The availability of metals to plants is a complex function of numerous environmental factors. Many of these factors are interrelated, and vary seasonally and temporally. The current study intended to understand the influence of seasonal fluctuations and the vegetation of salt marsh plants (SMPs; Halimione portulacoides, Juncus maritimus) on sediment’s mercury (Hg) and its pH and redox potential (Eh), as well as their cumulative effect on the plant’s Hg-accumulation and Hg-partitioning potential. The area selected for the study was Laranjo Basin at Ria de Aveiro lagoon (Portugal) where a known Hg gradient was existed due to chlor-alkali plant discharge. Three sampling sites (L1, L2 and L3) were selected along a transect defined by the distance from the main Hg source. Samples were also collected from the Hg-free site (R). Irrespective of the plant vegetation, Hg in sediments gradually increased with a decreasing distance towards Hg-point source. The sediment colonised by J. maritimus showed more Hg concentration compared with H. portulacoides irrespective of the season. As a whole, J. maritimus accumulated Hg more than H. portulacoides at all the sampling sites, whereas in root, stem and leaf, the concentration was ranked as: L1 > L2 > L3 in both the plant species and was differentially influenced by seasonal changes. Moreover, root of both plants exhibited highest Hg concentration compared with stem and leaf. In addition, the leaf of H. portulacoides exhibited more Hg than leaves of J. maritimus. Bioaccumulation and translocation factors and dry weight were differentially influenced by seasonal changes. Taking together the results, the physico-chemical properties of sediment especially the sediment-Eh seems to be influnced by the type of plant vegetation and seasonal changes which in turn may have influenced the chemistry of sediments; thus, it enfluences the bioavalability of Hg and the Hg-retention capacity of both salt marsh sediments (SMSs) and SMPs (bioaccumulation factor). Moreover, SMSs vegetated by J. maritimus exhibited a stronger capacity for the retention and phytostabilization of Hg belowground (in sediments and/or roots) than those dominated by H. portulacoides. Conversely, those SMSs extensively vegetated by H. portulacoides are expected to translocate more Hg to aboveground parts, acting as a potential source of this metal to the marsh ecosystem. Therefore, J. maritimus and H. portulacoides may be used repectively for phytostabilization (in rhizosediments) and phytoextraction (by accumulation in aboveground plant tissue for subsequent plant removal).

Phytoremediation is a promising alternative to conventional soil clean-up methods; however, up to date, there is still not enough information on plant species suitable for application in this field of science. Therefore, plant screening on contaminated sites can lead to the identification of further species of interest. In the present study, pedological and botanical characteristics of an industrialised area known for its metal contamination, in special with Zn—Esteiro de Estarreja, in Portugal—were examined in a 1-year screening. Twenty-seven species were found, with a higher occurrence and variability in the summer/spring season. Zinc levels in the tissues of the collected plant samples ranged from 34 mg kg−1 in shoots to 2,440 mg kg−1 in roots of different species. Species as Verbascum virgatum, Hypochoeris radicata, Phalaris arundinacea, Conyza bilbaoana, Paspalum urvillei and Aster squamatus have shown high Zn shoot accumulation and bioconcentration factors (BCFshoots > 1) and high metal translocation factors (TF > 1). Others, namely Spergularia capillacea, excluded Zn from the shoot tissues and stored the metal at the root zone (BCFroots > 1), behaving as tolerant plants. Plants were also screened for arbuscular mycorrhizal fungi colonisation, and only few species showed mycorrhizal presence, namely C. bilbaoana, Hirschfeldia incana, Epilobium tetragonum, Conyza sumatrensis, Pteridium aquilinum, P. urvillei and A. squamatus. The present work showed important indigenous species that can cope with installed harsh conditions and with potential for utilisation in phytoremediation strategies, either through metal removal to aerial parts or through its immobilisation in the root zone.

