Human Risk Research Articles

Can Rights be Enough?

The climate crisis is beset by depoliticization. Couched as an issue that experts must solve through technological or technocratic knowledge, discussion about how to address environmental degradation is not amenable to democratic action or dissensus. This paper argues that approaching climate change through a human rights framework risks reinscribing such depoliticization and that this is politically hazardous. Human rights discourse can impede the demos’ exercise of power, obscure exercises of hegemony, and, via a fixed notion of progress, discourage normative contestation. This discourse’s depoliticizing potential is further attested to by the debate over human rights’ relationship to the depoliticizing ideology of neoliberalism. Moreover, beyond the language of human rights, the larger legal phenomena of judicialization and juridification may further contribute to depoliticization. Depoliticization is risky because it can provoke politicizing backlashes likely to issue, in the case of climate change, in antidemocratically nationalistic and authoritarian responses to the environmental emergency.

New thiazolidin-4-ones as anti-cervical cancer agents targeting EGFR: design, synthesis, and computational studies.

A new series of 3,4-dihydronaphthalen-1(2 h)-ylidene)hydrazineylidene)-5-substituted thiazolidin-4-one derivatives were designed and synthesized. The new compounds were screened for in vitro antitumor activity against Hela cancer cell line. The compounds 7b, 7 h, and 7i produced more potent cytotoxicity than doxorubicin with IC50 values of 1.83 ± 0.1, 2.54 ± 0.14, 2.75 ± 0.15, and 3.63 ± 0.2 μM, respectively. They also showed a promising safety profile against WI-38 normal cells. In addition, compound 7b produced a promising multi-kinase inhibition against EGFR (WT) while being very selective toward the mutant forms (L858R and T790M) with IC50 values of 0.099 ± 0.006, 0.064 ± 0.006, and 0.026 ± 0.007 μM, respectively, in comparison to gefitinib and osimertinib. A study of the cell cycle in Hela cells showed that 7b arrests cell cycle in the pre-G1 phase and causes early and late apoptosis. Eventually, the molecular docking results showed that 7b had good-binding interactions with EGFRWT, EGFRL858R, and EGFRT790M. Compound 7b was predicted to have promising oral absorption, good drug-likeness, and low toxicity risks in humans. Moreover, MD simulations confirmed the stable complexes of 7b with EGFRWT, EGFRL858R, and EGFRT790M (with RMSD 0.12-0.35 nm, RMSF 0.2-0.55 nm, SASA 140-150, and Rg 1.80-2.00 nm).

Individual variation underlies large-scale patterns: Host conditions and behavior affect parasitism.

Identifying the factors that affect host-parasite interactions is essential for understanding the ecology and dynamics of vector-borne diseases and may be an important component of predicting human disease risk. Characteristics of hosts themselves (e.g., body condition, host behavior, immune defenses) may affect the likelihood of parasitism. However, despite highly variable rates of parasitism and infection in wild populations, identifying widespread links between individual characteristics and heterogeneity in parasite acquisition has proven challenging because many zoonoses exist over wide geographic extents and exhibit both spatial and temporal heterogeneity in prevalence and individual and population-level effects. Using seven years of data collected by the National Ecological Observatory Network (NEON), we examined relationships among individual host condition, behavior, and parasitism by Ixodid ticks in a keystone host species, the white-footed mouse, Peromyscus leucopus. We found that individual condition, specifically sex, body mass, and reproductive condition, had both direct and indirect effects on parasitism by ticks, but the nature of these effects differed for parasitism by larval versus nymphal ticks. We also found that condition differences influenced rodent behavior, and behavior directly affected the rates of parasitism, with individual mice that moved farther being more likely to carry ticks. This study illustrates how individual-level data can be examined using large-scale datasets to draw inference and uncover broad patterns in host-parasite encounters at unprecedented spatial scales. Our results suggest that intraspecific variation in the movement ecology of hosts may affect host-parasite encounter rates and, ultimately, alter zoonotic disease risk through anthropogenic modifications and natural environmental conditions that alter host space use.

