This study was conducted to determine whether phytoscreening techniques could be used to characterize the distribution of Hg in soil at the South River, VA. An estimated 500 to 1000 kg of Hg was released to the South River in the 1930s and 1940s from a synthetic fiber manufacturing plant located in Waynesboro, contaminating the floodplain downstream. Under background conditions (soil Hg <0.03 μg/g), phytoscreening sample Hg concentrations ranged from 1.9 to 3.9 ng/g. With soil Hg concentrations ranging from 0.1 to 94 μg/g in the top 30.5 cm of nearby soil, phytoscreening sample Hg concentrations ranged from 5.0 to 145 ng/g. The variability of Hg concentrations in soil solution over the scale of the entire rhizosphere of the large trees sampled was likely high. Furthermore, the mean depth of water uptake and the exact proximity of the soil profile samples for each tree could not be determined. Nevertheless, the phytoscreening results of this study could be used to reliably provide a qualitative delineation of Hg-contaminated soil.

The expansion in knowledge of the microbial community structure can play a vital role in the electrochemical features and operation of microbial fuel cells (MFCs). In this study, bacterial community composition in a dual chamber MFC fed with brewery waste was investigated for simultaneous electricity generation and azo dye degradation. A stable voltage was generated with a maximum power density of 305 and 269 mW m⁻² for brewery waste alone (2000 mg L⁻¹) and after the azo dye (200 mg L⁻¹) addition, respectively. Azo dye degradation was confirmed by Fourier transform infrared spectroscopy (FT-IR) as peak corresponding to –N=N– (azo) bond disappeared in the dye metabolites. Microbial communities attached to the anode were analyzed by high-throughput 454 pyrosequencing of the 16S rRNA gene. Microbial community composition analysis revealed that Proteobacteria (67.3 %), Betaproteobacteria (30.8 %), and Desulfovibrio (18.3 %) were the most dominant communities at phylum, class, and genus level, respectively. Among the classified genera, Desulfovibrio most likely plays a major role in electron transfer to the anode since its outer membrane contains c-type cytochromes. At the genus level, 62.3 % of all sequences belonged to the unclassified category indicating a high level of diversity of microbial groups in MFCs fed with brewery waste and azo dye. HIGHLIGHTS: • Azo dye degradation and stable bioelectricity generation was achieved in the MFC. • Anodic biofilm was analyzed by high-throughput pyrosequencing of the 16S rRNA gene. • Desulfovibrio (18.3 %) was the dominant genus in the classified genera. • Of the genus, 62.3 % were unclassified, thereby indicating highly diverse microbes. Graphical Abstract A schematic diagram of a dual chamber microbial fuel cell for azo dye degradation and current generation (with microbial communities at anode electrode)

Soils located adjacent to the Jiaojia gold mine were sampled and analyzed to determine the degree of which they were contaminated by trace elements (Hg, As, Cd, Pb, Cu, and Zn) in Shandong Province, China. All 18 samples exhibited mean Hg, As, Cd, and Pb concentrations in excess of local background values, while the mean concentrations of Cu and Zn were below the background values. In addition, the concentrations of trace elements in gold smelter (GS) soils were higher than in the gold mine (GM) soils. The result from a modified Tessier sequential extraction procedure was that with the exception of Cu in soils near the smelter, the trace elements were predominantly associated with the residual fraction. After residual fraction, most Hg was mainly humic acid and strong organic fraction, while most As was the humic acid. Cd was associated with the water soluble, ion exchange, and carbonate fractions compared with the other trace elements. Furthermore, Cu, Pb, and Zn were more concentrated in the humic acid and Fe/Mn oxide fraction. The fractions of trace elements were affected by soil pH and Ec (Electrical conductivity). The humic acid fraction of Hg as well as the ion exchange fraction of Cd and Zn displayed negative correlations with soil pH. The strong organic fraction of Hg, the Fe/Mn oxide fraction of Cd, and the carbonate fraction of Zn were positively related to the soil Ec. The strong organic fraction and ion exchange fraction of Zn were negatively related to soil Ec. However, the ion exchange and carbonate fractions of As showed significant positive correlations with soil pH. A calculated individual availability factor (A f ⁱ) is used; the values of each trace element in the soils are in the following order: Cu > Cd > Pb > Zn > As > Hg. When combined with a risk assessment code, data suggest that Hg, As, Pb, and Zn levels showed low risk for the environment, whereas Cd levels in soils adjacent to the GM and Cu levels in soils adjacent to the GS showed medium risk to the environment, and Cd levels in soils adjacent to the GS exhibited higher environment risk.

