Levels Of Trace Elements Research Articles

Trace element levels and bio-active compounds in ethanolic leaf extract of Chrysophyllum albidum characterised using gas chromatography – mass spectrometry

Aim and objectivesChrysophyllum albidum, also known as Africa star apple, has so many ethnobotanical uses in African healing system. Thus, a study that reveals possible trace elements and its phytochemical profile will give an essential insight to the bioactivity profile of the plant. The study was to identify the trace elements and the bioactive compounds present in Chrysophyllum albidum (C. albidum) leaf extract Materials and methodsThe ethanol leaf extract of Chrysophyllum albidum was evaluated for trace elements using an Atomic Absorption Spectrophotometry (ASS) while the chemical composition was analysed using Gas Chromatography-Mass Spectrometry (GC/MS). The identification of phytoconstituents using GC/MS was based on the instrument library, peak area and retention time. ResultThe ethanol leaf extract of C. albidum showed a high content of potassium, calcium, magnesium and sodium, while relative low content of manganese, iron, copper, zinc, lead and nickel. Total of 30 peaks representing 30 identified compounds were recorded in the GC/MS analysis. These include a variety of heterocyclic compounds such as fatty acids, organic compounds, esters, and disaccharides etc. The major constituents of the extract were: Sucrose (37.45%), followed by 1,2,3-Propanetriol,1-acetate (7.86%), di-Glyceraldehyde dimer (5.70%), 1-(3-Benzyl-2-thioureido)−1-deoxy-beta-d glucopyranose 2,3,4,6-tetraacetate (4.53%), 4 H-Pyran-4-one, 2,3-dihydro-3, 5-dihydroxy-6-methyl- (4.49%), 3-Deoxy-d-Mannoic lactone (3.14%), Glycerine (3.04%) and minor compounds that are less than 3%. ConclusionThe elemental composition of the leaf extract of C. albidum may be influenced by the environmental factors such as soil composition surrounding the plant’s roots, while a variety of bioactive compounds with diverse biological activities were present. Hence, the plant have a potential pharmacological activities.

The content of microelements in the blood of young bulls after correction of diets with deficient microelements

Micronutrients, or micronutrients, are an essential component of the diet of farm animals and play a key role in their health and performance. The importance of trace elements in physiological processes and ensuring the normal functioning of the animal body is highlighted. Micronutrients affect growth, fertility, the state of the immune system, the health of the skin and coat, and metabolism. This scientific study emphasizes the importance of a balanced consumption of trace elements in the diet of farm animals to achieve high-performance indicators and ensure their overall health. It is essential to consider that the deficiency or excess of trace elements in the diet of animals can lead to various problems with health and productivity. Therefore, accurate, balanced nutrition and control over the content of trace elements are critical aspects of animal husbandry. It is essential to consider that different species of animals can show different vulnerability to trace elements, and therefore, it is necessary to ensure the correct balance of trace elements in the diet of each species of animal to preserve their health and productivity. This article describes the feeding of deficient trace elements and their chelated compounds (Fe, Cu, Mn, Co, Zn). The research aimed to investigate the content of microelements (Cu, Pb, Mn, Co, Zn, Cd, Ni, Fe) in the blood of young cattle after correcting diets with deficient microelements. The obtained results show that the level of trace elements increased slightly in the animals of the 2nd, 3rd, and especially the 4th experimental group. Thus, at the end of the experiment, the content of trace elements in the cattle of the experimental groups was higher than in the animals of the control group. The highest amount of trace elements in the blood was observed in the fourth experimental group, which was fed chelated compounds of trace elements (methionates) in the following doses: CuMet(0.05), MnMet(0.1), ZnMet(0.1), FeMet(0.05), CoMet(0.03) mg/kg body weight.

Relationships between microvascular complications of diabetes mellitus and levels of macro and trace elements

Relationships between microvascular complications of diabetes mellitus and levels of macro and trace elements

Therapeutic effect of trace elements on multiple myeloma and mechanisms of cancer process.

