To study the impact of oxygen regimes on the removal of polycylic aromatic hydrocarbons (PAHs) in oil-spill-affected coastal marine sediments, we used a thin-layer incubation method to ensure that the incubated sediment was fully oxic, anoxic, or was influenced by oxic-anoxic switches without sediment stirring. Hydrocarbon content and microbial assemblages were followed during 60 days to determine PAH degradation kinetics and microbial community dynamics according to the oxygenation regimes. The highest PAH removal, with 69 % reduction, was obtained at the end of the experiment under oxic conditions, whereas weaker removals were obtained under oscillating and anoxic conditions (18 and 12 %, respectively). Bacterial community structure during the experiment was determined using a dual 16S rRNA genes/16S rRNA transcripts approach, allowing the characterization of metabolically active bacteria responsible for the functioning of the bacterial community in the contaminated sediment. The shift of the metabolically active bacterial communities showed that the selection of first responders belonged to Pseudomonas spp. and Labrenzia sp. and included an unidentified Deltaproteobacteria—irrespective of the oxygen regime—followed by the selection of late responders adapted to the oxygen regime. A novel unaffiliated phylotype (B38) was highly active during the last stage of the experiment, at which time, the low-molecular-weight (LMW) PAH biodegradation rates were significant for permanent oxic- and oxygen-oscillating conditions, suggesting that this novel phylotype plays an active role during the restoration phase of the studied ecosystem.

The weight; testis/body coefficient; levels of LDH, SDH, SODH, G-6PD, and testosterone; cell cycle; and cell apoptosis of the male mice were influenced after being treated with 200 mg/[kg/day] of rare earths suspension for 3 weeks. The “Raman fingerprints” of the human sperm DNA exposed to 0.040 mg/ml CeCl₃ were very different from those of the untreated; the Raman bands at 789 cm⁻¹ (backbone phosphodiester), PO₄ backbone at 1,094 cm⁻¹, methylene deformation mode at 1,221 cm⁻¹, methylene deformation mode at 1,485 cm⁻¹, and amide II at 1,612 cm⁻¹, of which intensities and shifts were changed, might be the diagnostic biomarkers or potential therapeutic targets. The injury mechanism might be that the rare earths influence the oxidative stress and blood testosterone barrier, tangle the big biomolecule concurrently, which might cause the testicular cells and vascular system disorder and/or dysfunction, and at the same time change the physical and chemical properties of the sperm directly.

The mechanism of lead (Pb) neurotoxicity has not been illustrated over the years. People pay more attention to dopaminergic neurotransmission, specifically dopamine receptor-2 (DRD2) Taq IA polymorphism, but no consensus has been reached. A total of 258 three-year-old children in Guiyu (exposed group) and Nanao (reference group), China were examined and their concentrations of blood lead (BPb) were determined. Cognitive and language scores of children were assessed using the Bayley Scales of Infant Development, third edition (BSID-III). Genotyping for the DRD2 polymorphism was carried out using a polymerase chain reaction (PCR) re-sequencing platform. The logistic stepwise regression analysis and stepwise regression analysis was used to explore associations among lead, neurodevelopment of children, and DRD2 Taq IA categories. Median values of Pb in Guiyu was higher than that of the reference group (11.30 ± 5.38 μg/dL vs. 5.77 ± 2.51 μg/dL, P < 0.001). Compared with the reference group, children from e-waste exposed area have lower cognitive scale scores (100 ± 25 vs 120 ± 20, P < 0.001) and lower language scale scores (99.87 ± 7.52 vs 111.39 ± 7.02, P < 0.001). The three kinds of genotype, A1/A1, A1/A2, and A2/A2, had no significant influences on BPb, cognitive scores and language scores (P > 0.05). Exposure of inhabitants, especially children to Pb from informal e-waste recycling activities might have contributed to higher levels of BPb and reduced cognitive and language scores observed in local children, however, the result obtained showed no significant association between DRD2 polymorphism and neurodevelopment of children exposed to lead.

