Non-essential Elements Research Articles

Distribution and dispersion of heavy metals in the rock-soil-moss system of the black shale areas in the southeast of Guizhou Province, China.

Black shales are easily exposed due to human activities such as mining, road construction, and shale gas development, which results in several environmental issues including heavy metal (HM) pollution, soil erosion, and the destruction of vegetation. Mosses are widely used to monitor metal pollution in the atmosphere, but few studies on the distribution and dispersion of HMs in the rock-soil-moss system are available. Here, mosses (Pohlia flexuosa Harv. in Hook), growing soils, and corresponding parent rocks were collected from black shale areas. After appropriate pretreatment, samples were analyzed for multiple elemental concentrations by ICP-AES and ICP-MS. The results show that black shale parent rocks have elevated HM concentration and act as a source of multiple metals. The overlying soil significantly inherits and accumulates heavy metals released from black shale. Significant positive correlations between HMs in P. flexuosa and the growing soils indicate that HMs are mainly originating from geological source rather than atmospheric deposition. Differential accumulation of HMs is observed between rhizoids and stems in our study. Moreover, P. flexuosa is able to cope with high concentrations of toxic metals without any visible negative effect on its growth and development. Finally, the bioconcentration factor (BCF) for all the HMs in P. flexuosa is less than 1, indicating that it has a tolerance and exclusion mechanism for these metals, especially for the non-essential elements As and Pb. Therefore, the luxuriant and spontaneous growth of P. flexuosa could be used as a phytostabilization pioneer plant in the black shale outcrop where vascular plants are rare.

Genetic engineering of glycinebetaine synthesis enhances cadmium tolerance in BADH-transgenic tobacco plants via reducing cadmium uptake and alleviating cadmium stress damage

Cadmium (Cd) is a toxic non-essential elements to plants, and its accumulation in plants can affect human health through the food chain. Glycinebetaine (GB) is an effective osmotic adjustment substance for plants to resist abiotic stress, and it plays important roles in various stresses. To investigate whether endogenous GB accumulation in vivo can enhance Cd tolerance, we used betaine aldehyde dehydrogenase (BADH) transgenic tobacco plants to explore the important role of GB under Cd stress conditions. The results showed that the tobacco exposed to cadmium stress, lead to growth inhibition and biomass reduction, decreased photosynthesis, decreased the absorption of essential minerals and increased oxidative stress. However, GB accumulation in transgenic tobacco plants significantly increased Cd tolerance, as evidenced by the decreased growth inhibition, enhanced photosynthetic rate and reduced reactive oxygen species accumulation. GB can regulate Cd uptake and transport, which results in reduced Cd accumulation. Moreover, GB also reduced K+ efflux under Cd stress and regulated ion transporter genes to maintain element balance. Our findings provide a novel role of GB in enhancing Cd stress tolerance in transgenic plants and thus propose GB as a potential candidate for relieving Cd toxicity in other crops.

Evaluation of essential and non-essential elemental composition of commonly used medicinal plants from district Peshawar, Khyber Pakhtunkhwa, Pakistan.

This study illustrates a profile of some essential and non-essential elements (Na, K, Mg, Ca, Cu, Zn, Mn, Fe, Pb, Cr, Cd, Co, Al, and Sn) in the aerial parts of six medicinal plants, i.e. Coriandrum sativum L., Mentha spicata L., Papaver somniferum L., Calotropis gigantean (L.) Dryand., Withania coagulans (Stock) Dunal, and Fagonia arabica L. widely consumed in district Peshawar, the capital city of Khyber Pakhtunkhwa, Pakistan. The samples were converted into liquid state via wet digestion method and analyzed for elemental composition by using atomic absorption spectrometry. After determining the concentration, hazard quotient (HQ) was calculated for the elements having available maximum permissible limit set by FAO/WHO or any other agency for 50 mg daily intake of the herbal plants by a person of body mass 70 kg. K/Na ratio for the studied plants varied between 14.88:1 and 113.75:1 which was in agreement with the reported permissible range. The amount of Mg, Ca, Cu, and Co was within the permissible limit in all the enlisted plants. However, the HQ value for Mg and Ca was greater than the safe limit for some of the plants. The concentration and HQ value of Zn, Mn, Fe, Pb, Cr, and Cd was beyond the permissible and unsafe limits for almost all the plants. This study suggests that the plants of this area must be pretreated for lessening the concentration of some elements before consumption.

