Many regulatory screening level exposure assessments are based on simple large scale conceptual scenarios. However, exposure, and therefore risks associated with chemicals, are characterised by high spatial variability. The Scenario assembly tool (ScenAT) is a global screening level model to enable spatially resolved local predictions of environmental concentrations of home and personal care chemicals. It uses the European Union Technical Guidance Document (TGD) equation to predict local scale freshwater concentrations (predicted environmental concentrations - PECs) of chemicals discharged via wastewater. ScenAT uses Geographic Information System (GIS) layers for the underlying socio-economic (population) and environmental parameters (per capita water use, sewage treatment plant connectivity, dilution factor). Using a probabilistic approach, we incorporate sources of uncertainty in the input data (tonnage estimation, removal in sewage treatment plants and seasonal variability in dilution factors) for two case-study chemicals: the antimicrobial triclosan (TCS) and the anionic surfactant linear alkylbenzene sulphonate (LAS). We then compare model estimates of wastewater and freshwater concentrations of TCS and LAS to UK monitoring data. Comparison showed that modeled PECs were on average higher than mean measured data for TCS and LAS by a factor 1.8 and 1.4, respectively. Considering the uncertainty associated with both model and monitoring data, the use of a probabilistic approach using the ScenAT model for screening assessment is reasonable. The combination of modelled and monitoring data enables the contextualisation of monitoring data. Spatial PECs can be used to identify areas of elevated concentration for further refined assessment.A probabilistic approach for large scale screening assessments to contextualise monitoring data for risk assessment.

Nano-aluminium oxide (nAl2O3) is one of the most widely used nanomaterials. However, nAl2O3 toxicity mechanisms and potential beneficial effects on terrestrial plant physiology remain poorly understood. Such knowledge is essential for the development of robust nAl2O3 risk assessment. In this study, we studied the influence of a 10-d exposure to a total selected concentration of 98 μM nAl2O3 or to the equivalent molar concentration of ionic Al (AlCl3) (196 μM) on the model plant Arabidopsis thaliana on the physiology (e.g., growth and photosynthesis, membrane damage) and the transcriptome using a high throughput state-of-the-art technology, RNA-seq. We found no evidence of nAl2O3 toxicity on photosynthesis, growth and lipid peroxidation. Rather the nAl2O3 treatment stimulated root weight and length by 48% and 39%, respectively as well as photosynthesis opening up the door to the use of nAl2O3 in biotechnology and nano agriculture. Transcriptomic analyses indicate that the beneficial effect of nAl2O3 was related to an increase in the transcription of several genes involved in root growth as well as in root nutrient uptake (e.g., up-regulation of the root hair-specific gene family and root development genes, POLARIS protein). By contrast, the ionic Al treatment decreased shoot and root weight of Arabidopsis thaliana by 57.01% and 45.15%, respectively. This toxic effect was coupled to a range of response at the gene transcription level including increase transcription of antioxidant-related genes and transcription of genes involved in plant defense response to pathogens. This work provides an integrated understanding at the molecular and physiological level of the effects of nAl2O3 and ionic Al in Arabidopsis.

We aimed to clarify the effects of ozone (O3) on photosynthetic ability of upper and lower canopy leaves of Fagus crenata Blume seedlings grown under different soil nutrient conditions. To accomplish this objective, we analyzed the response of photosynthetic parameters such as maximum carboxylation rate (Vcmax) to cumulative stomatal O3 uptake (ΣFst) and reduction rate of Vcmax per unit ΣFst as an index of detoxification capacity for O3. The seedlings of Fagus crenata were grown for two growing seasons (2014–2015) in nine treatments comprised of a combination of three levels of gas treatments (charcoal-filtered air or 1.0- or 1.5-times ambient O3 concentration) and three levels of soil nutrient treatments (non-fertilized or a supply of relatively low or high concentrations of compound fertilizer). The nutrient supply significantly increased the degree of O3-induced reduction in Vcmax in September. However, nutrient supply did not significantly increase ΣFst and reduce the detoxification capacity for O3. On the other hand, the degree of O3-induced reduction in Vcmax of upper canopy leaves was higher as compared with that of lower canopy leaves in August due to the higher ΣFst. However, the reduction rate of Vcmax per unit ΣFst in lower canopy leaves was higher than that in upper canopy leaves, indicating lower detoxification capacity for O3 in lower canopy leaves. Reduction rate of Vcmax per unit ΣFst over the threshold, which is assumed to be proportional to gross photosynthetic rate, was similar between upper and lower canopy leaves. Therefore, capacity of photosynthetic CO2 assimilation is likely to be associated with detoxification capacity for O3 in upper and lower canopy leaves of F. crenata seedlings grown under different soil nutrient conditions.

