Gut Sediments in a Burrowing Mayfly (Ephemeroptera, Hexagenia limbata): Their Contribution to Animal Trace Element Burdens, Their Removal, and the Efficacy of a Correction for Their Presence

1989 ◽  
Vol 46 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Landis Hare ◽  
Peter G. C. Campbell ◽  
André Tessier ◽  
Nelson Belzile

Nymphs of the burrowing mayfly Hexagenia limbata were collected in the field, returned to the laboratory, and dissected to remove the gut contents. Concentrations of four trace elements (As, Cd, Cu, Zn) were determined both for the gut contents and for the body. Trace elements in gut contents represented up to 22% of whole animal trace element burdens. Studies of depuration of H. limbata nymphs held in water for up to 48 h indicate that individuals vary substantially in the rate at which they egest gut contents and that 48 h is not sufficient to ensure a complete emptying of the gut. A model developed to compensate for the presence of gut contents in the determination of body trace element burdens was applied to H. limbata. Comparisons of model estimates with actual body burdens (without gut contents) show that the model accurately predicts As and Cu concentrations, but overestimates concentrations of Cd and Zn by as much as 20%. We suggest that the biases in the model result from assuming that: (a) trace element concentrations in gut sediments are equivalent to those in sediments sampled from the animal's surroundings, and (b) there is no weight loss of gut contents during sample digestion (a two-thirds weight loss of gut contents was in fact observed). These biases may be minimized by, respectively: (a) measuring trace element burdens of gut contents and (b) compensating for weight loss of gut contents during digestion.

2020 ◽  
pp. 48-54
Author(s):  
Vitaliya Morozova

There are more than 70 chemical elements in the human body. To date, the need for more than 20 trace elements has been determined: deficiency in them leads to disruption of the neural, immune and endocrine regulation and adaptive potential, increases the risk of infectious diseases and development of their chronicity. A prolonged absence of certain nutrients in the diet, or vice versa, excess of them in soil and water, can cause irreversible changes in the body. The article discusses physiological role of minerals, macro and micronutrients, features of their metabolism, content standards, causes of their shortage in the diet. Recommendations on the choice of material for the study of the trace element composition are given and possibilities of modern laboratory diagnostics are presented.


2006 ◽  
Vol 78 (1) ◽  
pp. viii
Author(s):  
Michael Bickel

Trace elements may have different functions in human and animal metabolism: some are toxic (e.g., Hg), others are essential to maintain good health (e.g., Ca), or they can be essential but also toxic, depending on the concentration in the body or in parts thereof (e.g., Se).The importance of various aspects of trace elements in relation to food is steadily increasing in the perception of the consumer and the respective authorities: food contaminants, essential and toxic elements, bioavailability and speciation, nutritional value and fortified food, reliable measurement of contents, etc. In addition, through the many minor and major food-related incidents during recent years the consumer is becoming more concerned about the quality and safety of food. As a result, research and development efforts in this area have also been increased and/or been redirected.TEF-2 was organized in Brussels 7-8 October 2004 by the Institute of Reference Materials and Measurements of the Joint Research Centre of the European Commission, with the support of the Department of Food Analysis, Institute of Agricultural and Food Biotechnology of the University of Warzaw, Poland and the Centre National de la Recherche Scientifique, France. It was carried through under the auspices of IUPAC.The objectives laid down for the symposium were- presenting state-of-the-art analytical methods for the enforcement of legal limits of trace elements in food;- disseminating new ideas and findings within the scientific community;- providing a forum for the exchange of new knowledge and experience between R&D, authorities, and industry; and- bringing together experts in the field with newcomers.TEF-2 was attended by 93 participants from 60 different institutions in 23 countries. It consisted of 26 lectures and 56 posters, structured according to the following four main topics:- trace elements in the food chain (from the environment to shelf product) including the effects of processing and of legislation- trace element bioavailability-toxicological and nutritional aspects- fortified food and supplementation legislation, manufacturing and labeling, standards- advances in trace element analysis in food matricesIt was emphasized that the field of trace elements in food is a lively research area, which generates interest and involvement from researchers, authorities, and industry, of course triggered and nurtured by the equally high interest of the consumer. A selection of the invited contributions to TEF-2 is presented in the subsequent seven papers in this issue.The importance of scientific exchange in this field was, again, recognized during TEF-2. Therefore, the continuation of this series of conferences was discussed, and the venue for the subsequent TEF-3 was decided. It will be organized by R. Lobinski of CNRS in Pau, France, at the beginning of October 2008.Michael BickelConference Editor