Enrichment Characteristics, Risk Evaluation, and Source Apportionment of Heavy Metals in Wabu Lake of Yangtze River to Huaihe River Water Diversion Project

Wabu Lake serves as a crucial junction within the Yangtze River to Huai River Water Diversion Project （Yangtze-Chao Lake-Wabu Lake-Huai River）, where clarifying the status and risk levels of heavy metal contamination in the lake is crucial for the aquatic ecological safety along the route of the project. Surface water and sediment samples from 24 locations in Wabu Lake were collected and analyzed for the contents of heavy metals （As, Zn, Pb, Ni, Cu, Cr, Fe, and Cd）. Risk evaluation and source apportionment of heavy metals in the lake were conducted using the human risk assessment （HRA） model, sediment quality guidelines （SQGs）, and positive matrix factorization （PMF） method. The results showed that the average concentrations of heavy metals （except for Cd and Pb） in the surface water were lower than the class III limits of the surface water quality standard （GB 3838-2002）. The average concentration of heavy metals （As, Zn, Pb, Ni, Cu, Cr, Fe, and Cd） in interstitial water were lower than the Criteria Continuous Concentration （CCC） of the National Recommended Water Quality Criteria. The average contents of As, Zn, Pb, Ni, Cu, Cr, and Cd in the sediment exceeded the background values by factors of 1.78, 1.85, 1.42, 1.77, 1.41, 1.38, and 3.46, respectively. In addition, the heavy metals Pb, Cd, and Cr in the Wabu Lake water posed severe risks to human health, with the cancer risk （CR） value for Cr reaching 6.14×10-5. The sediment quality guidelines （SQGs） indicated that the probability of adverse effects on lakes by As, Ni, and Cr was relatively high. The spatial distribution of risk areas showed that the risk control zones for As, Cr, and Ni in Wabu Lake covered almost the entire lake area. The PMF analysis indicated that the primary sources of heavy metals in Wabu Lake were exogenous inputs from industrial, agricultural, and residential activities in surrounding areas, followed by endogenous pollution caused by enclosed aquaculture. The subsequent focus should be on the pollution of heavy metals Cr, Cd, and Pb in the overlying water of Wabu Lake as well as the sediment ecological safety of As, Cr, and Ni in the sediment.

The Evolution of Microplastics Research: Global Trends and Agricultural Implications

ABSTRACTMicroplastics (MPs) are a growing concern due to their impact on ecosystems and human health. To identify the layout of the global research landscape, emerging topics, and future directions of MP research, particularly in the agricultural context, this study analyzed 16,134 publications from the period 2014 to 2023. The findings revealed a significant increase in MP publications, with China and India emerging as main contributors. Domestic citations, especially in emerging topics, have increased, potentially indicating reducing international information exchange. Seventy‐six topics were identified, with marine environments appearing in 39.8% of publications, while terrestrial (12.5%) and agricultural ecosystems (3.1%) showed substantial growth. At the same time, research on the effects of MP pollution is changing focus from aquatic life, such as fish (24.9%), to topics in the agricultural context, such as MP effects on soil microbes (3.5%) and terrestrial plants (6%). In the agricultural context, six main topics were identified: agricultural plastics, biosolids, pollutant interactions, microbial interactions, environmental risks, and human risks. The findings provide a comprehensive overview of the current research environment. Future research should prioritize understanding critical questions about MP sources, climate change effects, contaminant interactions, and impacts on microorganisms and human health. While exploring the long‐term impacts of MPs on agricultural ecosystems, international collaboration and information exchange should be emphasized to address regional research gaps. While these results reflect the dominant trends in the field, further research incorporating a broader set of countries and language sources could provide a more nuanced global perspective.

Repeated intratracheal instillation effects of commonly used vehicles in toxicity studies with mice