An intensive investigation was conducted to study the spatial distribution and temporal variety trend of mercury and arsenic in plant tissue and soil profile in the eastern of the Tibet Plateau and to explore the possible sources of these two elements. At present, rare information is available on mercury (Hg) and arsenic (As) of timberline forests in the Tibet Plateau. Here, we present preliminary results on these two elements in leaves, twigs, root, litterfall, and soil. Geostatistical analyst of the ArcGIS 10.0 was used to determine the trait of spatial distribution of these two elements. Total arsenic (TAs) mean concentrations in the leaves, twigs, root, litterfall, and A- and C-layer soil ranged from 0.12 mg kg⁻¹ (n = 60), 0.35 mg kg⁻¹ (n = 60), 0.48 mg kg⁻¹ (n = 42), 1.52 mg kg⁻¹ (n = 84), 16.51 mg kg⁻¹ (n = 69), and 26.72 mg kg⁻¹ (n = 69), respectively. Total Hg (THg) mean concentrations in leaves, twigs, root, litterfall, and A- and C-layer soil were 0.0121 mg kg⁻¹ (n = 60), 0.0078 mg kg⁻¹ (n = 60), 0.0171 mg kg⁻¹ (n = 42), 0.0479 mg kg⁻¹ (n = 84), 0.0852 mg kg⁻¹ (n = 75), and 0.0251 mg kg⁻¹ (n = 75), respectively. In general, litterfall trended to accumulate high concentrations of Hg and As. Mercury in the timberline forest showed an increasing trend, whereas arsenic concentrations showed a decreasing trend in A-layer soil and an increasing trend in C-layer soil due to the easy mobile ability of As. Southwest and southeast monsoon could be the influencing factors, and Hg emission from India and China was the possible source of this study area through using a HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model. It is believed that these observations may offer scientists and policymakers additional understanding of Hg and As concentrations in the remote timberline area, eastern of the Tibet Plateau.

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants and have therefore drawn much environmental concern. We aimed to compare aerobic degradation of different PBDE congeners under various treatments and reveal the bacterial community associated with PBDE degradation in sediment. Results of this study indicate that degradation rates of BDE-15 were enhanced 45.1 and 81.3 % with the addition of suspended and microencapsulated Pseudomonas sp., respectively. However, the degradation rates of BDE-28, BDE-47, BDE-99, and BDE-100 did not differ among experimental treatments. Degradation rates of PBDE congeners were in the order of BDE-15 > BDE-28 > BDE-47 > BDE-99 > BDE-100. Using a pyrosequencing-based metagenomic approach, we found that addition of various treatments altered the microbial community composition in the sediment. Twenty-four bacterial genera associated with degradation of PBDEs; six are the core bacterial genera common among PBDE degraders. The diverse bacterial composition among different PBDE congener degradation indicates different combinations of bacteria involved in degradation of different PBDE congeners.

Polybrominated diphenyl ethers (PBDEs) were the first brominated persistent organic pollutants (POPs) listed in the Stockholm Convention. Parties to the convention are currently establishing inventories for developing action plans for the environmentally sound management of PBDE-containing materials. The major use of commercial octabromodiphenyl ether (c-OctaBDE) has been in casings from cathode ray tube (CRT) TVs and computer monitors. Large quantities of used e-waste and electronic equipment have been exported to developing countries with Nigeria being a major importer in Africa. The casings from 382 TVs and computers imported from major world regions to Nigeria were sampled in backyards and waste dumps. The samples were screened with X-ray flourescence (XRF) for bromine and analysed by gas chromatography/ electron capture detection (GC/ECD) for brominated flame retardants (BFRs). A high proportion of the CRT casings (61 %) contained more than 10,000 ppm bromine from BFRs. Decabromodiphenyl ether (DecaBDE) was the major flame retardant used in TV sets and tetrabromobisphenol A (TBBPA) for computer CRTs.The screening suggests that average PBDE levels (of c-OctaBDE + DecaBDE) in Nigerian-stockpiled CRT casings were 1.1 % for TV and 0.13 % for PC CRTs. These are above the Restriction of Hazardous Substances (RoHS) limit and should be separated for RoHS compliant recycling. The Nigerian e-waste inventory of 237,000 t of CRT plastic would therefore contain approx. 594 t c-OctaBDE and 1,880 t of DecaBDE. In Nigeria, as for most developing countries, there is currently no adequate e-waste management, plastic separation or destruction capacity. The data highlight the urgent need to develop environmentally sound management for this large material flow.

