In this study, a spatial dynamic model was developed, to simulate nitrogen dynamics in Van Hoi commune, Tam Duong district, Vietnam, for different soil and land use types, under different irrigation and fertilizer regimes. The model has been calibrated using measured nitrogen concentrations in soil solution in March and August 2004 and validated for data from March and August 2005. Lateral flow was low in this level area. Percolation was the main process leading to high nitrogen leaching losses to ground water. Calculated annual leaching losses varied from 88 to 122 kg N ha-1 in flowers, 64 to 82 in vegetables of the cabbage group, 51 to 76 in chili, 56 to 75 in vegetables of the squash group, and 36 to 55 in rice.

Existing models estimating oil spill costs at sea are based on data from the past, and they usually lack a systematic approach. This make them passive, and limits their ability to forecast the effect of the changes in the oil combating fleet or location of a spill on the oil spill costs. In this paper we make an attempt towards the development of a probabilistic and systematic model estimating the costs of clean-up operations for the Gulf of Finland. For this purpose we utilize expert knowledge along with the available data and information from literature. Then, the obtained information is combined into a framework with the use of a Bayesian Belief Networks. Due to lack of data, we validate the model by comparing its results with existing models, with which we found good agreement. We anticipate that the presented model can contribute to the cost-effective oil-combating fleet optimization for the Gulf of Finland. It can also facilitate the accident consequences estimation in the framework of formal safety assessment (FSA).

The objective was to describe and model varia- tion patterns in individual fish responses to contaminants among estuaries, season and gender. Two hundred twenty- seven adult European flounders were collected in two sea- sons (winter and summer) in four estuaries along the Bay of Biscay (South West France), focusing on a pristine system (the Ster), vs. three estuaries displaying contrasted levels of contaminants (the Vilaine, Loire and Gironde). Twenty-three variables were measured by fish, considering the load of contaminants (liver metals, liver and muscle persistent organic pollutants, muscle polycyclic aromatic hydrocar- bons); the gene expression (Cyt C oxydase, ATPase, BHMT, Cyt P450 1A1, ferritin); the blood genotoxicity (Comet test); and liver histology (foci of cellular alteration–tumour, steatosis, inflammation, abnormal glycogen storage). Ca- nonical redundancy analysis (RDA) was used to model these variables using gender, season and estuary of origin as explanatory variables. The results underlined the homo- geneity of fish responses within the pristine site (Ster) and more important seasonal variability within the three contam- inated systems. The complete model RDA was significant and explained 35 % of total variance. Estuary and season respectively explained 30 and 5 % of the total independent variation components, whilst gender was not a significant factor. The first axis of the RDA explains nearly 27 % of the total variance and mostly represents a gradient of contami- nation. The links between the load of contaminants, the expression of several genes and the biomarkers were ana- lysed considering different levels of chemical stress and a possible multi-stress, particularly in the Vilaine estuary.

We investigated the effects of elevated pCO2 in seawater both on the acute mortality and the reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica with the purpose of accumulating basic data for assessing potential environmental impacts of sub-sea geological storage of anthropogenic CO2 in Japan. Acute tests showed that nauplii of T. japonicus have a high tolerance to elevated pCO2 environments. Full life cycle tests on T. japonicus indicated NOEC = 5800 µatm and LOEC = 37,000 µatm. Adult B. japonica showed remarkable resistance to elevated pCO2 in the acute tests. Embryonic development of B. japonica showed a NOEC = 1500 µatm and LOEC = 5400 µatm. T. japonicus showed high resistance to elevated pCO2 throughout the life cycle and B. japonica are rather sensitive during the veliger stage when they started to form their shells.

Some planktonic groups suffer negative effects from ocean acidification (OA), although copepods might be less sensitive. We investigated the effect of predicted CO2 levels (range 480-750 ppm), on egg production and hatching success of two copepod species, Centropages typicus and Temora longicornis. In these short-term incubations there was no significant effect of high CO2 on these parameters. Additionally a very high CO2 treatment, (CO2 = 9830 ppm), representative of carbon capture and storage scenarios, resulted in a reduction of egg production rate and hatching success of C. typicus, but not T. longicornis. In conclusion, reproduction of C. typicus was more sensitive to acute elevated seawater CO2 than that of T. longicornis, but neither species was affected by exposure to CO2 levels predicted for the year 2100. The duration and seasonal timing of exposures to high pCO2, however, might have a significant effect on the reproduction success of calanoid copepods.

