Biomagnification Research Papers - Academia.edu (original) (raw)

Total mercury (T-Hg) and organic mercury (mainly methylmercury, MeHg) concentrations in the most important compartments (water, sediment, macrophytes, zooplankton, mussels and fish) of the shallow and eutrophic Lake Candia (Turin, Northern Italy) were measured. The decreasing sequence of the T-Hg concentrations is as follows: cat-fish (143 µg kg -1 d.w.), zooplankton (77 µg kg -1 d.w.), Unio pictorum mancus (37.9 µg kg -1 d.w.), macrophytes (28.9 µg kg -1 d.w.). The content of mercury in mussel tissues increased with the size of the animal, but the relationship between Hg concentration and tissue weight was negative, indicating that the rate of mercury accumulation was lower than the tissue growth rate. The amount of mercury accumulated in the mussels living in the lake sediments was estimated to be 0.54 µg m -2 . The importance of mercury biomagnification is also discussed.

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- Limnology, Multidisciplinary, Macrophytes, FISH

Selenium concentrations were measured in water, sediments and organisms inhabiting a freshwater coal power station cooling reservoir. Se concentrations found were: water, 1.9 ± 2 µg L −1 ; sediment, 7 ± 1 µg g −1 ; phytoplankton, 3.4 µg g −1 ; zooplankton, 5.3 µg g −1 ; epiphytic algae, 1.3 ± 0.2 µg g −1 ; benthic algae, 8 ± 2 µg g −1 ; macrophyte leaves, 2.7-2.8 µg g −1 ; macrophyte roots, 0.5-6.5 µg g −1 ; detritus, 10 µg g −1 ; Oligochaeta, 11 µg g −1 ; Corbiculidae, 1.1 µg g −1 ; Insects, 3.7-8.3 µg g −1 ; Gastropoda, 3.2 µg g −1 ; Crustacea, 3.1-6 µg g −1 ; whole fish, 2.2-13 µg g −1 ; and fish liver, 134-314 µg g −1 . Bioconcentration factors were similar to those found in aquatic ecosystems with comparable Se concentrations in the water column. A food web was constructed with four main food chains (phytoplankton, epiphytic algae, benthic algae and sediment/detrital), with fish fed from multiple pathways. Biomagnification only occurs along food chains for flathead gudgeons and rainbow trout. Se concentrations in food sources were above the 3 µg g −1 dietary Se level considered to induce teratogenesis in fish spawning. Flathead gudgeons were found to be suffering teratogenesis and rainbow trout showed no evidence of teratogenesis.

- by Frank Krikowa
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- Ecotoxicology, Multidisciplinary, Biomagnification, New South Wales

Environmental Context. The fate and behaviour of trace pollutants are very strongly modified, and usually dominated, by their physical and chemical interactions with naturally occurring aquatic colloids (defined as solid phase material with one dimension between 1 nm and 1 µm). This review summarises the area and key advances in the field of natural aquatic colloids, including technique development and quantification of colloidal structure and interactions with pollutants.The review also discusses areas in which significant advances are likely to be made or are needed and, as such, provides a framework for further work in the next few years.

- by Kevin Wilkinson
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Environmental context. On a global scale, soils store more carbon than plants or the atmosphere. The cycling of this vast reservoir of reduced carbon is closely tied to variations in environmental conditions, but robust predictions of climate-carbon cycle feedbacks are hampered by a lack of mechanistic knowledge regarding the sensitivity of organic matter decomposition to rising temperatures. This text provides a critical discussion of the practice to conceptualise parts of soil organic matter as intrinsically resistant to decomposition or 'recalcitrant'.

- by Tabowei Churchill Onuosa
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Environmental context. Trafficked streets are air pollution hot spots where people experience high exposure to hazardous pollutants. Although monitoring networks provide crucial information about measured pollutant levels, the measurements are resource demanding and thus can be performed at only few selected sites. Fast and easily applied street pollution models are therefore necessary tools to provide information about the loadings in streets without measurement activities. We evaluate the Operational Street Pollution Model, one of the most commonly applied models in air pollution management and research worldwide.

- by Ole Hertel
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

PRESENTADA COMO REQUISITO PARCIAL PARA OBTENER EL GRADO DE : DOCTORA EN CIENCIAS MONTECILLO, TEXCOCO, EDO. DE MEXICO 2014 C OLEGIO DE POSTGRADUADOS INSTITUCIÓN DE ENSEÑANZA E INVESTIGACIÓN EN CIENCIAS AGRÍCOLAS CAMPUS MONTECILLO POSTGRADO... more

- by Mayra Carino
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- Bioaccumulation, Biomagnification

Environmental context. Recent developments in nanotechnology have focussed towards innovation and usage of multifunctional and superior hybrid nanomaterials. Possible exposure of these novel nanohybrids can lead to unpredicted environmental fate, transport, transformation and toxicity scenarios. Environmentally relevant emerging properties and potential environmental implications of these newer materials need to be systematically studied to prevent harmful effects towards the aquatic environment and ecology.

- by Nirupam Aich
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

The article shows the main processes governing the origin and fate of mercury in different environmental compartments
of the Amazon. No one knows exactly how much is the contribution of Hg to the environment among various
natural and anthropogenic processes, but the paper shows that these accumulation rates are increasingly high. The
organic form of mercury (methylmercury) is the most abundant and it is potentially the most toxic for living systems.
Aquatic systems are most affected due to their vulnerability to bioaccumulation and biomagnification processes of
methylmercury through the food chain that may affect humans.

