Following nine years since the Fukushima Dai-ichi Nuclear Power Plant Acciden (FDNPPA), it might be the time to draw a much clearer conclusion for the impact of FDNPPA on marine biota. In this work, the evolution of the FDNPPA derived ¹³⁴Cs, ¹³⁷Cs and ¹¹⁰ᵐAg in the neon flying squids in the Northwest Pacific from 2011 to 2018 were studied. The background level of ¹³⁷Cs in neon flying squids (<0.10 Bq/kgfᵣₑₛₕ wₑᵢgₕₜ with the average of 0.017 Bq/kgfᵣₑₛₕ wₑᵢgₕₜ) before FDNPPA were estimated. The radioactive levels of ¹³⁴Cs, ¹³⁷Cs and ¹¹⁰ᵐAg in neon flying squids decreased with time. ¹³⁴Cs and ¹¹⁰ᵐAg decreased at the half-lives of 7.6 months and 5.7 months at the population level, respectively. After May 2014, ¹³⁴Cs and ¹¹⁰ᵐAg cannot be detected and ¹³⁷Cs activities returned to the background level before FDNPPA. BCFs of cesium isotopes (3.7–17.7 with the average of 10.8) and ¹¹⁰ᵐAg (∼7 × 10⁴) for neon flying squids were estimated. The amount of ¹¹⁰ᵐAg released into the Northwest Pacific (∼20-∼26 TBq) were firstly calculated using a ¹³⁴Cs/¹¹⁰ᵐAgₐcₜᵢᵥᵢₜy ᵣₐₜᵢₒ method. Radiation dose assessment demonstrated that it was far from causing radiation harm to neon flying squids in the open ocean of Northwest Pacific and humans who ingested these neon flying squids.

The 2011 spill at platforms B and C of the Penglai 19-3 oil field in the Bohai Sea has been the worst oil spill accident in China. To assess long-term effects, a comprehensive monitoring program of chemical and biological variables (within a 2.2 km radius of the spill site) was conducted five years after the spill. Comparison of nutrient, Chl-a and oil concentrations in seawater, TOC, PAHs, heavy metals concentrations within the sediments, and the abundance and biomass of macrobenthic organisms to values obtained before and after the oil spill in previous studies indicate habitat recovery has occurred within the Bohai Sea following the episodic oil release. Observed elevated oil concentration in the water column and higher concentrations of two heavy metals, five PAHs, TOC, TOC/TN and lower values of δ¹³C, together with a reduction in macrobenthic biomass in near-field samples, suggest the influence of contaminants from chronic releases of oil and operational waste discharges within the vicinity of the oil platforms.

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, radionuclides released by this event were observed in the Pacific Ocean. Models predicted that these radionuclides would be transported to the Bering Sea; however, limited evidence currently reveals the transportation of these radionuclides to the Arctic Ocean. Here, we provide the first direct observation showing that FDNPP-derived 134Cs and 137Cs were present in subarctic regions and the Arctic Ocean (Chukchi Sea) in 2017. Furthermore, we conclude that these radionuclides were transported from the Pacific Ocean into the Bering and Chukchi Seas by ocean currents. Additionally, the 137Cs activity concentrations in the Bering Sea exceed those in all previous reports. Due to the continuous leaking of radionuclides from the FDNPP, we hypothesize that FDNPP-derived radionuclides will be continuously transported to the Arctic Ocean in the next several years. Our results suggest that though far away from Fukushima, the accident-derived anthropogenic radionuclides also influenced the Arctic Ocean by ocean currents.

Human factors/errors (such as inappropriate actions by operators and unsafe supervision by organizations) are a primary cause of oil spill incidents. To investigate the influences of active operational failures and unsafe latent factors in offshore oil spill accidents, an integrated human factor analysis and decision support process has been developed. The system is comprised of a Human Factors Analysis and Classification System (HFACS) framework to qualitatively evaluate the influence of various factors and errors associated with the multiple operational stages considered for oil spill preparedness and response (e.g., oil spill occurrence, spill monitoring, decision making/contingency planning, and spill response); coupled with quantitative data analysis by Fuzzy Set Theory and the Technique for Order Preference by Similarity to Ideal Solution (Fuzzy-TOPSIS) to enhance decision making during response operations. The efficiency of the integrated human factor analysis and decision support system is tested with data from a case study to generate a comprehensive priority rank, a robust sensitivity analysis, and other theoretical/practical insights. The proposed approach improves our knowledge on the significance of human factors/errors on oil spill accidents and response operations; and provides an improved support tool for decision making.

