Accumulation of Metals and Boron in Phragmites australis Planted in Constructed Wetlands Polishing Real Electroplating Wastewater

The concentration of metals (Al, Cu, Fe, Mn, Ni, Zn) and B were determined in the above- and belowground biomass of Phragmites australis collected from the microcosm constructed wetland system used for the polishing of real electroplating wastewater. Translocation factor and bioconcentration factor were determined. Pearson correlation test was used to determine correlation between metal concentration in substrate and above- and belowground parts of Phragmites australis. The obtained results suggested that Phragmites australis did not play a major role as an accumulator of metals. It was observed also that the substrate could have exerted an effect on the translocation of Ni, Cu, Zn and Mn. The analysed concentrations of metals and B in biomass were in the range or even below the concentrations reported in the literature with the exception of Ni. The aboveground biomass was found suitable as a composting input in terms of metals concentrations.     

Soil moisture effects on uptake of metals by Thlaspi, Alyssum, and Berkheya

Most commonly used hyperaccumulator plants for phytoextraction of metals evolved on soils where moisture is limited throughout much of the year. As these plant species are commercialized for use, they are frequently moved from the point of evolution to locations where environmental conditions may be significantly different. Greatest among these potential differences is soil moisture. The objective of this study was therefore to determine whether these plants could grow in soils with much higher soil moisture and whether they would continue to hyperaccumulate metals as soils approach saturation. We examined extractable soil metal concentrations, plant growth, and metal accumulation for the Ni hyperaccumulators, Alyssum murale and Berkheya coddii and the Zn hyperaccumulators Thlaspi caerulescens cultivars AB300 and AB336. Non-hyperaccumulating control species for each were also examined. In general, extractable soil concentrations of Ni decreased with increasing soil moisture content. Few significant effects related to Zn extractability were observed for any of the soil moisture treatments. The biomass of all tested species was generally greater at higher soil moisture and inhibited at low soil moisture. Further, plants accumulated large amounts of metals from soil at higher soil moisture. Highest foliar concentrations of Zn or Ni were found at the two highest WHCs of 80 and 100%. These results show that hyperaccumulators grow well under conditions of high soil moisture content and that they continue to hyperaccumulate metals. Thus, growing Thlaspi, Alyssum, and Berkheya for commercial phytoextraction under nonnative conditions is appropriate and suggests that this technology may be applied to a wide and diverse range of soil types, climatic conditions, and irrigation regimes.     

Trace Element Level in Different Tissues of <Emphasis Type="Italic">Rutilus frisii kutum</Emphasis> Collected from Tajan River,Iran

Tajan River is among the most significant rivers of the Caspian Sea water basin. In this study, the concentration of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in brain, heart, liver, gill, bile, and muscle of Rutilus frisii kutum which has great economic value in the Mazandaran state. Trace element levels in fish samples were analyzed by means of atomic absorption spectrometry. Nearly all non-essential metals levels (Ni, Pb, Cd) detected in tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, non-essential metals (Ni, Pb) were so much higher in muscle than the essential metals (Cu, Zn, and Mn) except Fe, which was higher than other metals in nearly all parts, except in gills. Fe distribution pattern in tissues was in order of heart > brain > liver > muscle > bile > gill. Distribution patterns of metal concentrations in the muscle of fish as a main edible part followed the sequence: Fe > Pb > Ni > Cu > Mn > Zn > Cd.     

Heavy Metal Accumulation in Four Species of Sea Turtles from the Baja California Peninsula, Mexico

Heavy metals were assessed in four species of sea turtles from the Baja California Peninsula, Mexico, representing the first report of heavy metal concentrations in tissues of post-yearling sea turtles from the Eastern Pacific. Concentrations of Cd measured in C. mydas kidney (653 μg/g dry wt) were the highest ever reported for any sea turtle species. Cd accumulated preferentially in kidney and the ratios of kidney to liver Cd in Baja California turtles were among the highest reported for sea turtles globally. Zn, Ni, and Mn concentrations were also significantly higher in kidney than other tissues, while Cu and Fe were greatest in liver, and all metals were lowest in muscle. With the exception of one value (69.9 μg/g in kidney of C. caretta), Pb was low in all tissues from Baja California. In comparisons across species, kidney of C. mydas had greater Zn and Ni concentrations as compared to other species, although there was no difference in liver metal levels among the species. Positive correlations were detected in the concentrations of Cd, Cu and Ni with the straight carapace length of C. caretta.     

