We investigated bottom-water hypoxia induced by freshwater discharge from two artificial dykes into Chunsu Bay (CSB), Korea, during the summer of 2010. Field observations and model results of the dynamic and water-quality parameters indicated that the triggering mechanism of the hypoxia was strong stratification formed by the freshwater discharge from both dykes, which limited the dissolved oxygen (DO) supply in bottom water. Beneath the pycnocline, DO was consumed by sediment oxygen demand (SOD) during the summer. To investigate these processes, model experiments were conducted using a simplified DO budget model coupled with a 3D hydrodynamic model. The DO concentration in the northern part of CSB reached hypoxic conditions very quickly after 3.4days of discharge and lasted 18days until normal conditions resumed. In sum, in the CSB, marked stratification and its maintenance played a critical role in hypoxia in bottom water.

Terrestrial runoff and flooding have resulted in major impacts on coral communities worldwide, but we lack detailed understanding of flood plume conditions and their ecological effects. Over the course of repeated flooding between 2010 and 2013, we measured coral cover and water quality on the high-latitude coral reefs of Hervey Bay, Queensland, Australia. In 2013, salinity, total suspended solids, total nitrogen and total phosphorus were altered for up to six months post-flooding. Submarine groundwater caused hypo-saline conditions for a further four months. Despite the greater magnitude of flooding in 2013, declines in coral abundance (∼28%) from these floods were lower than the 2011 flood (∼40%), which occurred immediately after a decade of severe drought. There was an overall cumulative decrease of coral by ∼56% from 2010 to 2013. Our study highlights the need for local scale monitoring and research to facilitate informed management and conservation of catchments and marine environments.

In this study, the occurrence and spatial distribution of 38 antibiotics in surface water and sediment samples of the Hailing Bay region, South China Sea, were investigated. Twenty-one, 16 and 15 of 38 antibiotics were detected with the concentrations ranging from <0.08 (clarithromycin) to 15,163ng/L (oxytetracycline), 2.12 (methacycline) to 1318ng/L (erythromycin–H2O), <1.95 (ciprofloxacin) to 184ng/g (chlortetracycline) in the seawater, discharged effluent and sediment samples, respectively. The concentrations of antibiotics in the water phase were correlated positively with chemical oxygen demand and nitrate. The source analysis indicated that untreated domestic sewage was the primary source of antibiotics in the study region. Fluoroquinolones showed strong sorption capacity onto sediments due to their high pseudo-partitioning coefficients. Risk assessment indicated that oxytetracycline, norfloxacin and erythromycin–H2O posed high risks to aquatic organisms.

Children's exposure to air pollutants is an important public health challenge. Particular attention should be paid to preschools because younger children are more vulnerable to air pollution than higher grade children and spend more time indoors. The purpose of this study was to compare the indoor air quality (IAQ) at nursery schools located in Gliwice, Poland.We investigated the concentrations of volatile organic compounds (VOCs), particulate matter (PM) and bacterial and fungal bioaerosols, as well as carbon dioxide (CO2) concentrations in younger and older children's classrooms during the winter season at two urban nursery schools, located within traffic and residential areas. The concentration of the investigated pollutants in indoor environments was higher than those in outdoor air. The results clearly indicate the problem of elevated concentrations of PM2.5 and PM10 inside the classrooms. High levels of CO2 exceeding 1000 ppm in relation to outdoor air also confirmed the low indoor air quality of classrooms. This is concerning in terms of the exposure effects on the health of children. The relation between IAQ in older and younger children's classrooms was also statistically significant in the case of PM and CO2.Improving ventilation, decreasing the occupancy per room and completing cleaning activities following occupancy periods can contribute to alleviating high CO2 and particle levels.

The work investigated concentration of trace metals in surface sediments (0–10cm; < 63μm grain size) from 15 sampling sites of diverse environmental stresses covering Hugli River Estuary (HRE) and Sundarban Mangrove Wetland (SMW), eastern coastal part of India. The trace metal concentrations in sediments exhibited an overall decreasing trend as follows: Cr (21.2–60.9)>Cu (11.60–102.47)>Ni (19.10–52.60)>Pb (7.09–183.88)>As (4.41–11.46)>Cd (0.02–4.4)>Ag (0.02–0.87). Both the geo-accumulation index (Igeo) and contamination factor (CF) values revealed significant pollution by Ag, Cd and Pb at Nurpur of HRE. Potential Ecological Risk Index (RI) (61.21±112.40) showed wide range of variations from low (19.76) to serious (463.20) ecological risk. A positive significant correlation was found between metals and organic carbon in sediments. The ecological risk associated with the trace metals in sediment was considered on the consensus based Sediment Quality Guidelines (SQGs). The work suggests that the trace metals present in sediments posed adverse effects on the sediment-dwelling organisms.