Accumulation, translocation, and toxicity of arsenic in barley grown in contaminated soil

AimsArsenic is a nonessential element for plants; however, high levels of As can inhibit plant growth. The toxicity of As is influenced mainly by its speciation in soil. The objectives of the present study were to determine the fractional composition of As in soil, its accumulation in plants, and its potentially toxic effects on the morphological, anatomical, and ultrastructural levels.MethodsIn a model experiment, barley (Hordeum sativum L.) was planted in Haplic Chernozem spiked with three different concentrations of As (20, 50 and 100 mg/kg). The fraction composition of As in the experimental soil was analysed using a method of sequential fractionation. The phytotoxic effects of As were analysed microscopically at the tissue, cellular, and intracellular levels.ResultsAnalysis of the fraction composition of As revealed a higher amount of mobile forms of As that contaminated the generative organs of plants. Oxides of Fe, Al, and Mn became the main soil components to retain As when contamination of As increased. Arsenic toxicity inhibited plant growth by affecting morphological parameters (shape, size, and colour). It caused impairment in the root cells and a reduction in the size of the chlorophyllic parenchyma in the leaves. The ultrastructural analysis found changes in the main cellular organelles (chloroplasts, mitochondria, and peroxisomes).ConclusionsThe bioconcentration factor (BCF), bioaccumulation factor (BF-soluble), and translocation factor (TF) allowed evaluation of plant protection mechanisms and determination of hazardous concentrations of As in soil. Despite the high buffering capacity of the soil, high As concentration affected morphological and ultrastructural parameters of the H. sativum.

Effects of silicon in plants with particular reference to horticultural crops - Review article

Silicon (Si) has long been considered as non-essential element for plant’s growth and production. Numerous efforts are being made for the discovery of its beneficial effects with large scale studies laying foundation for new findings and hypotheses. Therefore, Si has been suggested to be a quasi-essential element due to its positive effects against biotic and abiotic stresses alike. Though Si is the second most abundant element in the soil profile, its availability to plants is limited to the form of monosilicic acid only. Besides, plants’ ability to take-up Si and use it in their physiological processes also depends on the available transporters associated with it. Thus, the present review covers uptake and transport of silicon in plants as well as Si mediated physiological processes, including mechanisms underlying induced tolerance against biotic and abiotic stresses with a particular emphasis on horticultural species.

Freshwater aquatic reptiles (Testudines and Crocodylia) as biomonitor models in assessing environmental contamination by inorganic elements and the main analytical techniques used: a review.

Despite the general lack of studies that use reptiles as bioindicators, the value of freshwater turtles and crocodilians in ecotoxicology has been proven, due to their importance as sentinel species. The aim of this study was to compile information on the use of freshwater turtles and crocodilians as environmental biomonitors of inorganic element contamination. We searched for articles in databases using specific keywords. A total of 104 studies published between the years 1970 and 2020 were collected. We noted a general increase in the number of studies involving turtles and crocodilians during the study time period. The Order Testudines were the subjects of 46% of the analysed publications, and the Order Crocodylia accounted for 54%. Within these studies, we counted 39 species (turtles n = 29 and crocodilians n = 10). Forty chemical elements were evaluated in the analysed articles, of which the majority represented non-essential elements (Hg, Cd, Pb). Although internal organs constituted the main biological matrix chosen for each group (37%), we observed an increase in the use of non-destructive matrices in both groups (scale, blood, tail muscle, carapace). The majority of analysed studies used HNO3 for the sample decomposition, with the majority of analyses being performed using atomic absorption spectroscopy (53%). Mainly blank controls (19%), analyte recovery (18%) and replicates (18%) were used as methods of validating analytical procedures. Furthermore, the studies used certified reference materials, which measure the accuracy of the methods used. We conclude that the increase in the use of aquatic reptiles in environmental monitoring research is mainly due to their ability to reveal integrated changes in ecosystems, aiding in environmental public policy decision-making and effective management plans.

