soil K content. Environmental Science & Technology33, 2752–2757.

[52] Sanial, V., Buesseler, K.O., Charette, M.A., Nagao, S., 2017. Unexpected source of Fukushima-derived radiocesium to the coastal ocean of Japan. Proceedings of the National Academy of Sciences of the United States of America114, 11092–11096.

[53] Sharma, S., Singh, B., Manchanda, V.K., 2015. Phytoremediation: role of terrestrial plants and aquatic macrophytes in the remediation of radionuclides and heavy metal contaminated soil and water. Environmental Science and Pollution Research22, 946–962.

[54] Soudek, P., Tykva, R., Vaněk, T., 2004. Laboratory analyses of ¹³⁷Cs uptake by sunflower, reed and poplar. Chemosphere55, 1081–1087.

[55] Steinhauser, G., Brandl, A., Johnson, T.E., 2014. Comparison of the Chernobyl and Fukushima nuclear accidents: a review of the environmental impacts. Science of the Total Environment470–471, 800–817.

[56] Sun, G.X., Liu, X., Williams, P.N., Zhu, Y.G., 2010. Distribution and translocation of selenium from soil to grain and its speciation in paddy rice (Oryza sativa L.). Environmental Science & Technology44, 6706–6711.

[57] Syaifudin, M., Suzuki, M., Maruyama, H., Kubo, K., Watanabe, T., Shinano, T., 2023. Potassium applications reduced cesium uptake and altered strontium translocation in soybean plants. Soil Science and Plant Nutrition69, 88–98.

[58] Tamponnet, C., Martin-Garin, A., Gonze, M.A., Parekh, N., Vallejo, R., Sauras-Yera, T., Casadesus, J., Plassard, C., Staunton, S., Norden, M., Avila, R., Shaw, G., 2008. An overview of BORIS: bioavailability of radionuclides in soils. Journal of Environmental Radioactivity99, 820–830.

[59] Tian, S.H., Liang, T., Li, K.X., Wang, L.Q., 2018. Source and path identification of metals pollution in a mining area by PMF and rare earth element patterns in road dust. Science of the Total Environment633, 958–966.

[60] Tsukada, H., Hasegawa, H., Hisamatsu, S., Yamasaki, S., 2002. Transfer of ¹³⁷Cs and stable Cs from paddy soil to polished rice in Aomori, Japan. Journal of Environmental Radioactivity59, 351–363.

[61] Tsukada, H., Hisamatsu, S., Inaba, J., 2003. Transfer of ¹³⁷Cs and stable Cs in soil-grass-milk pathway in Aomori, Japan. Journal of Radioanalytical and Nuclear Chemistry255, 455–458.

[62] Tsukada, H., Takeda, A., Takahashi, T., Hasegawa, H., Hisamatsu, S., Inaba, J., 2005. Uptake and distribution of ⁹⁰Sr and stable Sr in rice plants. Journal of Environmental Radioactivity81, 221–231.

[63] Twining, J.R., Payne, T.E., Itakura, T., 2004. Soil-water distribution coefficients and plant transfer factors for ¹³⁴Cs, ⁸⁵Sr and ⁶⁵Zn under field conditions in tropical Australia. Journal of Environmental Radioactivity71, 71–87.

[64] Uchida, S., Tagami, K., Hirai, I., 2007. Soil-to-plant transfer factors of stable elements and naturally occurring radionuclides (1) upland field crops collected in Japan. Journal of Nuclear Science and Technology44, 628–640.

[65] Uchida, S., Tagami, K., Shang, Z.R., Choi, Y.H., 2009. Uptake of radionuclides and stable elements from paddy soil to rice: a review. Journal of Environmental Radioactivity100, 739–745.

[66] Velasco, H., Anjos, R.M., 2021. A review of ¹³⁷Cs and ⁴⁰K soil-to-plant transfer factors in tropical plants. Journal of Environmental Radioactivity235–236, 106650.

[67] Vosniakos, F.K., Kovačevic, D., 2012. ¹³⁷Cs and ⁴⁰K concentration in soil and their transfer to plant. In: Proceedings of the International Scientific Symposium "Agrosym 2012".

[68] Wallander, H., 2000. Use of strontium isotopes and foliar K content to estimate weathering of biotite induced by pine seedlings colonised by ectomycorrhizal fungi from two different soils. Plant and Soil222, 215–229.

[69] Wang, D., Wen, F.P., Xu, C.H., Tang, Y.L., Luo, X.G., 2012. The uptake of Cs and Sr from soil to radish (Raphanus sativus L.)-potential for phytoextraction and remediation of contaminated soils. Journal of Environmental Radioactivity110, 78–83.

[70] Wang, J., Wu, H., Wei, W., Xu, C., Tan, X., Wen, Y., Lin, A., 2022. Health risk assessment of heavy metal(loid)s in the farmland of megalopolis in China by using APCS-MLR and PMF receptor models: Taking Huairou District of Beijing as an example. Science of The Total Environment835, 155313.

[71] Wen, F.P., Wang, D., Xu, C.H., Xu, F.T., Zhang, Z.W., Zhang, X.X., 2009. Uptake and distribution of ¹³³Cs and ⁸⁸Sr in sunflower (Helianthus annuus L.). Bulletin of Botanical Research29, 592–596.