- by Dario Acha and +1
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- Bioaccumulation, Methylmercury, Mercury Pollution, Amazonian Studies

This report includes atomic absorption data from water column, elutriates and zooplankton that demonstrate that lead biomagnifies at El Niágara reservoir, Mexico. Results include field data (bioaccumulation factors) (BAFs) and laboratory data (bioconcentration factors) (BCFs). Two findings: high BAFs for invertebrate predator like Acanthocyclops robustus, Asplanchna brightwellii, Culex sp. larvae, and Hyalella azteca, compared to grazer species Moina micrura and Simocephalus vetulus; low BCF’s found for some predators, suggested that lead biomagnifications were taking place. The presence of Moina micrura in the gut of Asplanchna allowed us to design experiments where A. brightwellii was fed lead-exposed M. micrura neonates. The BAF of Asplanchna was 123,684, BCF was 490. Asplanchna individuals fed exposed Moina had 13.31 times more lead than Asplanchna individuals just exposed 48-h to lead, confirming that lead biomagnification occurs. Results of two fish species showed no lead biomagnification, suggesting that lead biomagnification might be restricted to invertebrate predators.

- by Isidoro Rubio-Franchini and +1
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- Environmental Toxicology, Aquatic Toxicology, Aquatic Invertebrates, Biomagnification

Semi-domesticated reindeer and wild moose meat samples were analyzed for polychlorinated dibenzo-pdioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). Both calves and adults were studied. Individual reindeer and moose meat samples and pooled reindeer calf meat samples were collected from the northern, the middle, and the southern reindeer herding regions in Finland. Samples represented the edible parts of carcasses.

- by SENTHIL KUMAR KURUNTHACHALAM
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- Engineering, Algorithms, Thermodynamics, Soil

Among-lake variation in mercury (Hg) concentrations in landlocked Arctic char was examined in 27 char populations from remote lakes across the Canadian Arctic. A total of 520 landlocked Arctic char were collected from 27 lakes, as well as sediments and surface water from a subset of lakes in 1999, 2002, and 2005 to 2007. Size, length, age, and trophic position (d15N) of individual char were determined and relationships with total Hg (THg) concentrations investigated, to identify a common covariate for adjustment using analysis of covariance (ANCOVA). A subset of 216 char from 24 populations was used for spatial comparison, after length-adjustment. The influence of trophic position and food web length and abiotic characteristics such as location, geomorphology, lake area, catchment area, catchment-to-lake area ratio of the lakes on adjusted THg concentrations in char muscle tissue were then evaluated. Arctic char from Amituk Lake (Cornwallis Island) had the highest Hg concentrations (1.31 mg/g wet wt), while Tessisoak Lake (Labrador, 0.07mg/g wet wt) had the lowest. Concentrations of THg were positively correlated with size, d15N, and age, respectively, in 88, 71, and 58% of 24 char populations. Length and d15N were correlated in 67% of 24 char populations. Food chain length did not explain the differences in length-adjusted THg concentrations in char. No relationships between adjusted THg concentrations in char and latitude or longitude were found, however, THg concentrations in char showed a positive correlation with catchment-to-lake area ratio. Furthermore, we conclude that inputs from the surrounding environment may influence THg concentrations, and will ultimately affect THg concentrations
in char as a result of predicted climate-driven changes that may occur in Arctic lake watersheds.

- by Wendy Michaud
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- Climate Change, Environmental Monitoring, Biological Sciences, Canada

Concentrations of DDTs and PCBs were determined in the zooplankton and in three different fish species (shad, whitefish and roach) collected seasonally during 2009 and 2010 in three sites in Lake Maggiore, a south-alpine lake that has been contaminated by DDT since 1996. As previously observed in 2008, even during 2009 DDTs concentrations were higher in zooplankton than in fish, probably due to the very unstable situation of the lake still influenced by local inputs. The situation changed in 2010, when all DDT compounds increased in fish to levels much higher than those measured in zooplankton. Biomagnification was statistically demonstrated for pp 0 DDE in all the three fish species, indicating a probable signal of recovery of the lake.

- by pietro volta
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- Environmental Monitoring, Multidisciplinary, Italy, DDT

The diet, habitat use and mercury concentration of the small fish species, the straight fin barb Barbus paludinosus, were studied in Lake Awassa, Ethiopia, for a period of 1 year from February 2003 to January 2004. Stable isotope signatures of nitrogen and carbon in different total length (L T) classes were used to determine trophic positions and organic carbon sources, respectively. Barbus paludinosus mainly occupied the protected benthic habitats (littoral and profundal) of the lake. The d 13 C values were in the range from À24 to À19%, indicating that the carbon source for B. paludinosus was benthic, as well. Small individuals (60 mm L T) mainly preyed upon ostracods, intermediate sizes (60-100 mm) on aquatic insects and gastropods, while a tiny cyprinodont fish Aplocheilichthys antinorii dominated the diet of large individuals (100-160 mm). The progressively increase in d 15 N with increasing L T also indicated a diet shift towards piscivory in larger individuals. The mercury concentration ranging from 0Á02 to 0Á74 mg kg À1 wet mass (wm), was unexpectedly high in this small species, and was significantly positively related to L T , as well as to d 15 N. Some large individuals had mercury concentrations < 0Á1 mg kg À1 wm, and low d 15 N, indicating substantial variations in diet between individuals of same size. The study suggests that other piscivorous species which include B. paludinosus in their diet may have a high mercury intake risk.