Trace Elements and Chronic Kidney Disease: A Cross-Sectional Study from Jamaica

Background: Several environmental studies have reported that low-level exposure to nephrotoxic elements increases the risk of chronic kidney disease (CKD). In developing countries, finite resources can limit epidemiological studies and environmental risk assessment; however, the unique soil profile in Jamaica has raised some concerns for the potential exposure to populations who are of high risk. Method: This study investigated the potential for using trace element profiling in CKD, by analysing blood concentration levels of vanadium, chromium, iron, cobalt, copper, zinc, selenium, strontium (Sr), arsenic, barium, cadmium, mercury, and lead. Trace element analysis was conducted using inductively coupled plasma mass spectrometry. Results: One hundred and fifty-eight individuals were included and were predominantly of African descent (98%) and their ages ranged from 21 to 90 years old. Three main correlation clusters were evident: firstly, vanadium, chromium, copper, silicon, and selenium, with mercury and barium more distantly related; secondly, lead, arsenic, nickel, and Sr; and thirdly, iron and zinc. Cadmium was an outlier. Blood Sr was strongly associated with estimated glomerular filtration rate (r = -0.83; p<0.001) and strong linear progression models (r2=0.96; p<0.001). Algorithmic models placed Sr as the highest-ranking trace element biomarker (area under the curve: 95.6%; p<0.001). Discussion: The decline in kidney function may result in the retention of non-essential trace elements. Strong corresponding trends between kidney function and blood Sr concentration indicate biomarker potential for a trace element with a unique profile in patients with CKD. Other significant relationships may also be unveiled as CKD biomarkers as trace element profiling is explored in the region.

Silicon application and plant growth promoting rhizobacteria consisting of six pure Bacillus species alleviate salinity stress in cucumber (Cucumis sativus L)

As water quality and availability decreases in many parts of the world, salinity is becoming a major challenge that reduces crop yield, even in soilless cultivation systems. Therefore, novel strategies are needed to promote plant salt tolerance in these systems. We hypothesized that the non-essential element silicon (Si) and plant-growth promoting Bacillus spp. can alleviate salt stress of cucumber (Cucumis sativus L.) grown in hydroponics. We tested this hypothesis by growing cucumber seedlings with and without salt stress (75 mM NaCl) and with and without 1.5 mM Si and an inoculum of six rhizosphere Bacillus species in a full-factorial design. Seedlings were grown in a climate room for two weeks in independent deep-water culture containers. The applied salt stress strongly reduced plant biomass, whereas Si application under salt stress resulted in a substantial increase in cucumber shoot and root biomass. This beneficial impact of Si was also observed in increased plant height, leaf area, specific leaf area, root length, specific root length, root surface area and root volume. The Bacillus species increased root dry weight, specific leaf area as well as specific root length. In seedlings grown under salt stress, Si application increased shoot and root Si concentration, whereas Cl− concentration was reduced in the plant shoots. A reduction in Cl− concentration of the shoots was also apparent in the Bacillus treatment. Under non-stress conditions, neither Si nor Bacillus species affected plant growth parameters. However, shoot mineral content was affected as Si application reduced shoot Cl−and Ca2+ concentrations, and inoculation with Bacillus species decreased K concentration. We conclude that Si does promote salt stress alleviation during the early growth stage of cucumber grown in deep water culture and this has implications for soilless crop production. Seed inoculation with Bacillus species showed a beneficial trend for some plant growth characteristics and nutrient status under high salinity, although not as pronounced as for Si.