In the human body, trace elements and other micronutrients play a vital role in growth, health and immune system function. The trace elements are Iron, Manganese, Copper, Iodine, Zinc, Cobalt, Fluoride, and Selenium. Estimating the serum levels of trace elements in hematologic malignancy patients can determine the severity of the tumor. Multiple myeloma (MM) is a hematopoietic malignancy and is characterized by plasma cell clonal expansion in bone marrow. Despite the advances in treatment methods, myeloma remains largely incurable. In addition to conventional medicine, treatment is moving toward less expensive noninvasive alternatives. One of the alternative treatments is the use of dietary supplements. In this review, we focused on the effect of three trace elements including iron, zinc and selenium on important mechanisms such as the immune system, oxidative and antioxidant factors and cell cycle. Using some trace minerals in combination with approved drugs can increase patients' recovery speed. Trace elements can be used as not only a preventive but also a therapeutic tool, especially in reducing inflammation in hematological cancers such as multiple myeloma. We hope that the prospect of the correct use of trace element supplements in the future could be promising for the treatment of diseases.

P10-11: Associations between blood levels of trace elements and cardiovascular risk factors in patients with rheumatoid arthritis

P10-11: Associations between blood levels of trace elements and cardiovascular risk factors in patients with rheumatoid arthritis

Assessment of Trace Element Concentrations in Groundwater Sources of a Rural Village in Kerala, India

Water is an essential part of all living organisms. India is already experiencing the effects of the impending global freshwater crisis in terms of water quantity and quality. The study, which was carried out in a rural village (Villiappally Gramapanchayath) in Kerala, sought to quantify the level of trace elements in the ground water and to determine how they affected the quality of the water suitable for human use. Twenty-two public wells that are used by the residents for their everyday needs are sampled in the pre-monsoon for the analysis. ICP-MS was used to analyse the water samples for the presence of the heavy metals Zn, Pb, Fe, Cd, As, and Al. The acquired value from ICP-MS analysis is compared with BIS standard values of drinking water quality. From the analysed heavy metals, cadmium and iron in some of the wells are exceeding the permissible limit of BIS. HPI of each well is carried out and find out that DW1, DW2 and DW14 is not fit for drinking purpose. By analysing the Metal Index (MI) out of 22 wells, 9 wells are pure in quality and others are slightly to moderately affected. Certain metals in different wells shows slight greater concentration than the permissible limits of BIS. These might be taken into account for a safer drinking water.

Effects of trace elements (Fe, Cu, Ni, Co and Mg) on biomethane production from paper mill wastewater

Abstract Trace elements have a significant effect on biochemical reactions and therefore the presence of optimum levels of trace elements is essential for bioreactor performances. In this study, the effects of five trace elements on biomethane production have been investigated. Experimental studies have been carried out with multiple batch reactors at 15 day HRT and mesophilic temperatures. The optimum concentrations for each of the trace elements Fe, Cu, Ni, Co and Mg were found as 5, 0.5, 0.5, 0.5 and 100 mg/L, respectively. Among tested trace elements, Cu was the one which provided the highest biomethane production. Cu addition was resulted in a 46 % increase in biomethane production followed by Co with 24 %. The biomethane production rate for these two trace elements was 191.70 and 110.77 ml CH4/g COD, respectively. Optimum levels for Ni, Fe and Mg increased biomethane production rate by approximately 14.3, 10 and 17 % compared to control groups, respectively. Because the exact amount of trace element requirement for each industry/reactor is different, specific case studies should be performed for each application. These results could be used as initial trace element concentrations for further continuous studies.

Co-delivery of streptomycin and hydroxychloroquine by labeled solid lipid nanoparticles to treat brucellosis: an animal study

Can brucellosis-related biochemical and immunological parameters be used as diagnostic and treatment indicators? The goal of this project was to look at biochemical parameters, trace elements, and inflammatory factors in the acute and chronic stages of brucellosis after treatment with streptomycin and hydroxychloroquine-loaded solid lipid nanoparticles (STR-HCQ-SLN). The double emulsion method was used for the synthesis of nanoparticles. Serum levels of trace elements, vitamin D, CRP, and biochemical parameters were measured in rats involved in brucellosis. The therapeutic effect of STR-HCQ-SLN was compared with that of free drugs. In both healthy and infected rats, serum concentrations of copper, zinc, iron, magnesium, potassium, and biochemical parameters of the liver were significantly different. By altering the serum levels of the aforementioned factors, treatment with STR-HCQ-SLN had a positive therapeutic effect on chronic brucellosis. Vitamin D levels declined (46.4%) and CRP levels rose (from 7.5 mg to less than 1 mg) throughout the acute and chronic stages of brucellosis. This study showed that by comparing the biochemical parameters and the levels of trace elements in the serum of healthy and diseased mice in the acute and chronic stages of brucellosis, it is possible to get help from other routine methods for diagnosis.