A considerable number of Ireland’s shellfish production areas co-occur with or are adjacent to Natura 2000 sites which are protected under European legislation. To investigate the general interaction between trestle oyster cultivation and the surrounding intertidal environment, six sites were selected within designated Natura 2000 sites. At each trestle site three Treatment areas were sampled. One Treatment area corresponded to potential impacts associated with cultivation activities occurring at trestle structures (designated the Trestle Treatment) while one Treatment area corresponded to potential impacts due to cultivation activities occurring along access routes (the Access Treatment). An area not subject to any known anthropogenic activity was used as a control (the Control Treatment). Potential impacts associated with Trestle Treatment areas included changes in sediment total organic matter (TOM) levels underneath trestles due to the bio-deposition of faecal/pseudofaecal material while the predominant impact associated with Access Treatment areas was compaction of sediments due to heavy vehicle traffic. In this study, macrobenthic communities at the sites were highly variable and exhibited low levels of diversity which prevented the detection of general effects of cultivation activity on community structure, diversity and secondary production. To overcome this variability, the Infaunal Quality Index (IQI) was used to assess impacts on Ecological Status (ES) of benthic communities (sensu Water Framework Directive). Relative to Control and Trestle Treatment areas, activities occurring at Access Treatment areas had a significant negative impact on ES. This study highlights the potential of the IQI for the management of aquaculture activity and provides validation for the use of the IQI in Irish intertidal environments. This study also highlights the IQI as a potential tool for assessing the conservation status of designated habitats in Natura 2000 sites.

Secondary organic aerosol (SOA) from the photooxidation of aromatic compounds is a very complex mixture containing products with a different chemical nature that are dependent on aging processes. In this study, we focus on the chemical characterization of major products that are formed from the OH–initiated oxidation of 1,3,5–trimethylbenzene and subsequent aging through OH–initiated reactions in the presence of NOx.The chemical composition of aged particles were measured in real–time by an aerosol laser time of flight mass spectrometer (ALTOFMS) coupled with Fuzzy C–Means (FCM) clustering algorithm. Experimental results demonstrated that methyl glyoxylic acid, 2–methyl–4–oxo–2–pentenoic acid, 3,5–dimethylbenzoic acid, 2–methyl–2,3–dihydroxyl–4–oxo–pentanoic acid, dimethyl–nitrophenol, 3,4–dimethyl–2–hydroxy–3–oxo–pentandioic acid, 2,4–dimethyl–2,3–dihydroxy–6–oxo–4–heptenoic acid, 2,4–dimethyl–4–hydroxy–2,3–epoxy– heptylic acid, 2,4–dimethyl–2,3,4–trihydroxy–5,6–dioxo–heptylic acid, and oligomer components were the predominant products in the aging particles. The possible reaction mechanisms leading to these aged products were also discussed and proposed.

Although cephalopod early life stage development often occurs in coastal areas where contamination is real and continuous, the physiological perturbations induced by contaminants have been rarely investigated. This study focused on the Zn as it is one of the trace metals the most concentrated in coastal waters, worldwide. As Zn-tolerance limits were unknown in juvenile Sepia officinalis, the aim of this study was to estimate the threshold inducing mortality during the 2-first weeks post-hatching, and to determine its sensitivity using digestive and immune enzymatic assays, as well as growth and behavior follow-up during the first 5weeks post-hatching. Our study highlighted a Zn-mortality threshold lying between 185 and 230μgl−1, and growth reductions occurring after 5-week at 108μgl−1 and above, associated with enzymatic perturbations. These results underline a relatively important sensitivity of juvenile cuttlefish to Zn, pointed out by a wide diversity of biomarkers.

Discharge of sewage to the coastal areas resulting in the deteriorating quality of seawater and polluted sediments has been one of important stressor in Kuwait. The objective of this study was to conduct spatial assessment of sewage contamination of coastal areas. The assessment was carried out by measuring fecal sterols as indicator of sewage contamination, in the marine sediments collected from 112 locations throughout the Kuwait’s marine areas. The samples were extracted and sterols separated. Derivatized sterols were analyzed by GC/MS in selected ion monitoring mode. The results showed that areas in the vicinity of the sewage outfalls were heavily contaminated. The western part of Kuwait Bay was worst in terms of contamination level. Two off-shore sites in Kuwait Bay were also classified as contaminated. Coprostanol levels in Kuwait Bay ranged from 0 to 39,428ng/g. Southern coastal areas were less severely contaminated.

One-hundred and thirty-four samples of mussels (Mytilus galloprovincialis) collected along Central Adriatic Sea in 2013 were examined to determine the levels of fifteen congeners of polybrominated diphenyl ethers (PBDEs). The purified samples were analysed by gas-chromatography coupled to tandem mass spectrometry (GC-MS/MS) applying the isotopic dilution. Only four congeners (PBDE 47, PBDE 99, PBDE 49 and PBDE 100) were present above the established limits of quantification with mean concentrations equal to 73, 30, 19 and 18pgg−1, respectively. The concentrations of PBDEs (sum) ranged from 27 to 386pgg−1, with the highest levels around the coastal area of Ancona town. The here found levels were comparable to those measured in mussels collected along Southern Adriatic Sea.