Metal Body Burden Research Articles

Are pesticide residues associated to rice production affecting oyster production in Delta del Ebro, NE Spain?

Pesticide usage in Delta del Ebro (NE Spain) during the rice growing season has been associated with oyster episodes of mortality that occur early in summer. However, there are no studies that have directly evaluated pesticide levels and effects in oysters (Crassotrea gigas) cultured in Ebro's Bays. In this study pesticide levels in water, metal body burdens and up to 12 different biochemical markers were monitored in gills and digestive glands of oysters transplanted from May to June in 2008 and 2009. Biochemical responses evidenced clear differences in oysters from 2008 and 2009. Oysters transplanted in 2009 showed their antioxidant defenses unaffected from May to June and consequently increased levels of tissue damage measured as lipid peroxidation and DNA strand breaks and of mortality rates. Conversely oysters transplanted in 2008 increase their antioxidant defenses from May to June, had low levels of lipid peroxidation and DNA damage and low mortality rates. Some pesticides in water such as bentazone and propanil together with high temperatures and salinity levels were related with tissue damage in oyster transplanted in 2008 but the observed large differences between years indicate that abiotic factors alone could not explain the high mortalities observed in 2009. An analysis of recent reported studies pointed out in the direction that in addition to abiotic factors the use of oysters sensitive to diseases may explain the observed responses.

Heavy metals health risk assessment for population via consumption of food crops and fruits in Owerri, South Eastern, Nigeria

BackgroundThis study assessed lead, cadmium, and nickel level in food crops, fruits and soil samples from Ohaji and Umuagwo and Owerri in South Eastern Nigeria and estimated the potential health risks of metals. Samples were washed, oven-dried at 70–80°C for 24 h and powdered. Samples were digested with perchloric acid and nitric acid. Metals were analysed with Unicam Atomic Absorption Spectrophotometer.ResultThe concentration of Pb, Cd, and Ni in Ohaji exceeded the maximum allowable concentrations for agricultural soil as recommended by EU. Lead, Cd, and Ni in the food crops were highest in Oryza sativa, Glycine max, and Pentabacta microfila respectively. Highest levels of Pb, Cd, and Ni, in fruits were detected in Canarium schweinfurthii, Citrus reticulata, Ananas comosus respectively. The true lead and cadmium intake for the rice based meal were 3.53 and 0.034 g/kg respectively. Whereas the true intake of lead and cadmium for the cassava based meal were 19.42 and 0.049 g/kg respectively.ConclusionLocal food stuff commonly available in South Eastern Nigeria villages may contribute to the body burden of heavy metal. This is of public health importance.

Contribution of soil, water and food consumption to metal exposure of children from geological enriched environments in the coastal zone of Lake Victoria, Kenya

Geologically enriched environments may contain high concentrations of some metals. In areas where industrial exposures remain superficial, children may be exposed to these geological metals through soil, drinking water and consumption of food locally grown. The aim of this study was to assess the contribution of soil, water and food consumption to cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), cobalt (Co) and titanium (Ti) body burden of children in the geologically metal rich coastal zone of Lake Victoria, Kenya. We evaluated the relationship between the metal body burden of children by analyzing the hair samples and the estimated metal intake through exposure to soil, drinking water, and food consumption. The body burdens of all metals in children at the exposed sites were high, suggesting environmental exposure. Most of the foods consumed resulted in metal intake below the maximum recommended daily intake. However, the net contribution of all food items jointly exceeded the recommended maximum daily intake at some of the exposure sites. Our results further demonstrated that the highest intake of metals occurred via ingestion of high quantities of the cyprinid fish Rastrineobola argentea. Positive linear relationships between the metal body burden in children and estimated daily intake were observed for Cd, Cr, Ti in children consuming high quantity of R. argentea; for Zn and Co in children highly exposed to soils and consuming high quantity of Brassica oleraceae, while Co burden in the body was associated with high consumption of maize meal. This study demonstrated that exposure to soil and consumption of higher quantities of some foods contributed to the increased metal body burdens of children in a geologically exposed region.

