Persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), have been detected in abiotic Arctic matrices: surface sediments and seawater from coastal areas in the Kongsfjorden were collected and analyzed. Levels of PCBs varied depending on the sampling site. Total PCB concentrations were between 11.63 (site C2W) and 27.69pgl−1 (site AW). These levels were comparable to those reported previously in lake sediments from the northern Svalbard.The occurrence and biodegradation potential of cold-adapted PCB-oxidizing bacteria in seawater and sediment along the fjord was also evaluated. After enrichment with biphenyl, 246 isolates were obtained with 45 of them that were able to grow in the presence of the PCB mixture Aroclor 1242, as the sole carbon source. The catabolic gene bphA was harbored by 17 isolates with affiliates to the genera Algoriphagus, Devosia and Salinibacterium that have been never reported as able to utilize PCBs, thus deserving further investigation. The total removal of Aroclor 1242 and selected PCB congeners was evaluated at 4 and 15°C for eight bphA-harboring isolates and Gelidibacter sp. DS-10. With few exceptions, tested strains showed greater efficiency at 15 than at 4°C. Isolates were able to reduce most chromatographic peaks by >50%, with some di- and trichlorobiphenyls that were quite totally removed (>90%).

Biota-Sediment Accumulation Factors (BSAFs) of nonylphenols (NPs) and polycyclic aromatic hydrocarbons (PAHs) in Ruditapes philippinarum from the Venice Lagoon (Italy) were determined with the aim to verify whether the routine biomonitoring studies are reliable in contaminated sites. Clams and sediments were collected in field campaigns (October 2003 to June 2004) in three sites of the Venice Lagoon. Results showed that Marghera and Campalto sediments were more contaminated by NPs and PAHs than Poveglia. Different trends were observed in the contamination of clams with the highest BSAFs found at Poveglia. BSAF trend appeared to be inversely related to the contaminant pressure on the sites. These results suggest that clam bioaccumulation is not always representative of the chemical pressure on aquatic biota. The direct correlation between sediment and biota concentrations in contaminated sites can be lost as a function of the site-specific conditions such as sediment toxicity and food availability.

Many people practice open defecation in south Asia. As a result, lot of human waste containing nutrients such as nitrogen (N) and phosphorus (P) enter rivers. Rivers transport these nutrients to coastal waters, resulting in marine pollution. This source of nutrient pollution is, however, ignored in many nutrient models. We quantify nutrient export by large rivers to coastal seas of Bangladesh, India and Pakistan, and the associated eutrophication potential in 2000 and 2050. Our new estimates for N and P inputs from human waste are one to two orders of magnitude higher than earlier model calculations. This leads to higher river export of nutrients to coastal seas, increasing the risk of coastal eutrophication potential (ICEP). The newly calculated future ICEP, for instance, Godavori river is 3 times higher than according to earlier studies. Our modeling approach is simple and transparent and can easily be applied to other data-poor basins.

Vitellogenin (Vtg) is a well-established biomarker of estrogenic exposure in aquatic animals. In vertebrates, Vtg gene transcription is controlled by the estrogen receptors (ERs). Although an ER ortholog is present in molluscs, its role as a transcriptional regulator remains elusive. Here, we tested the hypothesis that in the Sydney rock oyster, Saccostrea glomerata, the ER ortholog activates Vtg gene transcription through specific interaction with its promoter. Luciferase reporter assays indicated that sgER activated both a minimal promoter containing the consensus estrogen-responsive elements (EREs) and the sgVtg promoter in an estrogen-independent manner. The sgVtg promoter-luciferase activation was significantly reduced when any of three putative ERE half sites (½EREs) in the promoter were mutated. Electrophoretic mobility shift assay (EMSA) confirmed that sgER binds specifically to a 68-bp promoter sequence where these ½EREs reside. Overall, the results suggest that sgER is a constitutively active transcription factor that binds and activates the sgVtg promoter.

Severe PM2.5 pollution has become a great challenge to atmospheric pollution control in China. Most of previous aerosol source apportionment studies in China focused only on part of PM2.5 (e.g., organic matter in composition or PM1 in size) or lacked source contributions identified with necessary tempo-spatial variations, which makes the results not convincible enough for policy making. In this study, five various sites were selected for simultaneous PM2.5 observation in an industrial city in the Pearl River Delta (PRD) of South China during all four seasons of 2014. A positive matrix factorization (PMF) model was applied to the datasets of measured chemical species to perform source apportionment with the results as: (1) The annual mean PM2.5 concentration was 52.6 μg/m³, with secondary sulfate, vehicle emissions, secondary organic aerosol (SOA), and secondary nitrate identified as the major sources, contributing 24.6%, 14.5%, 12.0%, and 10.9% to PM2.5, respectively. Ship emissions, fugitive dust, biomass combustion, industrial emissions, and aged sea salt each contributed 3%–8%. (2) The tempo-spatial variations of sources reveal that secondary sulfate, SOA, biomass combustion, and ship emissions had obvious regional pollution characteristics; however, vehicle emissions, secondary nitrate, fugitive dust, and industrial emissions showed obvious local emission characteristics. (3) The exceeding standard polluted days (PM2.5>75 μg/m³) appeared with secondary nitrate, biomass burning, and SOA increasing mostly in concentration, which should be controlled more strictly. This study highlights the importance of SOA in PM2.5 pollution in China, which has been scarcely quantified for bulk PM2.5 in the literature.

