Two Source oils and five field collected oil residues from the Deepwater Horizon incident were chemically characterized. Water accommodated fractions (WAFs) of the Source oils and two of the field-weathered oils were prepared to evaluate the impact of natural weathering on the chemical composition and the acute toxicity of the WAFs. Toxicity test species representing different tropic levels were used (the primary producer Skeletonema costatum (algae) and the herbivorous copepod Acartia tonsa). The results suggest that the potential for acute toxicity is higher in WAFs from non-weathered oils than WAFs from the field weathered oils. The Source oils contained a large fraction of soluble and bioavailable components (such as BTEX (benzene, toluene, ethyl benzene, xylenes) and naphthalene), whereas in the surface collected oils these components were depleted by dissolution into the water column as the oil rose to the surface and by evaporative loss after reaching the sea surface.

This paper deals with the detection and quantification of APIs and other priority substances in the Arade River estuary (Portugal) providing the usefulness of Polar Organic Compound Integrative Samplers (POCIS). Thirteen APIs were detected whose variation was site and time dependent. Caffeine was at the highest concentration (804±209ng/L) followed by theophylline (184±44ng/L). Other APIs were analgesic, anticonvulsant, non-steroidal anti-inflammatory drugs, anti-lipidemic, anxiolytic and antidepressants. Twenty pesticides comprising atrazine, diuron, isoproturon, terbutryn and simazine included in the Water Framework Directive priority list were also site and time dependent. Carbendazim occurred at the highest concentration (45±18ng/L at site 1) but atrazine, diuron, isoproturon and simazine levels were below the Environmental Quality Standards. Although the summer impact was unclear, the results highlighted POCIS suitability for profiling these contaminants. This is to our knowledge the first study concerning APIs and pesticides in this area.

The dominant source of coastal pollution adversely affecting the regional coastal water quality is the seasonally variable urban runoff discharged via southern California’s rivers. Here, we use a surface transport model of coastal circulation driven by current maps from high frequency radar to compute two-year hindcasts to assess the temporal and spatial statistics of 20 southern California stormwater discharges. These models provide a quantitative, statistical measure of the spatial extent of the discharge plumes in the coastal receiving waters, defined here as a discharge’s “exposure”. We use these exposure maps from this synthesis effort to (1) assess the probability of stormwater connectivity to nearby Marine Protected Areas, and (2) develop a methodology to estimate the mass transport of stormwater discharges. The results of the spatial and temporal analysis are found to be relevant to the hindcast assessment of coastal discharges and for use in forecasting transport of southern California discharges.

Dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), 2,3,5,6-tetrabromo-p-xylene (pTBX) and pentabromotoluene (PBT) were measured in baby croaker (Collichthys lucidus) and mullet (Osteomugil ophuyseni) collected in 2005 and 2013 from the Pearl River Estuary. DDTs, HCHs, PCBs, and PBDEs were detected in two fish species at concentrations of 150–8100, 1.4–120, 22–560, 2.2–280ng/g lipid wt., respectively. The levels of these chemicals were significantly lower in 2013 than in 2005. The compositions for DDTs, HCHs, and PBDEs in 2013 differed from those in 2005, indicating source changes between the two sampling periods. DP, pTBX and PBT were detected at concentrations of ND–130ng/g lipid wt. No clear temporal trends were found for these contaminants. Overall, these results indicated the effectiveness of regulations and source controls in substantively reducing inputs of these contaminants to the Pearl River Estuary.

Carbonaceous species in PM10 and PM2.5 samples, collected from an urban location at Ahmedabad in India during summer, were analyzed to study variability in water-soluble organic carbon (WSOC) and secondary organic carbon (SOC) along with atmospheric water vapor content. A significant correlation between WSOC and SOC was found indicating major contribution of soluble organic compounds by secondary organic aerosol formation. A strong inverse dependence of WSOC and SOC on atmospheric water vapor content is observed in both PM10 and PM2.5 (at <45% relative humidity, RH) during daytime; whereas data collected during monsoon season at higher RH conditions do not exhibit such relation. Aerosol liquid water content (LWC) calculated from thermodynamic equilibrium model suggests that the decrease in secondary organic aerosol (SOA) with increase in RH occurs when LWC is absent or insignificant amount. The inverse correlation in summertime indicates possible decrease in the extent of heterogeneous photochemical oxidation of precursor volatile organic compounds on mineral aerosol surface with increase in ambient water vapor. These results have implications for SOA estimations on regional scales especially in arid and semi-arid regions where significant amount of fine mineral dust is present.