Field-based investigation on phytoremediation potentials of Lemna minor and Azolla filiculoides in tropical,semiarid regions: Case of Ethiopia

This study investigated the concurrent accumulation of eight heavy metals by two floating aquatic macrophytes (Lemna minor and Azolla filiculoides) cultivated in ambient media and blended wastewaters in the semiarid regions of Ethiopia. Both species accumulated heavy metals in varying degrees with a significant concentration gradient within the immediate water media. Highest bioconcentration factor (BCF) was determined for Mn and Fe in both plants. Results revealed that L. minor was high phytoaccumulator for Fe, Mn, Zn, and Co but moderate for Cd, Cu, Ni, and Cr. On the other hand, A. filiculoides was a high accumulator for Fe, Mn, Zn, and Cu, but its potency was moderate for Co, Cr, and Ni, but lower for Cd. Both species exhibited significant difference in accumulating Co, Zn, and Mn (p < 0.05). In general, the BCFs for both plants were comparable within the same treatment. In this study, stronger associations between the heavy metal concentrations in the plant tissues and in the grown water media were observed for A. filiculoides.     

Size dependent metal concentrations in two marine gastropod species

The effect of size on the accumulation of Cd, Cr, Cu, Mn, Ni, Fe and Zn in the muscle and viscera of the gastropodsMonodonta turbinata andCerithium vulgatum was investigated. The concentration of the essential metals Cr, Mn and Ni and the non-essential metal Cd decreased with increasing size in both of the species and tissues. The concentration of the essential metals Cu, Fe and Zn, showed a less constant relation with size.     

Phytoremediation of landfill leachate waste contaminants through floating bed technique using water hyacinth and water lettuce

Abstract

In the present study, the effectiveness of water hyacinth and water lettuce was tested for the phytoremediation of landfill leachate for the period of 15?days. Fifteen plastic containers were used in experimental setup where aquatic plants were fitted as a floating bed with the help of thermo-pole sheet. It was observed that both plants significantly (p?<?0.05/p?<?0.01/p?<?0.001) reduce the physicochemical parameters pH, TDS, BOD, COD and heavy metals like Zn, Pb, Fe, Cu and Ni from landfill leachate. Maximum reduction in these parameters was obtained at 50% and 75% landfill leachate treatment and their removal rate gradually increased from day 3 to day 15 of the experiment. The maximum removal rate for heavy metals such as for Zn (80–90%), Fe (83–87%) and Pb (76–84%) was attained by Eichhornia crassipes and Pistia stratiotes. Value of bioconcentration and translocation factor was less than 1 which indicates the low transport of heavy metals from roots to the above-ground parts of the plants. Both these plants accumulate heavy metals inside their body without showing much reduction in growth and showing tolerance to all the present metals. Therefore, results obtained from the study suggest that these aquatic plants are suitable candidate for the removal of pollution load from landfill leachate.     

Heavy metals distribution in the coral reef ecosystems of the Northern Red Sea

Concentrations of seven heavy metals (Cu, Zn, Pb, Cd, Ni, Co and Fe) were measured in the seawater, sediments, common scleractinian reef-building corals and soft corals (Octocorallia : Alcyonacea) at seven reef sites in the Northern Red Sea: I (Hurghada), II (Ras Za’farana), III (El-Ain Al-Sukhna), IV (El-Tur), V (Sha’b Rashdan), VI (Sharm El-Sheikh) and VII (Dahab). Levels of heavy metals were considerably elevated in seawater, sediments and corals collected from reef sites exposed to increased environmental contamination, as a result of diversified natural and anthropogenic inputs. Soft corals of genera Lithophyton, Sarcophyton and Sinularia showed higher concentrations of Zn, Pb, Cd and Ni than hard coral genera Acropora and Stylophora. Soft coral Sarcophyton trocheliophorum collected from El Ain Al-Suhkna (Gulf of Suez) had greater concentration of Cu, followed by hard corals Acropora pharaonis and Acropora hemprichi. The elevated levels of Zn, Cd and Ni were reported in the dry tissue of soft coral Sinularia spp. On the other hand, the soft coral Lithophyton arboreum displayed the highest concentration of Pb at Sha’b Rashdan (Gulf of Suez) and elevated concentration of Zn at Sharm El-Sheikh. Sediments showed significantly higher concentration of Fe than corals. The higher levels of Fe in hard corals than soft corals reflected the incorporation of Fe into the aragonite and the chelation with the organic matrix of the skeleton. The greater abundance of soft corals in metal-contaminated reef sites and the elevated levels of metals in their tissue suggesting that the soft corals could develop a tolerance mechanism to relatively high concentrations of metals. Although the effects of heavy metals on reef corals were not isolated from the possible effects of other stresses, the percentage cover of dead corals were significantly higher as the concentrations of heavy metals increased.     