A 3-year research program was undertaken to assess potential environmental disturbance caused by the Deepwater Horizon oil spill to the soft-bottom macrobenthic communities within Mexican waters of the northwestern Gulf of Mexico. Community properties and temporal/spatial variability were analyzed besides toxicant parameters such as hydrocarbons and trace-metals. Overall infaunal density increased, taxa proportion changed, and small-size opportunistic organisms prevailed throughout the study. Annual abundance-biomass comparison (ABC) curves revealed progressive stress scenarios from moderate to severe. Concentrations of vanadium, nickel, cobalt, PAHs and AHs increased gradually over time. However, low correlations between benthic density and biogeochemical variables were determined. Initially, sedimentary properties were the main drivers of benthic community structure; subsequently, nickel, vanadium and PAHs, indicative of anthropogenic effect, were highlighted. Interannual variability in the macroinfauna was attributed to the synergy of several environmental factors. Undoubtedly, compounds derived from fossil fuels had a significant disturbance role, but their source remains uncertain.

Panamá's extreme hydroclimate seasonality is driven by Intertropical Convergence Zone rainfall and resulting runoff. River discharge (Q) carries terrestrially-derived barium to coastal waters that can be recorded in coral. We present a Ba/Ca record (1996–1917) generated from a Porites coral colony in the Gulf of Chiriquí near Coiba Island (Panamá) to understand regional hydroclimate. Here coral Ba/Ca is correlated to instrumental Q (R=0.67, p<0.001), producing a seasonally-resolved Reduced Major Axis regression of Ba/Ca (μmol/mol)=Q (m3/s)×0.006±0.001 (μmol/mol)(m3/s)−1+4.579±0.151. Our results support work in the neighboring Gulf of Panamá that determined seawater Ba/Ca, controlled by Q, is correlated to coral Ba/Ca (LaVigne et al., 2016). Additionally, the Coiba coral Ba/Ca records at least 5 El Niño events and identified 22 of the 37 wet seasons with below average precipitation. These data corroborate the Q proxy and provide insight into the use of coral Ba/Ca as an El Niño and drought indicator.

In this paper three well known Gaussian dispersion models have been evaluated for a case study of a steel plant using complete and incomplete upper air meteorological data.In developing countries, the availability of surface and upper air meteorological data is limited. AMS/EPA Regulatory Model (AERMOD), Advanced Dispersion Modeling System (ADMS) and Industrial Source Complex Model (ISC3) have been evaluated for both real and estimated upper meteorological data and the results have been compared with field measurements both in the horizontal and vertical directions.The results show significant differences in predicted concentrations when modeling with real (actual) and estimated upper meteorological data. The differences ranged from 100% to 450%. Comparison of model performance suggests that AERMOD and ADMS with real meteorological data produce consistent results in the horizontal direction while ISC3 output over-predicts in general. In AERMOD and ISC3 the predicted concentrations have a similar trend of variation in the vertical direction but in ADMS the concentration variation in the vertical direction exhibited different trends. In general, the ADMS predicted concentrations under-estimated field observations.The paper suggests that upper data must be used for modeling and the default values must be used with care. In absence of upper meteorological data, users could estimate upper meteorological data by different available algorithm rather than only default option of models.

Canadian Arctic and Subarctic regions experience a rapid decrease of sea ice accompanied with increasing shipping traffic. The resulting time-space changes in shipping noise are studied for four key regions of this pristine environment, for 2013 traffic conditions and a hypothetical tenfold traffic increase. A probabilistic modeling and mapping framework, called Ramdam, which integrates the intrinsic variability and uncertainties of shipping noise and its effects on marine habitats, is developed and applied. A substantial transformation of soundscapes is observed in areas where shipping noise changes from present occasional-transient contributor to a dominant noise source. Examination of impacts on low-frequency mammals within ecologically and biologically significant areas reveals that shipping noise has the potential to trigger behavioral responses and masking in the future, although no risk of temporary or permanent hearing threshold shifts is noted. Such probabilistic modeling and mapping is strategic in marine spatial planning of this emerging noise issues.

Most of urban air quality studies focus on the megacities of North America, Europe and, recently, Asia. Meanwhile, the most polluted urban areas in the world are rapidly growing large, mid-size and small cities of Asia, Middle East, Africa and South America. This raises a question: why relatively smaller cities are more polluted than the megacities? This study presents the first comprehensive decade-long analysis of the effects of fuel and transport regulations on PM2.5 (particulate matter of aerodynamic diameter <2.5 μm) pollution in Quito, a medium-size city of South America. The effectiveness of a number of regulations is quantified through the elaboration of a high accuracy (98%) regression model. The model estimated that the PM2.5 concentrations were reduced by 67.6 μg/m3, combating the effect of city growth and intense motorization, reducing the annual PM2.5 concentrations to 17.4 μg/m3. This study is recommended as a guideline for thousands of other cities worldwide looking for optimal urban particulate pollution management.