Human biomonitoring of essential, nonessential, rare earth, and noble elements in placental tissues

Exposure to certain metals has been recognized as a risk factor for numerous complications in vulnerable population groups, particularly pregnant women. This investigation evaluated the levels of essential (Cr, Mn, Co, Cu, Zn, Se, Mo) and nonessential trace metals with recognized toxicity (Be, Al, Ti, V, Ni, Ga, As, Rb, Sr, Cd, Sb, Ba, Tl, Hg, Pb, Bi, Th, U), together with rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu), and noble metals (Ru, Rh, Pd, Re, Os, Ir, Pt, Au, Ag) in the placental tissues of healthy pregnant women (n = 105). The selection of participants was undertaken with special reference to specific confounding factors that could influence the trace element profiles. Among trace elements, Zn was the most abundant and Lu was the least abundant. Cd and Os placental levels show a tendency to increase with women's age. Compared with literature data, high levels of Ni were found. This is the first study that provides the composition levels of essential and toxic trace elements, rare earth elements, and noble metals in human placental tissues. Also, for the first time, normal (reference) ranges for 50 (ultra)trace elements in placental tissues are proposed. Reference ranges are especially important in biomonitoring studies, which nowadays give increasing importance to the analysis of solid tissues instead of body fluids. Overall, the information provided in this study can serve as a starting point for further clinical trials and/or prediction of potential risks to pregnancy.

Limpets as bioindicators of element pollution in the coasts of Tenerife (Canary Islands).

Currently, there is an increase in marine pollution around the world; the most affected areas are the coastal ones since on the coast is where anthropogenic pollution first acts. Therefore, it is important to have natural bioindicators as organisms that indicate us in the first instance of this pollution. The main objective of the present research is to determine if Patella aspera and Patella candei crenata show statistical differences in their element content in contaminated areas of the Island of Tenerife and to verify if limpets can be good bioindicators of marine pollution by trace elements and non-essential elements. A total of 160 limpets were taken from 4 slopes of the Island of Tenerife in the Canary Islands. The samples were analyzed using the ICP-OES to obtain results of essential trace elements (Cr, Cu, Fe, Li, Ni, and Zn) and non-essential elements (Al, B, Cd, Pb, and V). P. aspera showed a higher concentration of elements than P. candei crenata, and it was in the Buenavista locality where alarming values of Cd 0.658 ± 0.124 mg/kg were observed for P. aspera. These two limpet species have been found to be useful as bioindicators of marine pollution based on the concentrations of metals especially for Cd and Cu.

Essential and non-essential elements, and volatile organic compounds for the discrimination of twenty-three sweet cherry cultivars from Fundão, Portugal

The mineral contents and volatile profiles of 23 sweet cherry cultivars were determined. A total of 27 minerals were determined by ICP-MS and flame atomic absorption spectrometry, including 12 essential and 15 non-essential elements. K was the most abundant in all cultivars, while Tl was the one found in the smallest amounts. A total of 66 volatiles were identified using SPME/GC–MS, including 16 aldehydes, 23 alcohols, 6 ketones, 6 esters, 8 monoterpenes, 3 norisoprenoids, 2 hydrocarbons and 2 acids. Benzaldehyde, hexanal, nonanal, benzyl alcohol, (E)-2-hexen-1-ol, 1-hexanol, (Z)-2-hexen-1-ol, 2-ethyl-1-hexanol, linalool, α-terpineol and α-ionone were the major ones. Qualitative and quantitative differences were observed among the cultivars, which influenced nutritional potential and aroma. Cherries from Fundão region contain high concentrations of phytochemicals and nutritional components. 4-84, Burlat and Celeste might be considered some of the most interesting cultivars, since they are rich in essential minerals and present high diversity in volatiles.

Determination of essential and non-essential elements in Xylanthemum macropodum of Balochistan, Pakistan

Background: Medicinal plants have been used to treat various diseases for several years throughout the world. Xylanthemum macropodum is a medicinal plant with a vast application as a home remedy in Balochistan. Objective: The current study was conducted to determine the levels of essential and non-essential elements in Xylanthemum macropodum collected from Quetta (Balochistan, Pakistan). Methods: Analysis was conducted for eleven elements by using atomic absorption spectrophotometer and flame photometer. Results: The essential and non-essential elements that were detected in Xylanthemum macropodum are K, Na, Ca, Fe, Cu, Co, Ni, Mn, Cr, Cd and Pb, respectively. The result of the concentration of determined elements are in the order of K> Na> Ca> Fe> Cu> Co> Ni> Mn> Cd> Cr> Pb in Xylanthemum macropodum 3000> 1600> 790.25> 92.36> 85.31> 49.24> 40.94> 20.94> 6.655> 1.61> 1.18 µg/g respectively. Conclusions: Mn, Na and Pb were found within the permissible limit given by World Health Organization, while Ca, Cu, Fe, Ni, Cd and Cr were beyond the permissible limits. However, there is no permissible limit for K and Co.