In recent years, human pharmaceutical substances have been increasingly detected in the aquatic environment. Specific attention has been drawn to the occurrence of pharmaceutical substances at bank filtration sites which are used for drinking water production. In the course of the authorisation application for new pharmaceutical compounds, an environmental risk assessment is required. Currently, the expected concentration of the human pharmaceutical compound in groundwater at bank filtration sites is calculated following the guideline Pre-Authorisation Evaluation of Medicines for Human Use issued by the European Medicines Agency (EMEA 2006). A simple estimation is applied: The predicted environmental concentration (PECGW) is the predicted environmental concentration in surface water (PECSW) multiplied with 0.25. A new approach considering the hydraulic and hydrogeological characteristics of bank filtration sites as well as transport processes is presented in this study. First, a numerical groundwater flow model was developed to simulate the groundwater flow processes at bank filtration sites in general. Flow times were calculated as a function of the hydraulic and hydrogeological parameters: hydraulic conductivity, shore-well distance, screen depth and extraction rate. In a second step, the PECGW was calculated based on the compound concentration in surface water and the modelled groundwater flow times considering linear sorption and first-order decay. Sorption and degradation can only be calculated based on the data provided by the pharmaceutical company in the course of the authorisation application. The current approach following the EMEA guideline invariably connects the PECGW with the PECSW without considering sorption and/or degradation processes. We introduce an approach that incorporates the hydraulic process bank filtration and the main transport processes sorption and degradation. The new approach is compound specific as well as aquifer, flow and transport specific resulting in a more realistic PECGW value compared to the old approach.

Prediction of the sorption behavior of environmental pollutants is of utmost importance within the framework of risk assessments. In this work two approaches are presented with the aim to describe sorption of aromatic substances to geosorbents. First, analytical solutions of kinetic models were fitted to experimental data of batch sorption experiments with aniline and 1-naphthylamine onto animal manure-treated soil and the soil mineral montmorillonite. The models, accounting for equilibrium and nonequilibrium sorption coupled to transformation and/or irreversible sorption processes, could well reproduce the concentration course of the sorbates. Results suggest that the amounts transformed/degraded and irreversibly bound were higher for the soil than for the clay mineral. In the second part, quantum chemical calculations were performed on aniline and 1-naphthylamine interacting with acetic acid, acetamide, imidazole, and phenol as models of functional groups present in humic substances. Molecular modeling showed that formation of hydrogen bonds is the dominating binding mechanism in all modeled complexes, which are energetically very similar between aniline and 1-naphthylamine.

Diplopods are components of the edaphic fauna, which makes them suitable bioindicators of soil quality. Some characteristics of the fat body of diplopods make it suitable for ecotoxicological studies. This organ, composed of diffuse tissue, fills the body cavity; it presents intense metabolic activity associated with lipid, glycogen, protein, and uric acid storage, being also responsible for storage, neutralization, and excretion of substances that are not useful to the organism. The present study aimed to investigate whether the perivisceral fat body of Rhinocricus padbergi can be used as a target organ in ecotoxicological studies and to identify possible histological and histochemical biomarkers in this organ. Upon examining the perivisceral fat body of individuals of R. padbergi exposed to different concentrations of industrial soil contaminated with polycyclic aromatic hydrocarbons (∑ 2,749.0 mg/kg) and metals (∑ 40,355.8 mg/kg), we have found evidence that this organ is sensitive to environmental pollutants present in the soil. The loss of integrity of the cell boundary associated with cytoplasmatic disorganization and depletion in total proteins, neutral polysaccharides, calcium, and lipids can be considered stress biomarkers for R. padbergi.

The concentrations of selected metals—Cr, Ni, Cu, Zn, Cd, and Pb—were determined in the samples of Hypogymnia physodes lichen and Pleurozium schreberi moss collected in Polish and Czech Euroregions Praded and Glacensis. More specifically, the samples were collected in Bory Stobrawskie, Bory Niemodlińskie, and Kotlina Kłodzka (Poland) and in Jeseniki (Czech Republic). The concentration of metals in the samples was measured using the atomic absorption spectrometry (flame AAS technique and electrothermal atomization AAS technique). The results were used to calculate the comparison factor (CF) that quantifies the difference in concentration of a given bioavailable analyte × accumulated in lichens and mosses: CF = 2 (c x,lichen − c x,moss) (c x,lichen + c x,moss)−1. The values of CF greater than 0.62 indicate the most probable location of heavy metals deposited in the considered area. In this work, the method was used to show a significant contribution of urban emissions to the deposition of heavy metals in the area of Bory Stobrawskie and in the vicinity of Kłodzko City.