- by B. Rosseland
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- Zoology, Stable Isotopes, Ecology, Fish Biology

Understanding the mechanisms of bioaccumulation in food webs is critical to predicting which food webs are at risk for higher rates of bioaccumulation that endanger the health of upper-trophic predators, including humans. Mercury and organochlorines were measured concurrently with stable isotopes of nitrogen and carbon in key fishes and invertebrates of Lake Washington to explore important pathways of bioaccumulation in this food web. Across the food web, age and trophic position together were highly significant predictors of bioaccumulation. Trophic position was more important than age for predicting accumulation of mercury, ∑DDT, and ∑-chlordane, whereas age was more important than trophic position for predicting ∑PCB. Excluding age from the analysis inflated the apparent importance of trophic position to bioaccumulation for all contaminants. Benthic and pelagic habitats had similar potential to bioaccumulate contaminants, although higher ∑-chlordane concentrations in organisms were weakly associated with more benthic carbon signals. In individual fish species, contaminant concentrations increased with age, size, and trophic position (δ 15 N), whereas relationships with carbon source (δ 13 C) were not consistent. Lipid concentrations were correlated with contaminant concentrations in some but not all fishes, suggesting that lipids were not involved mechanistically in bioaccumulation. Contaminant concentrations in biota did not vary among littoral sites. Collectively, these results suggest that age may be an important determinant of bioaccumulation in many food webs and could help explain a significant amount of the variability in apparent biomagnification rates among food webs. As such, effort should be made when possible to collect information on organism age in addition to stable isotopes when assessing food webs for rates of biomagnification.

- by Jenifer McIntyre and +1
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- Bioaccumulation, Invertebrates, Multidisciplinary, Age

Abstract The impounding of the Three Gorges Reservoir
(TGR) at the Yangtze River caused large flooding of urban,
industrial, and agricultural areas, and profound land use
changes took place. Consequently, substantial amounts of
organic and inorganic pollutants were released into the reser-
voir. Additionally, contaminants and nutrients are entering the
reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aqua-
cultures, and households. The main aim of the presented
research project is a deeper understanding of the processes that
determines the bioaccumulation and biomagnification of or-
ganic pollutants, i.e., mainly pesticides, in aquatic food webs
under the newly developing conditions of the TGR. The proj-
ect is part of the Yangtze-Hydro environmental program, fi-
nanced by the German Ministry of Education and Science. In
order to test combinations of environmental factors like
nutrients and pollution, we use an integrated modeling ap-
proach to study the potential accumulation and biomagnifica-
tion. We describe the integrative modeling approach and the
consecutive adaption of the AQUATOX model, used as mod-
eling framework for ecological risk assessment. As a starting
point, pre-calibrated simulations were adapted to Yangtze-
specific conditions (regionalization). Two exemplary food
webs were developed by a thorough review of the pertinent
literature. The first typical for the flowing conditions of the
original Yangtze River and the Daning River near the city of
Wushan, and the second for the stagnant reservoir character-
istics of the aforementioned region that is marked by an inter-
mediate between lake and large river communities of aquatic
organisms. In close cooperation with German and Chinese
partners of the Yangtze-Hydro Research Association, other
site-specific parameters were estimated. The MINIBAT project
contributed to the calibration of physicochemical and bathy-
metric parameters, and the TRANSMIC project delivered hy-
drodynamic models for water volume and flow velocity
conditions. The research questions were firstly focused on
the definition of scenarios that could depict representative
situations regarding food webs, pollution, and flow conditions in the TGR. The food webs and the abiotic site conditions in
the main study area near the city of Wushan that determine the
environmental preconditions for the organisms were defined.
In our conceptual approach, we used the pesticide propanil as a
model substance.

- by Richard Ottermanns and +2
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- Bioaccumulation, Modeling and Simulation, Food Web Dynamics, Environmental Risk Assesment

M ercury is a persistent contaminant that biomagnifies up the food web, causing mortality, reproductive failure, and other health effects in predatory wildlife and humans . From 1930 to 1950, industrial mercuric sulfate entered the South River, a tributary of the Shenandoah River in Virginia (United States) (3). To determine whether this mercury contamination had moved into the adjacent terrestrial food web, we analyzed total mercury concentrations in blood from adults of 13 terrestrial-feeding bird species breeding within 50 m of the river (4). We compared these to breeding adults of the same species at uncontaminated reference sites . Twelve species had significantly higher mercury than that found in individuals from reference sites ( and table S1). We simultaneously sampled adults of five bird species with direct dietary connections to the aquatic mercury; their mercury concentrations were also significantly elevated relative to reference birds ( ). With the exception of a duck species, all aquatic birds had blood mercury ranging from 2 to 4 parts per million (ppm) (wet weight), about the level of adverse effects (5). Two terrestrial songbirds species, a wren and a vireo, had the highest blood mercury levels of any species, and a majority of terrestrial-feeding birds were in the same range as aquatic-feeding species.

- by Rachel Fovargue
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- Science, Diet, Multidisciplinary, Lepidoptera

Post Minamata incident there has been awareness about mercury toxicity even among the general public. Previous researches contributed a vast amount of data regarding acute mercury exposure, but gradually information about the low dose Expansion of methylmercury poisoning outside minamata: an epidemiological study on chronic methylmercury poisoninig outside of Minamata. Evidence of early nervous system dysfunction in Amazonian populations exposed to low-levels of methylmercury. Neurotoxicology 17 (1) 157-167] of mercury toxicity has been trickling in. With mercury contaminating rain-, groundand sea-water no one is safe. Polluted water leads to mercury laced fish, meat and vegetable. In aquatic environments, inorganic mercury is microbiologically transformed into lipophilic organic compound 'methylmercury'. This transformation makes mercury more prone to biomagnification in food chains. Consequently, populations with traditionally high dietary intake of food originating from fresh or marine environment have highest dietary exposure to mercury. Extensive research done on locals across the globe have already established this, persons who routinely consume fish or a particular species of fish are at an increased risk of methylmercury poisoning. The easy access of the toxicant to man through multiple pathways air, water, food, cosmetic products and even vaccines increase the exposure. Foetus and children are more susceptible towards mercury toxicity. Mothers consuming diet containing mercury pass the toxicant to foetus and to infants through breast milk. Decreased performance in areas of motor function and memory has been reported among children exposed to presumably safe mercury levels. Similarly, disruption of attention, fine motor function and verbal memory was also found in adults on exposure to low mercury levels. It is an occupational hazard for dental staff, chloralkali factory workers and goldminers, etc. Mercury has been found to be a causative agent of various sorts of disorders, including neurological, nephrological, immunological, cardiac, motor, reproductive and even genetic. Recently heavy metal mediated toxicity has been linked to diseases like Alzeihemer's, Parkinson's, Autism, Lupus, Amyotrophic lateral sclerosis, etc. Besides this, it poses danger to wildlife. Therefore, it becomes imperative to spread the information regarding the threat of mercury exposure amongst the scientists and masses. in the food web. Amongst three forms of mercury, the organic form is most toxic as it passes the blood brain barrier owing to its lipid solubility. The damage has vast implications with human beings at the top of food chain getting worst of the deal owing to biomagnification. This review was written to focus on recent researches showing adverse health effects of low doses of mercury, to instigate the requirement for a new era of pharmaceutical development and to create further awareness regarding environmental remediation.