Influence of Essential Trace Minerals and Micronutrient Insufficiencies on Harmful Metal Overload in a Mongolian Patient with Multiple Sclerosis

Parkinson's disease and other neurological disorders are prevalent in Mongolia. Our previous studies revealed a significant correlation of these diseases with high oxidative stress due to a high body burden of harmful metals, such as manganese, iron, lead, cadmium, and aluminum. This report describes a 37-year-old male Mongolian patient with multiple sclerosis and essential micronutrient deficiency. This patient demonstrated high oxidative stress, as shown by high urinary 8-hydroxy-2'-deoxyguanosine levels of 14.7 and 14.3 ng/mg creatinine (crea), although his hair levels of these toxic metals were markedly lower than other Mongolians. In addition, this patient was deficient not only in various essential minerals, including selenium, magnesium, copper, cobalt, vanadium, and nickel, but also in micronutrients such as vitamin B6, C, E, folic acid, niacin, and β-carotene. Furthermore, after taking 2,3-dimercaptosuccinic acid, a chelating agent, urinary excretion of lead, cadmium, manganese, aluminum, iron, copper, and lithium were increased 156-, 8.4-, 7.6-, 4.3-, 3.3-, 2.1-, and 2.1-fold, respectively. These results suggest that this patient suffered from a deficiency in micronutrients such as essential minerals and vitamins, which resulted in a disturbance in the ability to excrete harmful metals into the urine and hair. It is possible that a deficiency of micronutrients and a high burden of heavy metals play a role in the pathogenesis of multiple sclerosis. Nutritional treatment may be an effective approach to this disease.

Fluctuating asymmetry analysis on Porcellio scaber (Crustacea, Isopoda) populations living under metals-contaminated woody habitats

This field study aimed at determining the effect of metal-polluted environments on fluctuating asymmetry (FA) level of Porcellio scaber as a measure of developmental stability (DS). For this, woodlice and litter were collected on 8 sites of northern France located either away from metal pollution source or near metallurgical smelters. Physico-chemical parameters such as pH, C/N ratio and CaCO3 were measured in litter since they could have potential effects on woodlouse population. Moreover, Cd, Pb, and Zn concentrations in litter were determined to evaluate the contamination degree of each site. The metal body burdens were determined in woodlice to evaluate their impregnation degree. Fluctuating asymmetry levels on males and gravid females were performed on 9 traits (the 2nd and the 3rd articles of antennae, the 1st flagellum segment of the antennae, and the merus, carpus and propodus of the 6th and the 7th pereiopods) according (1) to each site and (2) to two habitat types (cf. metal-contaminated and uncontaminated habitats). Results showed close correlations between litter metal concentrations and metal body burdens in woodlice. However, contrary to the initial hypothesis that metal pollution would induce an increase of the FA level, this seemed to be lower for individuals from metal-contaminated habitats than for those from uncontaminated habitats, and particularly for males. The role of antennae and pereiopods on the foraging behavior and reproduction processes on woodlice were discussed and could explain these observations.

Relationships between body burdens of trace metals (As, Cu, Fe, Hg, Mn, Se, and Zn) and the relative body size of small tooth flounder (Pseudorhombus jenynsii)

Several studies have described strong relationships between body size and the accumulation of trace metals in animal tissues. However, few of these studies have utilized aging techniques to control for age related effects. We utilized relative body size (gy−1) of a model flounder species, Pseudorhombus jenynsii, in order to control for age related effects on growth and size measurements. We investigated links between relative body size, concentrations of trace metals in flounder muscle tissue, physico-chemical variables (temperature, salinity, pH, and turbidity), and levels of trace metals in the sediment. Flounder were sampled using an otter trawl net in the inner areas of eight estuaries that were either heavily modified or relatively unmodified by urbanization and industrial activity. Our results indicate that this commonly eaten fish is accumulating significant levels of some trace metals in their muscle tissue, both in relatively unmodified and heavily modified estuaries. Concentrations of Cu, Zn and Fe in muscle tissue, as well as temperature, showed a negative relationship to the relative body size of flounder. In contrast, Se and Hg in muscle showed a positive relationship to relative body size. Observed growth patterns indicate that these effects are not driven by age related differences in metabolic activity. Instead, our results suggest that differences in food supply or toxicological effects may be responsible for the observed relationships between relative body size and concentrations of Cu, Zn, and Se in muscle tissues. The use of otolith aging and growth measurement techniques represents a novel method for assessing the relationships between trace metal accumulation and the relative body size of fish in a field environment.

