Nitrobenzene is a toxic pollutant and was the main compound involved in the Songhuajiang accident in 2007, one of the largest water pollution accidents in China in the last decade. No aquatic life criteria for nitrobenzene have previously been proposed. In this study, published toxicity data of nitrobenzene to Chinese aquatic species were gathered, and six resident Chinese aquatic organisms were used in toxicity tests to supplement the existing toxicity data for nitrobenzene. Seventeen genuses mean acute values, three genuses mean chronic values to freshwater aquatic animals, and six genus toxicity values to aquatic plants were collected in total. A criterion maximum concentration of 0.018mg/L and a criterion continuous concentration of 0.001mg/L were developed based on these data, according to the U.S. Environmental Protection Agency guidelines. These criteria may be useful in the determination of water quality standard of nitrobenzene.

Three sets of model predicted values for speciated mercury concentrations and dry deposition fluxes over the Great Lakes region were assessed using field measurements and model intercomparisons. The model predicted values were produced by the Community Multiscale Air Quality Modeling System for the year 2002 (CMAQ2002) and for the year 2005 (CMAQ2005) and by the Global/Regional Atmospheric Heavy Metals Model for the year 2005 (GRAHM2005). Median values of the surface layer ambient concentration of gaseous elemental mercury (GEM) from all three models were generally within 30% of measurements. However, all three models overpredicted surface-layer concentrations of gaseous oxidized mercury (GOM) and particulate bound mercury (PBM) by a factor of 2–10 at the majority of the 15 monitoring locations. For dry deposition of GOM plus PBM, CMAQ2005 showed a clear gradient with the highest deposition in Pennsylvania and its surrounding areas while GRAHM2005 showed no such gradient in this region; however, GRAHM2005 had more hot spots than those of CMAQ2005. Predicted dry deposition of GOM plus PBM from these models should be treated as upper-end estimates over some land surfaces in this region based on the tendencies of all the models to overpredict GOM and PBM concentrations when compared to field measurements. Model predicted GEM dry deposition was found to be as important as GOM plus PBM dry deposition as a contributor to total dry deposition. Predicted total annual mercury dry deposition were mostly lower than 5 μg m⁻² to the surface of the Great lakes, between 5 and 15 μg m⁻² to the land surface north of the US/Canada border, and between 5 and 40 μg m⁻² to the land surface south of the US/Canada border. Predicted dry deposition from different models differed from each other by as much as a factor of 2 at regional scales and by a greater extent at local scales.

This study aims to evaluate toxic effects of exposure to chlortetracycline (CTC) in soil on reproductive endpoints (juvenile counts and cocoon counts), biochemical responses, and genotoxic potentials of the earthworm Eisenia fetida. Results showed that juvenile counts and cocoon counts of the tested earthworms were reduced after exposure to CTC. The effective concentrations (EC₅₀ values) for juvenile and cocoon counts were 96.1 and 120.3 mg/kg, respectively. Treatment of earthworms with CTC significantly changed the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione S-transferase (GST). An increase in malondialdehyde (MDA) indicated that CTC could cause cellular lipid peroxidation in the tested earthworms. The percentage of DNA in the tail of single-cell gel electrophoresis of coelomocytes as an indication of DNA damage increased after treatment with different doses of CTC, and a dose-dependent DNA damage of coelomocytes was found. In conclusion, CTC induces physiological responses and genotoxicity on earthworms.

Polycyclic Aromatic Hydrocarbons (PAHs) transported by surface runoff result in nonpoint source pollution and jeopardize aquatic ecosystems. The transport mechanism of PAHs during rainfall-runoff events has been rarely studied regarding pervious areas. An experimental system was setup to simulate the runoff pollution process on PAHs-contaminated soil. The enrichment behavior of soil-bound PAHs was investigated. The results show that soil organic matters (SOM), rather than clay particles, seem to be the main carrier of PAHs. The enrichment is highly conditioned on runoff and erosion processes, and its magnitude varies among PAH compounds. It is not feasible to build a simple and universal relationship between enrichment ratio and sediment discharge following the traditional enrichment theory. To estimate the flux of PAHs from pervious areas, soil erosion process has to be clearly understood, and both organic carbon content and composition of SOM should be factored into the calculation.