To contribute to the use of the tropical brown mussel Perna perna as a sentinel species for organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB), the present study reports data on the toxicokinetics of these compounds in P. perna. Specifically, the authors present data on OCP and PCB bioaccumulation for eight sampling months from three bays (SE Brazil) and two transplant experiments (each 1 month long). Although seasonality is observed in the total lipid content of the whole soft tissue, with summer samples showing higher values, no such seasonality is observed in the OCP and PCB concentrations bioaccumulated by the mussel P. perna. Because no seasonal effect is observed in the annual OCP and PCB concentrations bioaccumulated by P. perna, the use of this species as a sentinel organism to monitor organochlorinated compounds is encouraged. One month of transplantation is not enough to allow the transplanted specimens to reach the concentrations observed in animals reared at the destination site. Nevertheless, P. perna showed a clear tendency to depurate the DDT metabolites p,p′-DDD and p,p′-DDE after 1 month of transplantation.

Due to their mobility and toxicity, crude oil volatile organic compounds (VOCs) are representative components for oil pipeline contaminated sites detection. Therefore, contaminated location risk assessment, with airborne light detection and ranging (LIDAR) survey, in particular, requires ground-based determinative methods for oil VOCs, the interaction between oil VOCs and soil, and information on how they diffuse from underground into atmosphere. First, we developed a method for determination of crude oil VOC binary mixtures (take n-pentane and n-hexane as examples), taking synergistic effects of VOC mixtures on polydimethylsiloxane (PDMS) solid-phase microextraction (SPME) fibers into consideration. Using this method, we further aim to extract VOCs from small volumes, for example, from soil pores, using a custom-made sampling device for nondestructive SPME fiber intrusion, and to study VOC transport through heterogeneous porous media. Second, specific surface Brunauer–Emmett–Teller (BET) analysis was conducted and used for estimation of VOC isotherm parameters in soil. Finally, two models were fitted for VOC emission prediction, and the results were compared to the experimental emission results. It was found that free diffusion mode worked well, and an empirical correction factor seems to be needed for the other model to adapt to our condition for single and binary systems.

Nanomaterial (NM) release into wastewater treatment plants (WWTPs) is inevitable due to increased production and application throughout past decades and in the future. Concern arose about environmental risks and impact on activated sludge. Environmental risk assessment (ERA) for NMs according to established guidelines is considered not suitable, because NMs exhibit unique characteristics. For hazard identification on activated sludge, standard test organisms for aquatic toxicity testing are not meaningful. In this study, we developed an acute toxicity test for ciliates (Paramecium tetraurelia) as representatives of the important functional group of microbial predators and filter feeders. We chose silver nanoparticles (nAg) exemplarily for ion releasing nanoparticles and regarded toxicity by ions as well. Our results indicate that ions are more toxic (EC₅₀0.73 mg/L) than nanoparticles themselves (EC₅₀2.15 mg/L). However, nAg must be considered as a source of ions and requires size, surface coating, and compartment-specific ERA. We strived to develop such ERA based on our results, modeled environmental concentration data from literature, and surface area concentrations. Results indicated a probable risk toward activated sludge. This likely has effects on effluent water quality. We conclude that carefully modeled environmental concentrations are vital for more exact ERA for nAg and other NMs.

The present study examined the response of zebrafish embryos exposed to different concentrations (10, 20, 30, 40, 50, and 60 mg/L) of monocrotophos under static conditions for 96 h. We found that mortality had occurred within 48 h at all test concentrations, later insignificant mortality was observed. Monocrotophos (MCP) can be rated as moderately toxic to the Zebrafish embryos with a 96-h median lethal concentration (LC₅₀) of 37.44 ± 3.32 mg/L. In contrast, it greatly affected the development of zebrafish embryos by inducing several developmental abnormalities like pericardial edema, altered heart development, spinal and vertebral anomalies in a concentration-dependent manner. A significant percent reduction in length by 9–48 % and heart beats by 18–51 % was observed in hatchlings exposed to LC₁₀and LC₅₀concentrations at 96 h when compared to controls. The process of looping formation of heart at embryonic stage was greatly affected by the LC₅₀concentration of MCP. The neurotoxic potentiality of MCP was assessed by using a marker enzyme, acetylcholinesterase in both in vitro and in vivo experiments. MCP was found to be the most potent inhibitor of AChE in vitro with an IC₅₀value of 4.3 × 10⁻⁴ M. The whole-body AChE enzyme activity in vivo was significantly inhibited during the exposure tenure with the maximum inhibition of 62 % at 24 h.

