Food web on ice: a pragmatic approach to investigate the trophic magnification of chemicals of concern

Background The trophic magnification factor (TMF) is a metric that describes the average trophic magnification of a chemical through a food web. TMFs may be used for the risk assessment of chemicals, although TMFs for single compounds can vary considerably between studies despite thorough guidance available in the literature to eliminate potential sources of error. The practical realization of a TMF investigation is quite complex and often only a few chemicals can be investigated due to low sample masses. This study evaluated whether a pragmatic approach involving the large-scale cryogenic sample preparation practices of the German Environmental Specimen Bank (ESB) is feasible. This approach could provide sufficient sample masses for a reduced set of samples allowing screenings for a broad spectrum of substances and by that enabling a systematic comparison of derived TMFs. Furthermore, it was assessed whether plausible TMFs can be derived with the ‘Food web on ice’ approach via a comparison with literature TMF values. Results This investigation at Lake Templin near Potsdam is the first TMF study for a German freshwater ecosystem and aimed to derive TMFs that are appropriate for regulatory purposes. A set of 15 composite biota samples was obtained and analyzed for an extended set of benchmark chemicals such as persistent organic pollutants, mercury and perfluoroalkyl substances. TMFs were calculated for all substances that were present in > 80% of the biota samples. For example, in the case of polychlorinated biphenyls, TMFs from 1.7 to 2.5 were determined and comparisons to literature TMFs determined in other freshwater ecosystems showed similarities. We showed that 32 out of 35 compounds analyzed had TMFs significantly above 1. In the remaining three cases, the correlations were not statistically significant. Conclusions The derived food web samples allow for an on-demand analysis and are ready-to-use for additional investigations. Since substances with non-lipophilic accumulation properties were also included in the list of analyzed substances, we conclude that the ‘Food web on ice’ provides samples which could be used to characterize the trophic magnification potential of substances with unknown bioaccumulation properties in the future which in return could be compared directly to the benchmarking patterns provided here.

Exposure radius of a local coal mine in an Arctic coastal system; correlation between PAHs and mercury as a marker for a local mercury source

Mercury in the Arctic originates from emissions and releases at lower latitudes and, to a lesser extent, from local and regional sources. The relationship between mercury (Hg) and polycyclic aromatic hydrocarbons (PAHs) in sediment can be applied as an indicator of the mercury source. This research examines the Hg contamination gradient from a land-based coal mine to the surrounding coastal environment to quantify the impact of local sources. Total mercury and PAH (Σ14PAH) were measured in terrestrial and marine sediments as well as in marine biota. Samples were collected at the mine and two reference sites. Mercury and Σ14PAH concentrations in samples collected at the mine site were significantly higher than those at the reference sites. This was also found in the biota samples, although less pronounced. This work addresses the complexities of interpreting data concerning very low contaminant levels in a relatively pristine environment. A clear correlation between PAH and Hg concentration in sediment was found, although a large number of samples had levels below detection limits. PAH profiles, hierarchical clustering, and molecular diagnostic ratios provided further insight into the origin of PAHs and Hg, showing that signatures in sediments from the nearest reference site were more similar to the mine, which was not the case for the other reference site. The observed exposure radius from the mine was small and diluted from land to water to marine biota. Due to low contamination levels and variable PAH profiles, marine biota was less suitable for tracing the exposure radius for this local land-based Hg source. With an expected increase in mobility and availability of contaminants in the warming Arctic, changes in input of PAHs and Hg from land-based sources to the marine system need close monitoring. Graphical abstract

Levels of selected pesticides and trophic transfer of DDTs through the aquatic food web in the Lake Ziway ecosystem

The levels of 27 selected pesticides and trophic biomagnification of DDT were investigated in biota samples of the Lake Ziway in the Rift valley region, Ethiopia. Pesticide residues were analyzed using gas chromatography coupled with mass spectrometry (GC MS). Carbon source and trophic position were calculated by using 13C and 15N stable isotopes, individually, and trophic magnification factors (TMFs) were inferred. Among pesticides analyzed, only DDT and its metabolites (o,pʹ-DDD, o,pʹ-DDE, p,pʹ-DDD, and p,pʹ-DDE) were quantified in biota samples. The most prominent metabolite was p,pʹ-DDE with mean concentration ranging from the 0.22-7.7ngg− 1 wet weight. Moreover, the ratio of DDT/DDD + DDE in all the biota samples was less than 1 signifying historical DDT application. The trophic magnification factor (TMF) for p,pʹ-DDE, and ΣDDT were 1.18 and 1.19 respectively. Regression of log [ΣDDT] vs TL (trophic level) among all biota species showed a significant correlation, indicating that DDTs are biomagnifying along with the food web of Lake Ziway. The concentrations of DDTs and other organochlorine pesticides found in biota from Lake Ziway were, in general, lower than studies found in previous studies carried out in the same lake.