Labile P, Fe, and sulfide with the high spatial resolution in sediment porewater of five sites (A–E) of Dianchi Lake (China) were measured at same locations using AgI/Chelex-100, Chelex-100, and ferrihydrite DGT (diffusive gradients in thin films) probes. DGT derived P/Fe/S concentrations in sediment porewater on millimeter or sub-millimeter scale in order to reveal the element remobilization process and the mechanism of “internal P-loading” of sediments in Dianchi Lake. Decomposition of alga biomass in the uppermost sediment layer and the reductive dissolution of Fe-bound P in the anoxic sediment were the two main processes causing P release. A dynamic numerical model-DIFS (DGT-induced flux in sediments) was used to assess sediment-P reactivity (capacity of solid pool and rate of transfer) and P release risk by kinetic parameter—T C (1089∼20,450 s), distribution coefficient—K d (167.09∼502.0 cm³ g⁻¹), resupply parameter—R (from 0.242 to 0.518), and changes of dissolved/sorbed concentration, R and M at the microzone of DGT/porewater/sediment.

Increasing pollution pressures were placed in the coastal and estuarine ecosystems in China because of the elevated pollutants discharged from various sources. Polycyclic aromatic hydrocarbons (PAHs) in the environment were closely linked to human activities, which have been intensively studied for their geochemical interest as markers. In this review, the status of PAH contamination in China Sea was assessed by comprehensive reviews of the concentrations, sources, and fates of PAHs in sediments of China Sea. PAH concentrations in China Sea sediments decreased from north to south due to the higher emissions in North China. Atmosphere was probably the main carrier of PAHs in the north due to the higher contents of atmospheric fine particles and higher wind speeds. However, riverine inputs were probably the most important sources of PAHs in the coastal sediments of South China due to higher rainfall.

Among 348 microbial strains isolated from petroleum hydrocarbon-contaminated soil, five were selected for their ability to produce biosurfactant based on battery of screening assay including hemolytic activity, surface tension reduction, drop collapse assay, emulsification activity, and cell surface hydrophobicity studies. Of these, bacterial isolate DSVP20 was identified as Pseudomonas aeruginosa (NCBI GenBank accession no. GQ865644) based on biochemical characterization and the 16S rDNA analysis, and it was found to be a potential candidate for biosurfactant production. Maximum biosurfactant production recorded by P. aeruginosa DSVP20 was 6.7 g/l after 72 h at 150 rpm and at a temperature of 30 °C. Chromatographic analysis and high-performance liquid chromatography-mass spectrometry (HPLC-MS) revealed that it was a glycolipid in nature which was further confirmed by nuclear magnetic resonance (NMR) spectroscopy. Bioremediation studies using purified biosurfactant showed that P. aeruginosa DSVP20 has the ability to degrade eicosane (97 %), pristane (75 %), and fluoranthene (47 %) when studied at different time intervals for a total of 7 days. The results of this study showed that the P. aeruginosa DSVP20 and/or biosurfactant produced by this isolate have the potential role in bioremediation of petroleum hydrocarbon-contaminated soil.

The effects of inulin and mannanoligosaccharide (MOS) on the growth performance and non-specific immunity of grass carp were studied. Two doses of prebiotic fiber with 0.2 or 2 % of the fibers are being mixed into fish feed pellets. Fish growth as well as selected non-specific immune parameters of grass carp were tested in a feeding trial, which lasted for 8 weeks. Fish was fed at 2.5 % body mass per day. INU02, INU2, and MOS2 significantly improved relative weight gain, specific growth rate, protein efficiency ratio, and food conversion ratio of grass carp fed with food waste-based diet. In terms of non-specific immune response, grass carp showed significant improvement in all three tested parameters (total serum immunoglobin, bactericidal activity, and anti-protease activity). Adding 2 % of inulin (INU2) into food waste diets seemed to be more preferable than other supplemented experimental diets (INU02, MOS02, MOS2), as it could promote growth of grass carp as well as improving the non-specific immune systems of grass carp.