Dangerous goods are particularly hazardous, as they can be flammable, explosive, and toxic. These characteristics make them vulnerable to accidents, and such mishaps during port operations can lead to massive economic losses and even deaths. It is, therefore, necessary and important to analyze and study the dangerous goods accidents at ports, so as to identify major factors and prevent them. Formal concept analysis (FCA) is a powerful tool for rule extraction. This paper introduces FCA along with relevant documents and case studies to analyze the dangerous goods accidents at China’s ports, building a concept lattice model of dangerous goods accidents at China’s ports, and reduces the condition attributes to come up with three key attributes of dangerous goods accidents at China’s ports: warehousing management, facilities and equipment, goods registration and extract four effective diagnostic rules for dangerous goods accidents at ports. This paper proposes corresponding governance strategies to the rules of dangerous goods accidents, which can significantly prevent and manage dangerous goods accidents at China’s ports in the future. In the future, the concept scale can be introduced to study the problem that the influencing factor is multi-valued attribute so as to expand the scope of research.

Wildfires may play a role in redistributing radionuclides in the environment in combination with hydrological processes such as surface runoff and soil erosion. We investigated plot-scale radionuclide wash-off at forest sites affected by wildfires in the Chernobyl Exclusion Zone (CEZ). We also compared speciation of the washed-off radionuclides with those in previous studies conducted just after the accident in 1986. We observed the surface runoff and the radionuclide wash-off with a soil erosion plot at forest and post-fire sites during May–September 2018. In the post-fire site, 2.81 mm of surface runoff was observed in at least three flow events resulting from 285.8 mm total rainfall. The fluxes of dissolved and particulate ¹³⁷Cs were estimated as 4.9 and 161 Bq m⁻², respectively. The dissolved phase ⁹⁰Sr flux was estimated as 214 Bq m⁻². At the forest site, a single surface runoff (0.67 mm) event was generated by rainfall of 182.2 mm. The fluxes of dissolved and particulate ¹³⁷Cs wash-off values were 6.2 and 8.6 Bq m⁻², respectively. The flux of dissolved ⁹⁰Sr wash-off from the forest was estimated as 45.1 Bq m⁻². The distribution coefficient, which indicates the dissolved-particulate form of radionuclides, in the post-fire site was 30 times higher than that in the forest site, indicating the importance of particulate ¹³⁷Cs wash-off after fire in the CEZ. The entrainment coefficients for dissolved and particulate ¹³⁷Cs concentrations were around 50 times lower than those obtained in the corresponding position within the CEZ immediately after the accident in 1987. The effect of downward migration of ¹³⁷Cs over 30 years led to decreased entrainment coefficients for dissolved and particulate ¹³⁷Cs. The effect of downward migration of radionuclides was considered sufficient to indicate changes in normalized liquid and solid radionuclides wash-off entrainment coefficient and the distribution coefficient in this study.

The specific activities of natural (²¹⁰Pb, ²²⁶Ra, and ²³²Th) and artificial (¹³⁷Cs, ²³⁹,²⁴⁰Pu, and ²⁴¹Am) radionuclides in the sediments of two North Caucasus lakes were determined. The two lakes, Lake Khuko and Lake Donguz-Orun, differ in their sedimentation conditions. Based on the use of unsupported ²¹⁰Pbₑₓ and both Chernobyl-derived and bomb-derived ¹³⁷Cs as chronological markers, it was established that the sedimentation rates in Lake Khuko over the past 55–60 y did not exceed 0.017 cm y⁻¹. Sedimentation rates in Lake Donguz-Orun were found to be more than an order of magnitude higher. In the latter case, the sedimentation rates for the period from 1986 to the present were over 1.5 times higher than they were for the period 1963–1986. The differences in sedimentation rates were due to differences in the rates of denudation of their respective catchment areas. The specific activities of artificial radionuclides (¹³⁷Cs, 2600 Bq kg⁻¹; ²³⁹,²⁴⁰Pu, 162 Bq kg⁻¹; and ²⁴¹Am, 36 Bq kg⁻¹) and their ratios in the sediments of Lake Khuko show that their deposition was mainly due to global stratospheric fallout of technogenic radionuclides associated with nuclear bomb testing during 1954–1963—rather than fallout from the Chernobyl accident. Several factors, including the mode of precipitation, features of the surface runoff, and location of Lake Khuko, were responsible for the accumulation of artificial radionuclides.

