Application of measured in vitro dermal bioavailability of polycyclic aromatic hydrocarbons (PAH) in soil in detailed quantitative human health risk assessment

Our study shows that site-specific estimates of dermal exposure to selected polycyclic aromatic hydrocarbons contained in contaminated gasworks soil result in lower average daily exposure and risk to human health when compared to the generic assumptions used in risk assessment software. We use site specific in vitro dermal bioavailability flux (μg/cm2/h) for benzo[a]pyrene measured by earlier research published by the authors, where dermal flux provides an analogue of diffusion through the skin and into systemic circulation. We used measured in vitro dermal flux for gasworks contaminated soil containing 150 mg/kg of benzo[a]pyrene to estimate average daily exposure and risk using the Contaminated Land Exposure Assessment (CLEA) framework. Site-specific flux (0.00237 ng/cm2/hour) was used to calculate an uptake of 23.7 ng benzo[a]pyrene/m2 skin/hour, resulting in an average daily exposure (ADE) ranging from 20.7 and 37.3 ng benzo[a]pyrene/kg bw/day for the first six years of a female child’s life. The average ratio of average daily exposure to the Health Criteria Value (Index Dose) was 0.54, where a soil concentration of 278.4 mg/kg is equivalent to a ratio of ADE to Index Dose of one. The results show that for the dermal pathway only the risk to human health calculated using site-specific dermal flux is lower than using default values used in CLEA. In our discussion we highlight that dermal bioavailability varies between sites and PAH and that differences are likely to be influenced by the source of contamination and the physico-chemical properties of soil. The findings support an evidence-based shift toward sample-specific parameters in regulatory risk assessment frameworks, but the scalability, inter-laboratory reproducibility, range and contaminants tested and the cost-effectiveness of in vitro flux testing need to be researched further before broader regulatory adoption

Restoration of ecological interactions: the influence of site and landscape factors

Restoration has been extensively used in agricultural landscapes as a mitigation measure to reduce biodiversity loss in response to historic habitat destruction. Trophic interactions between insects and plants underpin key ecosystem processes and contribute to system robustness, which is a critical outcome for habitat restoration. We evaluate how restoration age, site size and landscape proximity to similar habitats impact the re-establishment of trophic linkages between empirically measured grassland plant-pollinator (60 sites; 1–76 years) and woodland plant-herbivore networks (60 sites; 13–67 years). In each case, sites were selected along a chronosequence with the goal of maximising variation along these temporal and spatial gradients. For both grassland and woodlands, older and larger sites typically support higher levels of connectance, nestedness and generality of the networks. In contrast, landscape proximity promotes these metrics for woodland webs but has the reverse effect for grassland webs. The similarities show common characteristics of community trophic re-establishment in response to local environmental drivers for these different ecosystems. Focusing on interactions rather than species identity highlights opportunities for targeted policies to restore ecosystem function in wider agricultural landscapes; for example, through increasing site size as well as the need for continuity of older sites

Agriculture on wet peatlands: the sustainability potential of paludiculture

•CONTEXT: Humanity must overcome the polycrisis of biodiversity loss, climate change and pollution. These challenges are especially urgent in peatlands, which develop slowly under waterlogged conditions, function as landscape filters and store large amounts of carbon. Drainage for agriculture, forestry or peat extraction leads to severe socio-ecological impacts, including greenhouse gas emissions, biodiversity loss, land subsidence, higher flood and drought risks and downstream pollution. •OBJECTIVE: This study evaluates paludiculture as an innovative wet agricultural land use that maintains wet peatlands, offers economic alternatives to drainage-based systems and reduces environmental impacts. •METHODS: We reviewed and synthesized ecological and socio-economic evidence from low- and high intensity paludiculture practices to assess their potential to balance human needs with peatland conservation. •RESULTS AND CONCLUSIONS: Paludiculture is a promising new agricultural land use that effectively reduces greenhouse gas emissions, supports biodiversity restoration and contributes to climate mitigation and sustainable development. Our findings show direct and indirect contributions to ten UN Sustainable Development Goals: no poverty, good health, clean water, clean energy, innovation, sustainable cities and communities, responsible production, climate action, life below water, and life on land. Nonetheless, challenges remain regarding economic viability, land-use competition and management. •SIGNIFICANCE: Paludiculture shows how wetland agriculture can create new revenue opportunities combined with ecological protection. By contributing to both climate and biodiversity goals, it is a sustainable alternative to drainage-based peatland use

Sub-Antarctic fjord circulation and associated icefish larval retention in a changing climate

