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Abstract

High mercury concentrations in freshwater fish from the Nordic region have been of concern for a long time. Ongoing monitoring of key ecological species occurs in these countries to follow the situation. Here, we investigated spatial and temporal trends in mercury concentrations in European perch (Perca fluviatilis) within the Swedish and Finnish aquatic environments, collated from national monitoring programmes collected between 1974 and 2005 (n = 5,172). Data were length and weight adjusted to remove perch size as a confounding factor. Temporal trend analyses and t tests comparing pre- and post-1996 mercury concentrations for each country (1974–1995; 1996–2005; perch adjusted to 200 g/25 cm), showed a significant decrease in mercury concentration in perch from Sweden (p < 0.001) and a possible increase in mercury concentration in perch from Finland (p < 0.001). No statistically significant geographical trends were seen. Average mercury concentrations exceeded both the current environmental quality standard (EQS) of 20 ng/g wet weight (ww) and a discussed EQS for the Nordic region of 200–250 ng/g ww. Despite large reductions in mercury use and production in these countries, concentrations in perch continue to be higher here than in other European areas, posing a continued environmental risk.

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... Recreational fishing, in Sweden, contributes approximately 3% of the total fish consumption, being perch, grayling, trout and pike the freshwater fish species commonly consumed (RISE, 2019). The growth of perch population depends on the ecological interactions within the biota species in the ecosystems and its diet varies over time (Havochvatten, 2021;Miller et al., 2013). Young perches start out as pelagic zooplankton feeders, then around 30 -80 mm they tend to become benthic invertebrate feeders; finally, when their length is above 130 mm their diet is primarily piscivorous (Havochvatten, 2021;Miller et al., 2013). ...
... The growth of perch population depends on the ecological interactions within the biota species in the ecosystems and its diet varies over time (Havochvatten, 2021;Miller et al., 2013). Young perches start out as pelagic zooplankton feeders, then around 30 -80 mm they tend to become benthic invertebrate feeders; finally, when their length is above 130 mm their diet is primarily piscivorous (Havochvatten, 2021;Miller et al., 2013). Perch is not a migratory species (Miller et al., 2013), hence, it is an ideal species for investigating local patterns of the biodistribution of pollutants. ...
... Young perches start out as pelagic zooplankton feeders, then around 30 -80 mm they tend to become benthic invertebrate feeders; finally, when their length is above 130 mm their diet is primarily piscivorous (Havochvatten, 2021;Miller et al., 2013). Perch is not a migratory species (Miller et al., 2013), hence, it is an ideal species for investigating local patterns of the biodistribution of pollutants. ...
Article
Wild European perch (Perca fluviatilis) is one of the most important freshwater fish species, in Sweden, due to its widespread and his value for recreational fishing. Little it is known regarding the biodistribution of naturally occurring radionuclides such as 238U, 234U, 226Ra, 210Po in perch. Therefore, in this study, perches from five lakes located in different counties in Sweden were collected to investigate the biodistribution of 238U, 234U, 226Ra, 210Po and 137Cs in organs and tissues of perch as well as their radiological impact. The results showed that uranium radionuclides ranged between 0.1 and 6 Bq/kg with an average value of 1.1 ± 1.5 Bq/kg. 226Ra varied from 0.4 to 8 Bq/kg with a mean concentration of 1.7 ± 1.9 Bq/kg. The ranged of 210Po was 0.5 - 250 Bq/kg, with an average value of 24 ± 52 Bq/kg. On the other hand, the highest activity concentration of 137Cs, 151 ± 1 Bq/kg, was detected in muscle samples of perch from Redsjösjön lake. For uranium radionuclides and 226Ra uptake from water is the main source whereas for 210Po and 137Cs the uptake is controlled by the perch diet. Regarding naturally occurring radionuclides, the perch tended to accumulated uranium radionuclides in fins, gills, and skin; 226Ra in bones, fins and skin and 210Po in the organs linked to digestive system. Finally, in case of consumption, it is advised the consumption of skinned fillets of perch due to the higher bioaccumulation of the radionuclides investigated in the skin and scales.
... Publications show that concentrations of Hg in many fish populations are increasing throughout the boreal forest regions, including the Nordic countries (e.g. Åkerblom et al., 2012;Braaten et al., 2014b;Miller et al., 2013) and North America (e.g. Gandhi et al., 2014;Riget et al., 2011, see details below). ...
... Patterns from Sweden are demonstrated by Åkerblom et al. (2014), covering four decades of Swedish fish Hg monitoring. Miller et al. (2013) found no significant statistical spatial pattern in perch Hg concentrations covering Sweden and Finland. The authors suggest that the lack of a typical north-to-south increase in fish Hg concentrations is due to the influence of various biological effects (e.g. ...
... The authors suggest that the lack of a typical north-to-south increase in fish Hg concentrations is due to the influence of various biological effects (e.g. age, size and diet) on Hg bioaccumulation (Miller et al., 2013). ...
Technical Report
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Mercury (Hg) emissions to the atmosphere cause elevated Hg levels in fish, even in many remote regions of the world. Here we present an extensive database of more than 50 000 measurements of Hg in fish, including 2 775 individual water bodies in Fennoscandia (Norway, Sweden, Finland, Russian part of Kola Peninsula) sampled between 1965 and 2015. The data have been analysed for spatial patterns and temporal trends, on raw and weight-adjusted data. The database presents a useful reference for assessment of impacts of environmental policy on Hg in freshwater fish (i.e. Convention on Long-Range Transboundary Air Pollution and The Minamata Convention on Mercury).
... The latter permits the normalization of fish Hg data both across fish species and on an individual basis without assumptions of linearity, for example, to generate a standard 1-kg pike value also for lakes without pike. Temporal trends in fish Hg concentrations have previously been assessed statistically by means of linear regressions (Håkanson et al. 1988;Johansson et al. 2001;Miller et al. 2013), t tests (Miller et al. 2013), and z tests of proportions of lakes (Å kerblom et al. 2012), but all these methods have limitations in describing non-linear changes and fluctuations. An application of generalized additive models (GAMs) provides the opportunity to capture non-linear trends and allow for the estimation of underlying trends in environmental data (Wood 2011). ...
... The latter permits the normalization of fish Hg data both across fish species and on an individual basis without assumptions of linearity, for example, to generate a standard 1-kg pike value also for lakes without pike. Temporal trends in fish Hg concentrations have previously been assessed statistically by means of linear regressions (Håkanson et al. 1988;Johansson et al. 2001;Miller et al. 2013), t tests (Miller et al. 2013), and z tests of proportions of lakes (Å kerblom et al. 2012), but all these methods have limitations in describing non-linear changes and fluctuations. An application of generalized additive models (GAMs) provides the opportunity to capture non-linear trends and allow for the estimation of underlying trends in environmental data (Wood 2011). ...
... On average the decrease was 20 %, which was less than, but still comparable to, the 30 % long-term decline found by linear regression and GAM on the extensive but much more heterogeneous dataset (Fig. 3a). A previous study compared Hg concentrations in perch (size adjusted to 200 g/ 25 cm) between 1974-1995 and 1996-2005 in Sweden that also showed a significant decrease of 21 %, while an increase of about 10 % was found in Finland (Miller et al. 2013). An increase was also found in perch and brown trout collected from southeastern Norway between 1991 and 2008 ). ...