Evaluation of water quality threats to the endangered Okaloosa darter (Etheostoma okaloosae) in East Turkey Creek on Eglin Air Force Base

The threatened Okaloosa darter (Etheostoma okaloosae) is found almost exclusively on the Eglin Air Force Base in the Choctawhatchee Bay watershed of Florida. Portions of this limited habitat are threatened with soil erosion, altered hydrology, and impaired water quality. In the present study, general water quality parameters (i.e., dissolved oxygen, specific conductance, pH, temperature, relative turbidity, and primary productivity) were characterized in East Turkey Creek, which is a body of water potentially impacted by treated wastewater sprayfields, and Long Creek, an adjacent reference stream that does not border the sprayfields. Water quality was assessed during a 30-day exposure using passive samplers for both non-polar and polar effluent parameters. Because the Okaloosa darter was listed as endangered at the time of sampling we chose a closely related species from the same creeks, the sailfin shiner (Pteronotropis hypseleotris) in which to measure metal body burdens. Additionally, fathead minnows (Pimephales promelas) were used for microarray analysis on gonad and liver tissues after 48h exposures to water collected from the two creeks and brought into the laboratory. Waters from all sites, including reference sites, affected the expression of genes related to various biological processes including transcription and translation, cell cycle control, metabolism, and signaling pathways, suggesting that the sum of anthropogenic compounds in the site waters may cause a generalized stress response in both liver and testis, an effect that could be related to the generally low populations of the Okaloosa darter. Furthermore, effects of site waters on fish gene expression may be related to the impact of human activities other than the wastewater sprayfields, as nearby areas are closed to the public for military testing, training, and administrative activities and due to ordnance contamination.

Evaluation of Potential Dietary Toxicity of Heavy Metals of Vegetables

Introduction: Consumers are exposed to a diversity of chemicals in all areas of life. Air, water, soil and food are all unavoidable components of the human environment. Each of those elements influences the quality of human life, and each of them may be contaminated. Objective: Levels of cadmium (Cd), lead (Pb), mercury (Hg) and nickel (Ni) in vegetables and soils from Ohaji, Umuagwo and Owerri in southern Nigeria were determined and the potential health risks assessed. Methods: Commonly grown vegetables, fruits and food crops were collected from three different sites in southern Nigeria, washed, oven-dried in a hot air oven at 70–80°C for 24 h. Dried samples were powdered using pestle and mortar and sieved through muslin cloth. Samples (0.5 g each) were digested with perchloric acid and nitric acid (1:4) solution. The presence of lead, cadmium and nickel were analyzed in samples using the Unicam Atomic Absorption Spectrophotometer (AAS) Model 929. Results: Concentrations of Cd, Ni and Pb in Ohaji exceeded maximum allowable concentrations for agricultural soil. Cadmium, Ni, and Pb in vegetables were highest in Murraya koenigii, Piper guineense and Amaranthus viridis Linn, respectively. The estimated yearly intake of Pb, Cd and Ni in commonly consumed vegetables, Green leaf (Amaranthus viridis), fluted pumpkin (Telfaria occidetalis) and Curry leaf (Murraya koenigii) in Nigeria were calculated to be 1,210, 150 and 456 mg.kg-1, respectively. Conclusion: Taken together it might be concluded that these vegetables may contribute to the body burden of heavy metals especially lead.

A quantitative evaluation of brain dysfunction and body-burden of toxic metals

SummaryBackgroundToxic metal exposure (e.g. Hg, Pb, As) exposure is known to induce significant adverse effects on human brain function. The aim this study was to assess toxic metal body-burden in relation to potential brain dysfunction in patients diagnosed with neurological disorders (NDs).Material/MethodsThe Liberty Institutional Review Board (Deland, FL) approved the present study. Quantitative, fractionated, random urinary porphyrin testing (μg/L) from the Clinical Laboratory Improvement Act/Amendment (CLIA)-approved Laboratory Corporation of America (LabCorp) and cortical perfusion index (CPi) values from single-photon-emission-computed-tomography (SPECT) brain scans were employed to evaluate a prospective cohort of qualifying patients with diagnosed NDs (n=52) presenting for medical care at an endocrinology practice in the Cincinnati, OH area.ResultsPatients with more severe in comparison to mild brain dysfunction had significant increases in the mean urinary concentration of uroporphyrins (uP), coproporphyrins I (cP I), and total cP (cP I + III), as well as a trend towards significantly increased mean urinary concentration of pentacarboxyporphyins (5cxP) and cP III. A significant positive correlation between Hg body-burden associated porphyrins (5cxP + cP I + cP III) and increased brain dysfunction was observed.ConclusionsThe present study associated brain dysfunction with Hg body-burden in a cohort of patients diagnosed with NDs, but the contributions of other heavy metals or genetic factors cannot be ruled-out. Additional studies should be conducted to evaluate the consistency of the present findings with examinations of other populations.