Metal ion toxicity and tolerance mechanisms in plants growing in acidic soil

<span>The abiotic factors have a wide effect on the growth of plants along with the cultivation of staple crops. The concentration of both essential and non-essential elements is impacted by number of biogeochemical factors. The low pH (≤5.0) of the soil is one such factor which poses variation in the levels of metal ions and mostly it leads to metal toxicity. The excess concentrations of the elements in the soil affects the growth, yield and the metabolic activities of the plants making them susceptible. However, some of the genotypes adapt themselves to metal toxicity condition by regulating their homeostatic genes leading to develop different strategies to undergo detoxification method. In the present review we discuss about the toxicity of Al, Fe and As which is a non-essential metal, an essential metal and an unwanted heavy metal. In a broad picture, to escape the toxic effects, plants have the strategy to exclude the excess metal outside the plant or include it in its storage cells. The insight of the present review aims at understanding these strategies in details which can be put into agricultural applications for developing better crops.</span>

Effects of Nano Silver Particles and Gibberellic Acid on Growth and Some Physiological Characteristics of Dalbergia Sissoo Roxb.

Recent studies show that Nanotechnology can be effectively used to enhance the characteristics of many types of trees including forest trees. Dalbergia Sissoo Roxb., which belongs to the Fabaceae family, is a forest tree that grows in dry land and water conservation areas. The aim of this study is to examine the effect of nano silver (NS) at (0, 30, 60 and 90 mg/L) and gibberellic acid (GA3) at (0, 50, 100 and 200 mg/L) concentrations on seed performance and subsequent growth of Dalbergia sissoo Roxb. The results reveal the enhancement of germination rate and velocity by using GA3 at 100 and 200 mg/L. NS90 treatment increased each of shoot and root fresh and dry weight, leaf area and plant height whereas GA50 treatment increased number of branches per plant and primary root length. Non-significant differences between treatments on Peroxidase enzyme activity and chlorophyll a content was observed whereas NS30 had the highest chlorophyll b and lowest total carotenoids. Shoot and root contents of some essential and non-essential elements differed between treatments. In roots, N90 treatment increased each of Cu and Mn elements, but it decreased Cl content. Although GA100 treatment increased Cl content, it decreased Mn. The paper concludes that the applications of nano-silver and GA3 on Dalbergia sissoo Roxb. have significant effects on its growth and physiological parameters.

Bioaccumulation of chemical elements in vegetables as influenced by application frequency of municipal solid waste compost

Municipal solid waste (MSW) compost is used to enrich soils by virtue of its bio-physicochemical properties. However, undesirable accumulation of chemical elements can reduce soil quality and cause food safety issues. A 5-yr field study was carried out to investigate the impact of Compost Quality Alliance (CQA)-tested MSW compost application frequency (annual, biennial and no-compost) on soil quality and chemical element accumulation in edible portions of lettuce (Lactuca sativa cv. Grand Rapids), beet (Beta vulgaris cv. Detroit Supreme), carrot (Daucus carota cv. Nantes), and green bean (Phaseolus vulgaris cv. Golden Wax). Analysis of soil showed that chemical elements were highest in annual application followed by biennial, but less in control (no-compost) and fallow soils. Soil background levels of chemical elements influenced the concentrations of iron (Fe) and manganese (Mn) in green bean, aluminum (Al) in green bean and beet, and barium (Ba) in carrot, beet, and lettuce. Cadmium (Cd) concentration in beet, lettuce, and green bean grown in the annual plot was increased by 48%, 52% and 62%, respectively while carrot recorded a 56% increase in the biennial plot compared with no-compost. Bioaccumulation factors were < 1 for all of the essential and non-essential trace elements in all of the plant species, except boron (B) and molybdenum (Mo). However, lettuce showed a higher tendency to accumulate Cd, rubidium (Rb), and strontium (Sr). Overall, the health risk for human consumption is low. Although long-term annual application of compost to vegetables seemed safe for human consumption, it is necessary to continuously monitor potential chemical element accumulation, particularly non-essential trace elements in soils and plants.