Article
Full-text available
The variability of mercury (Hg) levels in Swedish freshwater fish during almost 50 years was assessed based on a compilation of 44 927 observations from 2881 waters. To obtain comparable values, individual Hg concentrations of fish from any species and of any size were normalized to correspond to a standard 1-kg pike [median: 0.69 mg kg(-1) wet weight (ww), mean ± SD: 0.84 ± 0.67 mg kg(-1) ww]. The EU Environmental Quality Standard of 0.02 mg kg(-1) was exceeded in all waters, while the guideline set by FAO/WHO for Hg levels in fish used for human consumption (0.5-1.0 mg kg(-1)) was exceeded in 52.5 % of Swedish waters after 2000. Different trend analysis approaches indicated an overall long-term decline of at least 20 % during 1965-2012 but trends did not follow any consistent regional pattern. During the latest decade (2003-2012), however, a spatial gradient has emerged with decreasing trends predominating in southwestern Sweden.
... Also, ∑PCB concentrations in fish from Belgium (including the present study) showed to be often higher compared to other European countries (Blanchet-letrouvé et al., 2014;Ferrante et al., 2010;Fliedner et al., 2018;Mchugh et al., 2010;Szlinder-richert et al., 2014Szlinder-richert et al., , 2010. Finally, mercury concentrations in perch from Scandinavia were much higher than those measured in the present study (Miller et al., 2013;Negm, 2015;Sonesten, 2002). Variation in accumulation patterns and concentrations between countries, on the other hand, was to be expected to a certain level due to different pollution sources (e.g. point sources, atmospheric deposition). ...
... In contrast to the present study, De Jonge et al. (2014) did not find a significant relationship between accumulated HCB Belgium, Flanders (Malarvannan et al., 2014) 93-173 Belgium, Flanders (Maes et al., 2005) 0.002-192 5.0-1185 3.5-12,455 Belgium, Flanders (Maes et al., 2008) <LOQ-6.9 (0.2) Belgium, Flanders (Roose et al., 2003) 2.1-5.6 (3.9) 7.5-18 ( The Netherlands (Kwadijk et al., 2010) Germany (Hölzer et el, 2011) 260-310 Norway (Braaten et al., 2014) 221-448 Finland (Miller et al., 2013) <LOQ-0.024 f <LOQ-0.027 ...
Article
Full-text available
Many aquatic ecosystems are under persistent stress due to influxes of anthropogenic chemical pollutants. High concentrations can harm entire ecosystems and be toxic to humans. However, in case of highly hydrophobic compounds, their low water solubility precludes direct measurement in water, and thus alternative monitoring strategies are needed. In the present study, we investigated the extent to which bioaccumulated concentrations of persistent compounds can be predicted by concentrations in environmental compartments (water and sediment). Due to their high biomagnification potential, Hg and PFOS were included in this analysis as well. At 44 field locations in Flanders (Belgium), we monitored the concentrations of 11 priority compounds and their derivatives, included in the Water Framework Directive, in both sediment and water (where feasible) and biota (European perch, European eel and freshwater mussels). Besides, some sediment (i.e. total organic carbon (TOC) and clay content) and water characteristics were measured (i.e. pH, oxygen level, conductivity, nitrate, nitrite and dissolved organic carbon (DOC)). Measurements of HCB, HCBD, cis-heptachlorepoxide, HBCD and PFOS in sediment and ∑PCB in water showed a lower detection frequency than in fish samples. While PCB profiles were comparable between all matrices, for PBDE clear differences were detected between sediment and fish profiles, with BDE99 contributing the most for sediment (34%) and BDE47 for fish (≥44%), followed by BDE99 for perch (28%) and BDE100 for eel (25%). Water concentrations for PFOS and benzo(a)pyrene were predictive of respective bioaccumulated concentrations. HCB, ∑PCB and ∑PBDE, concentrations in fish were dependent on sediment concentrations and negatively related to organic compound levels (p < 0.05). Furthermore, pH and nitrite were negatively associated with accumulated concentrations in eel for HCB and PFOS, respectively (p < 0.05). Strong relationships between bioaccumulation and sediment and/or water concentrations strengthened the basis for surrogate monitoring methods. Finally, the extrapolation potential of Hg, ∑PBDE, PFOS, HBCD and ∑PCB between both fish species offered new opportunities in extrapolating different European monitoring frameworks.
... However, an important difference was observed between these two regions, with Hg concentration in the pike from Scandinavia higher than in NE North America: 730 vs. 640 μg kg -1 ww (Munthe et al. 2007). Miller et al. (2013) analysed data concerning Eurasian perch from Sweden and Finland covering the period 1974-2005. Swedish data from a later period (post-1996) show that in the fish from 22 and 72% lakes Hg concentrations were as high as >500 μg kg -1 ww and between 200 and 500 μg kg -1 ww, respectively. ...
... By contrast, after 1996 more lakes in Finland showed Hg concentrations in fish greater than 500 μg kg -1 ww (31%), while fewer lakes had fish Hg concentrations below 500 μg kg -1 ww (68%). Despite considerable reductions in Hg use and production as well as lower Hg atmospheric deposition in these countries, Miller et al. (2013) indicated that Hg concentrations in the fish exceeded the EQS/Hg (and EQS/Hg for the Nordic region was 200-250 μg kg -1 ww). Moreover, in both Finland and Sweden, the perch from over 90% lakes exhibited Hg concentration exceeding 100 μg kg -1 ww, which in North America is a level of concern for the protection of piscivorous mammals. ...
Book
The population explosion that began in the 1960s has been accompanied by a decrease in the quality of the natural environment, e.g. pollution of the air, water and soil with essential and toxic trace elements. Numerous poisonings of people and animals with highly toxic anthropogenic Hg and Cd in the 20th century prompted the creation of the abiotic environment, mainly in developed countries. However, the system is insufficient for long-term exposure to low concentrations of various substances that are mainly ingested through food and water. This problem could be addressed by the monitoring of sentinels – organisms that accumulate trace elements and as such reflect the rate and degree of environmental pollution. Usually these are long-lived vertebrates – herbivorous, omnivorous and carnivorous birds and mammals, especially game species. This book describes the responses of the sentinels most commonly used in ecotoxicological studies to 17 trace elements.
... However, an important difference was observed between these two regions, with Hg concentration in the pike from Scandinavia higher than in NE North America: 730 vs. 640 μg kg -1 ww (Munthe et al. 2007). Miller et al. (2013) analysed data concerning Eurasian perch from Sweden and Finland covering the period 1974-2005. Swedish data from a later period (post-1996) show that in the fish from 22 and 72% lakes Hg concentrations were as high as >500 μg kg -1 ww and between 200 and 500 μg kg -1 ww, respectively. ...
... By contrast, after 1996 more lakes in Finland showed Hg concentrations in fish greater than 500 μg kg -1 ww (31%), while fewer lakes had fish Hg concentrations below 500 μg kg -1 ww (68%). Despite considerable reductions in Hg use and production as well as lower Hg atmospheric deposition in these countries, Miller et al. (2013) indicated that Hg concentrations in the fish exceeded the EQS/Hg (and EQS/Hg for the Nordic region was 200-250 μg kg -1 ww). Moreover, in both Finland and Sweden, the perch from over 90% lakes exhibited Hg concentration exceeding 100 μg kg -1 ww, which in North America is a level of concern for the protection of piscivorous mammals. ...
Chapter
Full-text available
In nature, mercury (Hg) occurs in the elemental form (Hg⁰), as well as in inorganic (InHg) and organic (OrgHg) compounds. It is the only heavy metal that is liquid at room temperature and easily turns into a gas. Mercury vapours can be transported with air masses for hundreds and thousands of kilometres and—after falling down—contribute to the pollution of land and waters. In aquatic environments biogeochemical processes promote the natural microbial conversion of InHg to methylmercury (MeHg), the most bioavailable form of Hg.