Climate change is impacting high-latitude fjord circulation with consequences for the transport of marine biota essential for supporting local ecosystems. Currently, little is understood about oceanographic variability in sub-Antarctic island fjords such as Cumberland Bay, the largest fjord on the island of South Georgia in the Southern Ocean. Cumberland Bay is split into two arms, West Bay and East Bay, and is a key spawning site for the ecologically and commercially important mackerel icefish. Through the use of a high-resolution three-dimensional hydrodynamic model, the seasonal cycle in Cumberland Bay is found to be driven by a combination of boundary forcing influencing shelf exchange and deep inflow, atmospheric forcing influencing near surface temperatures and flows and freshwater forcing via subglacial discharge driving upwelling and strong outflow. There is a complex three-dimensional flow structure with a high degree of variability on short timescales due to wind forcing. Using model flow fields to drive an individual-based model parameterised for mackerel icefish larvae spawned in Cumberland Bay, we identify West Bay as a key retention zone. Successful retention of mackerel icefish larvae is found to be sensitive to complex circulation patterns driven by winds, freshwater and fjord-shelf exchanges and to changes in physical processes linked to climate change such as meltwater runoff and föhn wind events. This study highlights the importance of oceanographic variability in influencing ecological processes in fjords in our changing climate

Unifying occupancy-detection and local frequency scaling (Frescalo) models

Frescalo’s “local frequency scaling” and classical occupancy-detection models both seek to recover true species-occurrence signals from imperfect data. In this paper, we show that the two approaches rest on the same underlying detection mathematics. Occupancy models treat each site’s repeat visits as independent detection trials and separately estimate occupancy probability and per-visit detectability. Frescalo, by contrast, pools data across ecologically defined neighbourhoods, standardises for uneven effort, and infers a single discovery rate per species plus a species-specific “time-factor” to capture time trends. The occupancy–detection Bernoulli formulation can be linked directly to Frescalo’s Poisson/discovery framework, where occupancy and detectability combine into one rate parameter (which, when sampling is light, closely matches the product of occupancy and per-visit detectability). This connection clarifies how Frescalo’s neighbourhood-scale and time corrections function as a coarser-scale analogue of repeat-visit models. By casting Frescalo in occupancy modelling terms, we hope to promote further investigation into the adoption of occupancy model diagnostics, extensions and other tests within Frescalo analyses, improving transparency and rigour when working with less-structured biodiversity data

Geological factors in the sustainable management of mine water heating, cooling and thermal storage resources in the UK

Re-use of the UK's coal mine water heating, cooling and thermal storage resource is increasing in scale and the number of schemes. The upwards trajectory requires 3D planning, regulation and licensing to manage sustainable deployment. We review geological factors controlling thermal and flow processes in the anthropogenically-altered subsurface, critical for resource management with multiple users of the same space. Potential interactions of mine water geothermal schemes with the wider environment are also summarised, leading towards concepts of 3D mine water thermal blocks, protection zones, or management strategies integrating heating, cooling and storage demands. Factors such as the magnitude, extent and timescale of thermal processes to underpin management approaches are poorly quantified by data measured at-scale under varying pumping rates and thermal loads. We demonstrate early insights of how two infrastructures, the UK Geoenergy Observatory in Glasgow and the Coal Authority's Mine Water Heat Living Lab in Gateshead, can measure and monitor heat-flow processes in real world settings to provide an evidence base. For example, a thermal storage test at Glasgow showed rapid temperature changes in the rock and mine workings at the re-injection borehole and indicated an influence of lithologically-controlled transmissivity and thermal conductivity on temperature dissipation and recovery

Enhanced water stress on vegetation productivity with climate warming over the Northern Hemisphere

Water stress is a major environmental factor limiting vegetation productivity, however, large interactions between atmospheric and soil dryness still hinder a complete understanding of the main cause of the widespread drought-related decreased vegetation productivity. In this study, we investigated inter-annual changes in gross primary productivity during 1982 to 1998 and 1998 to 2018 using two independent remote sensing products. We also analyzed the impacts of temperature, soil moisture, and vapor pressure deficit on gross primary productivity trends during 1982 to 1998 and 1998 to 2018 to explore the causes of gross primary productivity declines during recent decades. Results show that gross primary productivity trend during 1998 to 2018 tends to stall after the year 1998 concurrent with a significant enhancement of a positive vapor pressure deficit trend during 1998 to 2018, particularly in forests, grasslands, and warmer regions. In the Northern Hemisphere, whilst increasing vapor pressure deficit plays a dominant role in weakening the gross primary productivity trend from 1998 to 2018, changing soil moisture and temperature also influences the trends as identified in different regional responses. In addition, results from 8 dynamic global vegetation models showed that the dynamic vegetation models fail to capture the inter-annual changes in gross primary productivity, likely due to an overestimation of gross primary productivity responses to soil water

Integrated carbon isotope stratigraphy and biostratigraphy of Cenomanian to Turonian carbonates from Jordan – An updated age model and sequence stratigraphic correlations with Oman