Occurrence of trace elements in print paper products: Non-carcinogenic risk assessment through dermal exposure

Over time, the risk assessment of dermal exposure to pollutants in print paper products has received considerable attention. Most studies have focused on organic pollutants, especially bisphenol A (BPA). However, little is known about the levels of trace elements in print paper products, despite the knowledge that these elements are components of printing inks and toners. This study was aimed at determining the concentrations of trace elements in 5 types of paper products, namely bulletins, magazines, special events program booklets, handbills, and newspapers. The average daily intake (ADI) of each element was subsequently estimated through dermal exposure to the papers. The detection frequency of the elements of interest was high (nearly 100%) in most paper products, with the exception of chromium, whose detection was low. In contrast, Ag was not detected in any sample. The levels of the elements in the paper products were low and comparable to those found in other personal and consumer products with the potential for skin contact. The range values of estimated ADIs were 1.70–3.90E-08, 2.30–18.2E-10, 2.60–16.4E-09, 3.65–5.75E-08, 1.29–4.38E-08, 6.23–15.6E-10, 1.51–2.80E-10, 1.43–9.16E-09, 0.00–9.47E-09, and 4.68–220E-08 mg/kg bw/day for Mn, Co, Ni, Cu, Zn, As, Cd, Pb, Cr and Fe respectively. These values were well below the dermal standard reference doses (RfD) for each element. The present results indicate that dermal exposure to trace elements from print paper products was low and does not pose significant risks for toxic (non-carcinogenic) effects on humans.

Bioaccumulation of Non-Essential Trace Elements Detected in Women's Follicular Fluid, Urine, and Plasma Is Associated with Poor Reproductive Outcomes following Single Euploid Embryo Transfer: A Pilot Study.

This study aims to determine the association of non-essential trace elements present in follicular fluid, plasma, and urine with reproductive outcomes of women undergoing intracytoplasmic sperm injection (ICSI), preimplantation genetic testing for aneuploidies (PGT-A) and single frozen euploid embryo transfer (SET/FET). This single-center, prospective cohort study included sixty women undergoing ICSI with PGT-A and SET/FET between 2018 and 2019. Urine, plasma and follicular fluid samples were collected on the vaginal oocyte retrieval day to simultaneously quantify ten non-essential trace elements (i.e., Ba, Sr, Rb, Sn, Ti, Pb, Cd, Hg, Sb, and As). We found several associations between the levels of these non-essential trace elements and clinical IVF parameters. Specifically, the increased levels of barium in follicular fluid were negatively associated with ovarian function, pre-implantation development and embryo euploidy, while elevated strontium concentrations in this biofluid were negatively associated with impaired blastulation and embryo euploidy. Elevated plasma strontium levels were negatively associated with ovarian function, fertilization and blastulation. Enhanced presence of other trace elements in plasma (i.e., rubidium and arsenic) were associated with a diminished ovarian function and limited the number of recovered oocytes, mature oocytes and zygotes, respectively. Fully adjusted models suggested significantly lower odds of achieving a live birth when increased concentrations of barium and tin were found in urine.

The Gastro-Protective Effect of Ulmus Rubra, Piper Nigrum, and Brassica Oleracea in Ethanol-Induced Model of Gastric Ulcer

Background: Gastric ulcer is a state that results from an imbalance between the erosive effect of acid and pepsin and the mucosal defense mechanism of the stomach; it is correlated with the lesions induced by ethanol. Methods: Forty-eight healthy albino rats weighing (150-200gm) were involved in the present study. The animals withholding food for 24hrs were allocated to six groups. Each group was given orally one of the following agents: distilled water for the control group, esomeprazole, aqueous extract of Ulmus rubra or Piper nigrum, or Brassica oleracea, then after one hour ethanol was given to all groups except group 1, which act as the control. Animals were sacrificed one hour later; the main parameters used in the present study were ulcer numbers and areas, preventive index, and changes in the trace elements (Zn and Cu) and serum electrolytes (Na+ and K+). Results: Ethanol was found to be highly ulcerogenic at high concentrations. The preventive index of these agents was 90%, 47.7%, and 91.8% for Ulmus rubra, Piper nigrum, and Brassica oleracea, respectively, in comparison with esomeprazole 94.7%. These agents also produced significant changes in trace elements levels of Zn and Cu but with no significant changes in electrolytes Na+ and K+. Conclusion: Both Ulmus rubra and Brassica oleracea extracts proved to have a potent gastroprotective effect against the ethanol-induced model of gastric ulcer and the possibility to be used in the management of peptic ulcer after assessment by clinical trials.