- by Soghra Haq
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- Genetics, Environmental Toxicology, Amyotrophic Lateral Sclerosis, Low Dose

The trophic transfer of organic pollutants with varying physical chemical properties was determined in both a pelagic and benthic food chain using δ 15 N as a continuous variable for assessing trophic levels. The trophic transfer of organic pollutants through the entire food chain in terms of food chain magnification factors (FCMFs) was quantified from the slope of the regression between ln [concentration] and δ 15 N. Organic pollutants with statistically significant FCMFs N1 were considered to biomagnify within the food chain, whereas those with FCMFs b 1 were considered to trophically dilute. Statistically significant FCMFs N1 were found for PCB congeners and organochlorine pesticides in the Baltic food chains whereas statistically significant FCMFs b1 were found for PAHs and PCNs due to trophic dilution resulting from metabolism. FCMFs were generally greater in the pelagic food chain than in the benthic food chain. However, estimated FCMFs for the benthic food chain are likely in error, as the δ 15 N method suggested a food chain structure which was not consistent with the known dietary patterns of the species. Biomagnification factors (BMFs) were additionally calculated as the ratio of the lipid normalized concentrations in the predator and prey species with adjustment for trophic level and were generally consistent with the FCMFs with BMF N1 for PCBs and organochlorines.

- by Erick Nfon
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- Marine Biology, Metabolism, Environmental Monitoring, Multidisciplinary

SAMPLES of ten vegetable plant species. namely; Abclmoschus
esculentus (Okra), Bela vularis var. cicla. (Chard) Beta vulgaris
L. (Carden), Apium geraveolens (Celery), Corchorus olitorius L.
(Jews mallow), Lactuca sativa (Lettuce), Allium cepa (Onion).
Raphans sativus (Radish), Eruca saliva mill (Rocket) and Spinacia
oleracea (Spinach); were collected from fields at Mostorod area
whereas its soils have been subjected to prolonged domestic and
industrial wastewater irrigation (about 35 years). Edibal plant samples were air dried, ground and wet digested then analyzed for its heavy metals ( Fe, Mn, Zn, Cu, Co, Cd, Ni, and Pb) content using Ion Coupled Plasma (ICP) technique.
Results revealed that vegetable plants species varied in their affinity to. accumulate metals in their edible parts. Irrigation with different wastewater significantly increased the concentration of all tested metals in vegetable plants especially the leafy species. Spinach accumulated the highest Fe and Mn levels Rocket accumulated the highest levels of Zn.
Pb and Co. However, Jews mallow exhibited the highest levels or Cu. Ni and Cd. These upnormal levels exceed the permissible metals intake as suggested by world health organization (WHO).
It is clear that, the prolonged irrigation with heavy polluted
wastewater on the alluvial soils of Mostorod area combined with
intensive vegetable cultivation will cause adverse effects on the
environment as well as arises health hazard problems. To minimize
the environmental hazards: a) wastewater effluents should be treated at sites where toxic metals originate, b) vegetable plants should not be grown under such condition, c) levels of potentially toxic elements needs to be continuously monitored.

- by mamdouh sabour
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- Biomagnification, Heavy Metals Pollution, Edible Leafy Vegetables

The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent Responsible editor: Michael Matthies Björn Scholz-Starke and Richard Ottermanns contributed equally to this work.

- by Björn Scholz-Starke
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- Bioaccumulation, Environmental Monitoring, Modeling and Simulation, Rivers

Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predatorprey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on δ 15 N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean δ 15 N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals.

- by Lawrence Duffy and +1
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- Principal Component Analysis, Stable Isotopes, Trace Metals, Environmental Monitoring
- by E. Tipping
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- Earth Sciences, Chemistry, Computational Chemistry, Ethics

Environmental Context. The composition of calcium carbonate in annual skeletal growth bands reflects the environmental conditions in which coral grows, enabling their use as long-term bio-monitors and archives of environmental conditions.... more

- by Niels Munksgaard
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Environmental context. Eutrophication can lead to the production of harmful algal blooms and is one of the world's most serious water quality issues. Phosphorus is potentially the limiting macro-nutrient in fresh, estuarine and some marine waters. Consequently, it plays a crucial role in determining the ecological status of many aquatic ecosystems. Considerable effort has been invested in monitoring dissolved reactive phosphorus and total phosphorus in the water column, but less is known about the speciation of phosphorus, particularly in the sediment. This compartment is an important and dynamic reservoir of phosphorus and a potential long-term source of phosphorus release to the water column by the sediment-water interface. This paper investigates the solid-phase speciation and reorganisation of phosphorus within the sediments of a shallow lake system in south-east Australia (the Gippsland Lakes) which suffers from recurring harmful algae blooms. Various strategies are proposed to determine the minimum realistic timescale required to deplete the sediment of labile and reactive phosphorus species.

