The environmental risk analysis of aquatic systems includes the evaluation of the likelihood that adverse ecological effects may occur as a result of exposure to one or more stressors. In harbor areas, pollution is provided by a complex mixture of substances with different levels of toxicity, persistence and bioaccumulation, which complicates the hazards characterization and their multiple effects. A study of the relationship between the environmental impact and the environmental risk assessment at a specific isolated oil handling facility was undertaken. The environmental risk of the oil handling facility, considering the consequences of specific pollutants, was estimated and the associated environmental impact was quantified based on a ‘weights of evidence’ approach. The contamination quantified at the potentially affected area around the monobuoy of Tarragona has proved to be related with environmental risk estimations but the lines of evidence obtained do not allow us to assert that the activity developed at this facility has an associated environmental impact.

A method based on phospholipid fatty acid (PLFA) analysis for profiling microbial communities in offshore produced water was optimized. The operation parameters affecting final PLFA profiling performance from the solid phase extraction (SPE) purification and fatty acid methyl esters (FAMEs) yielding process were investigated. Under the selected conditions, 92.9%, 96.3% and 92.8% of the spiked phospholipid standards C16:1 (cis-9) PC, C18:1 (cis-9) PC, and C19:0 PC were recovered, respectively, using 10mL methanol as elution solvent on a non-commercial SPE column. Over 90% of spiked C19:0 PC was recovered before sample transesterification. Four parameters including alkaline reagent, volume of acid for neutralization, time and temperature for FAMEs derivatization were examined. Gas Chromatography-Mass Spectrometry (GC-MS) was used to analyze FAMEs and the method linearities, recoveries of 29 FAMEs during transesterification, detection limits, relative standard deviations were presented. The results provided valuable information for biological reservoir souring control.

Light-sticks are used as bait in surface long-line fishing, to capture swordfish and other large pelagic predators. When discharged in the ocean, it may reach the beaches. The traditional Brazilian community of Costa dos Coqueiros, Bahia, use light-sticks as a medicine for rheumatism, vitiligo and mycoses. It may affect the marine life when its content leak in the open ocean. This work evaluated and identified the acute and chronic toxicity of the light-stick. A high acute toxicity was observed in the mobility/mortality of Artemia sp.; in the fertilization of sea urchin eggs, and a high chronic toxicity in the development of the pluteus larvae of the same sea urchin. The main compounds that probably caused toxicity were the volatiles such as the fluorescent PAH and oxidants such as the hydrogen peroxide. Its disposal in the open ocean is a potential threat for marine life.

Six marine biota species were collected from the Xuande Atoll, South China Sea to investigate the bioaccumulation of dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE) and dechlorane plus (DP). Pike conger (Muraenesox talabonoides) had the highest concentrations of halogenated organic pollutants (HOPs) among the six marine biota species. DDTs were the predominant HOPs, followed by PCBs and PBDEs, with minor contributions of DBDPE and DP. Twenty-one percent of samples had ratios of (DDE+DDD)/ΣDDTs lower than 0.5, implying the presence of fresh DDT inputs in the environment of the Xuande Atoll. The biomagnification factor values for DDTs, PCBs, PBDEs and DP were higher than 1, suggesting biomagnification of these contaminants in the marine food chains. Consumption of seafood from the Xuande Atoll might not subject local residents in the coastal areas of South China to health risks as far as HOPs are concerned.

Dinoflagellate community structure from two semi-enclosed areas along the South Andaman region, India, was investigated to assess the anthropogenic impact on coastal water quality. At the densely inhabited Port Blair Bay, the dominance of mixotrophs in water and Protoperidinoids in sediments was attributed to anthropogenic nutrient enrichment and prey availability. A significant decrease in dinoflagellate abundance from inner to outer bay emphasize the variation in nutrient availability. The dominance of autotrophs and Gonyaulacoid cysts at the North Bay highlight low nutrient conditions with less anthropogenic pressure. The occurrence of oceanic Ornithocercus steinii and Diplopsalis sp. could evince the oceanic water intrusion into the North Bay. Nine potentially harmful and red-tide-forming species including Alexandrium tamarense complex, A. minutum were identified in this study. Although there are no harmful algal bloom (HABs) incidences in this region so far, increasing coastal pollution could support their candidature towards the future HABs initiation and development.

The multiple-contamination of heavy metals and nutrients worsens increasingly and Ulva sp. green tide occurs almost simultaneously. To reveal the biological mechanism for outbreak of the green tide, Ulva pertusa was exposed to seven-day-multiple-contamination. The relation between pH variation (VpH), Chl a content, ratio of (Chl a content)/(Chl b content) (Rchla/chlb), SOD activity of U. pertusa (ASOD) and contamination concentration is VpH=1.72±0.38+1.68±0.72×10−4×Cammonia2 (p<0.05), Cchla=0.88±0.09−0.01±0.00×CCd (p<0.05), Rchla/chlb=0.72±0.04−0.35±0.08×10−4×CCd2 (p<0.05), and ASOD=25.64±2.35−0.41±0.09×10−2×CZn2+0.54±0.10×CZn (p<0.05), respectively. Cammonia, CCd and CZn is concentration of ammonia, Cd2+ and Zn2+, respectively. Comparing the contamination concentrations of seawaters where Ulva sp. green tide occurred and the contamination concentrations set in the present work, U. pertusa can adapt to multiple-contaminations in these waters. Thus, the adaption to multiple-contamination may be one biological mechanism for the outbreak of Ulva sp. green tide.

