Even though antimony (Sb) and arsenic (As) are chemical analogs, differences exist on how they are taken up and translocated in plants. We investigated 1) Sb uptake, efflux and speciation in arsenic hyperaccumulator Pteris vittata after 1 d exposure to 1.6 or 8 mg/L antimonite (SbIII) or antimonate (SbV), 2) Sb uptake by PV accessions from Florida, China, and Brazil after 7 d exposure to 8 mg/L SbIII, and 3) Sb uptake and oxidation by excised PV fronds after 1 d exposure to 8 mg/L SbIII or SbV. After 1 d exposure, P. vittata took 23–32 times more SbIII than SbV, with all Sb being accumulated in the roots with the highest at 4,192 mg/kg. When exposed to 8 mg/L SbV, 98% of Sb existed as SbV in the roots. In comparison, when exposed to 8 mg/L SbIII, 81% of the total Sb remained as SbIII and 26% of the total Sb was effluxed out into the media. The three PV accessions had a similar ability to accumulate Sb at 12,000 mg/kg in the roots, with >99% of total Sb in the roots. Excised PV fronds translocated SbV more efficiently from the petioles to pinnae than SbIII and were unable to oxidize SbIII. Overall, P. vittata displayed efficient root uptake and efflux of SbIII with limited ability to translocate and transform in the roots.

This review provides a summary of studies analysing metal concentrations in soils and soil solution at European roadsides. The data collected during 27 studies covering a total of 64 sites across a number of European countries were summarised. Highest median values of Cr, Cu, Ni, Pb, and Zn were determined in the top soil layer at the first 5 m beside the road. Generally, the influence of traffic on soil contamination decreased with increasing soil depth and distance to the road. The concentration patterns of metals in soil solution were independent from concentrations in the soil matrix. At 10-m distance, elevated soil metal concentrations, low pH, and low percolation rates led to high solute concentrations. Directly beside the road, high percolation rates lead to high annual loadings although solute concentrations are comparatively low. These loadings might be problematic, especially in regions with acidic sandy soils and a high groundwater table.

Freshwater aquatic organisms face the challenge of being exposed to a multitude of chemicals discharged by the human population. The objective of this study was to rank metals according to the threat they pose to aquatic organisms. This will contribute to a wider Chemical Strategy for freshwater which will risk-rank all chemicals based on their potential risk to wildlife in a UK setting. The method involved comparing information on ecotoxicological thresholds with measured concentrations in rivers. The bioconcentration factor was also considered as a ranking method. The metals; Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn, were analysed using this approach. Triclosan and lindane were used as comparative organic pollutants. Using a range of ranking techniques, Cu, Al and Zn came top of the list of concern, with Cu coming first.

Understanding temporal and spatial variation in soil chemicals is critical in exposure assessments. We measured eight metals in subsamples, duplicates (∼0.3 m), and repeat soil samples taken 1–6 years after initial sampling (∼5 m). We estimated variance components (VCs) of metal concentrations using nested analyses accounting for sampling area, land use and soil type, and calculated coefficients of variation (CVs) for repeat sample pairs. Total variance for all metals was similar, but VCs were proportioned differently by metal and sample type. Spatial variation explained the majority of variance in duplicate samples. CVs of metal concentrations were not significantly different over the long time interval, but repeat samples had larger VCs for unexplained error. Sampling area and land use were important for Ba and Mn, and Pb and Hg, respectively. Results suggest metals are stable over long times and suitable for exposure assessments, but that individual metal behavior should be considered.

Although carbon nanomaterials such as single-walled carbon nanotubes (SWCNT) are becoming increasingly prevalent in manufacturing, there is little knowledge on the environmental fate of these materials. Environmental degradation of SWCNT is hindered by their highly condensed aromatic structure as well as the size and aspect ratio, which prevents intracellular degradation and limits microbial decomposition to extracellular processes such as those catalyzed by oxidative enzymes. This study investigates the peroxidase and laccase enzymatic response of the saprotrophic white-rot fungi Trametes versicolor and Phlebia tremellosa when exposed to SWCNTs of different purity and surface chemistry under different growth conditions. Both unpurified, metal catalyst-rich SWCNT and purified, carboxylated SWCNTs promoted significant changes in the oxidative enzyme activity of the fungi while pristine SWCNT did not. These results suggest that functionalization of purified SWCNT is essential to up regulate enzymes that may be capable of decomposing CNT in the environment.