- by P. Monbet
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Environmental contextPerfluoroalkyl compounds are organic contaminants that exhibit strong resistance to chemical- and microbial-degradation. As partitioning between solid and aqueous phases is expected to control the transport of perfluoroalkyl compounds, we studied the molecular mechanisms of their adsorption–desorption at a representative Fe oxide surface using in situ molecular spectroscopy. The results provide valuable information on the types of bonds formed, and enable a better understanding of the transport and fate of these organic contaminants in natural environments. The kinetics and mechanisms of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) adsorption to nanoparticulate hematite (α-Fe2O3) from aqueous solutions were examined using in situ, flow-through attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. Results indicate that both PFOA and PFOS molecules are retained at the hydrophilic hematite surface and the adsorptio...

- by Jon Chorover
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- Earth Sciences, Computational Chemistry, Climate Change, Atmospheric Chemistry
- by Susan Bengtson Nash
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Two food webs from the Mar Menor coastal lagoon, differing in the distance from the desertstream through which mining wastes were discharged, were examined by reference to essential (Zn and Cu) and non-essential (Pb and Cd) metal concentrations and stable isotopes content (C and N). The partial extraction technique applied, which reflects the availability of metals to organisms after sediment ingestion, showed higher bioavailable metal concentrations in sediments from the station influenced by the mining discharges, in agreement with the higher metal concentrations observed in organisms, which in many cases exceeded the regulatory limits established in Spanish legislation concerning seafood.

- by Arnaldo Marin
- •
- Biofilms, Carbon, Invertebrates, Stable Isotopes

Environmental context Novel technology is used to examine oil contaminated soil to better understand this longstanding problem. The data indicate that oil forms a non-discriminant layer over all the soil components, which in their natural state would be exposed to water, and that it retains certain polar compounds while contributing other oil contaminants to the surrounding porewater and groundwater. Such molecular level information helps to better understand the reoccurrence of hydrophobicity in remediated soil, and could lead to novel clean-up methods. Comprehensive multiphase (CMP) NMR spectroscopy is a novel NMR technology introduced in 2012. CMP NMR spectroscopy permits the analysis of solid, gel and liquid phases in unaltered natural samples. Here the technology is applied to control and oil contaminated soils to understand the molecular processes that give rise to non-wettable soils. 13C solid-state NMR spectroscopy is found to be excellent for studying the bulk rigid compone...

- by Hashim Farooq
- •
- Earth Sciences, Chemistry, Computational Chemistry, Climate Change

Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta-and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.

- by Susan Shaw
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- Marine Biology, Environmental Science, Medicine, Biomagnification

The aim of the present study was to determine the distribution of per-and polyfluoroalkyl substances (PFASs) in three-egg clutches of Audouin's gull (Larus audouinii) breeding in Ebro Delta's colony according to the laying order (a, b and c eggs). Five PFASs were analyzed in 30 eggs (yolk and albumen separately), corresponding to 10 three-egg clutches. Carbon and nitrogen stable isotopes were measured as dietary tracers. PFASs were not detected in albumen. In egg yolks, perfluorooctane sulfonate (PFOS) was the main compound detected followed by perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHS) and perfluorooctanoic acid (PFOA). Perfluorooctane sulfonate (PFBS) was not detected. Mean RPFASs for aeggs was of 236 ± 57 ng g À1 yolk wet weight (ww), for b-eggs was of 140 ± 56 ng g À1 yolk ww and for c-eggs, 133 ± 54 ng g À1 yolk ww. PFOS concentration decreased according to the laying order of the eggs, showing significant differences between consecutive eggs. In addition, significant correlation (r 2 s = 0.7-0.9) was observed for PFOS concentration within the eggs from the same clutch. No relationship was found between PFOS levels and stable isotopes signatures.

- by Kurunthachalam Kannan
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Organochlorine compounds were analysed in three fish species of different feeding types from the area of Elephant Island in the Antarctic. In 1996, hexachlorobenzene (HCB) (means: 15-20 ng/g lipid), p,p 0 -DDE (5-13 ng/g lipid) and mirex (1-7 ng/g lipid) predominated, while PCBs were minor components (PCB 153: 0.4-2 ng/g lipid). Concentration patterns were species-dependent: PCB 180, PCB 153, mirex, nonachlor III, trans-nonachlor and the toxaphene compound B8-1413 were highest in the bottom invertebrate feeder Gobionotothen gibberifrons and lowest in the krill feeder Champsocephalus gunnari. Levels of p,p 0 -DDE, PCB 138 and heptachloro-1 0 -methyl-1,2 0 -bipyrrole (Q1), a natural bioaccumulative product, were highest in the fish feeder Chaenocephalus aceratus, whereas HCB was present in about equal concentrations in all species. Most compounds were taken up preferentially via the benthic food chain, the chlorinated bipyrrole via the pelagic food chain and HCB from the water. In antarctic fish, biomagnification was generally more important than bioconcentration. Between 1987 and 1996, most persistent organic pollutant (POP) levels showed significant increases in the benthos feeder and the fish feeder, while they remained nearly constant or increased less in the krill feeder. Hence, the former species represent indicator species for changing POP levels in Antarctica. Ratios (1996Ratios ( /1987 of average concentrations in G. gibberifrons were: PCB 138 0.7, HCB 0.8, B8-1413 1.5, PCB 180 1.7, PCB 153 1.8, p,p 0 -DDE 2.0, nonachlor III 2.9, trans-nonachlor 3.3, mirex 6.7. By comparison with trends in the northern hemisphere it is concluded that global distribution of HCB is close to equilibrium. Changing levels of other POPs reflect global redistribution and increasing transfer to antarctic waters probably due to recent usage in the southern hemisphere and climate changes.

