Artemisia fragrans is a plant species with ability of growing on heavy metal-polluted soils. Ecotypes of this species naturally growing in polluted areas can accumulate and tolerate different amounts of heavy metals (HM), depending on soil contamination level at their origin. Heavy metal tolerance of various ecotypes collected from contaminated (AP, SP) and non-contaminated (BG) sites was compared by cultivation on a highly HM-contaminated river sediment and a non-contaminated agricultural control soil.Tissue-specific HM distribution was analyzed by laser ablation-inductively-coupled plasma-mass spectroscopy (LA-ICP-MS) and photosynthetic activity by non-invasive monitoring of chlorophyll fluorescence.Plant-mineral analysis did not reveal ecotype-differences in concentrations of Cd, Zn, Cu in shoots of Artemisia plants, suggesting no differential expression of root uptake or root to shoot translocation of HM. There was also no detectable rhizosphere effect on HM concentrations on the contaminated soil. However, despite high soil contaminations, all ecotypes accumulated Zn only in the concentration range of generally reported for normal growth of plants, while Cu and Cd concentrations were close to or even higher than the toxicity level for most plants. As a visible symptom of differences in HM tolerance, only the AP ecotype was able to enter the generative phase to complete its life cycle. Analysis of tissue-specific metal distribution revealed significantly lower concentrations of Cd in the leaf mesophyll of this ecotype, accumulating Cd mainly in the leaf petioles. A similar mesophyll exclusion was detectable also for Cu, although not associated with preferential accumulation in the leaf petioles. However, high mesophyll concentrations of Cd and Cu in the SP and BG ecotypes were associated with disturbances of the photosynthetic activity.The findings demonstrate differential expression of HM exclusion strategies in Artemisia ecotypes and suggest Cd and Cu exclusion from the photosynthetically active tissues as a major tolerance mechanism of the AP ecotype.

The current air quality indices have been criticized for not capturing combined health effects of multiple air pollutants. We proposed an Air Quality Health Index (AQHI) based on the air pollution-mortality associations for communicating health risks of air pollution. Time-series studies were conducted to estimate the associations between air pollutants including sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), suspended particulate matter smaller than 2.5 μm in aerodynamic diameter (PM2.5) and mortality in Guangzhou from 2012 to 2015. The sum of excess mortality risk was calculated to construct the AQHI, which was then adjusted to an arbitrary scale. We then assessed the validity of AQHI. An interquartile increase (IQR) of AQHI was associated with 3.61% [95% confidence interval (95% CI), 2.85%–4.37%], 3.73% (95%CI, 2.18%–5.27%) and 4.19% (95%CI, 2.87%–5.52%) increase of mortality, respiratory and cardiovascular hospital admissions, respectively. Compared with the currently used Air Quality Index (AQI), AQHI had higher effects on mortality and morbidity. Our study suggests that AQHI might comprehensively capture the combined effects of air pollution, which make it be a more valid communication tool of air pollution-related health risk.

While studies on microplastics in the marine environment show their wide-distribution, persistence and contamination of biota, the freshwater environment remains comparatively neglected. Where studies on freshwaters have been undertaken these have been on riverine systems or very large lakes. We present data on the distribution of microplastic particles in the sediments of Edgbaston Pool, a shallow eutrophic lake in central Birmingham, UK. These data provide, to our knowledge, the first assessment of microplastic concentrations in the sediments of either a small or an urban lake and the first for any lake in the UK. Maximum concentrations reached 25–30 particles per 100 g dried sediment (equivalent to low hundreds kg−1) and hence are comparable with reported river sediment studies. Fibres and films were the most common types of microplastic observed. Spatial distributions appear to be due to similar factors to other lake studies (i.e. location of inflow; prevailing wind directions; propensity for biofouling; distribution of macroplastic debris) and add to the growing burden of evidence for microplastic ubiquity in all environments.

In the summer of 2010, more than 6 hundred wildfires broke out in western Russia because of an unprecedented intense heat wave that resulted from strong atmospheric blocking. The present study evaluated the CO2 emissions using GOSAT (Greenhouse gases Observing SATellite) data from July 23 to August 18, 2010 for western Russia. The results demonstrated that the GOSAT CAI (Cloud and Aerosol Imager) was well-suited for the identification of smoke plumes and that the GOSAT FTS (Fourier-Transform Spectrometer) TIR (Thermal InfraRed) could be used to calculate the height of the plumes at approximately 800 hPa (1.58 km). Using GOSAT data, we estimated that the 2010 fires in western Russia emitted 255.76 Tg CO2. We also calculated the CO2 emissions by employing the Biomass Burning Model (BBM) for the same study site and obtained a similar result of 261.82–302.48 Tg CO2. The present study proposes a new method for the evaluation of CO2 emissions from a wildfire using remote sensing data, which could be used to improve the knowledge of the burning of biomass at a regional or a continental scale, to reduce the uncertainties in modeling greenhouse gases emissions, and to further understand how wildfires impact the atmospheric carbon cycle and global warming.

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg⁻¹ was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organic acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm⁻¹, potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. More research is needed to characterize soil solutions in Pb contaminated urban soils to identify where P treatments might be effective and when competing cations, such as Ca, Fe, and Zn may limit low rate P applications for treating Pb soils.