Trace elements can be toxic when they cannot be easily removed after entering an ecosystem, so a long-term assessment is fundamental to guide ecosystem restoration after catastrophic pollution. In 1998, a pyrite mining accident in Aznalcóllar (south-western Spain) spilled toxic waste over a large area of the Guadiamar river basin, where, after restoration tasks, the Guadiamar Green Corridor was established. Eight years after the mine accident (2005–2006), the ground-dwelling insectivorous lizard Psammodromus algirus registered high trace-element levels within the study area compared to specimens from a nearby unpolluted control site. In 2017, 20 years after the accident, we repeated the sampling for this lizard species and also quantified trace elements in vegetation as well as in arthropod samples in order to identify remnant trace-element accumulation with the aim of assessing the transfer of these elements through the trophic web. We found remnant trace-element contamination in organisms of the polluted site compared to those from the unpolluted site. All trace-element concentrations were higher in arthropods than in plants, suggesting these compounds bioaccumulate through the trophic web. Lizards from the polluted areas had higher As, Cd, and Hg concentrations than did individuals from the unpolluted area. Lizard abundance between sampling periods (2005–06 and 2017) did not vary in unpolluted transects but strongly declined at polluted ones. By contrast, the Normalized Difference Vegetation Index indicated that in the study period, the vegetation was similar at the two sampling sites. These results suggest that, 20 years after the accident, the trace-element pollution could be the cause of a severe demographic decline of the lizard in the polluted area.

Shortly after an atmospheric release, the interception of radionuclides by crop canopies represents the main uptake pathway leading to food chain contamination. The food chain models currently used in European emergency decision support systems require a large number of input parameters, which inevitably leads to high model complexity. In this study, we have established a new relationship for wet deposited radionuclides to simplify the current modelling approaches. This relationship is based on the hypothesis that the stage of plant development is the key factor governing the interception of radionuclides by crops having horizontally oriented leaves (planophile crops). The interception fraction (f) and the leaf area index normalized (fLAI) and mass normalized (fB) interception fractions were assessed for spinach (Spinacia oleracea) and radish (Raphanus sativus) at different stages of plant development and for different contamination treatments and plant densities. A database of 191 f values for Cs-137 and Th-229 was built and complemented with existing literature covering various radionuclides and crops with similar canopy structure. The overall f increased with the plant growth, while the reverse was observed for fB. The fLAI significantly decreased by doubling the contaminated rainfall deposited. Fitting a multiple linear regression to predict the f value as a function of the standing biomass (B), and the radionuclide form (anion and cation) led to a better estimation of the interception (R² = 81%) than the ECOSYS-87 model (R² = 35%). Hence, the simplified modelling approach here proposed seems to be a suitable risk assessment tool as fewer parameters will minimize the model complexity and facilitate the decision-making procedures in case of emergencies, when countermeasures need to be identified and implemented promptly.

Activity concentrations of the radioactive cesium (¹³⁴Cs and ¹³⁷Cs) were investigated in invertebrates at two sites of moderately high and higher air radiation dose rates, 14 km and 11 km distances, respectively, from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) from 2013 to 2016. At a14-km point, the ¹³⁴⁺¹³⁷Cs concentrations of soils in coniferous and broadleaf forests increased from 2013 to 2014, and thereafter declined until 2016. The ¹³⁴⁺¹³⁷Cs concentrations of the phytophagous beetle Anomala cuprea (Hope) rapidly decreased by 76.1% from 2013 to 2014, reflecting reduction in those of broadleaves. The ¹³⁴⁺¹³⁷Cs concentration levels of the carnivorous beetle Dolichus halensis (Schaller) showed a relatively low levels. The ¹³⁷Cs concentrations of the necrophagous beetle Eusilpha japonica (Motshulsky) and coprophagous beetle Onthophagus lenzii (Harold) remained constant without reduction from 2013 to 2016. Average ¹³⁴⁺¹³⁷Cs concentrations throughout four years were the highest in the geophagous crustacean (Armadillidium vulgare Latreille), followed by necrophagous beetle and coprophagus beetle. The ¹³⁴⁺¹³⁷Cs concentrations in earthworms with gut contents were significantly correlated with those in soils at each habitat from 2014 to 2015 at a14-km point, and the concentration levels at an 11-km point in 2015 were remarkably high (898 kBq kg⁻¹). Transfer factors (TFs) in earthworms ranged from 1.02 to 2.66 at a 14-km point and 0.66 to 5.0 at an11-km point. The transfer and chronological changes of radiocesium in invertebrates were discussed in relation to food habits through trophic levels in woodlands and pasturelands.