Human biomonitoring on heavy metals in Ath: methodological aspects

The municipality of Ath is characterised by the presence, in its center, of two non-ferrous metal industries whose emissions make local residents concerned for their health. Therefore, authorities of the Walloon Region and the municipality of Ath undertook biomonitoring to assess the impact of those industrial emissions on heavy metal body burden in humans.This paper describes the study design and methodology used to carry out this human biomonitoring.A random sampling was done in the general population, in two areas of Ath: an area centered around the industries and a peripheral area. The target population was children (2.5-11 years) and adults (40-60 years) without occupational exposure. The three-stage sampling procedure consisted of a mixture of both mail and telephone recruitment. Firstly, 3259 eligible people, identified from a population register, were mailed an introductory letter. In a second stage, eligible individuals were contacted by phone to propose them to participate in the study. They were randomly contacted until the required sample size was obtained. In the third stage, a second mail was sent to those who agreed to participate with a questionnaire to be filled out. Finally, biological samples (blood and urine) from 278 persons were collected. The final participation rate of this study was 24%.This sampling procedure, especially designed for the purpose of this biomonitoring study in Ath, allowed us to recruit a sample representative of the population of children and adults of Ath, reaching the expected sample size in a short period of time.

Heavy metal sensitivity and bioconcentration in oribatid mites (Acari, Oribatida): Gradient study in meadow ecosystems

In this study we aimed to identify different reactions of oribatid species to heavy metal pollution and to measure concentrations of cadmium, zinc and copper in oribatid species sampled along a gradient. Oribatid mites were sampled seasonally during two years in five meadows located at different distances from the zinc smelter in the Olkusz District, southern Poland. Oribatids were shown to withstand critical metal concentration and established comparatively abundant and diverse communities. The highest abundance and species richness of oribatids were recorded in soils with moderate concentrations of heavy metals. Four different responses of oribatid species to heavy metal pollution were recognized. Heavy metals (Zn, Pb, Cd, Ni) and various physical (bulk density, field capacity, total porosity) and chemical (Kav, Pav, N, C, pH) factors were recognized as the structuring forces that influence the distribution of oribatid species. Analysis by atomic absorption spectrophotometry revealed large differences in metal body burdens among species. None of the species can be categorized as accumulators or non-accumulators of the heavy metals — the pattern depends on the metal. The process of bioconcentration of the toxic metal (regulated) and essential elements (accumulated) was generally different in the five oribatid species studied.

Evaluation of Bivalves as Bioindicators of Metal Pollution in Freshwater

The fresh water bivalves, Lamellidens corrianus, Lamellidens marginalis, and Indonaia caeruleus were exposed to chronic concentration of arsenic (0.1719ppm), cadmium (0.1284ppm), copper (0.033ppm), lead (1.50ppm), mercury (0.0443ppm) and zinc (1.858ppm) separately up to 30days in laboratory. Dry weight of each animal was used to calculate metal concentrations (μg/g) and the metal body burden (μg/individual). It was observed that lead (1235.4μg/g) and arsenic (37.9μg/g) concentration were highest in Lamellidens corrianus, zinc (3,032.3μg/g) was highest in Lamellidens marginalis, while mercury (5.87μg/g), cadmium (142μg/g) and copper (826.7μg/g) was highest in Indonaia caeruleus.

Bioaccumulation dynamics and exposure routes of Cd and Cu among species of aquatic mayflies

Consumption of periphyton is a potentially important route of metal exposure to benthic invertebrate grazers. The present study examined the bioaccumulation kinetics of dissolved and dietary Cd and Cu in five species of mayflies (class Insecta). Artificial stream water and benthic diatoms were separately labeled with enriched stable metal isotopes to determine physiological rate constants used by a biokinetic bioaccumulation model. The model was employed to simulate the effects of metal partitioning between water and food, expressed as the bioconcentration factor (BCF), as well as ingestion rate (IR) and metal assimilation efficiency of food (AE), on the relative importance of water and food to metal bioaccumulation. For all test species, the contribution of dietary uptake of Cd and Cu increased with BCF. For a given BCF, the contribution of food to the body burden increased with k(uf) , the metal uptake rate constant from food that combined variation in IR and AE. To explore the relative importance of water and diet exposure routes under field conditions, we used estimated site-specific aqueous free-ion concentrations to model Cd and Cu accumulation from aqueous exposure, exclusively. The predicted concentrations accounted for less than 5% of the observed concentrations, implying that most bioaccumulated metal was acquired from food. At least for the taxa considered in this study, we conclude that consumption of metal-contaminated periphyton can result in elevated metal body burdens and potentially increase the risk of metal toxicity.