Crops could accumulate trace metals by soil-root transfer and foliar uptake from atmospheric fallout, and an accurate assessment of pollution sources is a prerequisite for preventing heavy metal pollution in agricultural products. In this study, we examined Pb isotope rates to trace the sources of Pb in wheat grain grown in suburbs. Results showed that, even in zones with scarcely any air pollution spots, atmospheric fallout was still a considerable source of Pb accumulation in wheat. The concentration of Pb in wheat grain has poor correlation with that in farm soil. The Pb concentration in wheat grains with dust in bran coat was significantly higher than that in wheat grains, which indicates that Pb may accumulate by foliar uptake. The Pb isotope rate has obvious differences between the soil and atmospheric fallout, and scatter ratio is significantly closer between the wheat grain and atmospheric fallout. Atmospheric fallout is a more significant source of Pb concentration in wheat grains than in soil. As far as we know, this is the first study on the main sources of lead in grain crop (wheat) samples with isotope. This study aims to improve our understanding of the translocation of foliar-absorbed metals to nonexposed parts of plants.

The Santos and São Vicente Estuary has suffered extensively over the years from irregular industrial deposits. The present study aimed to evaluate liver disease prevalence and potential associated risk factors in four of the Estuary’s areas (Pilões and Água-Fria, Cubatão Center, Continental São Vicente, and Guarujá) and a reference area (Bertioga). This study consisted of a cross-sectional study design, in which a questionnaire was used to collect information in 820 households at each of the study areas. The proportion of total liver diseases, hepatitis, cirrhosis, and cancer (liver, biliary tract, and pancreas) per area were estimated. Pearson’s chi-square test and two proportion differences test were applied in order to evaluate associations between disease occurrence and areas and to test differences between two proportions, respectively. Single and multiple logistic regression models were applied to assess associations between disease prevalence and the different study areas. Liver disease prevalence was 1.5 % among all inhabitants and 1.4 % among those without any type of exposure. Among those who reported the presence of liver disease, a higher percentage of the participants that reported hepatitis (27.7 %) or other liver disease (48.7 %) did not report occupational or alcohol exposures. Hepatitis (77.8 %) was the most reported disease, and a statistical association between living in Pilões and Água-Fria and the occurrence of hepatitis was observed (Pearson’s χ ²: z = 18.1; p = 0.001). The consumption of locally-produced groceries (2.88; CI: 1.24–6.70) and water (5.88; CI: 2.24–15.45) were shown to be risk factors for the occurrence of liver disease. Thus, environmental exposure is still a public health problem present in the estuary region.

Veterinary antibiotics introduced into soil environment may change the composition and functioning of soil microbial communities and promote the spreading of antibiotic resistance. Actual risks depend on the antibiotic’s bioaccessibility and sequestration in soils, which may vary with contact time and soil properties. We elucidated changes in the horsebean plant’s bioaccessible oxytetracycline with increasing contact time in three different soils (cinnamon, red, and brown soil) and observed discrepancy in oxytetracycline dissipation using sequential extractions with H₂O-, 0.01 M CaCl₂-, and Mcllvaine- in the same three soils. The results showed lower quantities of oxytetracycline with increasing contact time over 20 days than the level in freshly contaminated soils but hugely discrepant quantities among the three tested soils. In addition, aging largely reduced dissipation of H₂O-, 0.01 M CaCl₂-, and Mcllvaine- extracted oxytetracycline in soils before planting. However, bioturbation helped increase the H₂O-, CaCl₂-, and Mcllvaine- extracted oxytetracyline from cinnamon and brown soils with aging. Lastly, correlation analysis indicated that bioaccessibility of oxytetracycline significantly correlates with the total of H₂O-, CaCl₂-, and Mcllvaine- extracted oxytetracycline (0.676**, p < 0.01) in soils, especially the H₂O- (0.789**, p < 0.01) and Mcllvaine- (0.686**, p < 0.01) extracted oxytetracycline with aging. Overall, this study provides some basic understanding of the aging effect on sequestration and bioaccessibility of veterinary antibiotics in soils.