Intratracheal instillation (ITI) is considered the most pragmatic approach for investigating the potential toxicities of various respiratory exposure materials. Various respiratory exposure materials, including nanomaterials, hazardous air pollutants, fine dust, and household biocides, have raised public health concerns because of limited toxicological information and increasing consumption. Hence, toxicity studies using ITI in laboratory animals are important to accurately assess the human risks associated with these respiratory-exposed materials. However, data to adequately support the study design of ITI toxicity studies, particularly those examining the effects of commonly used vehicles following repeated exposure are insufficient. Therefore, in this study, we examined the effects of 16 types of commonly used vehicles in toxicity studies following 14-day repeated ITI in mice. General health endpoints (mortality, clinical signs, and body weight) were monitored throughout the study period, and terminal endpoints (gross observation, lung weight, bronchoalveolar lavage fluid analysis, and lung histopathological examination) were assessed after terminal sacrifice. Saline and phosphate-buffered saline elicited the least response, whereas corn oil (50 µL) showed the most severe toxicity findings. In addition, several commonly used vehicles, including distilled water, sodium carboxymethyl cellulose, dimethyl sulfoxide, ethanol, Tween 20, and Tween 80, induced mild-to-severe toxicity in the respiratory system. Based on the results of this study, some commonly used vehicles in toxicity studies should be used with caution when the ITI exposure route is considered. These results provide important background information on the effects of vehicles in ITI toxicity studies along with valuable insights for designing toxicity studies using respiratory exposure materials.

Exploring landscape ecological risk with human activity intensity and correlation in the Kuye River Basin

IntroductionThe Kuye River Basin, a typical erosion area of the Loess Plateau region with the second largest tributary of the Yellow River Basin, faces significant environmental challenges and intense human activities. Balancing environmental sustainability and economic development in this region is urgent.MethodsTherefore, this study takes this basin as the object and evaluates the landscape ecological risk and human activity intensity from 2000 to 2022 based on land use/land cover, population distribution and nighttime lighting data. And a geographically weighted regression model was used to reveal the correlation between the two.Results and discussionResults showed that the average landscape ecological risk index in 2000, 2015, and 2022 were 9.01×10-4, 5.61×10-4, and 7.40×10-4, respectively. This shows that the overall landscape ecological risk index is low in the first 15 years and then gradually increases over time. Cultivated land, grassland and construction land are the main landscapes, the expansion of 7.95 times construction land is a key factor in the intensification of human activities, mainly concentrated in the northwest, followed by a gradual expansion towards the south-east, and likewise the landscape ecological risks follow the same trend. Medium to high intensity human activities exacerbate landscape ecological risks, with a significant positive correlation, while low intensity human activities cause little damage to landscape ecology. To achieve sustainability, it is necessary to effectively control construction land and improve land use structure. Then, in the planning work, priority will be given to the northwest region with high human activity intensity and high landscape ecological risks, and the governance direction will gradually shift to the southeast region. These findings provide empirical evidence to support decision-making and underscore the need for comprehensive strategies to mitigate landscape ecological risks and promote sustainable development in the Kuye River Basin.

Using structural equation modeling and intima-media complex texture features to assess cardiovascular disease risk in the common carotid artery

The potential for stroke risk in humans due to clinical cardiovascular disease (CVD), which leads to the hardening of the artery walls (atherosclerosis), can be assessed by examining the common carotid artery (CCA) in ultrasound images. Specifically, this can be done by measuring the intima media thickness (IMT), which represents the thickness of the arteries wall, and by analyzing texture features (TFs) of the CCA's intima-media complex (IMC) of the artery wall. In this paper, a sample of 612 longitudinal-section ultrasound images of the left and the right CCA from 158 men and 148 women, out of which 42 demonstrated clinical CVD, is studied. All images are intensity normalized and despeckled, with the IMC segmented through an in-house system of semi-automated segmentation, where the IMT is measured, and 40 different TFs are extracted. Then, employing structural equation modeling (SEM), these TFs, which are put in 6 groups (constructs), are collectively tested on how they are related to CVD. The influence of the IMT is also studied through a moderation analysis, while gender and age of the sub-jects of the study are tested with regard to their control effect. The main conclusions of the study are as follows. The 6 TFs groups and the IMT fit the measurement model very well. Also, 6 hypothesized paths for the impact of each TFs group on CVD are tested in a structural model, with 5 of them, namely Statistical Features (SF), Spatial Gray Level Dependence Matrices (SGLDM), Gray Level Difference Statistics (GLDS), Statistical Feature Matrix (SFM) and Laws Texture Energy Measures (LTEM), impacting CVD in a moderate manner (p-values between .04 and .07). The IMT is shown to play a strong moderating role (p-values of Δχ2 < .01), enhancing the level of impact of the TFs on CVD. Gender and age have a strong controlling effect on CVD (p-values of < .01). The precision of the findings of this study is considerably improved compared to those previously reported, because of the very good model fit (e.g., normed fit index (NFI) = 0.94) for both measurement and structural models. However, due to the moderate nature of the impact, supplementary work is required for testing either additional combinations of TFs, as well as testing other samples through the proposed model, for further evaluation of the CVD risk on symptomatic subjects at risk of atherosclerosis.