... Several recent studies of remote Boreal lakes, both from North America [7], [8] and Scandinavia [9], [10], [11], reports increasing concentrations of Hg in fresh water fish over the last few decades. In Scandinavia, the increase has occurred in a period where reduced or unchanged atmospheric deposition of Hg is reported, due to emission reductions in Europe [12], [13]. ...
... The size (i.e. length and weight), age and sex distributions ( Figure 3) are representative indicators of the perch present in typical Boreal dystrophic lake systems in Scandinavia [9], [11], [29], [53]. As expected from accumulation of Hg, model predicted Hg concentrations are significantly correlated to length, weight and age (length and age in Figure 2) in both lakes. ...
Article
The authors examined the seasonal and year-to-year variations of mercury (Hg) concentrations in populations of perch (Perca fluviatilis) from 2 boreal freshwater lakes in southeast Norway. Fish Hg concentrations were determined seasonally (spring, summer, and autumn) over 3 yr (2010, 2011, and 2012) to test the hypothesis that there are substantial changes in fish Hg concentrations during the year (seasonal variation) as well as annually. Concentrations were significantly (p < 0.0001) different in the 2 study lakes, with mean seasonal concentrations varying from 0.24 mg/kg to 0.36 mg/kg and from 0.29 mg/kg to 0.37 mg/kg, respectively. The Hg concentrations of both perch populations showed significant year-to-year (p < 0.0001) and seasonal variation (p < 0.01). The changing fish Hg concentrations were 25% and 28% (2010–2011) and 17% and 0% (2011–2012) in the 2 lakes over the 3 yr, respectively. The results demonstrate how the significant year-to-year increase is one of the variables related to changes in trophic position, shown through stable nitrogen (δ15N) isotope data. The seasonal variation is related to summer growth dilution. The results highlight the clear need for yearly studies of fish Hg concentrations, rather than the 3-yr cycle suggested by current European policy through the Water Framework Directive. The lack of yearly sampling may result in erroneous conclusions regarding fish Hg concentration time trends. Environ Toxicol Chem © 2014 SETAC
... Per-and polyfluorinated substances (PFAS), a group of chemicals of emerging concern, are not as extensively studied regarding the association between fish size (and age) and concentrations in fish tissues compared to well-known bioaccumulating pollutants, e.g., dioxins, PCBs, and mercury (Hållén et al., 2020;Miller et al., 2013;Polak-Juszczak et al., 2022). ...
... It was similar in the case of Scandinavian lakes, although THg concentration in this species was 4 times higher than in Poland. In the case of other predatory species, the perch (Perca fluviatilis), THg concentration measured in Sweden and Finland was over twice as high as in Poland (Miller et al. 2013;Braaten et al. 2019). The possible explanation for the high THg concentration in fish from Scandinavia is elevated concentration of Hg in the underlying bedrock, as its geology strongly influences the Hg level in the water and hence in aquatic fauna (Danielsson et al. 2011;www. ...
Article
Full-text available
The goal of this paper is to assess the current status and trends of total mercury (THg) contamination of the atmosphere and terrestrial ecosystems in Poland. The study shows that the reduced domestic and worldwide atmospheric emission of Hg resulted in decreased THg level in the terrestrial biotope and biosphere. Considering that Poland is one of the main Hg emitters in Europe, the THg concentrations in its abiotic environment are still elevated. However, the THg level in terrestrial organisms is relatively low, which is because a large proportion of Hg deposited on land is accumulated in organic-rich soils. Regarding the THg concentration, consumption of wildlife and livestock from Poland is safe for humans. Nevertheless, the authors indicate the need for effective environmental monitoring, based on selected bioindicators, which is crucial considering the slowing reduction of Hg emission combined with the consequences of the changing climate.
... Data of perch Hg concentrations was only available for four lakes, and it was excluded from the analyses. Because fish Hg concentrations are known to be positively related to fish age and size, pike Hg muscle concentrations were standardized individually for each lake by partial regression coefficients for weight of 1.0 kg and length of 52.5 cm of northern pike according to Miller et al. (2013) and equation (1): ...
Article
Full-text available
Global pollution of mercury (Hg) threatens ecosystem and human health. We measured total Hg (THg) and monomethylmercury (MMHg) concentrations in filter-feeding blackfly (Simulium spp.) larvae in the inflows and the outflows of six boreal lakes with no Hg point source pollution. THg in the larvae ranged from 0.03 to 0.31 mg kg−1 dw and MMHg between 0.02 and 0.25 mg kg−1 dw. The proportion of MMHg in the larvae was 74 ± 0.16% and ranged from 43 to 98% of THg, the highest proportions being comparable to those typically found in aquatic predatory insects and fish. We compared the larvae MMHg concentrations to river water quality, catchment land-use, and to size-adjusted lake pike THg data. Two of the investigated catchments have been affected by a multimetal biomine since 2008 and were characterized by higher conductivity and higher urban land-use activity. Larvae THg and MMHg concentrations were higher in the lake inflows than in outflows and associated with water conductivity and catchment land-use activity. Lake pike THg concentrations were highly correlated to lake outflow blackfly larvae MMHg concentrations. Our data illustrate that blackfly larvae take up high percentage of THg that is MMHg, which in turn is available for higher consumers in aquatic and terrestrial food webs.
... Monitoring data from other European countries show a similar picture (see discussion of PS data above). Sweden, for which most data are available, reports that the EQS for mercury and PBDE are exceeded nation-wide, and also the EQS for PFOS is frequently exceeded by freshwater fish [31,36,41,42]. In fish from Swedish inland waters, high concentrations of PCDD/F + dl-PCB are found. ...
Article
Full-text available
Background Bioaccumulating contaminants in surface waters are preferably monitored in fish for assessing the related risks to and via the aquatic environment. Consequently, the European Water Framework Directive (WFD) requires a monitoring of certain priority substances such as mercury, polybrominated diphenyl ethers (PBDE), perfluorooctane sulfonic acid and its derivatives (PFOS), hexachlorobenzene (HCB), hexabromocyclododecanes (HBCDD) and polychlorinated dioxins/dioxin-like compounds (dioxins) in freshwater and coastal fish. Tissue levels have to comply with biota environmental quality standards (EQSs) given in Directive 2013/39/EU. EQSs are justified either by risks for human health (assessed on the basis of fillet) or secondary poisoning of wildlife (based on whole fish). To support the practical implementation of the WFD biota monitoring in Germany, comparative investigations of target fish species caught at six sites were performed. Results At each site, at least three fish species listed in a national guidance document were sampled (e.g., chub, roach, bream, perch). Beside biometric data, concentrations of seven priority substances were determined in pooled fillet and carcass samples and whole fish data were calculated. The EQSs for PBDE and mercury were exceeded in nearly all fillet and whole fish samples. PFOS was above the EQS at several sites especially in perch, while HCB exceeded the EQS only at one site (Elbe River). All fillet and whole fish samples complied with the EQSs for dioxins and HBCDD. Based on wet weight concentrations of a homogeneous set of 20 composite sample pairs of 3–5 year-old fish, the following fillet-to-whole fish conversion factors were derived: mercury 0.81, PBDE 5.4, HCB 3.6, PFOS 2.7, dioxins 5.3, and HBCDD 1.8. Conclusions Recommendations on selection of target fish species, age or tissue given by EU and national guidance documents are practical and feasible. However, further adjustments of the samplings such as the determination of site-specific length–age relationships are required from both ecological and risk assessment perspectives. The derived conversion factors allow the translation of fillet-to-whole fish concentrations (and vice versa), and thus the EQS compliance assessment for the appropriate tissue (fillet for human health, whole fish for wildlife risks) if only one tissue is investigated.