- by Satie Taniguchi
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- Climate Change, Mass Spectrometry, Bioaccumulation, Water Pollution

Even at low concentrations in the environment, mercury has the potential to biomagnify in food chains and reaches levels of concern in apex predators. The aim of this study was to relate the transfer of total mercury (THg) and methylmercury (MeHg) in a Gulf of St. Lawrence food web to the trophic structure, from primary consumers to seabirds, using stable nitrogen (δ 15 N) and carbon (δ 13 C) isotope analysis and physical environmental parameters. The energy reaching upper trophic level species was principally derived from pelagic primary production, with particulate organic matter (POM) at the base of the food chain. We developed a biomagnification factor (BMF) taking into account the various prey items consumed by a given predator using stable isotope mixing models. This BMF provides a more realistic estimation than when using a single prey. Lipid content, body weight, trophic level and benthic connection explained 77.4 and 80.7% of the variation in THg and MeHg concentrations, respectively in this food web. When other values were held constant, relationships with lipid and benthic connection were negative whereas relationships with trophic level and body weight were positive. Total Hg and MeHg biomagnified in this food web with biomagnification power values (slope of the relationship with δ 15 N) of 0.170 and 0.235, respectively on wet weight and 0.134 and 0.201, respectively on dry weight. Values of biomagnification power were greater for pelagic and benthopelagic species compared to benthic species whereas the opposite trend was observed for levels at the base of the food chain. This suggests that Hg would be readily bioavailable to organisms at the base of the benthic food chain, but trophic transfer would be more efficient in each trophic level of pelagic and benthopelagic food chains.

- by Emmanuel Yumvihoze
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- Stable Isotope Analysis, Modeling, Stable Isotopes, Environmental Monitoring

Environmental context Ozone pollution in Houston, Texas, has been a public health concern for decades. Unusually large hourly changes in observed ozone concentrations have been correlated with a greater likelihood of violating the federal air quality standard. We investigate the geographic and chemical origins of these large hourly increases, which should help regulators better control ozone violations. Many of Houston’s highest 8-h ozone (O3) peaks are characterised by increases in concentrations of at least 40ppb in 1h, or 60ppb in 2h. These rapid increases are called non-typical O3 changes (NTOCs). In 2004, the Texas Commission on Environmental Quality (TCEQ) developed a novel emissions control strategy aimed at eliminating NTOCs. The strategy limited routine and short-term emissions of ethene, propene, 1,3-butadiene and butene isomers, collectively called highly reactive volatile organic compounds (HRVOCs), which are released from petrochemical facilities. HRVOCs have been assoc...

- by Harvey Jeffries
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- Earth Sciences, Computational Chemistry, Climate Change, Atmospheric Chemistry

Environmental context. The release of mining effluents exposes natural waters to excess metals and thereby threatens both human and environmental health. The present study explores the toxicity of aqueous mining effluents collected from a mining area in Sudbury (Ontario, Canada), using two different methods for determination of metal speciation, and an algal toxicity study. The results show reasonable correlation between metal speciation and the observed toxicity and suggest the importance of taking into account other factors related to water quality criteria such as nutrient concentrations, diluent water and presence of other toxic metals that can greatly influence the toxicological result. . The present study explores the toxicity of aqueous mining and municipal effluents from the Sudbury area (Canada) using equilibrium- and kinetics-based estimates of metal speciation and chronic toxicity studies using algae (Pseudokirchneriella subcapitata). Free metal ion concentration was dete...

- by David Lean
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- Earth Sciences, Computational Chemistry, Climate Change, Atmospheric Chemistry

CITATIONS 83 READS 263 7 authors, including: Some of the authors of this publication are also working on these related projects: Factors affecting the bioavailability of metals in turbid river systems View project Potential ecological... more

- by Mohammed Baalousha and +1
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Because it is very toxic and accumulates in organisms, particularly in fish, mercury is an important pollutant and one of the most studied. Nonetheless we still have an incomplete understanding of the factors that control the bioconcentration of mercury. Elemental mercury is efficiently transported as a gas around the globe, and even remote areas show evidence of mercury pollution originating from industrial sources such as power plants. Besides elemental mercury, the major forms of mercury in water are ionic mercury (which is bound to chloride, sulfide, or organic acids) and organic mercury, particularly methylmercury. Methylmercury rather than inorganic mercury is bioconcentrated because it is better retained by organisms at various levels in the food chain. The key factor determining the concentration of mercury in the biota is the methylmercury concentration in water, which is controlled by the relative efficiency of the methylation and demethylation processes. Anoxic waters and sediments are an important source of methylmercury, apparently as the result of the methylating activity of sulfatereducing bacteria. In surface waters, methylmercury may originate from anoxic 543 0066-4162/98/1120-0543$08.00 Annu. Rev. Ecol. Syst. 1998.29:543-566. Downloaded from arjournals.annualreviews.org by Universite de Montreal on 12/21/08. For personal use only.

- by Marc Amyot
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- Economics, Speciation, Ecology, Power Plant

Microorganisms are intimately involved in geochemical processes. For example, they are major players in the environmental cycling of important elements (e.g. carbon, sulfur, nitrogen, iron), rock weathering, and the formation of ores and petroleum. Identification of the environmental microbiota, commonly achieved via DNA techniques, is essential for an understanding of these processes. The main focus of this Rapid Communication is to demonstrate that endogenous DNA can be extracted from acidic, volcanic soil samples.

- by Roberto Anitori
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Environmental context. Poly-and perfluorinated alkyl substances (PFASs) include a wide range of individual compounds that are used in many consumer products, but only a few physicochemical property data are available for these chemicals. Here we provide estimates of physicochemical properties (vapour pressure, water solubility, etc.) of 130 individual PFASs derived with a quantum-chemical model. Our results provide insight into the effect of molecular structure on the properties of PFASs and a basis for estimating the environmental partitioning and fate of PFASs.

