News Article | May 19, 2017
The Norwegian Institute for Water Research (NIVA) and The Norwegian Institute for Air Research (NILU) report here on the presence of contaminants in the pelagic food chains in the lakes Mjøsa, Randsfjorden and Femunden and in supplementary material of fish from Tyrifjorden and Vansjø, sampled in 2015. Mercury and persistent organic pollutants (cVMS, PCBs, PBDEs, PFAS) were analyzed in samples of fish from all lakes, as well as pelagic crustaceans in Mjøsa. Among the key findings are that the siloxanes D5 and D6 show trophic magnification in Mjøsa and Randsfjorden and that PFTrA is the dominating PFAS in liver samples of fish. This data from Norwegian monitoring programs make the basis for a suggested EU ban of certain chemicals in personal care products. The levels of environmental contaminants in the pelagic food webs of lake Mjøsa, Randsfjorden and lake Femunden have been mapped since 2013. In these three lakes, there is moderate, little and negligible environmental influence, respectively, of discharges from the local communities, agriculture and industry. The research is done by The Norwegian Institute of Water Research (NIVA) and The Norwegian Institute of Air Research (NILU) on behalf of The Norwegian Environment Agency and is part of the monitoring program "Environmental pollutants in large Norwegian lakes" ("Miljøgifter i store innsjøer"). The monitoring program was started in 2013, and runs for four years. The results from 2015 were in November 2016 published in a comprehensive report, in which supplementary material from fish from lake Tyri (Tyrifjorden) and lake Vansjø were also included. High levels of siloxanes in fish have been recorded in the "Environmental pollutants in large Norwegian lakes" program over several years. This year´s recordings revealed a slight decline compared to previous years, but the levels of siloxanes are still high. Siloxanes are used in large amounts in personal care products like shampoos and soaps. The siloxanes investigated in this program are D4 -- octamethylcyclotetrasiloxane, D5 -- decamethylcyclopentasiloxane, and D6 -- dodecamethylcyclohexasiloxane. These chemicals are used in products that most of us have in our homes. Only in Europe, it is estimated that 20 kilo tons of siloxanes are emitted into the environment every year. The information about siloxanes, and how the chemicals behave when they enter the environment, is still limited, but the knowledge we currently have is worrying. "Siloxanes are not acute toxic, considering the fact that it is something we apply directly on our skin. The problem is that these substances are only slowly degraded in the environment and their concentration build up in the foodweb," says Eirik Fjeld, senior research scientist at NIVA. A few years ago, it was discovered that D4 is toxic to several organisms, and it was replaced with D5 in various personal care products. Now it now turns out that D5 is also harmful. D5 is not regulated by international conventions today, and one reason is that there has not been evidence that the compound builds up (biomagnifies) in the food web -- until now. Data from NIVA´s investigations 2010-2013 are the first to indicate that D5 does biomagnify. The results are controversial, and have evoked debate in the academic communities. Due to NIVA´s findings, D4 and D5 are listed on The Norwegian Environmental Agency´s list of unwanted chemicals, and within 2020, the discharge of D5 will be reduced drastically or totally stopped in Norway. The EU is following, and a restriction of D4 and D5 under the REACH regulations is under consideration. Eating fish from Norwegian lakes poses no risk, says Fjeld, but he stresses that siloxanes are substances that are only slowly degraded, and that we do not fully understand the consequences of them yet. "The precautionary principle, which is used in environmental management, indicates that siloxanes are not something we should emit into nature in an uncontrolled manner," Fjeld says. The municipalities with shoreline to lake Mjøsa have now come together to work for a cleaner lake. On the 10th of November, 55 politicians and specialists gathered at the milk factory at Kapp at the initiative of the museum Mjøsmuseet. This can be the beginning of a new campaign; a new "Action for Mjøsa" (Mjøsaksjon). As part of the "Environmental pollutants in large Norwegian lakes" program, NIVA and NILU have also taken samples of 25 perch off Storøya in lake Tyrifjorden, Hole municipality. The levels of PFOS (perfluoroctanesulfonic acid, a fluorinated compound) in lake Tyrifjorden were comparable with perch in lake Vansjø in Østfold county. Lake Vansjø, which is the smallest lake of the two, has had substantial inflow of PFOS from the local airport Rygge, where PFOS was used in fire extinguisher foams. "PFOS is among the contaminants that we follow closely both nationally and internationally," says Fjeld. He informs that PFOS is now banned in Norway and Europe. "It is concerning that a lake as big as Tyrifjorden has such high concentrations of the substance," he says. The sources of PFOS in lake Tyrifjorden are still unknown. The County Governor (Fylkesmannen) and The Norwegian Environment Agency is now working on establishing a new monitoring program which can follow up the results from the current findings, and they hope this will help identifying the sources of the fluorinated compounds. While legacy persistent organic pollutants (POPs) are declining, mercury shows an opposite trend; There are still high levels of mercury in several of the lakes included in the study. Lake trout from lake Randsfjorden and fish from lake Mjøsa holds the highest concentrations. The Norwegian Food Safety Authority gives dietary advice regarding consumption of fresh water fish. If a trout is bigger than 50 cm, it holds mercury concentrations that exceeds the recommendations of the EU and The Norwegian Food Safety Authority. It is estimated that more than half of the mercury found in air originate from old pollution that is evaporated from soil, water and sediments.
Cerrone F.,Institute of Water Research |
del Mar Sanchez-Peinado M.,Institute of Water Research |
Juarez-Jimenez B.,Institute of Water Research |
Juarez-Jimenez B.,University of Granada |
And 4 more authors.