A new integrated age model of the uppermost Albian to Coniacian Ajlun Group in West-Central Jordan is presented based on four complete outcrop sections along a ∼124 km N–S transect. Carbon isotope curves from this work are integrated with published carbon isotope data and constrained by new and existing nannofossil and ammonite biostratigraphy. Key identified carbon isotope events include the Mid-Cenomanian Event 1 (MCE 1), the Oceanic Anoxic Event 2 (OAE 2) at the Cenomanian/Turonian boundary and the Pewsey Event in the middle Turonian. The findings of this study corroborate and revise previous chemostratigraphic definitions in the study area, while also demonstrating a coeval origin of different lithostratigraphic units within the Ajlun Group. On the Arabian Plate scale, a detailed (3rd order) sequence stratigraphic correlation is made between Jordan and time-equivalent strata from the well-studied Natih Formation in Oman. These correlations help to evaluate the relative contributions of eustasy and tectonics on different plate tectonic settings, since the northeastern and eastern margins were heavily influenced by tectonic processes associated with the closure of the Neo-Tethys Ocean. In Oman, the creation of increased accommodation space (ca. 40 m) is observed relative to Jordan commencing in the interval between the MCE 1 and OAE 2. This suggests the onset of tectonic precursor events in Oman during the middle to late Cenomanian interval before the main tectonic phase in the Turonian, resulting in the termination of shallow water carbonate deposition. In contrast, Jordan remained in a largely passive margin setting

Increasing concentrations of polychlorinated biphenyls (PCBs) in Eurasian otters (Lutra lutra) from Wales suggest remobilisation from sediment sinks

Despite ongoing regulatory efforts to mitigate PCB pollution, their presence remains pervasive in the environment, with concentrations in top predators still reaching toxicologically significant levels. To assess temporal and spatial variation of PCB concentrations in Wales between 2010 and 2019, we analysed liver samples of a sentinel predator, the Eurasian otter (Lutra lutra), for 23 PCB congeners. PCBs were detected in all livers analysed, with PCB 153 recording the highest individual concentration (545.8 ug/kg wet weight); sixteen percent of otters had concentrations above a toxic threshold for dioxin-like PCBs. Statistical modelling revealed a negative correlation between concentrations of dioxin-like PCBs and otter body condition. While previous studies on otters from the UK showed declining PCB concentrations between 1983 and 2009, our model predictions indicated a significant increase between 2010 and 2019, mirroring trends seen in marine mammals. Higher concentrations were observed in otters from coastal, low-altitude areas. A multi-model inference approach was used to identify the best groups of predictors for each congener, suggesting that remobilisation of PCBs from riverine and coastal sediment sinks is now a major driver of PCB concentrations, with the impacts of climate change likely exacerbating remobilisation. While PCB concentrations are often below limits of detection in water, and below the current Water Framework Directive Environmental Quality Standard in fish, they remained at toxicologically relevant levels in otters from Wales. Our findings underscore the importance of biomonitoring across trophic levels, and suggest that current environmental quality standards for water and fish are not protective of top predators. Addressing environmental PCB contamination will require strengthened international efforts both to manage the significant sinks of legacy pollutants, as well as to meet climate change mitigation targets

Microplastics in the air: weather and polymer influences on deposition trends across a rural–urban gradient

Atmospheric microplastics are an emerging concern, yet their deposition dynamics across different landscapes and weather conditions remain poorly understood. We investigated microplastic deposition along a rural-to-urban gradient in England, sampling Wytham Woods (rural), Summertown (suburban), and Oxford City (urban) every 2–3 days from May to July 2023. Using high-resolution μFTIR spectroscopy, we quantified 21 polymer types across four size fractions (25–50 μm, 50–75 μm, 75–100 μm, and >100 μm) and analysed their deposition patterns in relation to weather variables. Deposition rates varied from 12 to 500 particles/m2/day, with Wytham Woods recording the highest overall deposition and Oxford City exhibiting the greatest polymer diversity. The 25–50 μm size fraction dominated in all sites, comprising up to 99 % of total deposition during high-concentration events. Polymer prevalence varied by site, with polyethylene terephthalate most abundant in Wytham Woods, polyethylene in Summertown, and ethylene vinyl alcohol in Oxford City. Weather conditions influenced deposition trends. Higher atmospheric pressure suppressed deposition, while increased wind speed and winds from the northeast enhanced it. Rainfall reduced overall deposition but increased the proportion of larger microplastics (50–75 μm). These findings challenge the assumption that urban areas consistently experience the highest microplastic loads, emphasising the impact of weather patterns on microplastic dispersion and deposition. This study highlights the need for further research into long-term deposition patterns of microplastics, focusing on specific polymer types and sizes, and their relationship with short-term and seasonal weather variations across diverse landscapes