scholarly journals THE EFFECT OF SELENIUM ON MERCURY TRANSPORT ALONG THE FOOD CHAIN

AGROFOR ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Primož ZIDAR ◽  
Špela KRŽIŠNIK ◽  
Marta DEBELJAK ◽  
Suzana ŽIŽEK ◽  
Katarina VOGEL MIKUŠ
Keyword(s):  
Food Chain ◽  
Contaminated Soil ◽  
Local Population ◽  
Trophic Levels ◽  
Food Chains ◽  
Chemical Transformations ◽  
Soil Concentration ◽  
Preliminary Results ◽  
Mercury Transport ◽  
Hg Accumulation

More than 500 years of mercury (Hg) production in Idrija (Slovenia) resulted in aconsiderable pollution of Idrija region with Hg. Although the mine is closed formore than 20 years, the total soil concentration of Hg may still reach up to severalhundred mgkg-1dry weightin local gardens and more that thousand inother urbanregions. Hg in soil undergoesdifferent chemical transformations and in someformsit may enterplants and higher trophic levelsin food chains, also withbiomagnification pattern.The local population is, besides air and dust, thus exposedto mercury also via consumption of locally produced food.Several studies showedthat the increased level of selenium in soil may reduce the uptake of mercury inplants but very few include other trophic levels in a food chain as well.In our pilotstudy we followed an impact of Seon Hg transport from soil to plants(Lactucasativa) and further to soil dwelling animals (Porcellioscaber). Lettuce wasplanted in a contaminated soil from Idrija and in soil with added HgCl2. The leavesof half of the plants weresprayed with Sesolution (5μg L-1)threeand five weeksafter planting.After six weeks plants were analyzed for Hg and Se and offered asfood to terrestrial isopods for two weeks. Our preliminary results revealed thatfoliar treatment of plants with Se may affect Hg accumulation in plants andtherefore further transport of Hg across the food chain.

scholarly journals Mercury Accumulation in Terrestrial Food Chains of the Liaohe Estuary Wetlands

2021 ◽  
Author(s):  
yuqi wang ◽  
Zheng Dongmei ◽  
Ma Huanchi ◽  
Li Huiying ◽  
Wang Bing
Keyword(s):  
Food Chain ◽  
Rice Field ◽  
Nitrogen Isotopes ◽  
Mercury Content ◽  
Trophic Levels ◽  
Food Chains ◽  
Mercury Accumulation ◽  
Stable Carbon ◽  
Carbon And Nitrogen ◽  
Global Pollutant

Abstract Mercury is a global pollutant that can accumulate in organisms and endanger human health. This paper studied the soil, plants and animals in the light beach, Suaeda wing wetland, reed wetland and rice field in the Liaohe Estuary in 2018 and 2019, and determined the stable carbon and nitrogen isotopes of animals and plants to construct the food chain. The results show that from 2018 to 2019, the accumulation of mercury in the soil of the light beach, Suaeda winged wetland and reed wetland of the Liaohe Estuary continued to increase, but the accumulation of mercury in paddy soil showed a decreasing trend; the mercury content in plant samples also showed a certain degree There is a positive correlation between the accumulation of mercury in the food chain and the construction of trophic levels in the food chain. Mercury can carry out efficient biomagnification and bioaccumulation through the food chain.

scholarly journals Stability trophic cascades in food chains

2018 ◽  
Vol 5 (11) ◽  
pp. 180995 ◽  
Author(s):  
David W. Shanafelt ◽  
Michel Loreau
Keyword(s):  
Simple Model ◽  
General Theory ◽  
Food Chain ◽  
Empirical Studies ◽  
Trophic Cascades ◽  
Trophic Levels ◽  
Individual Species ◽  
Food Chains ◽  
Top Down ◽  
The Stability