- by Matthew MacLeod
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

Environmental context. Hydrogen peroxide (H2O2) and organic peroxides (ROOH) are ubiquitously present in natural waters and primarily essential for several redox reactions. This study examines the effects of various dissolved organic substances on the formation of H2O2 and ROOH and their relationship with different water quality parameters in two Japanese rivers. This study suggests that fulvic acid is primarily responsible for production of H2O2 and ROOH in river waters. . Hydrogen peroxide (H2O2) and organic peroxides (ROOH) were examined in water samples collected from the upstream and downstream sites of two Japanese rivers (the Kurose and the Ohta). H2O2 concentrations during monthly measurements varied between 6 and 213 nM in the Kurose River and 33 and 188 nM in the Ohta River. ROOH varied between 0 and 73 nM in the Kurose River and 1 and 80 nM in the Ohta. Concentrations of peroxides were higher during the summer months than in winter. H2O2 concentrations correlated well wit...

- by Hiroshi Sakugawa
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- Earth Sciences, Chemistry, Computational Chemistry, Climate Change

This paper represents 1 of 9 papers generated from a SETAC Pellston Workshop titled ''Science-Based Guidance and Framework for the Evaluation and Identification of PBTs and POPs'' (January 2008, Florida, USA). The workshop objectives were to develop guidance and recommendations on the evaluation of substances fulfilling PBT and POP criteria, using scientific information such as experimental and monitoring data, as well as computer models.

- by Kent Woodburn
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- Environmental Science, Decision Making, Methodology, Bioaccumulation

Mercury (Hg) biomagnification occurs in many ecosystems, resulting in a greater potential for toxicological effects in higher-level trophic feeders. However, Hg transport pathways through different food-web channels are not well known, particularly in high-latitude systems affected by the atmospheric Hg deposition associated with snow and ice. Here, we report on stable carbon and nitrogen isotope ratios, and Hg concentrations, determined for 26, late 19th and early 20th century, polar bear (Ursus maritimus) hair specimens, collected from catalogued museum collections. These data elucidate relation-ships between the high-latitude marine food-web structure and Hg concentrations in polar bears. The carbon isotope compositions of polar bear hairs suggest that polar bears derive nutrition from coupled food-web chan-nels, based in pelagic and sympagic primary producers, whereas the nitrogen isotope compositions indicate that polar bears occupy> fourth-level trophic positions. Our resul...

- by Michael Hren
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- Oceanography, Chemistry, Toxicology, Carbon

The scientific literature contains little information regarding bioaccumulation and biomagnification of polychlorinated naphthalenes (PCNs) in food webs. Here we present new information on the food chain transfer of PCNs within a food chain in a subarctic environment. PCNs (tetra-to heptachloro congeners) were measured in surface sediments and in a marine benthic food chain, comprising amphipods, isopods, and fourhorned sculpins. Samples were collected from five locations in the Gulf of Bothnia, northern Baltic Sea. PCN concentrations in the sediments were similar to background levels determined previously in sediments from the northern hemisphere. Measurement of the carbon content of the sediments allowed the calculation of biota to sediment accumulation factors (BSAFs). Tetra-and penta-CNs exhibited BSAF values greater than one, while BSAFs for the more chlorinated PCNs were less than one. This suggests more efficient assimilation, by amphipods, of the less chlorinated PCNs. A decrease in ΣPCN concentrations from the lowest to the highest trophic level was demonstrated (amphipods: 10-69 ng/g lw; isopods: 3.9-16 ng/g lw; fourhorned sculpins: 0.54-1.5 ng/g lw). Biomagnification factors (BMFs) were calculated based on the concentrations of the congeners. These indicated that a few congeners biomagnified significantly: the highest BMFs (0.09-1.4) were found for 2,3,6,7-substituted congeners and those lacking adjacent hydrogen-substituted carbon atoms.

This article thoroughly investigates the severity of the prevailing environmental conditions and evaluates the resulting threats to food intake and public health in Bangladesh by establishing relationship among different contaminant transfer mechanisms to human. It describes the potential of certain contaminants to get bio-magnified through the food chain. A database was prepared on a number of contaminants in the study area that are responsible for rendering different foods vulnerable to produce long term or short-term health effects. Contaminants that have been identified in the food sources were categorized in a continuum based on their allowable daily intake. A protocol has been developed which will enable the assessment of the potential of a contaminant to bio-magnify through food chain to understand the contribution of a contaminant on different levels of food chain. The study also provides a detailed assessment of the public health risks associated with direct ingestion of ad...

- by Hossain Azam
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- Public Health, Health Risk Assessment, Biomagnification

Levels of heavy metals are usually higher in adult than young birds because they eat larger, more contaminated prey, or because they have had longer to accumulate metals in their tissues. Further, levels of contaminants are usually less in birds nesting on remote, offshore islands than in birds breeding closer to mainland areas that are urbanized and industrialized. We examined the feather levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in adult sooty terns (Sterna fuscata), gray-backed terns (Sterna lunata), and brown noddy (Anous stolidus, and adult and young white terns (Gygis alba, from Midway Atoll, and in adult and young sooty terns and adult brown noddy from Manana Island, Hawaii (chicks of other terns were not available). We tested and rejected the null hypotheses that metal levels are not significantly different among species, ages, and locations. Despite their small size, adult white terns had the highest levels of lead, arsenic and tin. Brown noddies had the highest levels of cadmium, chromium, manganese, and selenium. Sooty and white terns had the highest levels of mercury. Sooty tern adults had significantly higher levels of cadmium, mercury, and selenium than young, while young had significantly higher levels of arsenic and manganese. White tern adults had significantly higher levels of selenium and tin than young, while young had higher levels of cadmium and mercury than adults. Except for mercury, there were significant inter-location differences within species in all heavy metals. Contrary to expectation, where the differences were great, metals generally were higher in the feathers of terns and noddies from Midway than from Manana.