Journal of Microbiology and Biotechnology | Year: 2010
Azotobacter chroococcum H23 (CECT 4435), Azotobacter vinelandii UWD, and Azotobacter vinelandii (ATCC 12837), members of the family Pseudomonadaceae, were used to evaluate their capacity to grow and accumulate polyhydroxyalkanoates (PHAs) using two-phase olive mill wastewater (TPOMW, alpeorujo) diluted at different concentrations as the sole carbon source. The PHAs amounts (g/l) increased clearly when the TPOMW samples were previously digested under anaerobic conditions. The MNR analysis demonstrated that the bacterial strains formed only homopolymers containing β-hydroxybutyrate, either when grown in diluted TPOMW medium or diluted anaerobically digested TPOMW medium. COD values of the diluted anaerobically digested waste were measured before and after the aerobic PHA-storing phase, and a clear reduction (72%) was recorded after 72 h of incubation. The results obtained in this study suggest the perspectives for using these bacterial strains to produce PHAs from TPOMW, and in parallel, contribute efficiently to the bioremediation of this waste. This fact seems essential if bioplastics are to become competitive products.
Gonzalez-Martinez A.,University of Granada |
Leyva-Diaz J.C.,University of Granada |
Rodriguez-Sanchez A.,Institute of Water Research |
Munoz-Palazon B.,Institute of Water Research |
And 4 more authors.
Biofouling | Year: 2015
A bench-scale pure moving bed bioreactor-membrane bioreactor (MBBR-MBR) used for the treatment of urban wastewater was analyzed for the identification of bacterial strains with the potential capacity for calcium carbonate and struvite biomineral formation. Isolation of mineral-forming strains on calcium carbonate and struvite media revealed six major colonies with a carbonate or struvite precipitation capacity in the biofouling on the membrane surface and showed that heterotrophic bacteria with the ability to precipitate calcium carbonate and struvite constituted ~7.5% of the total platable bacteria. These belonged to the genera Lysinibacillus, Trichococcus, Comamomas and Bacillus. Pyrosequencing analysis of the microbial communities in the suspended cells and membrane biofouling showed a high degree of similarity in all the samples collected with respect to bacterial assemblage. The study of operational taxonomic units (OTUs) identified through pyrosequencing suggested that ~21% of the total bacterial community identified in the biofouling could potentially form calcium carbonate or struvite crystals in the pure MBBR-MBR system used for the treatment of urban wastewater. © 2015 Taylor & Francis.
News Article | December 27, 2016
Consumption of seafood is regarded as healthy since it contains high quality proteins, vitamins and omega-3 polyunsaturated fatty acids. But it might also put us at risk of exposure to environmental pollutants. How much do we know about our eating choices? One answer could come from a personal fish calculator designed by European researchers, to understand how much of our diet is healthy. It is very simple; you must select your age range, the amount and species consumed per week. Have you eaten spaghetti with clams and fried sardines? The device will quickly calculate your exposure to methylmercury and other pollutants. The calculator is the brainchild of the ECSafeSEAFOOD project, which has analysed the prevalence of marine toxins, microplastics and other chemical contaminants of growing concern, found in seafood sold in supermarkets across Europe. Contaminants of emerging concern are substances for which no maximum levels have been laid down in EU legislation nor require revision. "Sensitive, rapid and cost-effective screening methods were validated in a large set of seafood samples. Overall, the levels of contaminants in seafood were low, there are no risks for consumers. The only pollutants that may represent a concern for those who consume a lot of seafood were methylmercury and PBDE99 (industrial contaminants)", says António Marques from the Portuguese Marine and Atmospheric Institute (IPMA) in Lisbon, Portugal. "The exposure to these contaminants through seafood needs to be more finely assessed. Such information is crucial for the European food safety authorities to adjust the legislation", he adds. For example, no limits have been established for methylmercury in food. In the Po estuary in Italy, which is one of the top sites for mollusc farming in Europe, the scientists also found the highest level of pharmaceuticals such as the psychiatric drugs venlafaxine and citalopram, and the antibiotic azithromycin. Other contaminants raising concern are endocrine disrupters (EDCs) which are chemicals that may interfere with the body's hormonal gland system and cause various adverse effects. "Spanish consumers had the highest intake of endocrine disrupting compounds from seafood consumption, though the assessed intake was still below the tolerable weekly intake", explains Sara Rodriguez-Mozaz, researcher working at the Catalan Institute of Water Research (ICRA) in Girona, Spain, "Methylparaben, triclosan and bisphenol A were the most frequently detected EDCs." Other substances investigated by the researchers are microplastics (plastic particles smaller than 5 mm) that may act as a vector for chemical contaminants. The research revealed that up to 36.5% of the fish examined and 83% of crustaceans contained microplastics. The main challenges in the project were related to finding the right analytical methods. "Pharmaceutical and EDCs are found at very low levels in seafood, close to the current limits of detection of conventional analytical methodologies," says Rodriguez-Mozaz. The scientists collated their results in a database focusing "on unregulated contaminants that give rise to concern from an environmental and public health point of view". They invite "policy makers" to use their study "to help inform policy and advisory guidelines" and "authorities to highlight the deficits in seafood contaminant research". However, there is a happy ending. Despite the increase of chemicals in the marine environment, the low levels in seafood so far mean that we can still enjoy seafood during our Christmas holidays without worrying too much. Explore further: New screening, detection and extraction methods for priority contaminants in seafood