While previous studies have evaluated the change in stability for the addition or removal of individual species from trophic food chains and food webs, we know of no study that presents a general theory for how stability changes with the addition or removal of trophic levels. In this study, we present a simple model of a linear food chain and systematically evaluate how stability—measured as invariability—changes with the addition or removal of trophic levels. We identify the presence of trophic cascades in the stability of species. Owing to top-down control by predation and bottom-up regulation by prey, we find that stability of a species is highest when it is at the top of the food chain and lowest when it is just under the top of the food chain. Thus, stability shows patterns identical to those of mean biomass with the addition or removal of trophic levels in food chains. Our results provide a baseline towards a general theory of the effect of adding or removing trophic levels on stability, which can be used to inform empirical studies.

scholarly journals An Integrated Investigation of Atmospheric Gaseous Elemental Mercury Transport and Dispersion Around a Chlor-Alkali Plant in the Ossola Valley (Italian Central Alps)

Toxics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 172
Author(s):  
Laura Fantozzi ◽  
Nicoletta Guerrieri ◽  
Giovanni Manca ◽  
Arianna Orrù ◽  
Laura Marziali
Keyword(s):  
Elemental Mercury ◽  
Background Concentration ◽  
Dispersion Pattern ◽  
Central Alps ◽  
Gaseous Elemental Mercury ◽  
Mercury Transport ◽  
Close Proximity ◽  
Potential Impact ◽  
Hg Accumulation

We present the first assessment of atmospheric pollution by mercury (Hg) in an industrialized area located in the Ossola Valley (Italian Central Alps), in close proximity to the Toce River. The study area suffers from a level of Hg contamination due to a Hg cell chlor-alkali plant operating from 1915 to the end of 2017. We measured gaseous elemental Hg (GEM) levels by means of a portable Hg analyzer during car surveys between autumn 2018 and summer 2020. Moreover, we assessed the long-term dispersion pattern of atmospheric Hg by analyzing the total Hg concentration in samples of lichens collected in the Ossola Valley. High values of GEM concentrations (1112 ng m−3) up to three orders of magnitude higher than the typical terrestrial background concentration in the northern hemisphere were measured in the proximity of the chlor-alkali plant. Hg concentrations in lichens ranged from 142 ng g−1 at sampling sites located north of the chlor-alkali plant to 624 ng g−1 in lichens collected south of the chlor-alkali plant. A north-south gradient of Hg accumulation in lichens along the Ossola Valley channel was observed, highlighting that the area located south of the chlor-alkali plant is more exposed to the dispersion of Hg emitted into the atmosphere from the industrial site. Long-term studies on Hg emission and dispersion in the Ossola Valley are needed to better assess potential impact on ecosystems and human health.

Mercury in the Marine Environment: Concentration in Sea Water and in a Pelagic Food Chain

1973 ◽  
Vol 30 (2) ◽  
pp. 293-295 ◽  
Author(s):  
P. M. Williams ◽  
H. V. Weiss
Keyword(s):  
Biological Activity ◽  
Bottom Sediment ◽  
Food Chain ◽  
Mercury Concentration ◽  
Vertical Profile ◽  
Sea Water ◽  
Mercury Content ◽  
Trophic Levels ◽  
Single Station ◽  
Almost All

Mercury in seawater, in a pelagic food chain, and in bottom sediment was determined at a single station 430 km southeast of San Diego, California. The concentration of mercury in zooplankton slightly increased with depth of collection. The mercury content in almost all of the higher trophic levels of organisms collected at greater depths was indistinguishable from the concentration of mercury in zooplankton at these depths. Mercury concentration in the seawater column was essentially constant below 100 m and significantly higher at the surface. This vertical profile of mercury content is not ascribable to biological activity.