Bromide is a conservative tracer that is often applied with non-conservative solutes such as pesticides to estimate their retardation in the soil. It has been applied in concentrations of up to 250 g Br L−1, levels at which the growth of single-celled organisms can be inhibited. Bromide applications may therefore affect the biodegradation of non-conservative solutes in soil.The present study investigated the effect of potassium bromide (KBr) on the mineralisation of three pesticides – glyphosate, MCPA and metribuzin – in four agricultural A-horizon soils. KBr was added to soil microcosms at concentrations of 0, 0.5, 2.5 and 5 g Br− L−1 in the soil solution. The study concluded that KBr had a negative effect on pesticide mineralisation. The inhibitory effect varied depending on the KBr concentration, the type of pesticide and the type of soil. Furthermore, 16 S amplicon sequencing revealed that the KBr treatment generally reduced the abundance of bacteroidetes and proteobacteria on both an RNA and DNA level.Therefore, in order to reduce the effect of KBr on the soil bacterial community and consequently also on xenobiotic degradation, it is recommended that KBr be applied in a concentration that does not exceed 0.5 g Br− L−1 in the soil water.

In freshwater settings the toxicity of the trace metal nickel (Ni) is relatively well understood. However, until recently, there was little knowledge regarding Ni toxicity in waters of higher salinity, where factors such as water chemistry and the physiology of estuarine and marine biota would be expected to alter toxicological impact. This review summarizes recent literature investigating Ni toxicity in marine and estuarine invertebrates and fish. As in freshwater, three main mechanisms of Ni toxicity exist: ionoregulatory impairment, inhibition of respiration, and promotion of oxidative stress. However, unlike in freshwater biota, where mechanisms of toxicity are largely Class-specific, the delineation of toxic mechanisms between different species is less defined. In general, despite changes in Ni speciation in marine waters, organism physiology appears to be the main driver of toxic impact, a fact that will need to be accounted for when adapting regulatory tools (such as bioavailability normalization) from freshwater to estuarine and marine environments.

Human and ecosystem health concerns for arsenic (As) in the lower Athabasca River downstream of Athabasca Bituminous Sands (ABS) mining (Alberta, Canada) prompted an investigation to determine its forms in surface and groundwater upstream and downstream of industry. Dissolved As species, together with total and particulate As, were used to evaluate the potential bioavailability of As in water as well as to decipher inputs from natural geological processes and ABS mining and upgrading activities. Water samples were collected from the river in October at 13 locations in 2014 and 19 locations in 2015, spanning up to 125 km. Additional samples were collected from groundwater, tributaries and springs. “Dissolved” (<0.45 μm) As was consistently low in the Athabasca River (average 0.37 ± 0.01 and 0.34 ± 0.01 μg L⁻¹ in 2014 and 2015, respectively) as well as tributaries and springs (<1 μg L⁻¹), with As(V) as the predominant form. The average total As concentration was higher in 2014 (12.7 ± 2.8 μg L⁻¹) than 2015 (3.3 ± 0.65 μg L⁻¹) with nearly all As associated with suspended solids (>0.45 μm). In 2014, when total As concentrations were greater, a significant correlation (p < 0.05) was observed with thorium in particles > 0.45 μm, suggesting that mineral material is an important source of As. Naturally saline groundwater contained low dissolved As (<2 μg L⁻¹) and did not appear to be a significant source to the river. Arsenic in shallow groundwater near a tailings pond exceeded 50 μg L⁻¹ predominantly as As(III) warranting further investigation.

Air pollution continues to be a problem in the urban environment. A range of different pollutant mitigation strategies that promote dispersion and deposition exist, but there is little evidence with respect to their comparative performance from both an environmental and economic perspective. This paper focuses on examining different NO2 mitigation strategies such as trees, buildings facades coated with photocatalytic paint and solid barriers in Oxford Street in London. The case study findings will support ranking the environmental and economic impacts of these different strategies to improve personal exposure conditions on the footpath and on the road in a real urban street canyon. CFD simulations of airflow and NO2 dispersion in Oxford Street in London were undertaken using the OpenFOAM software platform with the k-ε model, taking into account local prevailing wind conditions. Trees are shown to be the most cost-effective strategy, with a small reduction in NO2 concentrations of up to 0.7% on the road. However, solid barriers with and without the application of photocatalytic paint and an innovative material (20 times more expensive than trees) can improve air quality on the footpaths more substantially, up to 7.4%, yet this has a significant detrimental impact on NO2 concentrations (≤23.8%) on the road. Photocatalytic paint on building surfaces presented a minimal environmental reductions (1.2%) and economic (>100 times more expensive than trees) mitigation strategy. The findings recognised the differences between footpath and road concentrations occurred and that a focused examination of three pollution hotspots can provide more cost effective pollution mitigation. This study considers how a number of pollutant mitigation measures can be applied in a single street canyon and demonstrates the strengths and weaknesses of these strategies from economic and environmental perspectives. Further research is required to extrapolate the findings presented here to different street geometries.

Uranium (U) can enter aquatic environments from natural and anthropogenic processes, accumulating in sediments to concentrations that could, if bioavailable, adversely affect benthic organisms. To better predict the sorption and mobility of U in aquatic ecosystems, we investigated the sediment-solution partition coefficients (Kd) of U for nine uncontaminated freshwater sediments with a wide range of physicochemical characteristics over an environmentally relevant pH range. Test solutions were reconstituted to mimic water quality conditions and U(VI) concentrations (0.023–2.3 mg U/L) found downstream of Canadian U mines. Adsorption of U(VI) to each sediment was greatest at pH 6 and 7, and significantly reduced at pH 8. There were significant differences in pH-dependent sorption among sediments with different physicochemical properties, with sorption increasing up until thresholds of 12% total organic carbon, 37% fine fraction (≤50 μm), and 29 g/kg of iron content. The Kd values for U(VI) were predicted using the Windermere Humic Aqueous Model (WHAM) using total U(VI) concentrations, and water and sediment physicochemical parameters. Predicted Kd-U values were generally within a factor of three of the observed values. These results improve the understanding and assessment of U sorption to field sediment, and quantify the relationship with sediment properties that may influence the bioavailability and ecological risk of U-contaminated sediments.