Iodine transfer to dairy cow's milk: a revised biokinetic model

A new biokinetic model for iodine in dairy cows was developed utilizing data from a 4×4 factorial feeding experiment with rumen-cannulated cows that were fed rapeseed cake containing substances known to influence iodine metabolism, and soybean meal without such effects. 131I was administered both intravenously and intra-ruminally to document metabolism pathways.The new model included compartments such as saliva and thyroid gland, often ignored in other models, and in contrast to previously available biokinetic models, it fitted well to our experimental data. Compared to cows fed soybean meal diet, rapeseed cake diet resulted in lower retention of 131I in body compartments, reduced 131I transfer to milk, and increased urinary excretion of 131I. Over time, low retention of iodine from diets containing goitrogenic substances like rapeseed would increase the risk of iodine deficiency, in both cattle and humans. Based on sensitivity analysis, milk, blood and liver pathways contributed the most to the model uncertainty.The proposed model should be relevant in elucidating mechanisms governing iodine uptake and metabolism in dairy cows, to predict how feeding can be used to optimize iodine concentrations in milk, and to reduce transfer of radioiodine through dairy products in case of fallout from nuclear events.

A physiologically based toxicokinetic model for microplastics and nanoplastics in mice after oral exposure and its implications for human dietary exposure assessment

Evidence of microplastics (MPs) and nanoplastics (NPs) in foods and daily-use products, along with their frequent detection in the human body, has raised concerns regarding their potential impact on human health through dietary ingestion. However, there is a lack of quantitative tools to simulate their bioaccumulation and tissue distribution following environmental exposure. To address this gap, we developed the first physiologically based toxicokinetic (PBTK) model for predicting the biodistribution of MPs and NPs in mice following oral exposure under various exposure scenarios. This novel model incorporated key kinetic mass transport processes, such as membrane permeability, albumin binding, and cellular uptake. We identified that the absorption rate in the gastrointestinal tract and fecal excretion rate constant had significant impacts on organ dosimetry. Our regression analysis indicated that the size-dependent dissociation constant and urine clearance rate constant sharply increased by a factor of 3 as NPs particle size increased to 1µm. Finally, we developed a graphical user interface to enable interactive visualization and analysis for future applications, supporting human dietary exposure and risk assessment using available food consumption data and MPs/NPs residue data. The simulation results offer a mechanistic perspective, enhancing understanding of the internal organ dosimetry burden and health impacts from dietary exposure to MPs and NPs.

Phthalate esters in dusts from different indoor and outdoor microenvironment and potential human health risk: A case study in Beijing

Phthalate esters (PAEs) are widely used plasticizers that can easily migrate from plastic products, thereby presenting potential health risks through exposure. While PAE concentrations in dust have received increasing attention, there is still a lack of comprehensive understanding regarding their environmental distribution, composition profiles, and associated human exposure risks in Beijing. This study investigated the presence of seven PAEs in 124 dust samples collected from eight indoor and four outdoor microenvironment types across the Beijing metropolitan area. The PAEs were detected universally in all samples, with di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and di-iso-butyl phthalate (DIBP) as the predominant compounds, accounting for 91.78%-99.91% and 91.22%-99.76% of total PAE concentrations (Σ7PAEs) in indoor and outdoor dust, respectively. Indoor dust exhibited significantly higher Σ7PAEs (range: 45.33-1212.41 μg/g, mean: 130.61 μg/g) compared to outdoor dust (range: 2.10-5.41 μg/g, mean: 3.38 μg/g). Among indoor microenvironments, taxis had the highest Σ7PAEs (mean: 1250.59 μg/g), followed by private cars, print shops, residences, furniture shops, shopping malls, dormitories and offices. Outdoor Σ7PAEs levels decreased in the order of roads, residential areas, green belts, and parks. Estimated daily exposure doses through dust ingestion were significantly higher than those from dermal absorption and inhalation for five occupational groups (taxi drivers, print shop workers, road workers, office workers, jobless people), indicating dust ingestion as the primary exposure route, with DEHP and DBP as the main contributors. While current exposure levels may not present significant non-cancer risks based on hazard quotient and hazard index estimations, it’s noteworthy that DEHP may pose a carcinogenic risk to taxi drivers. Potential risks cannot be overlooked considering the absence of toxicity thresholds, additional exposure pathways, and possible cocktail effects from coexisting pollutants.