Root and shoot elongation as an assessment of heavy metal toxicity and ‘Zn Equivalent Value’ of edible crops

Seeds of thirteen edible plant species were tested for their response to heavy metals during their early development. It was found that a short-term root elongation test of six days could be used to evaluate the degree of toxicity of aqueous samples containing heavy metals. Shoot elongation was found to be less sensitive to metals than root elongation.The seeds were sown in pots containing freshwater sand to which known concentrations of metal solutions were added. The relative toxicity of the three metals, copper, nickel and zinc, followed the pattern of Ni > Cu > Zn.Results on the relative toxicity of Zn : Cu: Ni to various plant species indicated that the ratios were species-specific. The Zn equivalent concept of Zn : Cu : Ni = 1 : 2 : 8 could not be applied to all the plant species tested.The root growth of seeds of Brassica parachinensis (flowering Chinese cabbage) placed on filter papers in petri dishes to which metal solutions were added were tested. The sensitivity ranking of the metals tested was found to be as follows: Ni > Cd > Cu > Al > Fe > Zn > Pb > Mn > Ag. There was no significant difference (p > 0.05) in percentage reduction in root elongation among the four different repeated trials.     

Evaluation and Potential Health Hazard of Selected Metals in Water,Sediments, and Fish from the Gomti River

The health hazard associated with the consumption of fish from the Gomti River in India, contaminated with the heavy metals Cr, Cu, Mn, Ni, Pb, and Zn was assessed in terms of target hazard quotients (THQs). The concentrations of metals (mg kg^?1, wet weight basis) in the muscle tissues of different fish species Mastacembelus puncalus, Clupisona garua, Cyrinous carpio, Botia lochachata, Channa punctatus, Heteropneustise fossilis, Puntius sofore, and Clarious batrachus ranged as follows: Cr (2.2–21.4), Cu (0.3–14.3), Mn (2.3–5.5), Ni (0.5–10.9), Pb (1.0–3.9), and Zn (12.3–46.9). The accumulation of metals in fish muscle tissue was in the order: Zn > Cr > Ni > Mn > Cu > Pb. THQs indicated a potential health hazard to children due to the consumption of fish contaminated with Ni and Pb; their THQs were greater than 1 for almost all fish species except for Ni in C. garua (THQ, 0.07) and C. carpio (THQ, 0.90). For adults, insignificant health hazard was associated with THQs less than 1 for all metals in the different fish species, but long-term exposure to these metals and subsequent bioaccumulation in the body may require additional investigation.     

Heavy Metals and Other Elements in Serum of Cattle from Organic and Conventional Farms

Concentrations of cadmium, lead, iron, zinc, copper, chromium, nickel, aluminium and arsenium were analysed in blood serum of cattle from organic (n = 20) and conventional (n = 21) farms. The elements were determined by inductively coupled plasma atomic emission spectrometry using an Optima 2000 DV instrument (Perkin Elmer Inc.). Animals from the organic farm were characterised by significantly lower (P < 0.01) serum concentrations of Pb, Zn, Fe, Cu, Cr, Ni, As and Al compared to animals from the conventional farm. The concentration of Cd was similar in animals from both organic and conventional farms. The concentration of toxic elements in cattle from organic and conventional farms studied was very low. The trace essential elements were generally within the adequate ranges except Zn and Cu, which were deficient. In organically reared animals, also serum Fe content was below the critical level for diagnosing iron deficiency. Pb was significantly correlated with Cd, Zn, Fe, Cu and Ni. A significant positive correlation between the concentration of Cd and Zn, Cu and Ni concentrations was only observed in cows from the organic farm. The present results suggest that organically raised animals are less exposed to harmful environmental influences such as the environmental pollution with heavy metals. On the other hand, these animals are at a greater risk of mineral deficiency compared to animals kept on conventional farms.     

