Increasing amount of aluminum (Al) gets into aquatic ecosystem through anthropogenic activity, but the knowledge about Al migration and relationships with sediments possessing different physico-chemical properties in eutrophic lakes is limited. Here, the Al migration rule and relationships with sediment nutritions in the Hangzhou West Lake, China was investigated, where a certain amount of residual Al-salts can enter because of the pre-treatment of the Qiantang River diversion project every day. Results revealed the obvious spatial distribution heterogeneity of Al in sediment vertical direction and horizontal direction following water flow. The Al content in sediment ranged 0.463–1.154 g kg⁻¹ in Maojiabu Lake, and ranged 9.862–40.442 g kg⁻¹ in Xiaonanhu Lake. Higher Al content distributed in upper layer sediment in lake with more disturbance. Total nitrogen (TN) contents were higher 0.917–3.387 mg g⁻¹ and 0.627–0.786 mg g⁻¹ in upper layer sediment than that in lower layer in Maojiabu Lake and Xiaonanhu Lake, respectively. Total phosphorus (TP) content ranged 0.779–2.580 mg g⁻¹, in which IP and Fe/Al-P contributed 24.9–80.8% and 17.0–51.6%, respectively. Correlations between Al content with nutrition, humic acid (HA) etc. of sediment regionally varied in Maojiabu and Xiaonanhu Lake. Spatial distribution of Al-salt in eutrophic lakes closely related with the physico-chemical characteristics of nutrients, humus, human disturbance and water division parameters. Results provides new insight into Al-salts migration and references for Al-risk evaluating in eutrophic lakes.

The increase in ambient fine dust particles (FDP) due to urbanization and industrialization has been identified as a major contributor to air pollution. It has become a serious issue that threatens human health because it causes respiratory diseases and skin aging. In the present study, the protective effect of the green tea catechin, (−)-epigallocatechin gallate (EGCG), against FDP (ERM-CZ100)-stimulated skin aging in human dermal fibroblasts (HDFs) was investigated. The results demonstrate that EGCG significantly and dose-dependently scavenged intracellular reactive oxygen species (ROS) in and increased the viability of FDP-stimulated HDFs. In addition, EGCG dose-dependently recovered collagen synthesis and inhibited intracellular elastase and collagenase activities. Moreover, EGCG decreased the expression of human matrix metalloproteinases (MMPs) via regulation of nuclear factor kappa B (NF-κB), activator protein 1 (AP-1), and mitogen-activated protein kinases (MAPKs) signaling pathways in FDP-stimulated HDFs. This study suggests that EGCG is a potential anti-aging candidate that can be used for FDP-induced skin aging as a therapeutic agent itself or as an ingredient in pharmaceutical and cosmeceutical products.

The Environmental Quality Standards (EQS) directive was an important improvement of long-term water quality monitoring at the European level, leading to the use of sediments and biota as relevant matrices for assessing priority substances under the European Water Framework directive. Currently, commonly accepted sediment EQS for Hg are missing in Europe. In this study we present a new, tiered approach to deriving sediment quality standards for Hg: the derivation of Predicted No-Effect Concentration (PNEC) from data in the literature, followed by adjusting values at regional scale, using ecological field data (macroinvertebrate community assessment) and field sediment ecotoxicity bioassays. The limited set of effect data available for Hg spiked-sediment ecotoxicity tests has resulted in unreliable PNEC values for sediment quality assessment. Field reference sites (n = 40) where the macroinvertebrate community status was assessed as High or Good were used to define the ecological background and threshold levels in sediments in northern Spain. Sediment QS developed in other areas were not suitable for specific basins in our study area, since they were within the range of our Hg background levels. Temporary sediment Quality Standards (QS) for Hg were developed for the Nalón River basin (where several mining districts occur), using field effect-based approaches such as sediment ecotoxicity data from Tubifex tubifex chronic bioassays and ecological assessment of macroinvertebrate communities. A proposal for Hg quality assessment in freshwater sediments of northern Spain is made based on ecologically relevant QS values, providing benchmark values for No-Effect and Effect Hg sediment concentrations.