Kinetics of mercury accumulation by freshwater biofilms

2017 ◽  
Vol 14 (7) ◽  
pp. 458 ◽  
Author(s):  
Perrine Dranguet ◽  
Vera I. Slaveykova ◽  
Séverine Le Faucheur
Keyword(s):  
Food Webs ◽  
Food Chain ◽  
Microbial Composition ◽  
Biofilm Thickness ◽  
Aquatic Microorganisms ◽  
Uptake Rate Constant ◽  
The Difference ◽  
Accumulation Kinetics ◽  
Kinetics Of ◽  
Hg Accumulation

Environmental contextMercury (Hg) is a major environmental contaminant due to its toxicity, accumulation and biomagnification along the food chain. We demonstrate that Hg accumulation by biofilms, one possible entry point for Hg into food webs, is rapid and depends on biofilm structure and composition. These findings have important implications for the understanding of Hg bioavailability and effects towards aquatic microorganisms. AbstractMercury contamination is of high concern due to its bioaccumulation, toxicity and biomagnification along the food chain. Biofilms can accumulate Hg and contribute to its incorporation in freshwater food webs. Nevertheless, the accumulation kinetics of Hg by biofilms is not well described and understood. The aim of the present study was thus to gain mechanistic understanding of Hg accumulation by biofilms. Kinetics of Hg uptake by biofilms of different ages (e.g. different compositions) was characterised by determining Hg contents in biofilms with and without a cysteine-washing step. Hg accumulation was rapid in both biofilms, with the uptake rate constant of the younger biofilm 10 times higher than that of the older biofilm. Moreover, accumulated Hg reached a plateau at 24h exposure in the younger biofilm, whereas it increased linearly in the older biofilm. The observed difference in Hg uptake by the studied biofilms is likely a result of the difference in biofilm thickness (and thus Hg diffusion inside the biofilm matrix) and microbial composition. These findings have important implications for the understanding of Hg bioavailability and effects towards aquatic microorganisms.

Research Progress in Enhancement Technology of Phytoremediation

2015 ◽  
Vol 768 ◽  
pp. 150-154
Author(s):  
Yi Yun Liu ◽  
Shuang Cui ◽  
Qing Han ◽  
Qian Ru Zhang
Keyword(s):  
Heavy Metal ◽  
Food Chain ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
New Technology ◽  
Research Progress ◽  
Agricultural Activity ◽  
Practical Application ◽  
Soil Environment ◽  
Article Analysis

Due to the influence of human, industrial and agricultural activity, a large amount of toxic and harmful heavy metal enter into the soil environment. Heavy metal can easily bio-accumulate through food chain, which cause serious damage to human health. Phytoremediation emerges as a new technology in exploration of effective methods for remediation and rebuild of heavy metal contaminated soils. Although phytoremediation shows great potential in remediation of heavy metal contaminated soil, there still exists many problems in practical application. This article analysis the problems existing in phytoremediation, summarizes the research progress of the technology in application from all the perspective of phytoremediation processes.

Chlorinated C 1 and C 2 hydrocarbons in the marine environment

1975 ◽  
Vol 189 (1096) ◽  
pp. 305-332 ◽  
Keyword(s):  
Carbon Tetrachloride ◽  
Acute Toxicity ◽  
Microbial Degradation ◽  
Chemical Industry ◽  
Aquatic Organisms ◽  
Trophic Levels ◽  
Food Chains ◽  
Laboratory Bioassay ◽  
Marine Food ◽  
Chemical Manufacture

A range of chlorinated hydrocarbons derived from C 1 and C 2 hydrocarbons is manufactured industrially. They are used as intermediates for further chemical manufacture and also outside the chemical industry as solvents or carriers. In the latter category losses in use are eventually dispersed to the environment. The distribution of some of these compounds, including chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene and trichloroethane, in the environment (air, water and marine sediments) has been investigated and the results are presented. The concentrations found have been compared with acute toxicity levels to fish and other aquatic organisms, ascertained by laboratory bioassay. The occurrence of the compounds has been determined in a number of marine organisms, especially those at higher trophic levels, and the accumulation of some of them has been investigated in the laboratory. Chemical and microbial degradation processes have been studied in the laboratory to help determine the course of their removal from the aqueous and aerial environment, and the half lives of some of the compounds have been estimated. It is concluded that these compounds are not persistent in the environment, and that there is no significant bioaccumulation in marine food chains.

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