This study assessed effects of a mixture of two pesticides, diazinon and permethrin, on 48-h sediment toxicity to Hyalella azteca in a constructed wetland mesocosm containing non-vegetated and vegetated sections. Sediment samples were collected at inflow, middle, and back points within each section 5, 24, 72 h, 7, 14, and 21 days post-amendment. Pesticides were detected in sediments throughout non-vegetated and vegetated wetland sections. H. azteca 48-h survival varied across sampling period, wetland location, and vegetation type with lowest survival occurring within the first 72 h of the inflow and middle locations of the non-vegetated section. Sediment toxicity was ameliorated by 14 and 7 days within the non-vegetated and vegetated sections, respectively. Relationships between pesticide concentrations and animal survival indicated toxicity was from both diazinon and cis-permethrin in the non-vegetated section and primarily cis-permethrin in the vegetated section. Results show that vegetation ameliorated pesticide mixture 48-h sediment toxicity to H. azteca earlier and to a greater extent than non-vegetated constructed wetlands. A 21-day retention time is necessary to improve 48-h H. azteca sediment survival to ≥90% in wetlands of this size.

Numerous time series studies have quantified the potential association between daily variations in air pollution and daily variations in non-accidental deaths. In order to account for the presence of unmeasured confounders, a smooth function of time trend is typically used as a proxy for these variables. We shed light on the validity of the results obtained by using this approach. Specifically, we use data from the National Morbidity, Mortality and Air Pollution Study database, and carry out a carefully designed simulation study. Our findings suggest that the use of a smooth function of time trend cannot fully account for the presence of unmeasured confounders, especially when their impact is strong relatively to the effect of air pollution, and when several unobservables are not included in the model.

In this study, the effects of industrial and urban pollution on Pb, Al, Cd, Cu, and Zn accumulation, peroxidase activity, and pigment and protein contents were investigated in shrub and tree leaves in Antakya, Turkey. We determined that industrial and traffic activities produce the most plant-incorporated air pollutants in Antakya City. Cu and Al amounts were high in plants in the urban street location and Cd, Pb, and Zn amounts where high for all plants in the industrial site. Acer negundo L. showed maximum Pb and Zn accumulation at the industrial site and Al accumulation for the urban street site. Higher Cd and Cu amounts were detected in Platanus orientalis L. and Nerium oleander L. in the industrial and urban street sites, respectively. Compared to the control site, decreases in pigment and total soluble protein contents and increases in peroxidase enzyme activity were more evident in industrial and urban street sites. Our results indicated that industry and urban air pollution is high in Antakya City and Pb pollution was at an especially alarming level for vegetation and human health.

Aqueous natural organic matter (NOM) impacted by two contrasting human impacts was analyzed using by multiresponse fluorescence, decoupled with the resolution routine PARAFAC. The first site is Chalk River, Ontario, Canada, near a pit formerly used to dispose low-level wastes. The second site is the Grand River in Cambridge, south-central Ontario, which is impacted by urban activities and agriculture. Our analysis included raw water, plus fractions from ultrafiltration and solid-phase extraction (SPE). The fluorescence spectra of the NOM, resolved with PARAFAC, showed three common features: humic-like components, at excitation/emission wavelengths 325-350/450-475 nm, fulvic-like components at 325/380-420 nm and protein-like components, at 275/300 nm. Ultrafiltration revealed that most of the NOM comprised fine material below 5,000 Da cut-off (<4% of the total) in the urban-impacted sites and the clean site at Chalk River, but the colloidal fraction (larger than 5,000 Da) was substantially higher in the contaminated water, with ∼18-26% of the total. The protein-like components in the contaminated Chalk River water were affected by ultrafiltration, but less so in the clean Chalk River sample and the urban-impacted waters. SPE preferentially removed the protein-like component in the contaminated Chalk River water (typically 89-95% signal decrease), but had a limited effect on humic- and fulvic-like components elsewhere. In conclusion, multiresponse fluorescence provided new information on the NOM quality from two contrasting sites, aided by ultrafiltration and SPE. These results are consistent with the in situ production of NOM in the Chalk River contaminated site, and natural production at the other sites.