The concentrations of heavy metals and other components in road dust from a Polish coal mining district were investigated. The sample was split into eight size fractions ranging from <5 μm to 1–2 mm applying the combined classification procedure of dry sieving and air classification. For most elements, significantly higher concentrations were found in the finest size fractions. In combination with the mass fractions of the various size fractions the concentrations of the components were calculated for this road dust assuming different upper size limits. The results demonstrate the important influence of the upper size limit applied on the composition of road dust. An analysis of the composition of road dust by particle size, instead of analysing whole road dust samples, proves to have several advantages. On the one hand, a reliable comparison of the results with the concentration data available in the literature is possible and on the other hand, the results can be used in assessments, for example resuspension or wash-off by rainfall, which require different upper size limits.Upper size limit applied in road dust sampling significantly influences the results. Combined sieving and air classification sample preparation procedure allows flexible use of the results.

Research is restricted regarding impacts of biomass burning (BB) on fine aerosol (PM₂.₅), due mainly to lack of specific BB tracers. This study aims to characterize the variability, distributions, and contributions of BB and fungal spores as sources of PM₂.₅ using a multiple organic tracer approach. PM₂.₅ samples were collected at four representative sites in Yangtze River Delta (YRD), China every 6 days for one year. In the laboratory, samples were analyzed for three anhydrides (levoglucosan, mannosan, and galactosan), two sugar alcohols (arabitol and mannitol), water-soluble inorganic ions, and elemental/organic carbon (EC/OC). Levoglucosan was the most abundant BB tracer (mean concentration = 81 ng/m³), and fungal spore tracers arabitol and mannitol had similar abundances (5.6 and 5.7 ng/m³, respectively). Anhydrides and sugar alcohols had high within-group correlations, indicating their respective common sources. Concentrations of tracers displayed large temporal variations but small spatial variations, suggesting strong seasonality in BB and fungal spore sources. BB sources were burning of grass, pine needles, hardwood and crop straw, which were originated from transboundary/cross-region transport and local fire spots. PCA analyses revealed that the common sources of fine aerosols in YRD were secondary inorganic aerosols, soil dust, BB and fungal spores.

Responses of streamflow and nutrient export to changing climate conditions should be investigated for effective water quality management and pollution control. Using downscaled climate projections and the Soil and Water Assessment Tool (SWAT), we projected future streamflow, sediment export, and riverine nutrient export in the St. Croix River Basin (SCRB) during 2020–2099. Results show substantial increases in riverine water, sediment, and nutrient load under future climate conditions, particularly under the high greenhouse gas emission scenario. Intensified water cycling and enhanced nutrient export will pose challenges to water quality management and affect multiple Best Management Practices (BMPs) efforts, which are aimed at reducing nutrient loads in SCRB. In addition to the physical impacts of climate change on terrestrial hydrology, our analyses demonstrate significant reductions in ET under elevated atmospheric CO₂ concentrations. Changes in plant physiology induced by climate change may markedly affect water cycling and associated sediment and nutrient export. Results of this study highlight the importance of examining climate change impacts on water and nutrient delivery for effective watershed management.

Excessive use of nitrogenous fertilizers and their improper management in agriculture causes nitrate contamination of surface and groundwater resources. This study was conducted along the seasonally flooded alluvial agricultural area of Indus River Basin to determine the spatial and temporal dynamics of nitrate concentrations in the groundwater along the river. Total of 112 samples were collected from shallow (30–40 ft) and deep groundwater (120–150 ft) wells at seven sites, 25 km apart from each other and covered an area of 170 km along the river, during four sampling campaigns between October 2016 to May 2017 i.e. in start, mid and end of dry season. The study period covered the whole agricultural cycle including the wet summer season with no agricultural activities under flooding and the sampling sites were always less than 2 km from the river bank. Nitrate concentrations of shallow wells were 15–54 and 20–45 mg L⁻¹ during the start and middle of dry season, respectively. However, at the end of the dry season, the highest nitrate concentrations of 35–75 mg L⁻¹ were recorded and 70% of these samples contained nitrate concentrations above the permissible limit 50 mg L⁻¹. Similar seasonal patterns of nitrate concentrations were observed in deep wells, however, δ¹⁸O data suggested lower recharge in deep well than shallow wells. The results illustrated that high nitrate concentrations in shallow wells were associated with high δ¹⁸O values indicating that the quantity of evaporated water infiltrated from the floodplain, possibly from distribution channels, along with the nitrate polluting shallow wells more than the deep wells. At the end of the dry season, nitrate concentrations exceeded the permissible limits in both shallow and deep wells, which possibly happened due to the horizontal movement of groundwater along with the nitrate mixing during vertical seepage of river water to the aquifers.

Plant-endophyte synergism has been demonstrated to play a key role in the phytoremediation of contaminated water and soil. Phytoalexins, a type of chemical component in the plant apoplast, can be produced by plants in response to stimulation by endophytes. Phytoalexins may have distinct effects on the nutritional and metabolic functions of endophytes; however, direct evidence is not available to prove the effect of phytoalexins on the hydrophobic organic contaminants (HOC)-degradation activity of endophytes. In this paper, three different types of phytoalexins, coumarin, resveratrol and rutin, were selected to study their effect on the removal of polycyclic aromatic hydrocarbons (PAHs) by an endophytic bacterium Methylobacterium extorquens C1. The effects of the three phytoalexins on bacterial sorption and intracellular enzymatic activities were tested to further analyze the mechanism by which the phytoalexins affect the PAH degradation performance of M. extorquens C1. The results showed that the removal rate of PAHs by M. extorquens C1 increased in the presence of low levels of the three phytoalexins. The most effective concentrations of coumarin, resveratrol and rutin were 0.20, 0.15, and 0.25 mg/L, respectively, and the removal rate of PAHs was increased by approximately 18.3–35.0%. At the optimal concentrations, the three phytoalexins significantly promoted the sorption of PAHs by M. extorquens C1, and also enhanced the activities of catechol dioxygenases and dehydrogenase of M. extorquens C1. The positive effect of phytoalexins on both bacterial sorption and intracellular enzymatic activities promotes the overall removal of PAHs from endophytes. These results may deepen our understanding of plant-microbe cooperative mechanisms in the degradation of organic pollutants and provide a new approach for chemically enhanced bioremediation in the future.

The issue of potential long-term or hereditary effects for both humans and wildlife exposed to low doses (or dose rates) of ionising radiation is a major concern. Chronic exposure to ionising radiation, defined as an exposure over a large fraction of the organism's lifespan or even over several generations, can possibly have consequences in the progeny. Recent work has begun to show that epigenetics plays an important role in adaptation of organisms challenged to environmental stimulae. Changes to so-called epigenetic marks such as histone modifications, DNA methylation and non-coding RNAs result in altered transcriptomes and proteomes, without directly changing the DNA sequence. Moreover, some of these environmentally-induced epigenetic changes tend to persist over generations, and thus, epigenetic modifications are regarded as the conduits for environmental influence on the genome.Here, we review the current knowledge of possible involvement of epigenetics in the cascade of responses resulting from environmental exposure to ionising radiation. In addition, from a comparison of lab and field obtained data, we investigate evidence on radiation-induced changes in the epigenome and in particular the total or locus specific levels of DNA methylation. The challenges for future research and possible use of changes as an early warning (biomarker) of radiosensitivity and individual exposure is discussed. Such a biomarker could be used to detect and better understand the mechanisms of toxic action and inter/intra-species susceptibility to radiation within an environmental risk assessment and management context.

Toxicity of hazard materials to organism is different between larvae and adult zebrafish. However, this different effect was seldom considered in toxicological modeling. Here, we measured Cd and Pb toxicity for larvae and adult zebrafish (Danio rerio) and assessed whether metal toxicity can be better simulated by the one-compartment or two-compartment toxicokinetic (TK) and toxicodynamic (TD) models with assumption of stochastic death (SD) and individual tolerance (IT), respectively. Results showed that, for larvae, the one-compartment model generally fitted the observed accumulation and survival better than two-compartment model. In contrast, for adult, the two-compartment model simulation satisfied the observed accumulation and survival better than one-compartment model. In addition, both the SD and the IT models generally described the Cd or Pb toxicity well, although the IT model predictions were slightly better than the SD model in adult fish, the opposite phenomenon was observed in larvae. Our results suggested that variations in both TK and TD parameters might be needed to quantify the toxicity sensitivity in larvae and adult zebrafish, and accounting these variations in mechanistic toxicological effect models (e.g. TK-TD) will allow more accurate predictions of hazard materials effects to organisms.