Locomotion in a sticky terrain

The mirid bug Pameridea roridulae lives mutalistically on the protocarnivorous plant Roridula gorgonias. The latter resembles an effective, three-dimensional flypaper trap which captures numerous flying insects. We have recently shown that P. roridulae bugs are not trapped by the plant, because they are covered with a layer of epicuticular grease, which is considerably thicker than in other insects. The present study demonstrates that the bugs’ morphology and locomotory characteristics also contribute to their specialisation for life on the adhesive plant surface. A structural analysis of the mirid bug’s attachment system, and an experimental study on its attachment ability were carried out. In traction force tests, maximum forces of 8.8 mN were measured on adaxial R. gorgonias leaves, corresponding to 126 times the bug’s body weight. On smooth surfaces, generated forces were only 47 times the bug’s body weight. Compared to closely related mirid bug species avoiding contact with plant adhesive secretion, P. roridulae is distinctly stronger and heavier, and holds its body close to the plant substrate. Two locomotion strategies on the glandular hairy plant surfaces are suggested for mirid bug species from the tribus Dicyphini: (1) avoidance strategy, characterised by the slim body held at a large distance from the plant surface by using long, slender legs, and (2) defense strategy, where trapping of the heavy bugs, situated close to the plant surface, is overcome by generating strong forces during locomotion and by having a thick anti-adhesive epicuticular greasy layer on the bugs’ cuticle.     

Metal Accumulation Screening of the Río Tinto Flora (Huelva,Spain)

Río Tinto (Huelva, Spain) is located in one of the most important mining regions in the world. Its soils are characterized by their extreme acidity and elevated concentrations of heavy metals. Due to these characteristics, the Tinto ecosystem is considered unique and an ideal location to study biological adaptations to this type of habitat. Plant species that present these adaptations might be useful to mining and other metal pollution restoration programs. This study reports the results for the screening of Ca, Mg, Na, Mn, Fe, Ni, Cu, Zn, As, and Pb in aerial tissues of 97 plant species from the Tinto basin flora. In addition, plant–soil relationships were analyzed using the biological absorption coefficient (BAC) to detect the main plant adaptations in the Tinto flora. The species selected are representative of the biomass of the main dominant edaphophile and climatophile vegetation communities of the three river sections, forest, and subseral stages. Plant and soil elemental analyses were performed using inductively coupled plasma–mass spectrometry technique (ICP-MS). The results indicate that in general, Tinto flora shows a pattern of accumulation of the analyzed elements in aerial tissues which agrees with the nutritional requirements of vascular plants (macronutrients > micronutrients > indifferent or toxic elements). Among macronutrients, Ca seems to be an essential element in this habitat. This element accumulates in the aerial plant tissues. Basically, the Río Tinto flora is made of Fe, Cu, Zn, Ni, As, and Pb excluders, although some analyzed species of Erica, Quercus, Lavandula, Cistus, Genista, and Cytisus genera can be considered Mn accumulators. The results of this study make up a body of fundamental knowledge of the strategies used by plants to thrive in habitats with high concentrations of toxic heavy metals. This information is vital when it comes to planning a restoration program. Plants must be selected and used according to the requirements, always respecting the characteristics of the territory and facilitating the development of suitable vegetation.     

Essential trace and toxic element distribution in the scalp hair of Pakistani myocardial infarction patients and controls

The pathogenesis of heart disease has been associated with changes in the balance of certain trace elements. The aim of this study was to evaluate the Zn, Fe, Cu, Cr, Ni, Pb, and Cd contents in scalp hair samples of myocardial infarction (MCI) patients hospitalized in the cardiac ward of National Hospital in Hyderabad city (Pakistan). Scalp hair samples were collected from 193 patients (104 male, 89 female) of 3 age groups (46–60, 61–75, and 76–90 yr), for a comparative study, 200 normal, healthy subjects (103 male, 97 female) of the same age groups residing in the same city were selected. All metals in scalp hair samples were assessed by a flame/graphite furnace atomic absorption spectrophotometer, prior to microwave-assisted and conventional wet acid digestion methods. Results were calculated in micrograms per gram. The mean values of Fe and Zn of scalp hair samples of MCI patients were significantly reduced compared to the control subjects of both genders. The mean Fe concentrations in male patients were 19.42, 12.36, and 6.98 vs 30.69, 24.42, and 16.75 for the control patients in the three age groups (46–60, 61–75, and 76–90 yrs, respectively). The mean Zn concentration in male patients were 169.2, 149.4, and 107.7 μg/g vs 206.1, 188.0, and 154.4 μg/g for the control group (p<0.002, 0.004, and 0.001) in all three age groups, respectively. These differences were also observed in the female study groups. The mean values of Pb, Cd, and Ni were significantly high in patients compared to healthy subjects (mean Pb in male patients: 11.85, 12.89, and 14.52 those of female patients were 11.88, 12.73, and 14.21 vs the male controls patients (6.08, 7.56, and 8.56) and female controls (5.99, 7.41, and 8.25) for all three age groups, respectively. The concentration of Ni and Cd in the scalp hair samples of the heart patients of both sexes were significantly higher compared to the control; in the case of Ni the range of significant difference for males was found to be p<0.001–0.009 and for females to be p<0.0.002–0.007 and significantly high concentration of Cd were observed in hair samples of patients than in controls in the range for males (p<0.001–0.009) and in females (p<0.001–0.011). The Zn/Cu and Zn/Cd ratios in the scalp hair (p<0.01) of the diseased groups were significantly lower than that of the healthy groups. Deficiency of essential trace metals and high level of toxic metals might play a role in the development of heart disease in the subjects of this study. Toxic metals might also cause diminished absorption of essential elements.     