Bioavailability of particulate metal to zebra mussels: Biodynamic modelling shows that assimilation efficiencies are site-specific

This study investigates the ability of the biodynamic model to predict the trophic bioaccumulation of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) in a freshwater bivalve. Zebra mussels were transplanted to three sites along the Seine River (France) and collected monthly for 11 months. Measurements of the metal body burdens in mussels were compared with the predictions from the biodynamic model. The exchangeable fraction of metal particles did not account for the bioavailability of particulate metals, since it did not capture the differences between sites. The assimilation efficiency (AE) parameter is necessary to take into account biotic factors influencing particulate metal bioavailability. The biodynamic model, applied with AEs from the literature, overestimated the measured concentrations in zebra mussels, the extent of overestimation being site-specific. Therefore, an original methodology was proposed for in situ AE measurements for each site and metal.

Using estimates of metal bioavailability in the soil and genetic variation of allozymes to investigate heavy metal tolerance in the earthworm Eisenia fetida (Oligochaeta)

In a recent study, we showed that the earthworm species Eisenia fetida, inhabiting an extremely high metal polluted compost heap on a wine farm, did not have elevated body loads of the metals but exhibited genotoxic tolerance when exposed to Cd in the laboratory ( Voua Otomo and Reinecke, 2010). To unravel the mechanism behind the surprisingly low metal body burdens on one hand and genotoxic tolerance on the other hand, we investigated the estimated bioavailability of these metals (Cu, Zn, Pb and Cd) using sequential extraction methods with CaCl 2 and di-ethylene-triamine-pentaacetic acid (DTPA) and allozyme polymorphism in this field population, a laboratory control as well as a long-term Cd exposed population. The amounts of mobile (extracted with CaCl 2) and mobilizable (extracted with DTPA) metals in relation to the total (extracted with nitric acid) metals were all below 0.05% for all four metals, suggesting low availability for uptake. The low availability of these metals could not be explained by physico-chemical properties of soil but by the phenomenon of aging of the metals. There was no difference in allozyme frequency between metal tolerant and non-metal tolerant populations of E. fetida. This suggested that the tolerance found in earlier studies could be a mere physiological adaptation

Assessment of the Metal Bioaccumulation in Three Species of Freshwater Bivalves

The metal concentration and body burden of three species of fresh water bivalves, Parreysia cylindrica, Parreysia corrugata and Corbicula striatella were estimated in laboratory experiment after exposure to chronic concentration of arsenic (0.1719 ppm), cadmium (0.23 ppm), copper (0.13 ppm), mercury (0.06 ppm), lead (2.4 ppm) and zinc (5.1 ppm) separately up to 30 days. Dry weight of each animal was used to calculate metal concentrations (μg/g) and the metal body burden (μg/individual). It was observed that zinc, lead and copper concentration and metal body burden was highest in the Corbicula striatella, mercury and arsenic was highest in Parreysia corrugata and cadmium was highest in Parreysia cylindrica. Therefore, Corbicula striatella is being proposed as sentinel organism for monitoring of zinc, lead and copper, Parreysia corrugata for mercury and arsenic, and Parreysia cylindrica for cadmium in fresh water ecosystem.

Quantitative immunodetection of metallothioneins in relation to metals concentration in spiders from variously polluted areas

Spiders inhabiting post industrial environments, such as waste heaps or ore-bearing areas, are exposed to high concentrations of metals, accumulated in the body of their prey and transferred along food chains. Therefore spiders are pressed to develop metal-neutralization strategies. Low-molecular, multifunction proteins: metallothioneins (MTs), often postulated as biomarkers of metal exposure, are known to bind metals and thus protect organisms against their toxic effects. Yet the proteins are still not well recognized in spiders. The aim of this study was to assess, by immunodetection method, ELISA, the concentration of metallothioneins in adult females of three web building spider species: Araneus diadematus (Araneidae), Agelena labyrinthica (Agelenidae) and Linyphia triangularis (Linyphiidae) from three variously polluted areas in southern Poland: Olkusz, ore-bearing post industrial site; Katowice–WeŁnowiec: post metallurgic waste heap, Pilica: the reference, rural, area. The concentration of metallothioneins has been analyzed in relation to the metal concentration in spiders body. The study gives the evidence that metallothioneins are reliably detectable by means of ELISA technique. The analysis of results obtained shows a strong species-dependence of the MTs level. Positive correlations between MTs concentration and metal body burden (mainly Zn and Pb) were found. This suggests that the proteins play an important role in the neutralization and regulation of metal ions in spiders. The same correlation indicate the possibility to consider MTs in spiders as biomarkers of metal exposure and effects. However, the species specificity as well as metal characteristics should be taken under account.

