Potential effects of natural emissions of hydrocarbons in the marine environment have been poorly investigated. In this study, a multidisciplinary weight of evidence (WOE) study was carried out on a shallow seepage, integrating sediment chemistry with bioavailability and onset of subcellular responses (biomarkers) in caged eels and mussels. Results from different lines of evidence (LOEs) were elaborated within a quantitative WOE model which, based on logical flowcharts, provide synthetic indices of hazard for each LOE, before their integration in a quantitative risk assessment.Evaluations of different LOEs were not always in accordance and their overall elaboration summarized as Moderate the risk in the seepage area. This study provided first evidence of biological effects in organisms exposed to natural hydrocarbon emissions, confirming the limit of chemical characterization as stand-alone criteria for environmental quality assessment and the utility of multidisciplinary investigations to determine the good environmental status as required by Environmental Directives.

ZnO and CuO nanoparticles (NPs) have widespread commercial uses and their impact on agricultural systems is unresolved. This study examined whether the metabolites washed from wheat (Triticum aestivum L.) roots modulated the metabolic response to the NPs of a biosensor generated in the root colonizer, Pseudomonas putida KT2440. The root wash components boosted light output of the biosensor consistent with their catabolism. Dose-dependent and rapid inhibition of cell metabolism occurred with both ZnO and CuO NPs in water suspensions but high light output was maintained in root wash. Root wash also protected biosensor output in challenges with Zn ions. However the root wash components did not protect culturability or biosensor light output upon exposure to Cu ions. Imaging by atomic force microscopy suggested that root wash materials coated the NPs. We deduced that the response of a microbe to these metal oxide NPs could be negated by components released from roots.

Fifteen polycyclic aromatic hydrocarbons (PAHs) in PM2.5 samples collected in five different cities (Hong Kong (HK), Guangzhou (GZ), Xiamen (XM), Xi'an (XA) and Beijing (BJ)) in China in the winter 2012–12 were analyzed by gas chromatography-mass spectrometry. The biological effects of organic extracts were assayed using the human bronchial epithelial cells BEAS-2B. All sixteen priority PAHs can be found in the PM2.5 samples of XA and BJ, but not in HK, GZ and XM, demonstrating the differential spatial source and distribution of PAHs. Our results showed that the total PAHs ranged from 3.35 to 80.45 ng/m3 air, leading by BJ, followed by XA, XM, GZ and HK. In the cell culture study, transcript levels of pro-inflammatory cytokine interleukin-6 (IL-6), CYP1A1 and CYP1B1 were found to be induced in the treatment. The cells exposed to extracts from XA and BJ demonstrated significant migratory activities, indicating a sign of increase of tumorigenicity.

Surface sediments collected from 2001 to 2011 were analyzed for total petroleum hydrocarbons (TPH) and five heavy metals. The sediment concentration ranges of TPH, Zn, Cu, Pb, Cd and Hg were 6.3–535μg/g, 58–332μg/g, 7.2–63μg/g, 4.3–138μg/g, 0–0.98μg/g, and 0.10–0.68μg/g, respectively. These results met the highest marine sediment quality standards in China, indicating that the sediment was fairly clean. However, based on the effects range-median (ERM) quotient method, the calculated values for all of the sampling sites were higher than 0.10, suggesting that there was a potential adverse biological risk in Bohai Bay. According to the calculated results, the biological risk decreased from 2001 to 2007 and increased afterwards. High-risk sites were mainly distributed along the coast. This study suggests that anthropogenic influences might be responsible for the potential risk of adverse biological effects from TPH and heavy metals in Bohai Bay.

The level and source of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments from the Gorgan Bay, Caspian Sea. The sum of 16 PAHs (ΣPAH16) concentrations varied from 107.87 to 516.18ngg−1dry weight, with average value of 270.96±150.47ngg−1dry weight. Ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene, naphthalene, fluoranthene and Pyrene occasionally and frequently may take place in the sediments of Gorgan Bay. PAHs source identification demonstrated that the PAHs come from mixed and pyrogenic origin.