Short shoots of Betula pendula Roth. as bioindicators of urban environmental pollution in Wrocław (Poland)

Concentrations of the elements Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, N, Ni, P, Pb and Zn were measured in leaves of Betula pendula from the polluted areas of Wrocław, Poland and from a control site, relatively free from pollution. From the same sampled trees, lengths of vegetative short shoots were measured to investigate the influence of environmental pollution. Length of the vegetative short shoots of B. pendula was positively influenced by the traffic intensity and by the concentration of Co, Cu, Fe, Ni and Pb in leaves of this species. Vegetative short shoots of B. pendula from polluted sites in Wrocław were significantly longer than that of the trees growing in a clean area. Thus, this feature may be used as a pollution bioindicator.     

Relationship Between Testate Amoeba (Protist) Communities and Atmospheric Heavy Metals Accumulated in <Emphasis Type="Italic">Barbula indica</Emphasis> (Bryophyta) in Vietnam

We studied the relationships between testate amoeba communities and heavy metal (Pb, Cd, Zn, Ni, Cu, Mn, and Fe) concentrations in the moss Barbula indica sampled at 29 sites in and around the city of Hanoi (Vietnam). Our first approach was to compare the heavy metal concentrations and testate amoeba variables between the city (zone 1) and the surrounding (zone 2). Mean moss concentrations of Pb, Cd, Zn, Ni, and Cu were significantly higher and testate amoeba species richness and abundance were significantly lower in zone 1 and the abundance of eight taxa differed significantly between the two zones. We then studied the correlation between heavy metals and testate amoebae. Species richness and abundance were correlated negatively to Pb concentration. Shannon H′ was negatively correlated to both Pb and Cd. The abundance of several species was negatively correlated with Pb, Cd, Zn, and Ni; however, at the community level, Pb emerged as the only significant variable in a redundancy analysis. Our results suggest that testate amoebae are sensitive to and may be good bioindicators for heavy metal pollution, especially lead. Further research is needed to understand the causal relationships underlying the observed patterns.     

Hyperaccumulation of nickel by two Alyssum species from the serpentine soils of Iran

Serpentine soils, which contain relatively high concentrations of nickel and some other metals, are the preferred substrate for some plants, especially those that accumulate Ni in their tissues. In temperate regions more Ni-hyperaccumulator plants are found in Alyssum than in any other genus. In this study, serpentine soils of two areas (Marivan and Dizaj) in the west/northwest of Iran and also perennial Alyssum plants growing on these soils were analyzed for Ni and some other metals. The highest concentrations of total metals in the soils of these areas for Ni, Cr, Co and Mn were 1,350, 265, 94 and 1,150 μg g⁻¹, respectively, while concentrations of Fe, Mg and Ca reached 3.55%, 16.8% and 0.585% respectively. The concentration of exchangeable Ni in these soils is up to 4.5 μg g⁻¹. In this study two Alyssum species, A. inflatum and A. longistylum, have been collected from Marivan and Dizaj, respectively. Analysis of leaf dry matter shows that they can contain up to 3,700 and 8,100 μg Ni g⁻¹, respectively. This is the first time that such high Ni concentrations have been found in these species. The concentrations of other metals determined in these species were in the normal range for serpentine plants, except for Ca, which was higher, up to 5.3% and 3.5%, respectively     

Total and speciation analyses of heavy metals in the sand fraction of Nigerian oil sands for human and ecological risk assessment