Effects of arsenic exposure on trace element levels in the hippocampus and cortex of rats and their gender differences

BackgroundExposure to arsenic (As) is a major public health challenge worldwide. Chronic exposure to As can cause various human health effects, including skin diseases, cardiovascular disease, neurological disorders, and cancer. Studies have shown that As exposure can lead to disturbances in the balance of trace elements in the body. Moreover, As readily crosses the blood-brain barrier and can be enriched in the hippocampus and cortex, causing neurotoxic damage. At present, there are few reports on the effect of As on trace element levels in the central nervous system (CNS). Therefore, we sought to explore As-induced neurotoxicity and the effects of As on CNS trace element levels. MethodsAn As-induced neurological injury model in rats was established by feeding As chow for 90 days of continuous exposure, and 19 elements were detected in the hippocampus and cortex of As-exposed rats by inductively coupled plasma mass spectrometry. ResultsThe results showed that the As levels in the hippocampus and cortex of As-exposed rats were significantly higher than those in the control group, The As levels in the cortex were significantly higher than in the hippocampus group. The levels of Cd, Ho, and Rb were increased in the hippocampus and decreased in Au, Ba, Ce, Cs, Pd, Se, Sr, and Tl in the As-exposed group, while the levels of Cd and Rb were increased and Se and Au were decreased in the cortex. Significant gender differences in the effects of As on hippocampal Cd, Ba, Rb, and Sr, and cortical Cd and Mo. ConclusionIt is suggested that elemental imbalance may be a risk factor for developing As toxicity plays a synergistic or antagonistic role in As-induced toxicity and is closely related to As-induced CNS damage.

Effects of Maternal Cigarette Smoking on Trace Element Levels and Steroidogenesis in the Maternal-Placental-Fetal Unit.

This study evaluates the interaction of toxic elements cadmium (Cd) and lead (Pb) due to exposure from cigarette smoking, essential elements, and steroidogenesis in the maternal-placental-fetal unit. In a cohort of 155 healthy, postpartum women with vaginal term deliveries in clinical hospitals in Zagreb, Croatia, samples of maternal blood/serum and urine, placental tissue, and umbilical cord blood/serum were collected at childbirth. The biomarkers determined were concentrations of Cd, Pb, iron (Fe), zinc (Zn), copper (Cu), and selenium (Se), and steroid hormones progesterone and estradiol in maternal and umbilical cord blood and the placenta. Three study groups were designated based on self-reported data on cigarette smoking habits and confirmed by urine cotinine levels: never smokers (n = 71), former smokers (n = 48), and active smokers (n = 36). Metal(loid)s, steroid hormones, urine cotinine, and creatinine levels were analyzed by ICP-MS, ELISA, GC-MS, and spectrophotometry. Cigarette smoking during pregnancy was associated with increased Cd levels in maternal, placental, and fetal compartments, Pb in the placenta, and with decreased Fe in the placenta. In active smokers, decreased progesterone and estradiol concentrations in cord blood serum were found, while sex steroid hormones did not change in either maternal serum or placenta. This study provides further evidence regarding toxic and essential metal(loid) interactions during prenatal life, and new data on sex steroid disruption in cord serum related to cigarette smoking. The results indicate that umbilical cord sex steroid levels may be a putative early marker of developmental origins of the future burden of disease related to harmful prenatal exposure to cigarette smoke.