... However, positive correlation between Hg in muscles of pike, perch, roach, bream and their size were found in previous studies [24,46,47]. Nozari et al. [48] found a positive correlation between these parameters in muscles of pike from Anzali International Wetland (Iran), while Miller et al. [49] reported a similar correlation in muscles of perch from Swedish and Finnish aquatic environments. This is accordance with the current results (Figures 4 and 5). ...
Article
Full-text available
The objectives of study were to determine heavy metals content (Zn, Cu, Mn, Fe and Hg) and fatty acids in selected organs of roach, Rutilus rutilus (L.); bream, Abramis brama (L.); pike, Esox lucius (L.); Eurasian perch, Perca fluviatilis (L.) collected from reservoirs of Warmia and Mazury region (northeastern Poland). Heavy metals were determined with atomic absorption spectrometry AAS. The fatty acids were analyzed using gas chromatography. In a few cases, differences in the content of heavy metals and fatty acids were not significant between species. The muscles of fish characterized significantly higher values of mercury than other organs (p ≤ 0.05), except for bream. The reverse regularity was observed in the case of content of Cu, Zn, Mn and Fe. Fatty acids having a desirable dietary effect in humans (DFA-Hypocholesterolaemic fatty acids) (74.00–74.84) were more than OFA (hypercholesterolaemic fatty acids), i.e., those undesirable (24.03–24.79). The lipid quality indexes AI (index of atherogenicity) (0.40–0.44) and TI (index of thrombogenicity) (0.18–0.24) in muscles of fish were low, which means that the meat of the fish may be recommended for human health. THQ (target hazard quotient) and HI (hazard index) as individual foodstuff were below 1, whereas HI for a specific receptor/pathway combination exceeded 1. This may suggest that eating meat from a given species is safe from a health point of view.
... Entsprechend der Auswertung für organische Stoffe können auch die Quecksilberdaten evaluiert werden. Signifikante Zusammenhänge zwischen den Quecksilber-Konzentrationen im Filet und im Ganzfisch wurden beispielsweise von Peterson et al. (2005) und Peterson et al. (2007 für Fische in den USA, von Miller et al. (2013) und Fauxneld et al. (2015 für Barsche aus Schweden sowie von Lepom und Wellmitz (2018) für Fische aus Binnengewässern in Deutschland beschrieben. Bei der vorliegenden Untersuchung können sowohl Einzelfischdaten als auch Daten von den jeweiligen Mischproben ausgewertet werden. ...
Technical Report
The aim of the present research project was to develop the basics for a suitable concept for the compliance monitoring of priority substances in fish that meets the requirements of the Water Framework Directive (WFD) and integrates the various objectives of WFD water monitoring, in particular compliance monitoring of environmental quality standards (EQS) and trend monitoring. For this purpose, approximately 20 fish each of three different fish species were sampled at six locations in German surface waters. Biometric data were recorded (e.g., weight, length, age) and pool samples of filet and carcass were analyzed separately for priority substances. These data were used to calculate the respective concentrations in whole fish. The information laid down in the RAKON Working Paper IV.3 by the German Working Group on Water Issues of the Federal States and the Federal Government (LAWA) was taken into account and the suitability of the recommended procedures to be implemented on site was examined. Based on the study results, recommendations were derived for the implementation of the WFD biota monitoring. Since routine water monitoring is the responsibility of the German Federal States, aspects of practical implementation were discussed with the responsible colleagues from the Federal States institutions in two technical meetings. (German languange report with English language summary)
... Because fish size varied significantly within lakes between years, and across lakes, a single length-adjusted annual log [Hg] was generated. This was achieved using a regression between log [Hg] and fish total length at the mean total length for all the fish (40.1 cm, Fig. SI-1) for each year and lake, a method of length adjustment used in previous studies (Evans et al., 2005;Miller et al., 2013). Our a priori requirements for an adjustment variable were that the variable exhibit a consistent relationship to log [Hg] among populations, and that the same adjustment method be applied to all lakes and all years. ...
Article
Climate warming and mercury (Hg) are concurrently influencing Arctic ecosystems, altering their functioning and threatening food security. Non-anadromous Arctic char (Salvelinus alpinus) in small lakes were used to biomonitor these two anthropogenic stressors, because this iconic Arctic species is a long-lived top predator in relatively simple food webs, and yet population characteristics vary greatly, reflecting differences between lake systems. Mercury concentrations in six landlocked Arctic char populations on Cornwallis Island, Nunavut have been monitored as early as 1989, providing a novel dataset to examine differences in muscle [Hg] among char populations, temporal trends, and the relationship between climate patterns and Arctic char [Hg]. We found significant lake-to-lake differences in length-adjusted Arctic char muscle [Hg], which varied by up to 9-fold. Arctic char muscle [Hg] was significantly correlated to dissolved and particulate organic carbon concentrations in water; neither watershed area or vegetation cover explained differences. Three lakes exhibited significant temporal declines in length-adjusted [Hg] in Arctic char; the other three lakes had no significant trends. Though precipitation, temperature, wind speed, and sea ice duration were tested, no single climate variable was significantly correlated to length-adjusted [Hg] across populations. However, Arctic char Hg in Resolute Lake exhibited a significant correlation with sea ice duration, which is likely closely linked to lake ice duration, and which may impact Hg processing in lakes. Additionally, Arctic char [Hg] in Amituk Lake was significantly correlated to snow fall, which may be linked to Hg deposition. The lack of consistent temporal trends in neighboring char populations indicates that currently, within lake processes are the strongest drivers of [Hg] in char in the study lakes and potentially in other Arctic lakes, and that the influence of climate change will likely vary from lake to lake.
... 9,10 Initially, monitoring was focused on lakes close to known point sources of Hg, but during the 1980s it was revealed that lakes in remote and pristine areas were exposed to increased loads of predominantly atmospherically deposited Hg. 11,12 High levels of Hg in monitored fish initiated new environmental legislations, including changes in the forest industry processes, and local emissions and releases were generally reduced. 9 Still, several Northern areas show significant increases in fish Hg concentrations the last decades, including Sweden, 13 Finland, 14 and Ontario (Canada), 15 although this rising trend is not found in all regions and for all fish species. In fact, a study of lakes in Sweden 16 shows declining Hg concentrations in fish between 2005 and 2015, something which fits with the observed declining trend of Hg deposition since at least the 1990s throughout Europe. ...
Article
Temporally (1965-2015) and spatially (55°-70°N) extensive records of mercury (Hg) in freshwater fish showed consistent declines in boreal and subarctic Fennoscandia. The database contains 54560 fish entries (n: pike>perch>>brown trout>roach≈Arctic charr) from 3132 lakes across Sweden, Finland, Norway, and Russian Murmansk area. 74% of the lakes did not meet the 0.5 ppm limit to protect human health. However, after 2000 only 25% of the lakes exceeded this level, indicating improved environmental status. In lakes where local pollution sources were identified, pike and perch Hg concentrations were significantly higher between 1965 and 1990 compared to values after 1995, likely an effect of implemented reduction measures. In lakes where Hg originated from long-range transboundary air pollution (LRTAP), consistent Hg declines (3-7‰ per year) were found for perch and pike in both boreal and subarctic Fennoscandia, suggesting common environmental controls. Hg in perch and pike in LRTAP lakes showed minimal declines with latitude, suggesting that drivers affected by temperature, such as growth dilution, counteracted Hg loading and foodweb exposure. We recommend that future fish Hg monitoring sampling design should include repeated sampling and collection of supporting information (pollution history, water chemistry, fish age, stable isotopes) to enable evaluation of emission reduction policies.