Heavy Metals in the Muscle and Hepatopancreas of Red Swamp Crayfish (Procambarus clarkii) in Campania (Italy).

Simple SummaryHeavy metals can represent a serious threat to marine and freshwater fauna through exposure, bioaccumulation and biomagnification processes. The aim of this study was to evaluate the presence of non-essential and essential elements in freshwater crayfish (Procambarus clarkii) edible tissues to establish the healthiness of this product and to evaluate the pollution status of the sampling sites from Campania region (Italy). The results suggest that crayfish were safe for human consumption and indicated mild contamination of heavy metals of the sampling areas. The aim of this study was to carry out a quali-quantitative analysis of the presence of non-essential and essential trace elements in freshwater crayfish (Procambarus clarkii) edible tissues to establish the healthiness of this product and to evaluate the pollution status of the sampling sites included in the present study. P. clarkii is one of the most common species of freshwater crustaceans in Italy, regularly consumed by local people. Moreover, the crayfish, due to its trophic position and diet, can be considered as an excellent bioindicator of the health status of the ecosystem. We collected sixty crayfish samples from two different sites in Campania (Italy): Villa Literno and Sessa Aurunca. Concentrations of trace elements were determined by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Our data showed low concentrations of Cd, Hg and Pb, with values below the European Commission MRL (Commission Regulation (EC) 1881/2006). We suggest that data obtained from this study showed that crayfish collected from Villa Literno and Sessa Aurunca were safe for human consumption. Furthermore, the results of this research indicated mild contamination of heavy metals of the sampling sites, indicating a good health status of the area’s aquatic ecosystem.

Analysis of essential and non-essential trace elements in the organs of a mother-fetus pair of spotted seals (Phoca largha) from the Sea of Japan.

Concentrations of 22 essential and non-essential trace elements (Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, Th, U, and Hg) were measured in the organs of a mother-fetus pair (at the last trimester of pregnancy) of spotted seals from the Sea of ​Japan. The concentrations of eleven elements are reported for the first time. Eight organs of the pair were examined: lungs, heart, liver, kidneys, intestines, spleen, muscles, and bones. All trace elements detected in the organs of the mother were found also in the organs of the fetus at various concentrations. Placenta is not an effective barrier to prevent non-essential elements from getting into the fetus, but can control entry of some of them, e.g., aluminum, cadmium, and mercury. In most organs of the fetus, the concentrations of toxic trace elements (beryllium, antimony, thorium, and uranium) were noticeably higher than in the same organs of the mother, which indicates that during pregnancy female removes excess of non-essential trace elements by transferring them to the fetal body through the placental barrier.

Prenatal exposure to a mixture of elements and neurobehavioral outcomes in mid-childhood: Results from Project Viva

BackgroundLead (Pb), manganese (Mn), selenium (Se) and methylmercury (MeHg) can be neurotoxic individually, despite Mn and Se also being essential elements. Little is known about the joint effects of essential and non-essential elements on neurobehavior, particularly for prenatal exposures. ObjectivesTo evaluate associations of prenatal exposure to multiple elements with executive function and neurobehavior in children. MethodsParticipants included 1009 mother-child pairs from the Project Viva pre-birth cohort. We estimated maternal erythrocyte Pb, Mn, Se, and Hg concentrations prenatally. In 6-11-year old children (median 7.6 years), parents and teachers rated children's executive function-related behaviors using the Behavior Rating Inventory of Executive Function (BRIEF) Global Executive Composite score and behavioral difficulties using the Strengths and Difficulties Questionnaire (SDQ) total difficulties score. We evaluated associations of element mixtures with neurobehavior using Bayesian kernel machine regression (BKMR), multivariable linear regression, and quantile g-computation. ResultsMedian erythrocyte Pb, Mn, Se, and Hg concentrations were 1.1 μg/dL, 33.1 μg/L, 204.5 ng/mL, and 3.1 ng/g, respectively. Findings from BKMR and quantile g-computation models both showed worse (higher) parent-rated BRIEF and SDQ z-scores with higher concentrations of the mixture, although estimates were imprecise. When remaining elements were set at their median within BKMR models, increases in Pb and Se from the 25th to 75th percentile of exposure distributions were associated with 0.08 (95% CI: 0.02, 0.19) and 0.07 (95% CI: 0.03, 0.16) standard deviation increases in parent-rated BRIEF scores, and 0.08 (95% CI: 0.02, 0.17) and 0.05 (95% CI: 0.03, 0.13) standard deviation increases in SDQ scores, respectively. There was no evidence of element interactions. DiscussionAlthough associations were small in magnitude, we found a trend of worsening neurobehavioral ratings with increasing prenatal exposure to an element mixture. However, we may be observing a limited range of dose-dependent impacts given the levels of exposure within our population.