Heavy metals in human bones from the Roman Imperial Period

Background/Aim: Heavy metals are elements known for their toxic effects even at low concentrations, and human exposure to these elements spans history. This study aimed to investigate trace element levels in the bones of individuals from the Roman Imperial Period. The objectives were to determine the values of specific metals, including heavy metals, make a rough comparison with present-day values, and gain insights into the environmental conditions of that era. Methods: Due to the use of dry bone samples, ethical committee approval was not required for this research. The study analyzed element levels in human bones dated back to the Roman Imperial Period (218-244 AD), unearthed in 2018 during excavations in Turkey-Kayseri. Only bones that archaeologists verified to belong to the specified period were included, while those with uncertain origins were excluded. The samples were taken from os coxae of 15 individuals (eight males and seven females) to analyze Ca, P, Zn, Cu, Pb, and Hg levels. Instrumental techniques such as Wavelength Dispersive X-ray Fluorescence (WDXRF) (X-ray fluorescence) and ICP-MS (Inductive Coupling Plasma-Mass Spectrometer) were used to determine element concentrations. The Ca/P ratio was assessed for diagenesis evaluation, and statistical analysis was performed using Statistical Package for Social Sciences (SPSS) 22.0, with a significance threshold set at P-value <0.05. Results: The Ca/P ratio for the general population was calculated as 2.34 (0.10). The mean concentrations of heavy metals in the bones were as follows: Cu 18.27 (11.04) ppm, Pb 13.30 (5.66) ppm, Zn 27.22 (13.84) ppm, and Hg 2.45 (2.86) ppm. The corresponding P-values for Ca, P, Ca/P, Cu, Zn, Pb, and Hg were 0.109, 0.120, 0.104, 0.063, 0.113, 0.089, and 0.070. No statistically significant difference emerged when comparing elemental accumulations between males and females. Notably, copper and mercury levels were higher in Roman Imperial Period bones than contemporary ones, whereas zinc levels were lower, and lead concentrations aligned with reference values. Conclusion: The study results underscore the historical exposure of Roman Imperial Period individuals to heavy metals. These findings suggest that environmental health concerns related to heavy metal exposure date back millennia, emphasizing the long-standing nature of this issue.

Levels of Essential and Trace Elements in Mozzarella Available on the Slovak Market with the Estimation of Consumer Exposure.

The aim of this study was to determinate the content of some elements in a specific dairy product, mozzarella, in a particular area of western Slovakia and to evaluate the estimation of the risk to the consumers based on the contribution to the provisional tolerable weekly intake. The consumption of mozzarella can contribute to the intake of important elements in the diet, such as calcium and magnesium, along with others. The contents of some toxic and trace elements were low and have not exceeded the permitted limit. In addition, the contribution to PTWI was found to be very low, which means that the consumption of mozzarella possesses no risk to humans. It is concluded that the data obtained in this study can help as a valuable addition to methodological and scientific material in the field of food safety of dairy products and their positive impact on human health.

Effects of Diets Containing Different Levels of Copper, Manganese, and Iodine on Rumen Fermentation, Blood Parameters, and Growth Performance of Yaks.

Copper, manganese, and iodine are part of a yak's required trace elements. However, knowledge about their dietary requirements is scarce. Therefore, an experiment was conducted to evaluate rumen fermentation, blood parameters, and growth performance and screen out the optimum levels of trace elements in yaks' diet. Here, 18 three-year-old castrated yaks were randomly divided into four groups, which fed with diets containing basal (CON: 4.40, 33.82, and 0 mg/kg) and low-level (LL: 10.00, 40.00, and 0.30 mg/kg), middle-level (ML: 15.00, 50.00, and 0.50 mg/kg), and high-level (HL: 20.00, 60.00, and 0.70 mg/kg) copper, manganese, and iodine for 30 days. With the increase in trace elements, yaks' daily weight gain (DWG), rumen pH, ammonia nitrogen, microbial protein (MCP), and volatile fatty acids levels and serum triglycerides and urea nitrogen levels showed firstly increasing and then decreasing trends and reached the highest values in ML, and serum ceruloplasmin and total superoxide dismutase (T-SOD) activities showed continuously increasing trends. Yaks' DWG, rumen MCP, butyrate, and valerate levels and serum triglycerides, urea nitrogen, ceruloplasmin, and T-SOD levels in ML were significantly higher than CON. Therefore, the recommended levels of copper, manganese, and iodine in growing yaks' diet are 15.00, 50.00, and 0.50 mg/kg (ML), respectively.

Evaluation of Trace Elements in Coffee and Mixed Coffee Samples Using ICP-OES Method.