... In paper I, perch was chosen as a model species for accumulation of Hg and Se in Lake Norheim and Lake Norsjø, with background in availability and its wide application in studies on Hg accumulation in Scandinavia ( Miller et al., 2013). Perch were easily obtained at all three sites, and the subsampling for further analysis, was made in order to reduce variation in potential predictor ___ ...
... No comparative fish monitoring data are available for the river sampling sites under investigation. However, high Hg concentrations in Swedish freshwater fish have also been reported by others (e.g., Åkerblom et al., 2014;Miller et al., 2013;Nyberg et al., 2012) and are attributed mainly to atmospheric depositions (Meili et al., 2003). For roach (Rutilus rutilus) which resemble bream with respect to feeding behavior and trophic level ( (Ribeiro et al., 2005). ...
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... Since the ESB routinely archives pooled samples, it is not possible to apply normalization procedures based on fish length or age. Nevertheless, the dependency of Hg levels in fish on fish size and age has been demonstrated in numerous studies (e.g., Bache et al. 1971;Dušek et al. 2005;Farkas et al. 2003;Miller et al. 2013;Noël et al. 2013). Decreasing Hg levels were also found in bream sampled in Lake Belau (B) and the Rhine sites R1 (Weil) and R4 (Bimmen). ...
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We measured total Hg and stable isotopes (delta C-13 and delta N-15) in northern pike (Esox lucius) from 19 Boreal Shield lakes with undisturbed, logged, or burned watersheds. Average Hg level in standard 560-mm northern pike, on a dry weight basis, was significantly higher in logged lakes (3.4 mug.g(-1)) than in reference lakes (1.9 mug.g(-1)). Average Hg concentrations in burned lakes (3.0 mug.g(-1)) did not differ significantly from those in logged and references lakes. Concentrations of Hg normalized to trophic position determined from isotopic composition yielded similar results. Mercury levels were above the WHO safe consumption limit in all logged lakes. Mercury in northern pike was correlated with methyl mercury in zooplankton (+), total N (+), pH (-), alkalinity (-), sulfate (+), dissolved organic C loading (+), and light attenuation in lake water (+). Stepwise multiple regressions explained 79% of the variability in Hg in fish and included methyl mercury in zooplankton, pH, and sulfate as independent variables. Explained variability increased to 92% when a second-order lake with an exceptionally large drainage area was excluded. Our results suggest that extensive logging activities may disrupt the natural cycling of Hg in watersheds and increase Hg levels in the aquatic biota.
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The flux of elemental mercury vapor from intact mill tailings (36 to 1270 mug Hg/g), soil (7 mug Hg/g), and cinnabar ore (934 mug Hg/g) was measured as a function of temperature (20°-60°C) and wind velocity (0.2-0.8 m/s) using a controlled environment, open gas-exchange system. Continuous air movement over core surfaces in the gas-exchange chamber resulted in a logarithmic decline in mercury flux with time. Measurement of the effect of environmental parameters on mercury flux was done after attainment of a quasi steady state of flux. Prior to attainment of this state the activation energy for mercury flux was less than the molar heat of vaporization of element mercury (14 kcal/mol). At steady state the substrate-to-air flux of mercury vapor increased logarithmically with temperature, mimicking the element's vapor pressure curve; and activation energies (16.4 to 25.7 kcal/mol) for mercury flux were higher than the molar heat of vaporization of elemental mercury due to physicochemical properties of the soil (e.g., porosity, organic matter, clay content) that affect gas-phase mercury transport and fate. A change in wind velocity from 0.2 to 0.8 m/s resulted in an increase in mercury flux by a factor of 2 for a core with >150mugHg/g and no significant response from two cores with
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Chamber and micrometeorological mercury flux data collected during the Nevada STORMS intercomparison study were used to identify natural and methodological factors controlling data variability. Micrometeorological and chamber measurements revealed that flux variability at a site is closely related to the Hg concentrations in the substrate, which were found to vary with mineral composition, grain size, and sampling depth. Environmental factors also influenced flux variability. Following two rainfall events, fluxes measured by chamber and micrometeorological methods increased substantially. The micrometeorological flux was enhanced five fold following the rain event. Fluxes measured by both methods were also influenced by net radiation and temperature as evidenced by their tendency to follow the diel cycle in these variables. Day-time fluxes were 6 times greater than nighttime fluxes. Data analysis revealed that interactions between environmental and geochemical variables complicate relationships between the flux and these variables. Understanding the variability at a flux monitoring site is important to establish relationships for scaling up and for the development of consistent sampling protocols that allow comparisons from one study to another and adequately quantify mercury fluxes from natural sites to provide representative emission data that can be used for scaling up to regional and global scales.
Article
Field measurements of mercury air-surface exchange from natural settings were made in various Canadian landscapes. Soil and water samples were analyzed for mercury concentrations, and air-surface exchange fluxes from these substrates were determined using dynamic chamber, micrometeorological, or modeling methods. Environmental variables, including air and soil/water temperature, solar radiation, humidity, and wind speed, were monitored concurrently with the air-surface exchange to better understand the processes affecting the environmental cycling of mercury. Average mercury fluxes from aquatic landscapes ranged from 0.0 to 5.0 ng m−2 h−1 with total mercury concentration in water ranging from 0.3 to 6.5 ng L−1. A significant correlation (R2 = 0.47) was found between gaseous Hg fluxes and total Hg concentration in water. Mean gaseous Hg fluxes from forest soils varied from −0.4 to 2.2 ng m−2 h−1, while those from agricultural fields ranged from 1.1 to 2.9 ng m−2 h−1. Non-mineralized bedrock, sand, and till sites yielded fluxes ranging from −0.03 to 5.9 ng m−2 h−1. Mean fluxes from mercuriferous geological substrates at various locations were large compared to non-mercuriferous sites, ranging from 9.1 to 1760 ng m−2 h−1, and represent natural emissions. The corresponding total mercury substrate concentrations ranged from 0.360 to 180 ppm. A significant correlation (R2 = 0.66) was found between Hg fluxes and total Hg concentrations in mineralized and non-mineralized substrates. These gaseous Hg flux measurements represent a significant contribution to understanding natural mercury cycling, but there are still insufficient data and knowledge of processes to properly scale up fluxes from natural sources in Canada.
Article
Eleven laboratories from North America and Europe met at Mace Head, Ireland for the period 11–15 September 1995 for the first international field intercomparison of measurement techniques for atmospheric mercury species in ambient air and precipitation at a marine background location. Different manual methods for the sampling and analysis of total gaseous mercury (TGM) on gold and silver traps were compared with each other and with new automated analyzers. Additionally, particulate-phase mercury (Hgpart) in ambient air, total mercury, reactive mercury and methylmercury in precipitation were analyzed by some of the participating laboratories. Whereas measured concentrations of TGM and of total mercury in precipitation show good agreement between the participating laboratories, results for airborne particulate-phase mercury show much higher differences. Two laboratories measured inorganic oxidized gaseous mercury species (IOGM), and obtained levels in the low picogramm-3 range.