Author(s):  
Diana Flood

Migratory fish-eating birds occupy the highest trophic positions of aquatic ecosystems and as such serve as invaluable end-point indicators of the presence and bioaccumulation of anthropogenic contaminants. The birds’ main route of contaminant exposure is through food consumption. Migration can complicate this pathway by introducing numerous feeding habitats and thus, potential sources of contamination. Birds possess a number of depuration mechanisms that permit them to reduce their contaminant burden, namely the elimination of metals and mercury (Hg) through their feathers, feces and eggs. Trace element concentrations found in the feathers reflect the contaminants circulating in the body at the time of feather growth, representing local exposure and potential mobilization from internal tissues. Molt schedules and patterns are important considerations when selecting feathers to link feeding ecology with contaminants, as migratory birds’ feathers grow on and represent different sites. Stable nitrogen (δ15N) and carbon (δ13C) and hydrogen isotopes (δD) can reveal feeding ecology and habitat use during their annual cycle. Consequently, anthropogenic and natural sources of metal accumulation can be linked to those ecological variables. This study will examine the assimilation of trace element in male Caspian Tern (Sterna caspia) and Double-crested Cormorant (Phalacrocorax auritus) breast feathers grown on wintering sites and stable isotope signatures will be used to determine origin of contaminants. The aims for this study are to determine (i) whether isotopic signatures of feathers grown on wintering sites can explain variations in feather trace element concentrations, (ii) whether isotopes can determine the source of contamination, and (iii) whether differences in trace elements between individuals are determined by location of wintering ground or species.


2019 ◽  
Vol 11 (11) ◽  
pp. 1551-1557
Author(s):  
G. Carrone ◽  
D. Onna ◽  
E. Morzan ◽  
R. Candal ◽  
Y. S. Minaberry ◽  
...  

Improvement of the analytical performance of TS-FF-AAS, for determination of trace elements (Ag, Cd, Pb and Se) in different matrices, by using nanoparticle coatings over the inner furnace wall.


1996 ◽  
Vol 06 (01n02) ◽  
pp. 273-276 ◽  
Author(s):  
P. HATAMI ◽  
H. PEYROVAN ◽  
H. AFARIDEH ◽  
S. SHOJAEI

Mineral trace element concentration of human saliva from healthy volunteers, were investigated by Proton-Induced X-ray Emission (PIXE) analysis. The specimens were bombarded with Proton beams of 2 MeV from a Van de Graaff accelerator at NRC . The object of this measurement was to find a normal range of trace element concentration for Iranian people.


2020 ◽  
Vol 21 (2) ◽  
pp. 3-12
Author(s):  
A.A. Skalny ◽  

Currently, there is no doubt about the prevailing influence of the level of physical activity of an individual on the functional state of the body. However, the available literature data on the impact of physical stress on the body's supply of trace elements and their distribution in tissues are largely contradictory. This review of available literature data provides an insight into the relationship between physical activity and microelement homeostasis. The influence of human physical activity on the exchange of toxic (lead, cadmium, Nickel, etc.) and essential trace elements, such as iron, selenium, copper, cobalt, chromium, and zinc is reviewed. Based on the analyzed works, it is concluded that in order to correct the metabolic and microelement status of a person during physical activity, the most reasonable and necessary is the modulation of homeostasis of zinc and selenium.