Effects of storage conditions on the stability and distribution of clinical trace elements in whole blood and plasma: Application of ICP-MS

BackgroundKnowledge of trace element stability during sample handling and preservation is a prerequisite to produce reliable test results in clinical trace element analysis. MethodAn alkaline dissolution method has been developed using inductively coupled plasma mass spectrometry to quantify eighteen trace element concentrations: vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, bromine, molybdenum, cadmium, antimony, iodine, mercury, thallium, lead, and bismuth in human blood, using a small sample volume of 0.1 mL. The study evaluated the comparative effects of storage conditions on the stability of nutritionally essential and non-essential elements in human blood and plasma samples stored at three different temperatures (4 °C, −20 °C and −80 °C) over a one-year period, and analysed at multiple time points. The distribution of these elements between whole blood and plasma and their distribution relationships are illustrated using blood samples from 66 adult donors in Queensland. ResultsThe refrigeration and freezing of blood and plasma specimens proved to be suitable storage conditions for many of the trace elements for periods up to six months, with essentially unchanged concentrations. Substantially consistent recoveries were obtained by preserving specimens at −20 °C for up to one year. Ultra-freezing of the specimens at −80 °C did not improve stability; but appeared to result in adsorption and/or precipitation of some elements, accompanied by a longer sample thawing time. A population sample study revealed significant differences between the blood and plasma concentrations of six essential elements and their relationships also varied significantly for different elements. ConclusionBlood and plasma specimens can be reliably stored at 4 °C for six months or kept frozen at −20 °C up to one year to obtain high quality test results of trace elements.

Year-round element quantification of a wide-ranging seabird and their relationships with oxidative stress, trophic ecology, and foraging patterns

Multidisciplinary approaches are essential to diligently assess environmental health status of ecosystems. In this study, year-round chemical elements' exposure and impacts were assessed on the wide-ranging Cory's shearwater Calonectris borealis breeding in Berlenga Island, offshore Portugal, North Atlantic Ocean. The aim was to identify potential contamination and oxidative stress sources associated with trophic ecology, habitat and spatial use, and foraging patterns. A set of 20 chemical elements were quantified, along with oxidative stress biomarkers, stable isotope analyses, and GPS tracking data. Birds presented higher accumulation to some non-essential elements along the year (i.e. arsenic, As; cadmium, Cd; mercury, Hg; lead, Pb; and strontium, Sr), in which concentrations were similar or surpassed other procellariform seabird populations all over the world. No significant differences were found for any of the elements between different periods within the breeding season, with exception of Hg. However, a Principal Component Analysis taking into consideration a group of elements showed differences between pre-laying and chick-rearing periods, with overall higher concentrations in the former. Individuals spending more time engaging in an intensive search for food, and in more coastal environments, presented overall higher element concentrations, and particularly Hg. Contrary to expectations, no relationships were found between chemical elements and oxidative stress. On the other hand, spatial use and foraging patterns of Cory's shearwaters influenced their oxidative stress responses. Our results highlight the need for multidisciplinary approaches to deepen understanding of the large-scale vulnerability of bioindicators such as seabirds and, by extension, the overall environmental health of ecosystems in which they rely.