A Toolbox for the Determination of Nitroaromatic Explosives in Marine Water, Sediment, and Biota Samples on Femtogram Levels by GC-MS/MS

To determine the amount of the explosives 1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, and its metabolites in marine samples, a toolbox of methods was developed to enhance sample preparation and analysis of various types of marine samples, such as water, sediment, and different kinds of biota. To achieve this, established methods were adapted, improved, and combined. As a result, if explosive concentrations in sediment or mussel samples are greater than 10 ng per g, direct extraction allows for time-saving sample preparation; if concentrations are below 10 ng per g, techniques such as freeze-drying, ultrasonic, and solid-phase extraction can help to detect even picogram amounts. Two different GC-MS/MS methods were developed to enable the detection of these explosives in femtogram per microliter. With a splitless injector, limits of detection (LODs) between 77 and 333 fg/µL could be achieved in only 6.25 min. With the 5 µL programmable temperature vaporization—large volume method (PTV-LVI), LODs between 8 and 47 fg/µL could be achieved in less than 7 min. The detection limits achieved by these methods are among the lowest published to date. Their reliability has been tested and confirmed by measuring large and diverse sample sets.

ANALISIS KADAR MERKURI PADA BIOTA AIR DENGAN NANOPARTIKEL PERAK SECARA CITRA DIGITAL DI LOKASI PENAMBANGAN EMAS KABUPATEN LEBONG

This study aimed at determining of how the sensitivity of silver nanoparticles (NPP) in detecting metal mercury in aquatic biota samples through digital imagery. The Sampling of aquatic biota was carried out in the gold mining location of Lebong Tambang village in Lebong district (102 ° 12'00 "-102 ° 18'05" BT and 3 ° 10'00 "-3 ° 17 ' 00 "LS.) The aquatic biota samples analyzed included fish, shellfish, shrimp and plants as well as comparison samples such as water and sediment. The Analysis of mercury level was carried out from December 2018 - March 2019 by using NPP of digital imagery method. The digital imagery method was used as a detector to replace the conventional spectrophotometer. The result of mercury level in aquatic biota with NPP in digital imagery was susceptible compared to the UV-Vis spectrophotometry method. It can be seen from the Limit Of Detection (LOD) score of the digital imagery method with the SLR data analysis technique by using a digital camera that is equal to 2.305 ppb, where the score was smaller than the LOD value in spectrophotometry which is 300 ppb. The results of the analysis of mercury level by using digital imagery method were obtained the concentration on pool shells of 196.8 ppb, in pond fish samples of 155.7 ppb, in shrimp samples of 81.2 ppb, in river fish samples of 81.1 ppb, and in plant samples of 50.9 ppb. thus, these results indicate that the presence of mercury ions in the samples of aquatic biota tested has levels above the threshold, which means samples of fish, shrimp, shellfish and plants were risk to be consumed

Recent Status of Global Polychlorinated Biphenyls Contamination

Organic pollutants are continuously disrupting the equilibrium of nature. Polychlorinated Biphenyls are a member of the broad family of man-made organic chemicals well-known as chlorinated hydrocarbons. Due to their chemical stability, high boiling point and electrical insulating properties, non-flammability, Polychlorinated Biphenyls are used in various commercial as well as industrial applications. Polychlorinated Biphenyls residues remain in the ecosystem and bioaccumulate in various organisms due to their persistent nature and resistance against natural breakdown agents. This leads to the enlisting of approximately 209 chlorinated congeners in the list of persistent organic pollutants (POPs) under the Stockholm Convention. Their residues have been detected in various environmental components even though their production has been banned for more than a decade. High residues of Polychlorinated Biphenyls in water bodies, aquatic faunas, soils and sediments, air, and biota samples have been reported. Therefore, the current review aims at depicting the source and dynamics of Polychlorinated Biphenyls in the environment as well as the exploitation of various detection tools for the analysis of Polychlorinated Biphenyls. Besides, it provides a critical description of worldwide contamination scenarios of Polychlorinated Biphenyls and the need for further advancement in the detection and extensive identification.