Article
Over a distance of approximately 800 km simultaneous measurements of total gaseous mercury (TGM) were performed at four sampling sites between Stockholm and Berlin. The time resolution of mercury concentration measurements was 5 min. During the sampling period from 26 June to 7 July 1995, event sampling for precipitation was carried out using bulk samplers. In addition to the mercury data, the most common meteorological and air-quality parameters were determined. Comparing the TGM background concentrations at the four sites, a weak but statistically significant south-to-north declining TGM gradient was found. From the most southern sampling site to the northern most site median values of 1.93, 1.78, 1.53 and 1.54ngm-3 TGM were detected. Compared with the median TGM concentration observed at the two Swedish sites, the regional background concentration near Berlin was elevated by about 25%. Whereas the 0.5h average TGM concentration varies at the Swedish sampling sites in a very narrow range of only 0.69ngm-3, a much broader range of 3.28ngm-3 was observed at the southern sites. The increased TGM variability near Berlin was characterised by a diurnal cycle with a distinct maximum in the early morning hours (about 4:00a.m.) before sun rise. The short time variability of the TGM concentration measured at the four sites on the south-to-north transect shows regional differences. A decreasing variability from the most southern to the most northern site became evident.
Article
During the last decade a new pattern of Hg pollution has been discerned, mostly in Scandinavia and North America. Fish from low productive lakes, even in remote areas, have been found to have a high Hg content. This pollution problem cannot be connected to single Hg discharges but is due to more widespread air pollution and long-range transport of pollutants. A large number of waters are affected and the problem is of a regional character. The national limits for Hg in fish are exceeded in a large number of lakes. In Sweden alone, it has been estimated that the total number of lakes exceeding the blacklisting limit of 1 mg Hg kg-1 in 1-kg pike is about 10 000.
Article
Contents of organic and inorganic mercury in food chain specimens, as well as sedimentation in two natural Finnish lakes and three impounded reservoirs, were studied. The proportion of organic mercury to total mercury varied in individual specimens from 32.7 to 100%. Sedimentation (settleable solid) with very high contents of organic matter had ratios of organic to total mercury ranging from 2.4 to 87.3%. These variations were similar in each of five water ecosystems studied. Benthic invertebrates had higher ratios of organic to total mercury than reported earlier. Total mercury concentrations in fish, zoobenthos and zooplankton of young impounded reservoirs were significantly higher than those of natural lakes. To explain this it is suggested that humic materials transfer mercury to the water and thence into the food chain.
Article
Recent observations of elevated mercury levels in fish caught in remote lakes has renewed research into mercury cycling. This article initially examines the mechanisms of mercury elevation within lake ecosystems. The method of analysis of the Adirondack lakes is described, and the results are presented, including detailed discussion of lake water chemistry and levels of mercury within fish. -R.Gower
Article
Dynamic Flux Chambers (DFCs) are commonly applied for the measurement of non-point source mercury (Hg) emissions from a wide range of surfaces. A standard operating protocol and design for DFCs does not exist, and as a result there is a large diversity in methods described in the literature. Because natural and anthropogenic non-point sources are thought to contribute significantly to the atmosphere Hg pool, development of accurate fluxes during field campaigns is essential. The objective of this research was to determine how differences in chamber material, sample port placement, vertical cross sectional area/volume, and flushing flow rate influence the Hg flux from geologic materials. Hg fluxes measured with a Teflon chamber were higher than those obtained using a polycarbonate chamber, with differences related to light transmission and substrate type. Differences in sample port placement (side versus top) did not have an influence on Hg fluxes. When the same flushing flow rate was applied to two chambers of different volumes, higher fluxes were calculated for the chamber with the smaller volume. Conversely, when two chambers with different volumes were maintained at similar turnover times, the larger volume chamber yielded higher Hg fluxes. Overall, the flushing flow rate and associated chamber turnover time had the largest influence on Hg flux relative to the other parameters tested. Results from computational fluid dynamic (CFD) modeling inside a DFC confirm that the smaller diffusion resistance at higher flushing flows contributes to the higher measured flux. These results clearly illustrate that differences in chamber design and operation can significantly influence the resulting calculated Hg flux, and thus impact the comparability of results obtained using DFC designs and/or operating parameters. A protocol for determining a flushing flow rate that results in fluxes less affected by chamber operating conditions and design is proposed. Application of this protocol would provide a framework for comparison of data from different studies.
Article
The environmental impact on the mercury level in perch (Perca fluviatilis L.) is examined using Partial Least Squareregression (PLS) on 48 environmental descriptors assessingland use, various catchment area and lake characteristics,lake water chemistry, and fish stock. The lake specificintercepts of Hg content vs. fish length regressions are usedto describe the Hg level in the fish. The Hg levels in perchfrom 78 circumneutral lakes were largely influenced by landuse in the surroundings. Boreal forest lakes had the highestHg burden in the fish, while fish from lakes heavilyinfluenced by arable land possessed lower contents. The Hglevels also showed a negative relationship to the concentrationsof dissolved ions and total nutrients in lake water, and to theperch growth rate, whereas the relationship was positive to theconcentration of TOC/humic matter. Lake pH did not have any significant influence on the Hg content in perch in these circumneutral lakes. The Hg levels in perch from lakes surrounded by large amounts of wetland were less satisfactorily explained by the presently examined environmental descriptors, which suggests that the Hg burden in fish from these lakes are influenced by other factors.
Article
The propensity to resist chemical, photo-chemical or biological degradation processes, coupled with a high degree of mobility — due to favorable physical-chemical properties such as relatively high vapor pressure and low solubility in water - bestows upon some chemical substances the necessary pre-requisites for extensive cycling among environmental compartments. Certain inorganic and organometallic species of Hg exhibit the aforementioned characteristics. This paper presents field measurement data, collected in Canada and Sweden, that provide information concerning the direction and magnitude of the material fluxes associated with transfer processes of Hg in the natural environment. The results of the field measurements reported here point to the importance of the natural phenomena of emission or re-emission (i.e., volatilization processes) involving the release of volatile Hg species from lake and soil surfaces into the overlying air, at least under warm weather conditions. Consequently, volatilization fluxes of Hg from natural surfaces should be taken into account when constructing biogeochemical cycles for this element and when calculating mass balances or budgets for Hg on local, regional and global scales.
Article
Samples for measurements of total gaseous mercury (Hg) in air have been collected since 1980 in south-western part of Scandinavia. A collection program for precipitation samples used to determine changes in depositional fluxes of total Hg has been in operation since 1987. A comparison of today's total gaseous Hg levels in air and the total Hg concentrations in precipitation with the ones found earlier, shows a clear decrease with time. At the Swedish west-coast, yearly average air concentrations and median levels of 3.3 and 3.1 (1980–1984), 3.2 and 2.8 (1985–1989), and 2.7 and 2.6 ng Hg/m3 (1990–1992), respectively, were found. Increased average and median winter concentrations were always found, with levels at 3.7 and 3.4, 3.7 and 3.3, and 3.0 and 2.7 ng Hg/m3 for the respective time period. Higher winter values were expected due to increased anthropogenic emissions and changes in the mixing height of the atmosphere. The corresponding total wet deposition rates decreased from 27 (1987–1989) to 10 g Hg/m2 yr. (1990–1992). A finding of special interest was the decreased number of episodic events of high total gaseous Hg levels in air, from 1990 and further on. In addition, the frequency distribution of the concentrations of Hg in air seems to be different for these years compared to the other two time periods. A frequency distribution of air concentrations of Hg more resembling a normal distribution was found for the years 1990 to 1992. The decrease of the atmospheric burden of total gaseous Hg and deposition of total Hg are most probably connected to lower emissions in source areas on the European continent. It seems logical to state that the problem of high Hg depositional fluxes to Scandinavia, is best solved by abatement strategies on the regional scale.