2021 ◽  
Author(s):  
◽  
Monique Francis Holmes

<p>Heavy metals in the marine environment are a worldwide issue due to their toxicity, non-biodegradability and their ability to accumulate and magnify in organisms. Increased human activity has caused higher inputs of heavy metals, resulting in escalated pressures on delicate coastal ecosystems. A means of assessing the natural environment and how it is changing in response to pollution and other environmental degradation is through the use of biological indicator or biomonitor species. These organisms provide information on the bioavailability of metals present in the environment. In recent years amphipods, a diverse order of small crustaceans, have been increasingly used as bioindicators of disturbed aquatic communities. They are widespread and important components of many food webs, and likely to be frequently exposed to metal contamination through both sediment and seawater. The aim of this research was two-fold: 1) to use amphipods to examine variation across sites and species in concentration of 20+ trace elements and 2) to examine whether the uptake of two metals, copper (Cu) and neodymium (Nd), is mediated by the presence of the other metal or an elevated seawater temperature.  To investigate variation of trace element concentrations across sites, the amphipod Eusiroides monoculoides was collected from three sites in the Wellington region, approximately 5 km apart: Oriental Bay, Evans Bay and Point Halswell. To investigate differences amongst species comparisons were made between Eusiroides monoculoides, Apohyale papanuiensis and Sunamphitoe mixtura when they occurred at the same site. Analysing the trace element concentrations of 36 metals was done using an Inductively Coupled Mass Spectrometer (ICPMS). Overall, although these sites were not greatly distant from each other, there were differences among sites. Evans Bay in general had the highest concentration of trace elements. Further, there were also species-specific differences and S. mixtura was the species with the highest concentration of trace elements. There was also a size effect, where the average dry weight of S. mixtura was negatively related to the concentration of trace elements in the body.  To assess the effects of heavy metals Cu and Nd in both an ambient (14 °C) and elevated (20 °C) temperature, an experiment was run at Victoria University’s Coastal Ecology Lab (VUCEL). Sand hoppers, Bellorchestia quoyana, were collected from a single site in Wellington (Scorching Bay) and assigned to eight treatments: ambient and warm controls in raw seawater and ambient and warm seawater doped with Cu, Nd and Cu and Nd together. Amphipods from treatments with Cu and Nd added had significantly higher concentrations of these metals from the controls, however temperature had no effect, and neither was there an interaction between the metals. Similar to S. mixtura from the field study, dry weight of B. quoyana was negatively related to the concentration of trace elements in the body.  Results from this work demonstrate that when using amphipods as bioindicator species it is important to consider species and size specific effects. This thesis also provides baseline data for 20+ elements from three Wellington sites and demonstrates that there can be unexpected variation across relatively small spatial scales. The laboratory experiment did not yield results that coincided with the consensus of the literature. The experiment showed that at least in this case, temperature did not mediate the uptake of metals and there was a negative relationship between size and metal uptake.</p>


1994 ◽  
Vol 8 (1) ◽  
pp. 87-91 ◽  
Author(s):  
R. Ophaug

Although the fluorine in human tissues may exist in both inorganic and organic (covalently bound) forms, the inorganic fraction is clearly the most relevant for assessing human exposure to, and utilization of, environmental fluoride. There is now general agreement that the inorganic fraction of total tissue fluorine can be accurately determined by a variety of analytical techniques. One of the basic questions considered at this workshop is whether the analysis of a specific tissue or body fluid can provide an estimate of how much of the fluoride to which an individual is exposed actually enters and accumulates in the body. The analysis of hair and nails has been used as an indicator of exposure and utilization for several trace elements, including fluoride. Due to methodological uncertainties regarding sampling and pre-analysis treatment, however, it is presently not possible clearly to distinguish fluoride which is incorporated into hair and nails during formation (endogenous) from that which becomes associated with the tissues following exposure to the environment (exogenous). Consequently, although the fluoride content of hair and nails is clearly increased by environmental exposure to fluoride, the conclusion that these tissues are suitable indicators of fluoride utilization and accumulation in the body is premature.


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