Models for the formation of biogenic iodine in marine aerosols have been proposed in the literature. Here, we analyse the possible species and reactions that could occur in the proposed models. We calculate the enthalpies of formation for the species and the enthalpies of corresponding reactions. We propose a modified model using iodous acid (HOIO) and reactions that are particularly suited to humid conditions.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organised by Dr. Branimir Jovancicevic 相似文献
Environmental appearance of Q1, a natural heptachloro compound with the molecular formula C9H3Cl7N2, was studied in samples from different sites all over the world. Q1 was expected to have a bipyrrole backbone, similar to other compounds ascribed to natural sources. A method for isolation of Q1 was developed by combination of adsorption chromatography on silica and normal phase HPLC with an amino phase. UV-detection of Q1 supports the aromatic character of the compound.
The high levels detected in samples of marine mammals and birds suggested that Q1 is both a persistent and a bioaccumulative contaminant. This was underscored by calculated log KOW in the range of other lipophilic organohalogens. In accordance with earlier studies, highest Q1 concentrations were found in the Southern Hemisphere, but with a highly selective GC/ECNI-MS-SIM method, detection of Q1 was also achieved in many samples from the Northern Hemisphere. In addition to marine mammals and birds, Q1 was also detected in fish from the Mediterranean Sea and the Antarctic. Traces were also detected in SRM 1588 certified cod liver oil, but Q1 was not detected in fish from Hong Kong and Lake Baikal. 相似文献
Marine ecosystems are under high demand for human use, giving concerns about how pressures from human activities may affect their structure, function, and status. In Europe, recent developments in mapping of marine habitats and human activities now enable a coherent spatial evaluation of potential combined effects of human activities. Results indicate that combined effects from multiple human pressures are spread to 96% of the European marine area, and more specifically that combined effects from physical disturbance are spread to 86% of the coastal area and 46% of the shelf area. We compare our approach with corresponding assessments at other spatial scales and validate our results with European-scale status assessments for coastal waters. Uncertainties and development points are identified. Still, the results suggest that Europe’s seas are widely disturbed, indicating potential discrepancy between ambitions for Blue Growth and the objective of achieving good environmental status within the Marine Strategy Framework Directive.Supplementary informationThe online version of this article (10.1007/s13280-020-01482-x) contains supplementary material, which is available to authorized users. 相似文献
Surficial sediment samples were wet digested (HNO3‐HCI‐HF) and analysed by atomic absorption spectroscopy. The background values in the area, and the Pollution Index Load in the sampling points were calculated. Metal inputs of continental origin are specially important in Deva, Oria and Urola river mouths. 相似文献