Article
 Understanding the mechanisms of mercury evaporation from soil to the atmosphere is necessary for tracing the fate of mercury in the biological environment and for assessing potential health effects and the impact of anthropogenic mercury emissions on the environment. In this article an integrating overview of the current knowledge of the mechanisms of mercury evaporation is presented. Abiological and biological formation of Hg(0) and/or (CH3)2Hg in the uppermost soil layers are the rate limiting processes of mercury evaporation from soils in background areas; the evaporation rate in background areas is probably strongly influenced by deposited airborne mercury. The evaporation rate limiting factors in mercury enriched mineralized areas with large fractions of total mercury being volatile mercury species (relative to background soil in the non-mineralized vicinity) meteorological variations and the transport characteristics of soils for volatile mercury species. Mercury evaporation rates from background soils are usually <0.2 μg·m–2·h–1 and significantly smaller than from mercury-enriched mineralized areas.
Article
It is well known that mercury (Hg) emission from soils is largely controlled by solar radiation and soil temperature, exhibiting diel cycles that closely follow diel variations of solar radiation. To study soil Hg emission processes, we conducted experiments by measuring soil Hg emission fluxes under controlled conditions in the laboratory with a dynamic flux chamber using outside ambient air as flushing air. Unexpectedly, we observed consistent, recurring diel cycles of Hg emissions from dry soils held at constant temperature in the dark in our laboratory. The peaks of the emissions also seemed subject to some seasonal variation and to respond to local weather conditions with lower flux peaks in wintertime and on cloudy or rainy days. Finally, much lower soil Hg emission fluxes were observed in the presence of Hg-free zero air than in the presence of outside ambient air. It is hypothesized that some unidentified air-borne substance(s) in the ambient air might be responsible for the observed diel cycles of soil Hg emission. Further elaborate mechanistic investigations are clearly needed to test the initial working hypotheses and uncover the cause for this interesting, mysterious phenomenon. The present work and recent finding of enhancement of Hg emissions from soil and mineral particles by O3 seem to point to a research need to probe the possible role of near-ground atmospheric chemistry in Hg air/soil exchange.
Article
High precision and low blank contamination were achieved with a Teflon™ dynamic chamber for measuring, soil mercury flux. Using this chamber, background soil mercury flux averaged between 2 and 7 ng m−2 h−1 over forest soil, and between 12 and 45 ng m−2 h−1 over open field soil. Spatial heterogeneity of soil mercury flux at duplicate plots co-located within 2 m was small but significant, differing by 20–50%. Elevated mercury emission over field soil occurred in the presence of direct sunlight at the open field sites. Solar radiation, soil temperature and soil moisture were all significant factors effecting mercury emission from soil. Solar radiation affected the reduction of naturally occurring, inorganic soil mercury compounds to volatile elemental mercury (Hg°). We estimate that background soil accounts for the gross emission of ∼ 109 g yr −1 of Hg° to the atmosphere, with approximately two-thirds of this total from sunlight-exposed soil and the remainder from forest and other shaded-soil ecosystems.
Article
In order to evaluate and understand the processes of water-air and soil-air exchanges involved at background sites, an intensive field measurement campaign has been achieved during the summer of 1995 using high-time resolution techniques (10 min) at two sites (land and water) in southern Québec (Canada). Mercury flux was measured using a dynamic flux chamber technique coupled with an automatic mercury vapour-phase analyser (namely, Tekran®). The flux chamber shows that the rural grassy site acted primarily as a source of atmospheric mercury, its flux mimicked the solar radiation, with a maximum daytime value of ∼ 8.3 ng m−2 h−1 of TGM. The water surface location (St. Lawrence River site located about 3 km from the land site) shows deposition and evasion fluxes almost in the same order of magnitude (−0.5 vs 1.0 ng m−2 h−1).The latter is influenced to some extent by solar radiation but primarily by the formation of a layer of stable air over the water surface in which some redox reactions might promote evasion processes over the water surface. This process does not appear over the soil surface. As a whole, soil-air exchange rate is about 6–8 fold greater than the water-air exchange.
Article
This paper presents a broad overview and synthesis of current knowledge and understanding pertaining to all major aspects of mercury in the atmosphere. The significant physical, chemical, and toxicological properties of this element and its environmentally relebant species encountered in the atmosphere are examined. Atmospheric pathways and processes considered herein include anthropogenic as well as natural sources of Hg emissions to the atmosphere, aerial transport and dispersion (including spatial and temporal variability), atmospheric transformations (both physical and chemical types), wet and dry removal/deposition processes to Earth's surface. In addition, inter-compartmental (air-water/soil/vegetation) transfer and biogeochemical cycling of mercury are considered and discussed. The section on numerical modelling deals with atmospheric transport models as well as process-oriented models. Important gaps in our current knowledge of mercury in the atmospheric environment are identified, and suggestions for future areas of research are offered.
Article
During May 2005–June 2006, measurements of total gaseous mercury (TGM) concentrations were carried out by using a set of automatic atmospheric mercury vapor analyzer (Tekran 2537A) at Moxi base station (102°07′E, 29°40′N, 1640 m a.s.l.) of the Gongga alpine ecosystem observation and experiment station of Chinese academy of sciences (CAS) which belongs to the Chinese ecosystem research network (CERN). A seasonal distribution pattern of TGM in ambient air was observed on the descending order of winter, fall, spring, and summer. Geometric mean TGM concentration over the sampling periods was 3.98 ng m−3 with a range from 0.52 to 21.03 ng m−3. The measurements showed a noticeable diurnal TGM distribution pattern with high concentration during daytime compared to nighttime; the maximum and the minimum concentration appeared near solar noon and immediately before sunrise, respectively. TGM concentrations were regulated by the wind directions, and wind from the southeastern direction carried more mercury than any other direction suggesting that anthropogenic sources, such as local zinc smelting activities and fuel combustion, played a predominant role in the elevation of TGM concentrations in this area.
Article
The samples are digested in nitric acid and evaporated to near dryness. Hydrogen peroxide is then added for complete oxidation of fat residues. Determination of metals is performed by flameless AAS with graphite furnace and results evaluated by the method of standard addition. The method is suitable for the determination of some non-volatile metals in fish livers in which the amount of available sample is limited; Pb, Cd, Cu and Zn have been determined in such samples.
Article
The concentrations of selected metals, such as Hg, Cd, Pb, Cu and Zn, were determined in muscle and liver of perch (Perca fluviatilis) from the Pomeranian Bay and Szczecin Lagoon, southern Baltic. The concentrations of Hg in muscle and Cd, Pb and Cu in liver increased with the age of the specimens analysed. The positive relationship between muscle Hg and age (weight-length) is probably attributed to the specific bioaffinity for organic matter of CH3Hg with a high biological half-life, which generally constitutes the dominant pool of the total Hg in the fish muscle. ANOVA analysis clearly demonstrated that in the Pomeranian Bay there were significant seasonal variations of muscle Hg and hepatic Cd, Pb and Cu. Factor analysis supported seasonal differences in muscle and especially hepatic samples; specifically, summer muscles were clearly separated from winter ones. Muscle samples corresponding to the winter season had relatively high concentrations of Hg Cd and Pb. The concentrations of muscle Hg (corresponding to 70–105 μg CH3Hg eaten weekly) are comparable to the PTWI (permissible tolerable weekly intake) recommended by WHO (200 μg CH3Hg). The muscle Cd and Pb levels are significantly lower than the PTWI's and do not constitute any threat for man.