The study aims to examine relationships between microbial community structure and mixed pollutants of polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs) in constructed wetland microcosms, planted with Excoecaria agallocha or Kandelia obovata, two common mangrove plant species, and under two tidal regimes, everyday tidal (Te) and no tidal flooding (Tn). Results showed both microbial community structure and the retained amounts of pollutants were significantly determined by tidal regime, while the effect of plant species was small. Higher amounts of PAHs but lower amounts of PBDEs were always retained in sediments under Te than Tn regimes. Accordingly, temporal and vertical distributions of microbial community structure differed greatly between the two tidal regimes. Redundancy analysis further revealed significant correlation between a subgroup of the mixed PAHs and PBDEs with variation in microbial community structure. The findings will help to propose specific strategies to improve the bioremediation efficiency of constructed wetland.

The spatial distribution of metal bioavailability (Ni, Cu, Zn, and Pb) was first evaluated within the waters of Daliao River watershed, using the diffusive gradient in thin films (DGT) and chemical equilibrium models. To assess potential risks associated with metal bioavailability, site-specific 95% protection levels (HC5), risk characterizations ratios (RCR) and ratios of DGT-labile/HC5 were derived, using species sensitivity distribution (SSD). The highest bioavailability values for metals were recorded in the main channel of the Daliao River, followed by the Taizi River. Dynamic concentrations predicted by WHAM 7.0 and NICA-Donnan for Cu and Zn agreed well with DGT results. The estuary of the Daliao River was found to have the highest risks related to Ni, Cu, and Zn. The number of sites at risk increased when considering the total toxicity of Ni, Cu, and Zn.

Canopy-level stomatal conductance over a warm-temperate mixed deciduous and evergreen broadleaf forest in Japan was estimated by the Penman–Monteith approach, as compensated by a semi-empirical photosynthesis-dependent stomatal model, where photosynthesis, relative humidity, and CO2 concentration were assumed to regulate stomatal conductance. This approach, using eddy covariance data and routine meteorological observations at a flux tower site, permits the continuous estimation of canopy-level O3 uptake, even when the Penman–Monteith approach is unavailable (i.e. in case of direct evaporation from soil or wet leaves). Distortion was observed between the AOT40 exposure index and O3 uptake through stomata, as AOT40 peaked in April, but with O3 uptake occurring in July. Thus, leaf pre-maturation in the predominant deciduous broadleaf tree species (Quercus serrata) might suppress O3 uptake in springtime, even when the highest O3 concentrations were observed.

Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active ingredients through contact with contaminated soil: imidacloprid (logKow = 0.57), atrazine (logKow = 2.5), triadimefon (logKow = 3.0), fipronil (logKow = 4.11) or pendimethalin (logKow = 5.18). All amphibians had measurable body burdens at the end of the exposure in concentrations ranging from 0.019 to 14.562 μg/g across the pesticides tested. Atrazine produced the greatest body burdens and bioconcentration factors, but fipronil was more permeable to amphibian skin when application rate was considered. Soil partition coefficient and water solubility were much better predictors of pesticide body burden, bioconcentration factor, and skin permeability than logKow. Dermal uptake data can be used to improve risk estimates of pesticide exposure among amphibians as non-target organisms.

Various diffuse polyhalogenated aromatic hydrocarbons (PHAHs) exert common toxicity through the aryl hydrocarbon receptor (AhR). Apex predators spatially and temporally integrate diffuse contamination and simultaneous exposure can cause additive toxicity. We investigated the extent to which PCBs, still amongst the most prevalent PHAHs accumulated by predators, accounted for total PHAH toxicity in raptors and fish eating birds from Britain. We analysed egg or liver extracts from six species and compared chemically determined ΣPCB-TEQs concentrations with total AhR-mediated toxicity determined using the chemical-activated luciferase gene expression bioassay (CALUX-TEQ). Dioxin-like PCB profiles in eggs and livers were dominated by congeners 118, 105 and 167. ΣPCB-TEQ and CALUX-TEQ concentrations were positively associated but not in a 1:1 relationship. ΣPCB-TEQ were broadly similar to CALUX-TEQ concentrations in eggs and livers with CALUX-TEQ concentrations >50–80 and 160–320 pg g−1 lipid respectively, but were lower than CALUX-TEQ concentrations in less contaminated samples.