- by Roberto Ramos
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- Arsenic, MARINE POLLUTION, Multidisciplinary, Pacific Islands

Several recent studies have shown that the use of δ 15 N analysis to characterize trophic relationships can be useful for tracing biocontaminants in food webs. In this study, concentration of total mercury was measured in tissues from 112 individuals representing 27 species from the arctic marine food web of Lancaster Sound, Northwest Territories. Samples ranged from particulate organic matter through polar bears (Ursus maritimus). Using δ 15 N values to identify trophic position, we found that total mercury in muscle tissue biomagnified in this food web. Polar bears were a notable exception, having a lower mean mercury concentration than their main prey, ringed seals (Phoca hispida). Most vertebrates showed greater variance in mercury concentration than invertebrates, and there was a trend in seabirds toward increased variability in mercury concentration with trophic position. Within species, we found no evidence of bioaccumulation of mercury with age in the muscle tissue of clams (Mya truncata) or ringed seals. Because stable nitrogen isotopes illustrated the relationship in this biome between trophic position and mercury level on a continuous, quantitative scale, we were able to determine that log 10 [Hg] (µg/g dry weight) = 0.2(δ 15 N) -3.3. The measurement of δ 15 N values and mercury concentration allowed us to quantitatively assess mercury biomagnification within this extensive arctic marine food web.

- by Keith Hobson
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- Zoology, Ecology, Water Pollution, Isotopic Analysis

An approach for comparing laboratory and field measures of bioaccumulation is presented to facilitate the interpretation of different sources of bioaccumulation data. Differences in numerical scales and units are eliminated by converting the data to dimensionless fugacity (or concentration-normalized) ratios. The approach expresses bioaccumulation metrics in terms of the equilibrium status of the chemical with respect to a reference phase. When the fugacity ratios of the bioaccumulation metrics are plotted, the degree of variability within and across metrics is easily visualized for a given chemical because their numerical scales are the same for all endpoints. Fugacity ratios greater than 1 indicate an increase in chemical thermodynamic activity in organisms with respect to a reference phase (e.g., biomagnification). Fugacity ratios less than 1 indicate a decrease in chemical thermodynamic activity in organisms with respect to a reference phase (e.g., biodilution). This method provides a holistic, weight-of-evidence approach for assessing the biomagnification potential of individual chemicals because bioconcentration factors Q2 , bioaccumulation factors, biota-sediment accumulation factors, biomagnification factors, biota-suspended solids accumulation factors, and trophic magnification factors can be included in the evaluation. The approach is illustrated using a total 2393 measured data points from 171 reports for 15 nonionic organic chemicals that were selected based on data availability, a range of physicochemical partitioning properties, and biotransformation rates. Laboratory and field fugacity ratios derived from the various bioaccumulation metrics were generally consistent in categorizing substances with respect to either an increased or decreased thermodynamic status in biota, i.e., biomagnifications or biodilution, respectively. The proposed comparative bioaccumulation endpoint assessment method could therefore be considered for decision making in a chemicals management context. Integr Environ Assess Manag 2011;7:1-15. ß 2011 SETAC

- by Lawrence Burkhard and +1
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- Bioaccumulation, Environmental Monitoring, Risk assessment, Biological Sciences

Environmental context. Phytoplankton form the base of marine food-webs, and hence they have been proposed as the likely source of many arsenic compounds found in marine animals. Because of the difficulties associated with field experiments with phytoplankton, attempts to test this hypothesis have relied mainly on laboratory experiments. This study assesses the environmental validity of this research approach by investigating the influence of the culturing experimental protocol on the uptake, accumulation and biotransformation of arsenic by marine phytoplankton.

- by Frank Krikowa
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

- by Kurunthachalam Kannan
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- Earth Sciences, Computational Chemistry, Ethics, Climate Change

We assessed the content of heavy metals in the liver and the DNA damage in blood cells of insectivore bats in the Catarinense Carboniferous Basin, Southern Brazil. Three bats species (Molossus molossus, Tadarida brasiliensis and Eptesicus diminutus) were collected in a coal mining area and in a control area. The heavy metal content in bats was detected according to the PIXE technique and the DNA damage was assessed by the Comet assay. The contents of Cr, Ni, Cu and Pb in M. molossus and of Cu and Fe in T. brasiliensis from the coal mining area was higher than in the animals from the control area. In both areas differences in metal contents in the liver were observed between the bat species. The parameters assessed by the Comet assay were significantly higher in E. diminutus as compared to M. molossus and T. brasiliensis. Values of both Comet assay parameters were significantly higher in the mining area as compared to the control area only for T. brasiliensis.

- by Daniela Leffa
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- Ecotoxicology, Carbon, DNA damage, Chiroptera

Environmental context The electrochemical detection of many sulfur compounds in natural waters is based on the deposition of a HgS layer at the Hg electrode. In samples containing metal ions in excess of sulfide species, electrochemical exchange reactions between the HgS and the metal ion produce metal-sulfide voltammetric peaks. These peaks can easily be misinterpreted as dissolved sulfide species, and hence do not reflect the bulk state of the solution. Cyclic voltammetry on a Hg electrode was used to investigate the influence of metal ion (Zn, Cd, Cu, Fe, Pb, Co) on HgS deposition–dissolution in seawater conditions. Due to the exchange of electrons between Hg2+ from a HgS layer and free metal (M2+) from the solution (HgSlayer + M2+ + 2e– ↔ MSlayer + Hg0), the Hg electrode becomes the site for surface metal sulfide (MS) formation. The exchange reaction is reversible, and the surface-formed MS layer reduces at a more negative potential than HgS (MSlayer + 2e– + H+ → M0 + HS). The p...

- by Ivana Coha (Milanović)
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- Earth Sciences, Chemistry, Computational Chemistry, Climate Change