[72] White, P.J., Broadley, M.R., 2000. Tansley Review No. 113 Mechanisms of caesium uptake by plants. New Phytologist147, 241–256.

[73] Wu, H., Lin, A.Q., Xing, X.D., Song, D.X., Li, Y., 2021. Identifying core driving factors of urban land use change from global land cover products and POI data using the random forest method. International Journal of Applied Earth Observation and Geoinformation103, 102475.

[74] Wu, N., Zhang, J.W., Mao, H.R., Zhang, G.S., Zhao, Z.Q., 2024. Geochemical behavior of stable strontium isotopes during continental weathering process: a review. Geosystems and Geoenvironment3, 100144.

[75] Wu, W.H., Zheng, H.B., Xu, S.J., Yang, J.D., Liu, W., 2013. Trace element geochemistry of riverbed and suspended sediments in the upper Yangtze River. Journal of Geochemical Exploration124, 67–78.

[76] Xu, Z., Mi, W.B., Mi, N., Fan, X.G., Zhou, Y., Tian, Y., 2020. Characteristics and sources of heavy metal pollution in desert steppe soil related to transportation and industrial activities. Environmental Science and Pollution Research27, 38835–38848.

[77] Xue, J.L., Zhi, Y.Y., Yang, L.P., Shi, J.C., Zeng, L.Z., Wu, L.S., 2014. Positive matrix factorization as source apportionment of soil lead and cadmium around a battery plant (Changxing County, China). Environmental Science and Pollution Research21, 7698–7707.

[78] Yang, H.R., Huang, K., Zhang, K., Weng, Q., Zhang, H.C., Wang, F.E., 2021. Predicting heavy metal adsorption on soil with machine learning and mapping global distribution of soil adsorption capacities. Environmental Science & Technology55, 14316–14328.

[79] Yao, B.M., Chen, P., Zhang, H.M., Sun, G.X., 2021. A predictive model for arsenic accumulation in rice grains based on bioavailable arsenic and soil characteristics. Journal of Hazardous Materials412, 125131.

[80] Yao, B.M., Wang, S.Q., Xie, S.T., Li, G., Sun, G.X., 2022. Optimal soil Eh, pH for simultaneous decrease of bioavailable Cd, As in co-contaminated paddy soil under water management strategies. Science of the Total Environment806, 151342.

[81] You, Z.M., Li, Y.S., Meng, F.S., Zhang, R.X., Xie, C.X., Liang, Z.J., Zhou, J.Y., 2025. Interpretable machine learning approaches for predicting prostate cancer by using multiple heavy metal exposures based on the data from NHANES 2003–2018. Ecotoxicology and Environmental Safety302, 118730.

[82] Zeng, Y., Shen, C., Zhang, B.L., Ren, J., Huang, Z.B., Hou, H., 2026. Unraveling the threshold and interaction effects of environmental variables on cadmium contamination in rice grains. Journal of Environmental Sciences160, 450–460.

[83] Zhang, B.L., Hou, H., Huang, Z.B., Zhao, L., 2023. Estimation of heavy metal soil contamination distribution, hazard probability, and population at risk by machine learning prediction modeling in Guangxi, China. Environmental Pollution330, 121607.

[84] Zhang, S.Y., Zhang, J.J., Niu, L.L., Chen, Q., Zhou, Q., Xiao, N., Man, J., Ma, J.Q., Wei, C.L., Zhang, S.H., Luo, Y.M., Yao, Y.J., 2024. Escalating arsenic contamination throughout Chinese soils. Nature Sustainability7, 766–775.

[85] Zhang, Z.J., Ninomiya, K., Yamaguchi, Y., Kita, K., Tsuruta, H., Igarashi, Y., Shinohara, A., 2018. Atmospheric activity concentration of ⁹⁰Sr and ¹³⁷Cs after the Fukushima Daiichi nuclear accident. Environmental Science & Technology52, 9917–9925.

[86] Zhao, W.H., Ma, J., Liu, Q.Y., Dou, L., Qu, Y.J., Shi, H.D., Sun, Y., Chen, H.Y., Tian, Y.X., Wu, F.C., 2023. Accurate prediction of soil heavy metal pollution using an improved machine learning method: a case study in the Pearl River Delta, China. Environmental Science & Technology57, 17751–17761.

[87] Zheng, G.L., Pemberton, R., Li, P., 2017. Assessment of Cs and Sr accumulation in two epiphytic species of Tillandsia (Bromeliaceae) in vitro. Chemistry and Ecology33, 51–60.

[88] Zhu, J., Hao, Y., Chen, C., Wang, T., Chen, K., Zhang, L.L., Zhang, A.M., Xie, T., Zhang, Q.L., 2024. Transformation and environmental risk of ⁹⁰Sr and ¹³⁷Cs under extreme rainstorm at a proposed nuclear facility site in China. Journal of Environmental Radioactivity278, 107498.

[89] Zhu, Y.G., Williams, P.N., Meharg, A.A., 2008. Exposure to inorganic arsenic from rice: a global health issue?. Environmental Pollution154, 169–171.

RIGHTS & PERMISSIONS

Higher Education Press