Coastal lagoons are ecosystems that are relatively enclosed water bodies under the influence of both the terrestrial and the marine environment, being vulnerable to human impacts. Human activities, such as mining extraction, are significant anthropogenic coastal stressors that can negatively affect ecosystems and communities. In light of the above, the objective of this research is to examine the influence of metal mining activities on the composition of sediments of a Mediterranean coastal lagoon, named Mar Menor. This paper presents a comprehensive characterization for grain size, mineralogy, geochemistry and organic matter of sediments of this coastal lagoon, investigating their variation along space and time. Sedimentation dynamics are ruling clearly the grain size predominant in each area of the Mar Menor coastal lagoon, determining the existence of entrainment, transport and sedimentation areas. For minerals, elements and organic matter, sedimentation dynamics are also determining their distribution.

Kuwait is a country with low rainfall and highly concentrated industrial and domestic effluents entering its coastal waters. These can be both treated and untreated. In this study we sampled a series of coastal and open-sea sites and used a variety of analyses to identify those sites requiring the most attention. We used a high throughput GC–MS screen to look for over 1000 chemicals in the samples. Estrogen and androgen screens assessed the potential to disrupt endocrine activity. An oyster embryo development screen was used to assess biological effect potential.The chemical screen identified sites which had high numbers of identified industrial and domestic chemicals. The oyster screen showed that these sites had also caused high levels of developmental abnormalities with 100% of embryos affected at some sites. The yeast screen showed that estrogenic chemicals were present in outfalls at 2–3ng/l E2 equivalent, and detectable even in some open water sites.

The 2011 oil spill in the Bohai Sea was the largest spill event in China. Nine sediment cores were taken near the spill site and environmental factors including Polycyclic Aromatic Hydrocarbon (PAHs), oils, sulfides, organic carbon were measured 6months later. Benthic foraminifera were separated into >150μm (large) and 63–150μm (small) size fractions for 2-cm depth interval of each sediment core. Statistical analyses suggested that the species composition of living foraminifera was impacted by oils, PAHs and sulfides. Large foraminifera were more sensitive to the oils than the small. Abnormal specimens were positively correlated with oils or PAHs. Small forms, however, tended to have high reproduction and mortality. Pollution-resistant and opportunistic taxa were identified to calculate a Foraminiferal Index of Environmental Impacts (FIEI). The FIEI increased from low to high oil-polluted station and from deep layer to surface sediment reflects the impact of oil pollution in this area.

We present a simple neural network and data pre–selection framework, discriminating the most essential input data for accurately forecasting the concentrations of PM10, based on observations for the years between 2002 and 2006 in the metropolitan region of Lisbon, Portugal. Starting from a broad panoply of different data sets collected at several air quality and meteorological stations, a forward stepwise regression procedure is applied enabling to automatically identify the most important variables for predicting the pollutant and also to rank them in order of importance. The importance of this variable ranking is discussed, showing that it is very sensitive to the urban location where measurements are obtained. Additionally, the importance of Circulation Weather Types is highlighted, characterizing synoptic scale circulation patterns and the concentration of pollutants. We then quantify the performance of linear and non–linear neural network models when applied to PM10 concentrations. In the light of contradictory results of previous studies, our results show no clear superiority for the case studied of non–linear models over linear models. While all models show similar predictive performances, we find important differences in false alarm rates and demonstrate the importance of removing weekly cycles from input variables.

Knowledge of the droplet size distribution (DSD) from the Deepwater Horizon (DWH) blowout is an important step in predicting the fate and transport of the released oil. Due to the absence of measurements of the DSD from the DWH incident, we considered herein hypothetical scenarios of releases that explore the realistic parameter space using a thoroughly calibrated DSD model, VDROP-J, and we attempted to provide bounds on the range of droplet sizes from the DWH blowout within 200m of the wellhead. The scenarios include conditions without and with the presence of dispersants, different dispersant treatment efficiencies, live oil and dead oil properties, and varying oil flow rate, gas flow rate, and orifice diameter. The results, especially for dispersant-treated oil, are very different from recent modeling studies in the literature.