Key active mercury methylating microorganisms and their synergistic effects on methylmercury production in paddy soils

Rice contamination with neurotoxic methylmercury (MeHg) from paddy soils is an escalating global concern. Identifying the microorganisms responsible for mercury (Hg) methylation in these soils is essential for controlling Hg contamination in the food chain and mitigating health impacts. Current research often focuses on total Hg-methylating microorganisms, overlooking the contributions of active ones, which can lead to either overestimating or neglecting the specific roles of microorganisms in Hg methylation within paddy soils. In this study, active Hg-methylating microorganisms in paddy soils were identified using a combination of DNA-SIP, Hg isotope labelling, and Hg methylation gene sequencing techniques. Our findings revealed that Geobacter and Anaerolinea are pivotal active Hg-methylating microorganisms across a contamination gradient in paddy soils. Transcriptomic analysis of soils from major rice-producing provinces in China confirmed the widespread and synergistic involvement of these microorganisms. Microbial incubation further validated their interaction significantly enhances Hg methylation, with Me198Hg concentrations increasing 2.8-fold compared to Geobacter alone and 5.2-fold compared to Anaerolinea alone. These findings enhance our understanding of microbial Hg methylation in paddy soils, providing critical insights for accurately predicting soil MeHg load, rice grain MeHg contamination, and human MeHg exposure risks.

Update of a database of toxicological effects of pesticides in view of performing cumulative risk assessments. Part 1: Catalogue of toxicity endpoints and data model for the collection of toxicity endpoints.

Abstract A catalogue of toxicity endpoints was developed for a consistent collection of toxicological information. The toxicity endpoints of relevance for cumulative risk assessment were organised in a table for each target organ/tissue/system (cumulative assessment group (CAG) at level 1) including information on specific toxicological effect(s) (CAG at level 2), indicators that reflect the relevance for the CAG at level 2, and descriptions/interpretations that allow an understanding of the CAG at level 2. A data model for the collection of toxicity endpoints was developed to ensure the possibility of integration of the collected data to the EFSA OpenFoodTox database, in order to extend it to non‐critical endpoints. The collection of toxicity endpoints and grouping of active substances were performed for a total of 328 active substances and 165 of their metabolites. The data model was filled in for all the OpenFoodTox columns as far as possible and essential information which could not be entered in the OpenFoodTox columns were noted in the ‘Remark column’. In total, 29 CAGs at level 1 have been evaluated for inclusion of specific toxicological effects (CAGs at level 2), whereas four CAG1 targets (gastrointestinal tract, immune system, lungs and skin) were not evaluated as the effects observed in these CAG1 targets were not considered relevant for CAGs at level 2. A number of toxicological effects considered adverse and of relevance for human risk assessment, but generally not relevant for CAGs at level 2, include mortality, clinical signs of toxicity, changes in bodyweight and body weight gain, changes in food consumption and water consumption, changes in clinical biochemistry and urinalysis parameters and changes in organ weights without histopathological changes. © National Food Institute, Technical University of Denmark, 2024

The effect of altered sleep timing on glycaemic outcomes: Systematic review of human intervention studies.