Hairs as biomonitors of hazardous metals present in a work environment

Human beings come across metal exposure not only through contaminated water and food, but through their metal body burden which increases by working in the environment that is contaminated and not safe. These hazardous metals present in the workplace increases the risk of both illness and injury. Illness tends to develop over time following repeated exposure to a hazard, whereas injury usually occurs instantly. Human biomonitoring is a popular method to cogitate the metal exposure of the work place. The present investigation was carried out to access the metal body burden of males belonging to different profession by using hairs analysis, which is one of inexpensive and useful biomonitors of occupational exposure of hazardous metals. Among the three groups under study (such as traffic constables, cloth dyers and office workers), lead and zinc concentrations were detected to be higher among traffic constables, while hairs analysis of cloth dyers show that copper, chromium, cadmium and manganese were present in greater amount as compared to other groups. Intra correlation of these metals among all categories was also carried out. Lead showed antagonistic relation with zinc, chromium, cadmium and manganese and synergistic relation with copper in the case of traffic constables. The present study reveals that metal toxicity in hair samples of office workers, dyers and traffic personnel, vary with their occupation. So there is instantaneous need for public awareness about the hazards of different occupations in order to enable these personnel take necessary precautionary measures. Key words: Metals, occupational, toxicity, hair, traffic personnel, dyers, office workers.

Relationships between physiological characteristics and trace metal body burdens of banded garden spiders Argiope trifasciata (Araneae, Araneidae)

Banded garden spiders ( Argiope trifasciata) were collected at the Ballona Wetlands, a metal contaminated salt marsh. The relationship between spider body size and individual metal loads was investigated. Biochemical markers were identified in spider fecal material and found to correlate to body metal levels. Body metal dry weight concentrations of Cd, Cr, Cu, Zn and total metals in female A. trifasciata exhibited distinct patterns of spatial and annual variation during 2006 and 2007. Spider body size was homogeneous across sites in both years, while increased Cd and Cr concentrations were sometimes associated with a reduction in spider size, though the influence of Cr was quite minor. Spiders with higher body Cu levels showed a reduction in peak area for hypoxanthine and an un-identified component in fecal material chromatograms. Spatial and annual differences in metal bioaccumulation are likely mediated by variation in site-specific environmental parameters and rainfall, while the negative relationships between body size and metal levels are presumably a consequence of a spider's expenditure of energy for metal tolerance mechanisms vs. foraging and growth. Finally, correlating body metal levels with excreta products constitutes a novel method to non-invasively predict metal levels in spiders.

Hepatic antioxidant responses related to levels of PCBs and metals in chicks of three Arctic seabird species

The efficiency of antioxidant defenses and relationship with body burden of metal and organic contaminants has not been previously investigated in arctic seabirds, neither in chicks nor in adults. The objective of this study was to compare such defenses in chicks from three species, Black-legged kittiwake ( Rissa tridactyla), Northern fulmar ( Fulmarus glacialis), and Herring gull ( Larus argentatus), and the relationship with tissue concentrations of essential metals such as selenium and iron and halogenated organic compounds, represented by polychlorinated biphenyl (PCB). The results showed significant species-specific differences in the antioxidant responses which also corresponded with metal and PCB levels in different ways. The capability to neutralize hydroxyl radicals (TOSC-HO•) and the activities of catalase and Se-dependent glutathione peroxidases (GPX) clearly increased in species with the higher levels of metals and PCBs, while the opposite trend was observed for Se-independent GPX, TOSC against peroxyl radicals (ROO•) and peroxynitrite (ONOOH). Less clear relationships were obtained for glutathione levels, GSH/GSSG ratio, glutathione reductase and superoxide dismutase. The results showed differences in antioxidant efficiency between the species, and some of these defenses exhibited dose–response-like relationships with measured levels of selenium, iron and ΣPCBs. PCBs, selenium and iron levels were positively related to the responses of antioxidants with potential to reduce HO•/H2O2 (Se-dependent GPX, CAT and TOSC against HO•). However, direct causal relationships between antioxidant responses and contaminant concentrations could not be shown on individual level. Varying levels of metals and contaminants due to different diet and age were probably the main explanations for the species differences in antioxidant defense.