Total metal analysis and metal speciation of sand fraction of Nigerian oil sands were done to extract and partition heavy metals into six operationally defined fractions in order to assess environmental and health implications of the oil sand development. Soxhlet extraction of bitumen from the oil sand was done using toluene. Traces of water and extracting solvent were removed at 70°C from the sand fraction using oven. Elemental analysis was performed by Atomic Absorption Spectrophotometry. The heavy metals except Cu have low Pollution index values. Negative geo-accumulation index was obtained for the metals except Cu, indicating that the oil sands were uncontaminated with the metals. Strong and significant positive correlations existed between Fe/Pb, Zn/Cu, Cd/Pb, Ni/Cd, Ni/Pb, Cd/Fe, Ni/Fe and Cr/Zn, while strong and significant negative correlations existed between Mn/Pb and As/Mn, indicating common sources or chemical similarities and vice versa. T-test results indicated significant differences between the concentrations of the metals. Cross-plot analysis showed strong positive correlation between the sand fraction and Nigerian bitumen. Speciation analysis indicated highest and lowest indices of metal mobility for Zn and Pb, respectively. This study concluded that the sand fraction may not pose any environmental risks from elemental point of view.     

Host-herbivore studies of Stenoscepa sp. （Orthoptera：Pyrgomorphidae）, a high-Ni herbivore of the South African Ni hyperaccumulator Berkheya coddii （Asteraceae）

Nymphs of Stenoscepa sp. feed on leaves of the Ni hyperaccumulator Berkheya coddii at serpentine sites in Mpumalanga Province, South Africa. These sites contain Ni hyperaccumulators, Ni accumulators, and plants with Ni concentrations in the normal range. We conducted studies to： （i） determine the whole-body metal concentration of nymphs （including those starved to empty their guts）; （ii） compare Stenoscepa sp. nymphs against other grasshoppers in the same habitat for whole-body metal concentrations; and （iii）compare the suitability of Ni hyperaccumulator and Ni accumulator plants as food sources for Stenoscepa sp. and other grasshoppers. Stenoscepa nymphs had extremely high whole-body Ni concentrations （3 500μg Ni/g）. This was partly due to food in the gut, as starved insects contained less Ni （950 pg Ni/g）. Stenoscepa nymphs survived significantly better than other grasshoppers collected from either a serpentine or a non-serpentine site when offered high-Ni plants as food. In a host preference test among four Berkheya species （two Ni hyperaccumulators and two Ni accumulators）, Stenoscepa sp, preferred leaves of the Ni hyperaccumulator species. A preference experiment using leaves of three Senecio species （of which one species, Senecio coronatus, was represented by both a Ni hyperaccumulator and a Ni accumulator population） showed that Stenoscepa sp. preferred Ni accumulator Senecio coronatus leaves to all other choices. We conclude that Stenoscepa sp. is extremely Ni-tolerant. Stenoscepa sp. nymphs prefer leaves of hyperaccumulator Berkheya species, but elevated Ni concentration alone does not determine their food preference. We suggest that the extremely high whole-body Ni concentration of Stenoscepa nymphs may affect food web relationships in these serpentine communities.     

Production of Nicotinamide Adenine Dinucleotide Glycohydrolases by Bacteria

The distribution of heavy metals (Fe, Mn, Zn, Cu, Pb, Ni and Cd) were investigated in various organs and tissues of striped dolphin, Stenella coeruleoalba. The animals were caught alive at Taiji, on the coast of Kii Peninsula, during the open season in December 1978. Determination of the metals was made by atomic absorption spectrophotometry and significant differences of metal concentration in the positions of the muscle, blubber and skin, respectively, were observed. The front ventral muscle of matured dolphins showed the highest concentrations of Zn and Cd and lowest Fe when compared to other parts of the muscle. Most of the metals recorded relatively low concentrations in melon rather than in the other lipid layers of blubber. In skin tissue, the concentrations of Fe, Mn and Zn were significantly higher in black-colored skin than in white skin. Moreover, a difference in the concentrations of metals according to bone position was observed. In general, high concentrations of most of the metals were found in liver, kidney and bone, with low concentrations in brain and the lipid layer of blubber. Furthermore, relatively high concentrations of Cu, Mn and Zn were found in skin, and for Mn, Zn, Ni and Cd it was likewise in pancreas and the reproductive organs. Based upon these results, the nature of the organ(s) of a dolphin that has to be selected for ecological and hygienic comparison was discussed.