Alterations in sleep timing can lead to disturbances in glycaemic control, although the evidence is inconsistent. Therefore, this systematic review summarizes results from human intervention studies of altered sleep timing on glycaemic outcomes. As part of a broader search on the effect of altering timing of sleep, physical activity and dietary intake, Medline and Embase were searched from inception to February 2023, and subsequent reference searches were done. With the help of a machine learning-aided program 'ASReview', we selected any type of intervention study in the general adult population, which acutely delayed sleep by ≥2 h for at least one night, while the total time in bed was the same between early and late sleep. Quality assessment was done using the quality assessment tool for quantitative studies. In total, 14 studies (159 adults with normal or increased weight) were identified. Methodological quality was high (n = 4), moderate (n = 7) or low (n = 3). Acute delays of sleep onset showed unfavourable effects in 10 out of 27 measured glycaemic outcomes (one-six studies reported on each outcome) with outcomes mostly measured in the postprandial period, compared to (early) nighttime sleep. Acutely delaying sleep timing might have unfavourable effects on glycaemic outcomes, compared to (early) nighttime sleep. Future research does however need better controlled trials, also measuring and controlling sleep quantity, sleep quality, physical activity and dietary intake, with longer follow-up periods, consistent outcomes and designs and more diverse populations to provide targeted advice regarding the optimal timing for sleep. This review is part of a larger search 'The effect of altering timing of physical activity, sleep and energy intake on glycaemia and Type 2 Diabetes risk in humans', of which the protocol was registered in the PROSPERO database on 27 November 2021 under number: CRD42021287828.

First evidence of microplastic ingestion by the European grayling, Thymallus thymallus, in sub-Arctic regions: Insights on plastic pollution and preliminary risk assessment in the Teno River (Finland)

Marine litter pollution affects even remote environments such as the Arctic regions and their biodiversity. However, due to the inaccessibility and difficulty of regular observations in these environments, further studies are needed to fill the knowledge gaps. In this regard, the present investigation provides new insights on microplastic contamination levels in Arctic riverfish by analyzing, for the first time, plastic ingestion by the European grayling Thymallus thymallus from the Teno River (northern Finland), an important fishery resource and vulnerable species; and performing a preliminary ecological risk assessment of microplastics in the Finnish river using the European grayling. Plastic abundance and characterization were explored, and microplastic concentrations and polymer hazardous were also used to assess human and environmental risk. The higher frequency of occurrence (%O = 50) observed in the riverfish and the characterization of the extracted plastic confirm that riverine environment is one of the main pathways for microplastic pollution in Arctic regions and suggest the influence of the surrounding environment and human activities, mainly recreational fishing. Finally, the preliminary risk assessment highlights an ecological threat to the Teno River. This research represents a first step for the study of a commercially important Arctic freshwater species as well as in remote Arctic rivers and support identification of priorities, the application of management strategies and further environmental and human-health risk assessments according to the recommendation of Arctic Monitoring Plan and Monitoring Guidelines.

Review on Semi-Autonomous Robots for Satellite Maintenance and Refueling

As the number of satellites in Earth's orbit continues to grow, the need for efficient satellite servicing solutions becomes increasingly pressing. Currently, about 9,900 satellites are in orbit, with over 3,300 of these being inactive, posing a threat as space debris. Traditional methods for satellite maintenance and refueling are complex, expensive, and risky. The development of semi-autonomous robots, powered by advancements in artificial intelligence and robotics, presents a more efficient alternative. These robots can perform complex maintenance and refueling tasks with minimal human intervention, reducing costs and risks associated with satellite servicing. This paper investigates the design, technological advancements, and operational strategies behind these robots, and how they can mitigate space debris while enhancing the sustainability of satellite operations. Key Words: Maintenance, Satellites, Refuelling, Robots.

Addressing the Human Rights Risks of Financing the Arms Industry: Insights from Banks’ Corporate Policies

Abstract This article examines recent measures undertaken by major commercial banks to mitigate and address human rights risks associated with their financial dealings in the arms industry. By reviewing the corporate policies of 20 leading banks that provide financing to top arms manufacturing and exporting companies, the article provides insights into three significant aspects of banks’ efforts: the development of defence sector policies, the implementation of risk assessments for adverse human rights impacts, and the application of exclusion clauses. These measures highlight the increasing recognition by banks of the need to address the ethical, social and human rights implications of financing arms deals, contributing to the broader regulatory and normative framework governing the arms industry.