To evaluate the health status at six different study areas, we used the generalized linear model approach with selected biochemical markers in resident fish from uncontaminated and contaminated sites. We also confirmed the independence between the biochemical indices and the morphometric indices including the hepato-somatic index (HSI), gonado-somatic index (GSI), and condition factor (CF) in fish from the sampling areas. The effect of area on the presence of biotransformation markers (ethoxyresorufin-O-deethylase activity; EROD) was significantly high in Masan Bay. The area with the greatest effect on acetylcholinesterase (AChE) activity was Jindong Bay, while there was no significant effect of GSI, HSI, CF, and sex in the EROD model and HSI, CF and sex in the AChE model. These results clarify that fish from Masan, Gwangyang and Jindong Bay were affected by pollutant stress, and the analysis of sensitive biochemical responses allowed for an improved interpretation of the results.

This paper presents the first detailed investigation on the residual levels of organochlorine insecticide (OCI) concentrations in the Cochin estuarine sediment. It aims in elucidate their distribution and ecological impact on the aquatic system. Concentrations of persistent organochlorine compound (OC) were determined for 17 surface sediment samples which were collected from specific sites of Cochin Estuarine System (CES) over a period of November 2009 and November 2011. The contaminant levels in the CES were compared with other worldwide ecosystems. The sites bearing high concentration of organochlorine compounds are well associated with the complexities and low energy environment. Evaluation of ecotoxicological factors suggests that adverse biological effects are expected in certain areas of CES.

Uptake and biological effects of synthetic glucocorticoids (GCs) were analyzed using common carp (Cyprinus carpio). Fish were exposed to clobetasol propionate (CP) or clobetasone butyrate (CB) individually or in mixture at 1μgL−1 for 21days. Bioconcentration factor (BCF) of CB was calculated as 100, and BCF of CP was less than 16. No effects were found in fish erythrocyte and leukocyte numbers and serum glucose levels after exposure to the selected GCs. On the other hand, serum concentrations of free amino acids significantly increased in GC-exposed groups. Thus, exposures to synthetic GCs at relatively low concentrations seemed to cause enhancement of protein degradation and subsequent increase of serum free amino acids without a corresponding increase in serum glucose levels, an effect which might be related to partial induction of gluconeogenesis by GC.

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the sediment from the Hormuz strait, Persian Gulf. The sum of 16 PAHs (ΣPAH) concentrations varied from 72.17 to 277.77ngg−1 dry weight, with an average value of 131.20±59.29ngg−1 dry weight. An ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene and acenaphthylene occasionally may take place in the sediment of Hormuz strait. PAH source identification showed that the PAHs in the sediments come from pyrogenic and mixed origin. Based on classification of pollution levels, sediments from Hormuz strait could be considered as low to moderately polluted with PAHs.

Continuous seawater disinfection by chlorine dioxide (ClO₂) was studied at residual concentrations of 0.2 and 0.4 mg ClO₂ L⁻¹ and compared with sodium hypochlorite (NaClO) disinfection at 1 mg L⁻¹ of free chlorine. The results revealed that both disinfectants decrease the biological activity and cell counts in seawater. When NaClO was used, both the cell counts and the adenosine triphosphate (ATP) level were diminished (1.8 log and 76 %, respectively); however, when ClO₂ was used, the ATP level decreased to the same level as with NaClO (78–84 %), but the cell counts were reduced only weakly (~0.1 log). The biofilm concentration in seawater without disinfectants reached 700 pg ATP cm⁻² after 40 days, whereas in the treated lines, the biofilms remained below 1 pg ATP cm⁻² irrespective of the disinfectant and dose used. ClO₂ generated much less trihalomethanes than NaClO (<1 vs. 154 μg L⁻¹). Bromoform (77–96 %) was the predominant chemical species found in disinfected seawater.