The rootless duckweed Wolffia globosa can accumulate and tolerate relatively large amounts of arsenic (As); however, the underlying mechanisms were unknown. W. globosa was exposed to different concentrations of arsenate with or without l-buthionine sulphoximine (BSO), a specific inhibitor of γ-glutamylcysteine synthetase. Free thiol compounds and As(III)–thiol complexes were identified and quantified using HPLC – high resolution ICP-MS – accurate mass ESI-MS. Without BSO, 74% of the As accumulated in the duckweed was complexed with phytochelatins (PCs), with As(III)–PC₄ and As(III)–PC₃ being the main species. BSO was taken up by the duckweed and partly deaminated. The BSO treatment completely suppressed the synthesis of PCs and the formation of As(III)–PC complexes, and also inhibited the reduction of arsenate to arsenite. BSO markedly decreased both As accumulation and As tolerance in W. globosa. The results demonstrate an important role of PCs in detoxifying As and enabling As accumulation in W. globosa.

Studies were reviewed that investigated the combined effects of ionising radiation and other stressors on non-human biota. The aim was to determine the state of research in this area of science, and determine if a review of the literature might permit a gross generalization as to whether the combined effects of multi-stressors and radiation are fundamentally additive, synergistic or antagonistic. A multiple stressor database was established for different organism groups. Information was collected on species, stressors applied and effects evaluated. Studies were mostly laboratory based and investigated two-component mixtures. Interactions declared positive occurred in 58% of the studies, while 26% found negative interactions. Interactions were dependent on dose/concentration, on organism's life stage and exposure time and differed among endpoints. Except for one study, none of the studies predicted combined effects following Concentration Addition or Independent Action, and hence, no justified conclusions can be made about synergism or antagonism.

We assessed the compliance of a Dutch landscape, dominated by dairy farming, with environmental quality standards using a combination of model calculations and measurements. The total ammonia emission of 2.4 kton NH₃ yr⁻¹ does not exceed the environmental quality standard (2.6 kton NH₃ yr⁻¹). Nevertheless, the total N deposition (on average 24.4 kg N ha⁻¹ yr⁻¹) is such that critical N loads are exceeded at 53% of the nature areas. The deposited N mainly results from non-agricultural sources and agricultural sources outside the area (72%). The calculated average NO₃ ⁻ concentration in the upper groundwater does not exceed the 50 mg l⁻¹ threshold. Calculated annual average N-total and P-total concentrations in discharge water are relatively high but these cannot be directly compared with thresholds for surface water. The results suggest that compliance monitoring at the landscape scale needs to include source indicators and cannot be based on state indicators alone.

Asthma is currently defined as a chronic inflammatory disease of the airway. Several evidence indicate that vehicle emissions in cities is correlated with the allergic respiratory diseases. In the present study, we evaluated in the A549 cells the production and release of IL-4, IL-5 and IL-13 after treatment with sub-micron PM₁.₀ particles (PM₁.₀), Parietaria officinalis (ALL), and PM₁.₀ + ALL together. Our data demonstrated that PM₁.₀ + ALL together exhibited the greatest capacity to induce A549 cells to enhance the expression of IL-4 and IL-5 compared with the only PM₁.₀ or ALL treatment. Interestingly, IL-13 that is necessary for allergen-induced airway hyper responsiveness, is increased in cells treated with PM₁.₀ + ALL together, but is higher expressed when the cells are treated only with the allergen. Our data support the hypothesis that the urban environment damage the acinar lung units and activates cells of the immune system.

Gold nanoparticles (AuNPs) have important technological applications resulting in an increased potential for release to the environment, and a greater possibility of toxicological effects. The marine bivalve Scrobicularia plana was exposed to AuNPs of size 5, 15 and 40nm during a 16 d laboratory exposure at 100μg Au L⁻¹. After exposure to AuNPs forming aggregates (>700nm), the clams accumulated Au in their soft tissues. Biochemical (biomarkers) and behavioral (burrowing and feeding) responses were investigated. Au NPs were responsible of metallothionein induction (5, 40nm), increased activities of catalase (15, 40nm) and superoxide dismutase (40nm) and of glutathione S-transferase by the three sizes of AuNPs indicating defense against oxidative stress. Exposure to AuNPs impaired burrowing behavior. However, it must be underlined that these effects were observed at a dose much higher than expected in the environment.

Salinization is a major and growing threat to freshwater ecosystems, yet its effects on aquatic invertebrates have been poorly described at a community-level. Here we use a controlled experimental setting to evaluate short-term stream community responses to salinization, under conditions designed to replicate the duration (72 h) and intensity (up to 5 mS cm⁻¹) of salinity pulses common to Mediterranean rivers subjected to mining pollution during runoff events. There was a significant overall effect, but differences between individual treatments and the control were only significant for the highest salinity treatment. The community response to salinization was characterized by a decline in total invertebrate density, taxon richness and diversity, an increase in invertebrate drift and loss of the most sensitive taxa. The findings indicate that short-term salinity increases have a significant impact on the stream invertebrate community, but concentrations of 5 mS cm⁻¹ are needed to produce a significant ecological response.