Scientifically sound risk assessment strategies and derivations of environmental quality standards for metals present in freshwater environments are currently hampered by insufficient chronic toxicity data collected from natural ecosystems, as well as inadequate information on metal speciation. Thus, the aim of the present study was to evaluate the impact of freshwater containing multiple metals (Cd, Cr, Cu, Ni, Pb and Zn) on the chronic toxicity (72h) to the alga Pseudokirchneriella subcapitata and compare the observed toxicity results to the total and free metal concentration of the samples. Based on the information obtained herein, an additive inhibitory free multi-metal ion concentration index, calculated as the sum of the equivalent toxicities to the free metal ion concentration of each sample, was developed. The proposed index was well correlated to the observed chronic toxicity results, indicating that the concentration addition, when expressed as the free-ion activity, can be considered a reliable indicator for the evaluation of ecological risk assessments for natural waters containing multiple metals.

Samples of dried marine macroalgae (Fucus serratus, Palmaria palmata and Ulva lactuca) have been analysed for trace elements by a novel, non-destructive approach involving a Niton field-portable-X-ray fluorescence (FP-XRF) spectrometer configured in a low density plastics mode with thickness correction. Detection limits for a 200-s counting time ranged from <5 μg g⁻¹ for As and Pb in F. serratus and As in P. palmata to several tens of μg g⁻¹ for Cd, Sb and Sn in all species tested. Arsenic, Cu, Pb and Zn were detected by the XRF in samples collected from a protected beach (n = 18) and in samples therefrom that had been exposed to additional aqueous elements in combination (n = 72) with concentrations returned (in μg g⁻¹) ranging from 3.9 to 39.7 for As, 13.0 to 307 for Cu, 6.1 to 14.7 for Pb and 12.5 to 522 for Zn. Independent measurements of trace elements in the macroalgae by ICP-MS following nitric acid digestion revealed a direct and significant proportionality with concentrations returned by the XRF, with slopes of the XRF-ICP relationships (As = 1.0; Cu = 2.3; Pb = 2.4; Zn = 1.7) that can be used to calibrate the instrument for direct measurements. The approach shows potential for the in situ monitoring of macroalgae in coastal regions that is currently being investigated.

The removal effects of main toxic organic pollutants in semi-coking wastewater by combined treatment process were investigated, while the genotoxicity relevance of wastewater from different treatment units were monitored by using Vicia faba bioassays. Results showed that 37 kinds of toxic organic pollutants were detected in the crude sewage, most of them were removed by physicochemical pretreatment, and the total concentration of organic pollutants decreased from 4826 mg L⁻¹ to 546 mg L⁻¹. After pretreatment, benzenes, phenols, quinolines and indoles in the wastewater were mainly removed by anaerobic/aerobic biodegradation, but the polycyclic aromatic hydrocarbons (PAHs) were removed mainly by advanced treatment, total concentration of toxic organic pollutants was lower than 0.5 mg L⁻¹ in the effluent. Genotoxicity evaluation results showed that the wastewater from coagulating sedimentation unit or foregoing had significant mutagenic properties. However, the micronuclei (MN) frequency (‰, which was calculated by observing 1000 cells) induced by wastewater after adsorption with modified coke was only 8.06‰, it was no significant difference compared with negative control (7.43‰). It could be concluded that the adsorption treatment was required for the safety of effluent, and the physicochemical-biochemical combined process in this study was suitable for high concentration semi-coking wastewater treatment.

Studies have shown that pig manure is a reservoir of antibiotic resistance genes (ARGs). However, little is known about the characteristics of ARGs in the manure of piglets and adult pigs fed on different diets. In the present study, the ARG characteristics of the manure of piglets and adult pigs fed on different diets (feed, grain) were analyzed using high-throughput fluorescence quantitative PCR. Correlations between heavy metals, antibiotics, and ARGs in pig manure were analyzed. The results showed that the heavy metal and antibiotic contents in the manure of pigs receiving feed significantly exceeded those in the manure of pigs receiving grain. The heavy metal and antibiotic contents were higher in manure of piglets than in that of adult pigs. Feed significantly increased the ARG diversity in the pig manure. The ARG diversity was higher in manure of piglets than in that of adult pigs. In the manure of pigs receiving feed, 25 (from piglets), 12 (from adult pigs) ARGs were enriched significantly compared with pig fed with grain. In particular, sat4 (in piglets) and vatE-01 (in adult pigs) showed the highest enrichment, being increased by 59 and 19-fold, respectively. The ARG diversity correlated positively with the concentrations of antibiotics and heavy metals in the manure.