Article
The spatial and temporal variability of Hg emissions from urban paved surfaces was assessed through repeated measurements under varying environmental conditions at six sample sites in Toronto, Ontario, Canada. The results show significant spatial variability of the Hg emissions with median values ranging from below detection limit to 5.2 ng/m2/h. Two of the sites consistently had higher Hg emissions (on several occasions >20 ng/m2/h) than the other 4, which were equivalently low (maximum emission: 2.1 ng/m2/h). A surrogate measure of the pavement Hg concentrations was obtained during each day of sampling through the collection of street dust. The median street dust concentration also showed significant spatial variability (ranging from 9.6 to 44.5 ng/g). Regression analysis showed that the spatial variability of the Hg emissions was significantly related to the street dust concentrations. Controlled experiments using Hg amended street dust confirmed the relationship between Hg surface concentration and emission magnitude. Within a given sample site, Hg emissions varied temporally and multiple regression analysis showed that within-site variability was significantly influenced by changes in solar radiation with only a minor effect from surface temperature. Controlled experiments using shade cloths confirmed that solar radiation can have a large influence on the magnitude of Hg emissions within a given site. The emissions measured in Toronto were contextualized through comparison sampling in Austin, Texas. The Hg emissions measured in Austin were within the range detected in Toronto and also showed significant correlation with Hg street dust concentrations between sites. To provide a holistic assessment of Hg emissions from urban environments, samples were also collected from other common urban surfaces (soil, roofs, and windows). Soils consistently had higher emissions than all the other surfaces (7.3 ng/m2/h, n = 39).
Article
Four seasonal sampling campaigns were carried out in the Florida Everglades to measure elemental Hg vapor (Hg°) fluxes over emergent macrophytes using a modified Bowen ratio gradient approach. The predominant flux of Hg° over both invasive cattail and native sawgrass stands was emission; mean day time fluxes over cattail ranged from ∼20 (winter) to ∼40 (summer) ng m−2 h−1. Sawgrass fluxes were about half those over cattail during comparable periods. Emission from vegetation significantly exceeded evasion of Hg° from the underlying water surface (∼1–2 ng m−2 h−1) measured simultaneously using floating chambers. Among several environmental factors (e.g. CO2 flux, water vapor flux, wind speed, water, air and leaf temperature, and solar radiation), water vapor exhibited the strongest correlation with Hg° flux, and transpiration is suggested as an appropriate term to describe this phenomenon. The lack of significant Hg° emissions from a live, but uprooted (floating) cattail stand suggests that a likely source of the transpired Hg° is the underlying sediments. The pattern of Hg° fluxes typically measured indicated a diel cycle with two peaks, possibly related to different gas exchange dynamics: one in early morning related to lacunal gas release, and a second at midday related to transpiration; nighttime fluxes approached zero.
Article
Estimates of atmospheric emissions of mercury from anthropogenic sources in Europe in 1995 are presented with the information on emissions of both total mercury and its major chemical and physical forms. The 1995 anthropogenic emissions of total emissions were estimated to be about , a decrease of 45% compared to these emissions in 1990. Combustion of fuels, particularly coal has been the major source of anthropogenic emissions contributing to more than half to the total emissions. The emissions from coal combustion have not changed significantly over the past decade. Major decrease has been estimated for emissions from industrial processes, particularly the chlor-alkali production using the Hg cell process. In 1995 the European emissions of anthropogenic mercury contributed about 13% to the global emissions of this element from anthropogenic sources. The anthropogenic Hg emissions in Europe were still higher than the natural emissions in the region, estimated to be about 250– per year. The accuracy of estimates of anthropogenic emissions of Hg in Europe in 1995 is considered to be between 25 and 50%. The most accurate seem to be the estimates for combustion sources, while the most incomplete data were collected and/or estimated for waste disposal. The emissions of gaseous elemental mercury contributed about 61% to the emissions of the total mercury, while the contribution of gaseous bivalent mercury and particulate mercury was 32 and 7%, respectively.
Article
The paper reviews the current state of knowledge regarding global emissions of mercury and presents a new inventory of global emissions of mercury to the atmosphere from anthropogenic sources for the year 2000. The largest emissions of Hg to the global atmosphere occur from combustion of fossil fuels, mainly coal in utility, industrial, and residential boilers. As much as two-thirds of the total emission of ca. 2190 ton of Hg emitted from all anthropogenic sources worldwide in 2000 came from combustion of fossil fuels. Emissions of Hg from coal combustion are between one and two orders of magnitude higher than emissions from oil combustion, depending on the country. Various industrial processes account for additional 30% of Hg emissions from anthropogenic sources worldwide in 2000. Major contribution to emissions from this source category comes from gold production using Hg technology. The Asian countries contributed about 54% to the global Hg emission from anthropogenic sources in 2000, followed by Africa (18%) and Europe, including the European part of Russia (11%). China heads the list of the 10 countries with highest Hg emissions from anthropogenic activities. With more than 600 ton of Hg, China contributes about 28% to the global emissions of mercury.It is expected that future changes of Hg emissions from anthropogenic sources worldwide until the year 2020 should be within ±20% of the current estimates, although this assessment should be treated with great caution.Emission estimates for various continents presented in this paper were used to prepare global emission maps. These maps are presented in a companion paper (Wilson et al., 2005. Spatial distribution of global anthropogenic mercury atmospheric emissions. Atmospheric Environment, in this issue).
Article
European perch (Perca fluviatilis) harvested from three lakes of Central Italy were studied in different seasonal periods of a year to evaluate their nutritional quality and some safety aspects related to the pollution of the aquatic environment. The lakes considered, located in the Latium region, differed with respect to their volcanic (Bolsena and Bracciano Lakes) or artificial (Salto Lake) origin. Fillets of fish caught in the three lakes were characterised by good protein (17–19%) and mineral contents and low lipid levels (0.6–1.2%) throughout the year. Total lipids were characterised by low cholesterol levels (41.9–74.7 mg/100 g) and high percentages of total n − 3 polyunsaturated fatty acids (27.7–33.8% of total fatty acids), in particular docosahexaenoic acid (14.2–25.3% of total fatty acids). The qualitative analysis of the stomach content of perch confirmed their predatory feeding behaviour. The chemical and nutritional profiles of perch from the three lakes were comparable except for rubidium and cesium levels, which were higher in the muscle tissues of perch from the volcanic lakes. These minerals may represent elements of traceability of the origin of fish. Low levels of organochlorine pesticides and polychlorinated biphenyls, well below the Italian and European action limits, were detected in the muscle tissue of perch from all three lakes.
Article
The micrometerological modified Bowen ratio method was used for the first time to quantify fluxes of elemental mercury vapor (Hg[sup 0]) over contaminated soils during the spring and fall of 1993. We determined fluxes using relationships among the concentration gradients and fluxes of water vapor (measured with fast-response sensors and eddy correlation) and measured gradients in Hg[sup 0] (sampled with a multi-replicate, high-precision device). The contaminated soils consistently exhibited significant emission of Hg[sup 0] to the atmosphere. Fluxes associated with winds from the primary source area ranged from [approximately]10 to [approximately]200 ng m[sup [minus]2] h[sup [minus]1], up to several orders of magnitude above background. Fluxes increased exponentially with soil temperature, yielding a temperature coefficient similar to nitrogen oxide (exp[ T[sub soil]], for T[sub soil] = 7-29[degrees]C). These results provided confidence in the method for Hg[sup 0] because the gradients and fluxes behaved predictably. Fluxes appear to be controlled by volatilization of existing contaminant elemental Hg plus reduction of Hg[sup 2+] to Hg[sup 0] in soil solution. We modeled the emission from an area of contaminated soils within approximately 20-50 m of our site using the flux/soil temperature relationship and annual temperature data. 55 refs., 8 figs., 1 tab.