In southern Sri Lanka, irrigation influences the concentrations of faecal bacteria and inorganic toxic contaminants in groundwater. We develop a groundwater vulnerability map describing the potential human health implications of harmful constituents in the Uda Walawe Basin, by overlaying geological and land use data with information describing the irrigation system, the oxygen isotope composition of water bodies, and the concentrations of selected contaminants. Given the limited data available, we examine the spatial distribution of harmful constituents and the potential human health risks. Fluoride poisoning from groundwater is the greatest health threat in our study area, where fluoride concentrations ranging from 0.1 to 9.2 mg/L are associated with a geologic origin. Arsenic occurs in high concentrations, up to 0.4 mg/L, in areas with low recharge, although the source of arsenic is not clear. Nitrate concentrations are low, ranging from 0.4 to 23 mg/L, despite high fertilizer inputs, except in areas with low recharge and non-favourable reducing conditions, where concentrations up to 136 mg/L are found. Faecal bacteria decrease from surface water via shallow groundwater to deep groundwater. Irrigation water appears to play a major role in increasing microbial contamination and diluting inorganic constituents in groundwater. Hence, the most important determinants for mapping groundwater vulnerability are local geology and infiltration of irrigation water. The method we present provides a qualitative, yet practical, alternative to commonly used vulnerability mapping techniques for countries where high human health risk via consumption of groundwater is inevitable, and thus acts as a tool for selecting preventive and curative measures.

The human diet is recognised as one possible major exposure route to the overall perfluorinated alkylated substances (PFAS) burden of the human population, resulting directly from contamination of dietary food items, as well as migration of PFAS from food packaging or cookware. Most European countries carry out national monitoring programs (food basket studies) to monitor contamination with pollutants. Usually, for PFASs, non-coordinated approaches are used in Europe, since food basket studies are mainly carried out by national authorities following national requirements and questions, making comparisons between different countries difficult. A harmonised sampling campaign collecting similar food items in a uniform procedure enabling direct comparison between different regions in Europe was designed. We selected four countries (Belgium, Czech Republic, Italy and Norway), representing the four regions of Europe: West, East, South and North. In spring 2010 and 2011, 20 different types of vegetables were sampled in Belgium, Czech Republic, Italy and Norway. Perfluorinated carboxylic acids (PFCAs) were the main group of detected PFASs, with perfluorinated octanoic acid (PFOA) as the most abundant PFCA (with exception of samples from Czech Republic), followed by perfluorinated hexanoic acid and perfluorinated nonanoic acid. Dietary intake estimates for PFOA show only low human exposure due to vegetable consumption for adults and children, mostly governed by high intake of potatoes.

The hatching process of the Pacific abalone Haliotis discus hannai was prolonged at a pH of 7.6 and pH 7.3, and the embryonic developmental success was reduced. The hatching rate at pH 7.3 was significantly (10.8%) lower than that of the control (pH 8.2). The malformation rates at pH 7.9 and pH 8.2 were less than 20% but were 53.8% and 77.3% at pH 7.6 and pH 7.3, respectively. When newly hatched larvae were incubated for 48 h at pH 7.3, only 2.7% of the larvae settled, while more than 70% of the larvae completed settlement in the other three pH treatments. However, most 24 h old larvae could complete metamorphosis in all four pH treatments. Overall, a 0.3-unit reduction in water pH will produce no negative effect on the early development of the Pacific abalone, but further reduction in pH to the values predicted for seawater by the end of this century will have strong detrimental effects.

The bacteriological and physicochemical characteristics of water and sediment collected in four fisheries situated in the north of Cameroon were evaluated. In these locations, all the analysed parameters (temperature, pH, salinity, conductivity, turbidity, suspended matter, organic matter, phosphates, sulphates, nitrates, chloride, calcium, magnesium, iron and nitrogen) were the highest, except for chlorides. Total mesophile aerobic flora varied between 1.4±0.50×105 in Tibati and 5.57±0.50×106 CFU/mL in Lagdo. Salmonella concentration was comprised between 66.66±1.62 in Tibati and 274±3.16 CFU/mL in Yagoua. There was about 10±0.50 CFU/mL Vibrio in Lagdo and 342.27±5.53 CFU/mL in Maga. Staphylococcus concentration was between 1.4±0.55×103 CFU/mL in Tibati and 4.44±0.9×104 in Maga. Clostridia were comprised between 0.33±0.00 in Tibati and 226.66±4.29 CFU/mL in Maga while Pseudomonas concentration was comprise between 16.26±0.70 in Tibati and 326.66±6.00 CFU/mL in Lagdo. Faecal Streptococcus varied between 0.33±0.00 in Tibati and 238.66±8.15 CFU/mL in Yagoua. The total mesophile aerobic flora was significantly high (P<0,005) in Lagdo while Clostridium, faecal streptococcus, and Streptococcus concentration were significantly high in Maga, Yagoua and Lagdo. Lake's sediments in Maga were the most infected. The different analysis revealed that the fisheries were relatively polluted. Some of the bacteria counted like Pseudomonas and Vibrio might be pathogenic for fishes. (Résumé d'auteur)