Few studies in developmental toxicology have focused on whether early life contaminant exposure affects future susceptibility. Investigations in frogs suggested that early life exposure to a pesticide resulted in higher tolerance to a subsequent challenge. This led to the hypothesis that early-life stage exposures can alter phenotypically plastic traits during development, resulting in induced tolerance. Here, we used Gulf killifish (Fundulus grandis) to test the role of detoxification pathway priming in this inducible tolerance. In frogs, the induced tolerance is present five days after the end of the pre-exposure, but absent after a month. We show that a pre-exposure early in life with carbaryl, induces the activity of cytochrome P450 1A (CYP1A) and increases the ability of pre-exposed groups to metabolize carbaryl, likely because of activation of the aryl hydrocarbon receptor (AHR) pathway. Embryos pre-exposed to carbaryl had a 350–500% increase in CYP1A activity, threefold greater capacity to metabolize carbaryl and were more tolerant to a lethal challenge five days after the end of pre-exposure. However, ten days later the differences in CYP1A activity, metabolic capacity and tolerance between pre-exposed and control groups were no longer present. Thus, we conclude that the increase in tolerance observed in pre-exposed fish embryos was due to the activation of the AHR and other metabolic pathways, resulting in a prolonged increase in biotransformation capacity. This allowed individuals to more efficiently deal with subsequent chemical challenges for a short period after the initial pre-exposure. However, this induced tolerance was only short-lived due to the recycling of biotransformation enzymes in the cells as part of general cellular protein maintenance. These findings suggest that induced tolerance was likely due to induction of defense mechanisms during the duration of response to the original stressor, rather than a more permanent change in their ability to respond to future challenges.

Cadmium (Cd) uptake and accumulation in crop plants, especially in wheat (Triticum aestivum) and rice (Oryza sativa) is one of the main concerns for food security worldwide. A field experiment was done to investigate the effects of limestone, lignite, and biochar on growth, physiology and Cd uptake in wheat and rice under rotation irrigated with raw effluents. Initially, each treatment was applied alone at 0.1% and combined at 0.05% each and wheat was grown in the field and then, after wheat harvesting, rice was grown in the same field without additional application of amendments. Results showed that the amendments applied increased the grain and straw yields as well as gas exchange attributes compared to the control. In both crops, highest Cd concentrations in straw and grains and total uptake were observed in control treatments while lowest Cd concentrations was observed in limestone + biochar treatment. No Cd concentrations were detected in wheat grains with the application of amendments except limestone (0.1%). The lowest Cd harvest index was observed in limestone + biochar and lignite + biochar treatments for wheat and rice respectively. Application of amendments decreased the AB-DTPA extractable Cd in the soil while increasing the Cd immobilization index after each crop harvest. The benefit-cost ratio and Cd contents in plants revealed that limestone + biochar treatment might be an effective amendment for increasing plant growth with lower Cd concentrations.

Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic annual ruderal plant and native to Northern America, but now also spreading across Europe. Air pollution and climate change will not only affect plant growth, pollen production and duration of the whole pollen season, but also the amount of allergenic encoding transcripts and proteins of the pollen. The objective of this study was to get a better understanding of transcriptional changes in ragweed pollen upon NO2 and O3 fumigation. This will also contribute to a systems biology approach to understand the reaction of the allergenic pollen to air pollution and climate change. Ragweed plants were grown in climate chambers under controlled conditions and fumigated with enhanced levels of NO2 and O3. Illumina sequencing and de novo assembly revealed significant differentially expressed transcripts, belonging to different gene ontology (GO) terms that were grouped into biological process and molecular function. Transcript levels of the known Amb a ragweed encoding allergens were clearly up-regulated under elevated NO2, whereas the amount of allergen encoding transcripts was more variable under elevated O3 conditions. Moreover transcripts encoding allergen known from other plants could be identified. The transcriptional changes in ragweed pollen upon elevated NO2 fumigation indicates that air pollution will alter the transcriptome of the pollen. The changed levels of allergenic encoding transcripts may have an influence on the total allergenic potential of ragweed pollen.