Three to six-month-old juveniles of Acropora tenuis, A. millepora and Pocillopora acuta were experimentally co-exposed to nutrient enrichment and suspended sediments (without light attenuation or sediment deposition) for 40days. Suspended sediments reduced survivorship of A. millepora strongly, proportional to the sediment concentration, but not in A. tenuis or P. acuta juveniles. However, juvenile growth of the latter two species was reduced to less than half or to zero, respectively. Additionally, suspended sediments increased effective quantum yields of symbionts associated with A. millepora and A. tenuis, but not those associated with P. acuta. Nutrient enrichment did not significantly affect juvenile survivorship, growth or photophysiology for any of the three species, either as a sole stressor or in combination with suspended sediments. Our results indicate that exposure to suspended sediments can be energetically costly for juveniles of some coral species, implying detrimental longer-term but species-specific repercussions for populations and coral cover.

The ultraviolet (UV)-based advanced oxidation process (AOP) is a powerful technology commonly utilised in recent potable water reuse (PR) schemes. The AOP involves the generation of highly reactive free radicals (e.g. hydroxyl, HO•) and is primarily applied for the removal of two target trace organic chemicals—N-nitrosodimethylamine (NDMA) and 1,4-dioxane — in the PR schemes. Both of these organics are not well removed by the reverse osmosis (RO) process. NDMA is a probable carcinogen and is often present in reclaimed water at concentrations higher than the guidelines established for PR. This review aimed to provide an understanding of the current UV-based advanced oxidation technologies for NDMA removal in PR, their limitations and the future of advanced technologies for their removal. NDMA is readily photolysed by direct UV irradiation, while an AOP such as UV/H₂O₂ process is necessary for the destruction of 1,4-dioxane. Unfortunately, the generation of hydroxyl radicals through UV photolysis of H₂O₂ is largely inefficient with conversion on the order of 20% under normal plant operations and the addition of H₂O₂ (e.g. 3 mg/L) provides only a negligible improvement in NDMA destruction. However, AOP can also be achieved without continuous chemical addition through the application of UV irradiation to heterogeneous photocatalysts (e.g. TiO₂). The UV/TiO₂ process generates hydroxyl radicals and singlet oxygen molecules, both of which degrade NDMA into by-products (e.g. methylamine or dimethylamine). Recent studies revealed that modification of the surface morphology of TiO₂ can not only enhance NDMA destruction but also alter the composition of the degradation by-products.

Atmospheric reactive nitrogen (N) has induced large impacts on air pollution and ecosystem health worldwide. Atmospheric reactive N emission and deposition have largely increased in China since 1980 due to rapid agricultural, industrial, and urban development. But scientific gaps still remain in the regional and temporal variability in atmospheric N emissions and deposition. Meanwhile, the environmental impacts of N pollution and deposition are of great concern in China. This paper overviews the status of anthropogenic N emissions and deposition and their linkages to air pollution in China. The major findings include two aspects: (1) anthropogenic reactive N (e.g., NH₃ and NOₓ) emissions contribute greatly to secondary inorganic aerosol formation and haze pollution and (2) dry N deposition is comparable in importance to wet N deposition, suggesting that both dry and wet deposition should be quantified simultaneously. Future research challenges on atmospheric N emission and deposition are discussed as well. China needs to (1) reduce the uncertainties of national emission inventory of various N species, especially organic N compounds; (2) establish national networks for atmospheric N concentration and deposition monitoring; and (3) evaluate ecological and environmental impacts of N pollution and deposition in typical ecosystems. Last but not least, N deposition modeling tools should be improved based on localized parameters and further used in future N regulation.

This paper presents a systematic but preliminary study on the levels, sources and risk of exposure to polycyclic aromatic hydrocarbons (PAHs) in the Yellow River estuary by examining 16 priority PAHs listed by the U.S. EPA in four main environmental media (soil, surface water, groundwater and sediment). The concentration of individual PAHs in each medium in the study area was compared with the reported PAH values in China and abroad and to related environmental quality standards. The pollution levels of PAHs were found to be moderate in the soil and sediment, and low in the surface water and groundwater. Wood, coal combustion and petroleum inputs are the main PAH sources in soil and sediment, while petroleum inputs and petroleum combustion are the main PAH sources in surface water and groundwater. This indicates that PAH input caused by the high-speed inflow of external water over a long time has made a definite contribution to the occurrence of PAHs in surface water and groundwater in the study area. Furthermore, the mean value of the sum of the Excess Lifetime Cancer Risk (∑ELCR) exposure to PAHs in all media exceeded the generally acceptable risk level of 1.0E−06 recommended by the USEPA for carcinogenic chemicals, and the relative proportion contributed by DBA to the ∑ELCR was the greatest.