This research examines the concentration of 10 trace elements including arsenic (As), lead (Pb), chromium (Cr), zinc (Zn), iron (Fe), cobalt (Co), cadmium (Cd), nickel (Ni), manganese (Mn), and aluminum (Al) from among 36 different samples of coffee (3 brands and 2 types of simple and instant) and mixed coffee (3 brands and 4 types of simple, creamy, chocolate and sugar free) collected from market of Iran's and analyzed by using ICP-OES (inductively coupled plasma-optical emission spectrometry). The recovery, limit of quantification (LOQ), and limit of detection (LOD) ranged from 93.4 to 103.1%, 0.06 to 7.22, and 0.018 to 2.166 µg/kg, respectively. The findings showed that the highest and lowest average concentrations were 498.72 ± 23.07 μg/kg (Fe) and 3.01 ± 1.30 μg/kg (As) in coffee and mixed coffee samples. Also, in all samples, the maximum concentration of trace elements was related to Fe (1353.61 µg/kg) and the minimum concentration was related to Al, As, Co, Cr, Ni, Pb, and Zn that were not detected (ND). The samples of mixed coffee had highest levels of trace elements compared to coffee samples. In coffee samples, type of instant coffee had highest levels of trace elements compared to simple coffee and mixed coffee samples. The type of creamy mixed coffee had highest levels of trace elements (except Ni and Cr) compared to other type of mixed coffee samples. Finally, trace elements were less than the standard levels of Iran and other countries (in all samples); therefore, it does not threaten Iranian consumers.

Research progress on correlations between trace element levels and epilepsy.

Research investigating the correlation between human trace element levels and disease alterations is growing. Epilepsy, a common nervous system disease, has also been found to be closely related to abnormal levels of trace elements. Studies continue to explore mechanisms of various trace elements involved in epileptic seizures through experimental animal models of epilepsy. Thus, we reviewed the research progress on the correlation between trace element levels and epilepsy in recent years and found that the trace elements most closely related to epilepsy are mainly metal ions such as selenium, iron, copper, zinc, and manganese. These results indicate that the changes in some trace elements are closely related to the increase in epilepsy susceptibility. In addition, after treatment with drugs and a ketogenic diet, the concentration of trace elements in the serum of patients with epilepsy changes. In other words, the abnormality of trace element concentrations is of great significance in the occurrence and development of epilepsy. This article is a literature update on the potential role of trace element imbalance in the development of epilepsy, providing new references for the subsequent prevention and treatment of epilepsy.

Burden of rare earth elements and trace elements in feathers of magellanic penguins (Spheniscus magellanicus) from the southern Chilean Patagonia

Patagonia is one of the last pristine regions on the southern hemisphere. The impact of rare earth element (REEs) and trace elements (TEs) in this region have received little attention. The main goal was to assess REEs burden in feathers of adult magellanic penguins (Spheniscus magellanicus). Sampling was performed at Magdalena Island of the Chilean Patagonia during the austral summer of 2011. Multi-elemental determination of 16 REEs and 24 TEs was performed with ICP-MS. The levels of REEs, TEs, and stable isotopes (δ15N, δ13C, and δ34S) were measured to assess the factors that condition the avian exposure to environmental contaminants. The results showed an increase of the levels of REEs and TEs from the calamus to the feather's tip. In the whole feather, the highest levels corresponded to Ce, which exhibited more than two order of magnitude than Lu and Tm levels. Similar to other penguin species, magellanic penguins can be vectors of REEs and metals in remote regions. Stable isotopes revealed that trophic ecology may influence some of the element concentrations in feathers of magellanic penguins, an issue that requires deeper attention.

Bioaccumulation of trace elements and hydrocarbons in chondrichthyans of the western Arabian Gulf: Environmental and human health risk assessment and implications for conservation

This is a first attempt to assess the levels of trace elements, PAHs, and TPHs in six elasmobranch species (Carcharhinus dussumieri, C. sorrah, Chiloscyllium arabicum, Gymnura poecilura, Sphyrna lewini, S. mokarran) from the Arabian Gulf. The chemical analysis showed that the concentrations of contaminants differed significantly between liver and muscle samples with both pelagic and benthic species and all families. For all species, contaminant concentrations were significantly higher in the liver than in the muscle. While muscle contaminant concentrations differed significantly with respect to species' lifestyles and families, those of liver showed no significant differences between pelagic and benthic species, neither between the four families nor between the six species. None of the analysed contaminants exceeded the internationally recognized standards in all studied species. These results enrich the knowledge on the bioaccumulation of contaminants in elasmobranchs and allow to assess the environmental status of the Arabian Gulf.