Impact of Geographic Location on Risks of Fintech as a Representative of Financial Institutions

The activities of contemporary financial institutions require significant geographic expansion. Even the increased level of industry digitalisation does not minimise the importance of the physical assets of financial institutions. The environmental factors specific to each geographic region can significantly influence the efficiency of operations of financial institutions. The goal of the article is to determine the impact of the geographic location of physical assets via environmental risks affecting the other risks of fintech as a representative of financial institutions. The impact is determined by the employment of the PLS-SEM model implemented in SmartPLS 4.0 software. The model determines the impact of environmental risks on governance risks, operational risks, human resources and safety risks, ICT risks, compliance risks, and strategic risks. These groups of risks form the latent variables, which comprise the experts’ estimation of threats and vulnerabilities impacts and their likelihoods. After testing five hypotheses, two of them were supported—environmental risks impact human resources safety risks and operational risks.

Machine Learning a Probabilistic Structural Equation Model to Explain the Impact of Climate Risk Perceptions on Policy Support

While a flurry of studies and Integrated Assessment Models (IAMs) have independently investigated the impacts of switching mitigation policies in response to different climate scenarios, little is understood about the feedback effect of how human risk perceptions of climate change could contribute to switching climate mitigation policies. This study presents a novel machine learning approach, utilizing a probabilistic structural equation model (PSEM), for understanding complex interactions among climate risk perceptions, beliefs about climate science, political ideology, demographic factors, and their combined effects on support for mitigation policies. We use machine learning-based PSEM to identify the latent variables and quantify their complex interaction effects on support for climate policy. As opposed to a priori clustering of manifest variables into latent variables that is implemented in traditional SEMs, the novel PSEM presented in this study uses unsupervised algorithms to identify data-driven clustering of manifest variables into latent variables. Further, information theoretic metrics are used to estimate both the structural relationships among latent variables and the optimal number of classes within each latent variable. The PSEM yields an R2 of 92.2% derived from the “Climate Change in the American Mind” dataset (2008–2018 [N = 22,416]), which is a substantial improvement over a traditional regression analysis-based study applied to the CCAM dataset that identified five manifest variables to account for 51% of the variance in policy support. The PSEM uncovers a previously unidentified class of “lukewarm supporters” (~59% of the US population), different from strong supporters (27%) and opposers (13%). These lukewarm supporters represent a wide swath of the US population, but their support may be capricious and sensitive to the details of the policy and how it is implemented. Individual survey items clustered into latent variables reveal that the public does not respond to “climate risk perceptions” as a single construct in their minds. Instead, PSEM path analysis supports dual processing theory: analytical and affective (emotional) risk perceptions are identified as separate, unique factors, which, along with climate beliefs, political ideology, and race, explain much of the variability in the American public’s support for climate policy. The machine learning approach demonstrates that complex interaction effects of belief states combined with analytical and affective risk perceptions; as well as political ideology, party, and race, will need to be considered for informing the design of feedback loops in IAMs that endogenously feedback the impacts of global climate change on the evolution of climate mitigation policies.

Spatial and Temporal Dynamics of Chemical and Microbial Contamination in Nonurban Floodwaters.

During major flood events, waterborne contaminants are relatively poorly characterized. This is due to logistical difficulties associated with obtaining water samples in potentially dangerous flood conditions. Herein, we report analyses of water samples from a large, flooded landscape in Victoria, Australia, during a major flood event. We collected 83 samples from seven rivers and 18 river locations as far apart as 520 km. The sampling campaign covered a 26-day window, with 3 samples taken weekly from each site. Floodwater samples were analyzed for 778 contaminants and 544 microbial species were identified using eDNA. Our study shows that 85 contaminants were detected in floodwaters. Fungicides, phthalates, plant macronutrients, metal(loid)s and PPCPs were better explained by land uses, whereas herbicides and insecticides were explained by a mixture of land use and water flow data. Potentially pathogenic orders with the highest detection rates were Enterobacterales (82.4%), Mycobacteriales (70.6%) and Legionellales (58.8%). Contaminants and microbial signatures responded to rainfall, water flow and water level, demonstrating increased and varied human and environmental risks of exposure during the sampling window. Our work underlines the importance of rigorous and timely monitoring and provides an evidence-base for decision making during increasingly frequent and intense climate driven flood events.