The use, environmental fate and ecological risks of antibiotics applied in tilapia cage farming were investigated in the Tha Chin and Mun rivers in Thailand. Information on antibiotic use was collected through interviewing 29 farmers, and the concentrations of the most commonly used antibiotics, oxytetracycline (OTC) and enrofloxacin (ENR), were monitored in river water and sediment samples. Moreover, we assessed the toxicity of OTC and ENR on tropical freshwater invertebrates and performed a risk assessment for aquatic ecosystems. All interviewed tilapia farmers reported to routinely use antibiotics. Peak water concentrations for OTC and ENR were 49 and 1.6 μg/L, respectively. Antibiotics were most frequently detected in sediments with concentrations up to 6908 μg/kg d.w. for OTC, and 2339 μg/kg d.w. for ENR. The results of this study indicate insignificant short-term risks for primary producers and invertebrates, but suggest that the studied aquaculture farms constitute an important source of antibiotic pollution.

Floods are an important factor determining riverine pollution loads, including toxic mercury (Hg). The impact of the Vistula River flood in 2010, which was the biggest one recorded in 160 years and its influence on marine environment was studied. Mercury concentration was analyzed in river and sea water, suspended matter, phytoplankton and sea surface sediment. Flood and gulf water contained several times higher concentration of Hg (exceeded reference values safe for aquatic organisms) than before or after the flood. In 2010 the Vistula introduced into the Baltic ca. 1576 kg of Hg, of which 75% can be attributed to the flood water. Increase of water temperature, decrease of oxygen content contended increasing of dissolved mercury concentration, which was transported far into the Baltic. This phenomenon led to an increase of Hg concentration in phytoplankton and during many months in surface sediments. It is a potential threat to marine organisms.

The chemical composition of Beijing aerosol was measured during summer and winter. Two distinct episodes were identified. Water-soluble potassium (K+) increased significantly during the firework episode in winter with an episode to non-episode ratio of 4.97, whereas the biomass burning (BB) episode in summer was characterized by high episode to non-episode ratios of levoglucosan (6.38) and K+ (6.90). The BB and firework episodes had only a minor influence on the water-soluble OC (organic carbon) to OC ratio. Based on separate investigations of episode and non-episode periods, it was found that: (i) sulfate correlated strongly with both relative humidity and nitrate during the typical winter period presumably indicating the importance of the aqueous-phase oxidation of sulfur dioxide by nitrogen dioxide, (ii) oxalate and WSOC during both winter and summer in Beijing were mainly due to secondary formation, and (iii) high humidity can significantly enhance the formation potential of WSOC in winter.

The AQUATOX model considers the direct toxic effects of chemicals and their indirect effects through foodwebs. For this study, the AQUATOX model was applied to evaluating the ecological risk of Polybrominated diphenyl ethers (PBDEs) in a highly anthropogenically disturbed lake-Baiyangdian Lake. Calibration and validation results indicated that the model can adequately describe the dynamics of 18 biological populations. Sensitivity analysis results suggested that the model is highly sensitive to temperature limitation. PBDEs risk estimate results demonstrate that estimated risk for natural ecosystems cannot be fully explained by single species toxicity data alone. The AQUATOX model could provide a good basis in ascertaining ecological protection levels of “chemicals of concern” for aquatic ecosystems. Therefore, AQUATOX can potentially be used to provide necessary information corresponding to early warning and rapid forecasting of pollutant transport and fate in the management of chemicals that put aquatic ecosystems at risk.

The levels of 25 elements in house dust collected from 100 general Japanese residences were measured. Factor analysis was applied on the multi-element data to explore source of Pb (median concentration 49.1 mg/kg) in house dust. Six factors were extracted and Pb was found to have great loading on the fifth factor with Sb and Sn, suggesting solder (Sn), and plastic and metals (Sb) may be the sources of Pb in the house dust of Japanese residences. No significant loading was found on soil-related factors indicating non-significant contribution of Pb in track-in soil. Seven heavy metals (Cd, Cu, Mo, Pb, Sb, Sn, and Zn) were found in house dust at >10 times more condensed than crustal abundance. Health risk of these elements to children via the ingestion of house dust was estimated based on the comparison with tolerable daily intake and found to be non-significant for most of the elements.

Assessing protein responses to endocrine disrupting chemicals is critical for understanding the mechanisms of chemical action and for the assessment of hazards. In this study, the response of the liver proteome of male rare minnows (Gobiocypris rarus) treated with 17β-estradiol (E2) and females treated with 17α-methyltestosterone (MT) were analyzed. A total of 23 and 24 proteins were identified with differential expression in response to E2 and MT, respectively. Pyruvate carboxylase (PC) was the only common differentially expressed protein in both males and females after E2- and MT-treatments. The mRNA as well as the protein levels of PC were significantly down-regulated compared with that of the controls (p < 0.05). Our results suggest that endocrine disruptors interfere with genes and proteins of the TCA cycle and PC may be a sensitive biomarker of exposure to exogenous steroid chemicals in the liver of fish.

Three types of labeled silica nanoparticles were used in transport experiments in saturated sand. The goal of this study was to evaluate both the efficiency of labeling techniques (fluorescence (FITC), metal (Ag(0) core) and radioactivity (110mAg(0) core)) in realistic transport conditions and the reactive transport of silica nanocolloids of variable size and concentration in porous media. Experimental results obtained under contrasted experimental conditions revealed that deposition in sand is controlled by nanoparticles size and ionic strength of the solution. A mathematical model is proposed to quantitatively describe colloid transport. Fluorescent labeling is widely used to study fate of colloids in soils but was the less sensitive one. Ag(0) labeling with ICP-MS detection was found to be very sensitive to measure deposition profiles. Radiolabeled (110mAg(0)) nanoparticles permitted in situ detection. Results obtained with radiolabeled nanoparticles are wholly original and might be used for improving the modeling of deposition and release dynamics.

Carbon monoxide (CO) emissions in China in 2005–2010 were estimated by inversion, using the Green's function method from vertical CO profiles derived from MOPITT Version 5 satellite data and a tagged CO simulation, and validated with independent in situ observations from the World Data Centre for Greenhouse Gases. Modeling with a posteriori emission successfully reproduced CO outflow from the continent to the East China Sea, Sea of Japan, and Japanese islands during winter and spring, and compensated for underestimates in central and eastern China in summer. A posteriori emissions showed large seasonal variations in which December and March emissions were on average 23% larger than August emissions, consistent with other studies. Estimated Chinese CO emissions were 184.4, 173.1, 184.6, 158.4, 157.4, and 157.3 Tg/year for 2005–2010, respectively. The decrease after 2007 is partly attributed to Chinese socioeconomic conditions and improved combustion efficiency.

This study is intended to examine the quality and quantity of floating plastic debris in the River Seine through use of an extensive regional network of floating debris-retention booms; it is one of the first attempts to provide reliable information on such debris at a large regional scale. Plastic debris represented between 0.8% and 5.1% of total debris collected by weight. A significant proportion consisted of food wrappers/containers and plastic cutlery, probably originating from voluntary or involuntary dumping, urban discharges and surface runoff. Most plastic items are made of polypropylene, polyethylene and, to a lesser extent, polyethylene terephthalate. By extrapolation, some 27 tons of floating plastic debris are intercepted annually by this network; corresponding to 2.3 g per Parisian inhabitant per year. Such data could serve to provide a first evaluation of floating plastic inputs conveyed by rivers.

Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol®1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally.