Distribution of dissolved metals in seawater of Jinzhou Bay, China

Based on the datum line survey in August 2005 and June and August of 2006, water samples were collected in 30 sites to examine the trend of spatial distribution and temporal change of dissolved metals in seawater of Jinzhou Bay, China. The results showed that copper (Cu), lead (Pb), zinc (Zn), and cadmium (Cd) concentrations ranged from 1.71 to 3.49, 0.38 to 1.19, 21.77 to 39.16, and 1.65 to 2.01 microg/L, respectively. Except for Zn, the dissolved metal concentrations in August 2006 were much higher than those in August 2005. The concentrations in June 2006 were also higher than those in August 2006. The highest concentrations of dissolved metal were determined in samples collected from southwest of the Bay near sewage outfalls of Huludao Zinc Plant and Bohai Shipyard and the mouths of Wuli and Cishan rivers. The concentrations of dissolved metals increased inshore as compared with offshore. The principal contaminated factors were Zn, Cd, and Pb in the Jinzhou Bay. Significant positive correlations existed between the concentrations of Cu and Cd (0.016), as well as Zn and Cd (0.000). The overall results revealed that the Bohai Sea was one of the most contaminated areas by dissolved metals compared to other coastal areas in China.     

Decennary Variations of Dissolved Heavy Metals in Seawater of Bohai Bay,North China

Characteristics of the spatial and temporal distributions of selected dissolved heavy metals (Cu, Zn, Pb, Hg and Cd) in Bohai Bay, north China was investigated. Water samples from 22 sites were collected and analyzed for the selected metals with atomic absorption spectrometry from the year of 1996 to 2005. Relatively high concentrations of Cu, Zn, Pb and Hg were detected, with maximum concentrations in the 10-year period of 16.30, 422.00, 40.40, 0.23 μg/L respectively. The concentrations of Cd in all samples were quite low, with maximum level of 0.89 μg/L. The spatial distribution of dissolved Cu, Zn and Pb was analogous, where their average concentrations generally descended from the coastline to the central areas of the bay. Differently, for Hg and Cd, relatively high concentrations occurred not only in inshore but also in offshore areas. Measured data of heavy metals were compared with sea water quality standard of China (SWQSC). Cd concentrations in all samples were below SWQSC Grade-I. The percentages of Cu, Zn, Pb, and Hg at Grade-III levels in Bohai Bay were 2.67%, 30.00%, 30.43% and 0.36%, respectively, suggesting the severe contamination of Zn and Pb in this area. Terrestrial inputs via different rivers and sewages may be the important source for the heavy metals contamination.     

Spatial and Temporal Variations of Heavy Metals in Surface Sediments in Bohai Bay, North China

Characteristics of the spatial and temporal distributions of selected heavy metals (Cu, Zn, Cd, Pb and Hg) in Bohai Bay, north China was examined. Surface sediment samples from 15 sites were collected and analyzed for the selected metals with atomic absorption spectrometry (AAS) from the year of 1997–2007. Mean concentrations of metals in the 11-year period showed that Hg and Zn concentrations slightly fluctuated, while Cu, Cd and Pb concentrations in sediments varied with time. High levels of heavy metals occurred not only along the shoreline but also at some site in the inner part of the bay, suggesting the contamination sources of heavy metals from both terrestrial inputs and the atmospheric deposition. Compared with the environmental background values of selected heavy metals it indicated that anthropogenic activities influenced the sediment quality. The contamination factor \textCⁱ_f {\text{C}}^{i}_{f} , which is used to evaluate the pollution of the environment, showed that the contamination by selected heavy metals was moderate. Cd, Zn and Pb were the main polluting elements in this area.     

Heavy Metals in the Blue Crab (<Emphasis Type="Italic">Callinectes sapidus</Emphasis>) in Mersin Bay,Turkey

The concentrations of four metals (copper, cadmium, zinc and lead) were quantified in blue crabs (Callinectes sapidus) tissues collected in January, April, June and September at two stations in Mersin Bay, northeastern Mediterranean Sea, using ICP-MS. The metal concentrations in crabs from the two stations differed significantly. The hepatopancreas was the major organ accumulating metals, followed by gill and muscle tissues. Except for lead, the highest concentrations of metals were measured in the hepatopancreas. The hepatopancreas had higher concentrations of all heavy metals (Cu 321.1?±?4.30; Zn 182.2?±?3.40; Cd 48.2?±?2.00) compared to gill (Cu 90.2?±?1.35; Zn 104.3?±?2.30; Cd 22.3?±?3.40) and muscle (Cu 19.1?±?1.10; Zn 55.1?±?3.25; Cd 2.5?±?0.20). Among the metals analyzed, Cu, Zn and Pb were the most abundant in the different tissues while Cd was the least abundant in C. sapidus. Seasonality in the levels of the four metals was determined.The highest concentrations of all metals were observed in the June (Zn 55.1?±?3.25; Cu 19.1?±?1.10; Cd 2.5?±?0.20; Pb 5.1?±?0.18) compared to all other months (Zn 34.1?±?3.23; Cu 11.1?±?1.15; Cd 0.9?±?0.20; Pb 3.1?±?0.21).     

Spatial and temporal patterns in heavy metals concentration in street dust in a hot desert region

This investigation reports temporal and spatial variations in heavy metal concentration in street dusts in the State of Bahrain. Monitoring sites were chosen to include an urban area with high traffic density, commercial, industrial, and remote areas. The overall mean levels for Pb, Zn, Ni, Cu and Cd were 395, 80, 40, 20 and 1.5 mg kg^‐1, respectively. The general pattern of occurrence in order of decreasing concentration was Pb > Zn > Ni > Cu > Cd. The highest levels of Pb, Zn and Cu were found in the high traffic density area, and strong positive correlations were found between these metals, suggesting that automobiles exhaust are the dominant source of these metals. The results did not reveal statistically significant differences on the levels of Pb, Zn and Cu between months. Summer average values for Pb, Zn and Cu exceeded corresponding winter values. In cold regions opposite patterns were observed. In general Ni and Cd followed different patterns than that reported for Pb, Zn and Cu. Our results reveal relatively widespread contamination of heavy metals, and that all sites studied were statistically not different from each other, except a high traffic density site, indicating that Bahrain can be considered as one big urban center.     

Speciation of heavy metals in recent sediments of three coastal ecosystems in the Gulf of Cádiz, southwest Iberian Peninsula

A live-step sequential extraction technique was used to determine the partitioning of Cr, Mn, Fe, Cu, Zn, Cd, and Pb among the operative sedimentary phases (exchangeable ions, carbonates, manganese and iron oxides, sulfides and organic matter. and residual minerals) in coastal sediment from three locations in the southwest Iberian Peninsula. Two sites are located close to industrial areas, the salt marshes of the Odiel River and Bay of Cádiz, and one in a nonindustrial area, the Barbate River salt marshes. The Odiel River salt marshes also receive the drainage from mining activities in the Huelva region. In the sediments from the Bay of Cádiz and Barbate River salt marshes, Cr, Cu, Fe, and Zn were extracted from the residual fraction at percentages higher than 60%. In the sediments from the Odiel River salt marshes, concentrations of all the metals, except Cu. Zn, and Cd, exceeded 60% in the residual fraction as well. In the sediments from the Bay of Cádiz and Barbate River salt marshes, the main bioavailable metals were Mn and Cd; in those from the Odiel River salt marshes, the main bioavailable metals were Zn and Cd, respectively. The environmental risk was determined by employing the environmental risk factor (ERF), defined as ERF = (CSQV - Ci/CSQV), where Ci is the heavy metal concentration in the first four fractions and CSQV is concentration sediment quality value (the highest concentration with no associated biological effect). Our results showed that the sediments from the Cádiz Bay and Barbate River salt marshes do not constitute any environmental risk under the current natural conditions. In contrast, in the Odiel River salt marshes, Cu, Zn, and Pb yielded ERFs of less than zero at several sampling stations and, consequently, pose a potential threat for the organisms in the area. This is a consequence of the high levels of metals in the area derived from the mining activity (pyrite) and industrial activities and the association of these heavy metals with more labile fractions of the sediments.     

Trace Metal Concentrations in Sediments and Oysters of Botany Bay,NSW, Australia

Surfical sediment (< 63 µm) trace metal concentrations (Zn, Cu, Pd, Cd, As) were analyzed from seven sites in Botany Bay, NSW, Australia, to assess the extent of contamination from the surrounding urban areas. The northwest shoreline of Botany Bay contained high surfical sediment trace metal concentrations relative to the southern shoreline. Surfical sediment Pb concentrations (10–120 µg/g) were above the current ANZECC/ARMCANZ interim sediment guideline value (50 µg/g) for the protection of benthic ecosystems at the northwest sites. Cooks River was identified as a major source of trace metals. Oysters grown in Botany Bay have greater Zn, Cu, and Cd concentrations than two relatively pristine reference locations, Jervis Bay and Batemans Bay, indicating that the Botany Bay region has elevated biologically available metal concentrations. Oyster tissue trace metal concentrations were below the Australian and New Zealand Food Authority standards. Translocation of oysters to sites around the bay identified Pb and Cd as the only trace metals to be accumulated over 3 months. Copper concentrations in transplanted oysters declined at most sites, indicating that the sites investigated in this study have less bioavailable copper than Woolooware Bay, the source of the oysters. The shallow waters along the southern shoreline are protected from the tidal flow that carry contaminated sediments and the biologically available trace metals appear to be low.Received: 31 May 2002/Accepted: 13 December 2002     

Element differences and evaluation of the dietary intake from farmed oysters and mussels collected at different sites along the Croatian coast of the Adriatic Sea

Concentrations of the macroelements Ca, Mg, K and Na, microelements Cr, Cu, Fe, Mn and Zn and toxic metals As, Cd, Hg and Pb were determined in oysters and mussels collected at farming sites in the northern, central and south Adriatic Sea. Mean concentrations in oysters were (mg kg⁻¹): As 4.51, Ca 1551, Cd 1.44, Cu 53.6, Cr 0.23, Fe 45.9, Hg 0.047, K 2476, Mg 895, Mn 2.80, Na 7148, Pb 0.52, Zn 675. Mean values in mussels were (mg kg⁻¹): As 4.71, Ca 601, Cd 0.37, Cu 1.91, Cr 0.29, Fe 49.6, Hg 0.026, K 2246, Mg 1043, Mn 2.49, Na 7992, Pb 0.58, Zn 28.8. Significant differences in the concentrations of toxic metals and elements were found in oysters and mussels among farming sites. Obtained Cd, Hg and Pb concentration in oysters and mussels were lower than the limit levels set by the European Community. However, Cd concentration exceeded the limit level of 1 mg kg⁻¹ in oysters from all locations except Lim Bay. The estimated daily intakes (EDIs) indicate that oysters are a good source of Ca, Cu and Zn. The higher Cu and Zn concentrations than the toxicity reference values suggest a risk for consumers if larger quantities of oysters are consumed frequently.     

Trace metal concentrations in edible tissue of snapper, flathead, lobster, and abalone from coastal waters of Victoria, Australia

The concentrations of heavy metals in the edible tissue of commonly fished species of the Victorian coast of Australia are reported. The metals studied were As, Cd, Cu, Hg, Pb, Se, and Zn and the fish species examined were snapper (Pagruss auratus), flathead (Platycephalus bassenssis and Neoplatycephalus richardsoni), lobster (Jasus edwardsii), and abalone (Haliotis rubra). None of the fish species studied had average concentrations exceeding the maximum levels specified for As, Cd, Hg, and Pb by the Food Standards Australia and New Zealand Food Standards code. Additionally, the concentrations of Cu, Se, and Zn were close to or below the median values generally expected in these species. Essential trace elements Se and Zn were found to be well regulated by all fish species. Although also essential, Cu was not so well regulated, especially in abalone. Nonessential metals As, Cd, and Hg are not regulated in the studied fish and their concentrations in the fish tissue are dependent on size and fishing zone. Metal concentrations were not largely affected by sex. Surprisingly, the concentrations of metals in fish in Port Phillip Bay, a zone, which includes the major cities of Melbourne and Geelong and is known to have high concentrations of metals in the water and sediment, were not consistently higher than those in other less-populated fishing zones.     

Heavy metals in wetland plants and soil of Lake Taihu, China

Properties of vertical distribution of soil near water bodies are vary considerably from those of land and may greatly affect the transportation of heavy metals in wetlands. Vertical distributions of heavy metals (Cr, Cd, Cu, Pb, and Zn) in the soil of aquatic-terrestrial ecotone (ATE) of Lake Taihu, China, and in wetland plant tissues were studied. Generally, concentrations of heavy metals decreased with increasing depth in the top 40-cm cores and then increased slightly with increasing depth. This investigation indicated that concentrations of Cd, Cr, Pb, and Zn exceeded the geochemical background values in the Taihu Lake area. Concentrations of Cd at all depth soil columns exceeded the Environment Quality Standard for Soils of China. Correlation analysis showed that concentrations of Zn, Cr, Cd, and Pb correlated significantly with one another, suggesting that they had the same origin. The concentration of Cu was negatively correlated with root biomass, which may explain the lower concentration of copper in the soil cores. The dominant plants of the wetland were Phragmites australis and Ludwigia prostrata, and heavy metal accumulated primarily in the root tissue. The general order was root > rhizome > stem > leaf, whereas in L. prostrata, leaf was the main tissue for Cr accumulation. Both P. australis and L. prostrata had the highest concentration factor (CF) to Cu, and CF was 20.3 and 15.8, respectively. Aquatic-terrestrial ecotone plants are more effective in controlling Cu pollution than other heavy metals. This will be very significant for ATE reestablishment near Cu-polluted sites.     

Sensitivity of the freshwater prawn, Macrobrachium lanchesteri (Crustacea: Decapoda), to heavy metals

Adult Macrobrachium lanchesteri were exposed for a 4-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn) and lead (Pb) concentrations. Mortality was assessed and median lethal times (LT??) and concentrations (LC??) were calculated. At the end of the 4-day period, live prawns were used to determine bioconcentration of the metals. LT?? and LC?? increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC??s for 96 hours for Cu, Cd, Zn and Pb were 32.3, 7.0, 525.1 and 35.0 μg/L, respectively. Cu, Cd, Zn and Pb bioconcentration in M. lanchesteri increases with exposure to increasing concentrations and Cd was the most toxic to M. lanchesteri, followed by Pb, Cu and Zn. Comparison of LC?? values for metals for this species with those for other freshwater crustacean organisms reveals that M. lanchesteri is equally or more sensitive to heavy metals than most other tested crustaceans.     

Trace element and metallothionein concentrations in seabirds from the Canadian Arctic

Livers and kidneys were collected for five seabird species from the Canadian Arctic during the 1983 and 1991 to 1993 breeding seasons. Livers were analyzed for Cd, Hg, Pb, and Se, and kidneys were analyzed for Cd, Cu, Zn, and metallothionein (MT). Concentrations of the essential elements, Cu and Zn, were in agreement with those previously published in the literature. Thick-billed murres (Uria lomvia) from Ivujivik on the Hudson Strait/Hudson Bay coast in northwestern Quebec (Canada) had the highest mean renal concentrations of Cu, Zn, and Cd. Among the four species collected from Prince Leopold Island, northern fulmars (Fulmarus glacialis) had the highest hepatic concentrations of both Cd and Hg. The highest Se concentrations were found in northern fulmars and black-legged kittiwakes (Rissa tridactyla) from Prince Leopold Island. Hepatic Pb concentrations were low (<0.3 microg/g dry wt) in all species at all locations. Metallothionein concentrations were positively correlated with Cd and Zn for all species combined but were not correlated with Cu in any species. No significant relationships were found between MT and Cu or Zn in black guillemots (Cepphus grylle) or glaucous gulls (Larus hyperboreus). To our knowledge, this is the first report of MT concentrations and their relationships with trace metals in Arctic seabirds.     

Heavy Metals in Livers of Waterbirds from Spain

Wetlands tend to accumulate heavy metals from local sources, such as Pb shot used for waterfowl hunting, and from regional sources, such as atmospheric deposition and riverine or marine inputs. We determined concentrations of six heavy metals (Cr, Mn, Cu, Zn, Cd, and Pb) in livers of waterbirds shot by hunters in five Spanish wetlands to study the different factors that can contribute to the accumulation of these metals (sex, age, diet, grit, and Pb shot ingestion). Differences among wetlands were observed only for Cr, Cu, and Cd. Differences among species were observed for all the metals, and Cu was notably higher in pochards (Aythya and Netta genus) than in other waterfowl. Cu, Zn, and Cd concentrations increased with age, and only Pb showed differences related to sex, with males having higher concentrations than females. Most metals other than Pb were correlated with each other. Lead was dependent on Pb shot ingestion. Grit ingestion positively correlated with concentrations of Cr and to a lesser extent with Mn, Zn, and Cd. Ingestion of grit or shot may obscure relationships between metals and diet. Herbivorous species, which had more grit in the gizzard, had higher Cr, Zn, and Cd concentrations. Granivorous birds, which have the highest rates of Pb shot ingestion, had the highest concentrations of Pb. Grit and Pb shot ingestion are both important sources of heavy metals for waterbirds. Lead was the single metal studied whose concentrations exceeded toxicity thresholds. Received: 5 March 2002/Accepted: 12 June 2002     

Simultaneous Speciation Analysis of Trace Heavy Metals (Cu,Pb, Cd and Zn) in Seawater from Sishili Bay,North Yellow Sea,China

Different species of trace heavy metals (HMs) in seawater samples were simultaneously analyzed by anodic stripping voltammetric method, an analytical technique that does not require sample pre-concentration or the addition of reagents. The effects of the crucial parameters, deposition potential and time, on the determination of HMs were investigated. Concentrations of the total dissolved, dissolved active, and dissolved inert HMs were obtained through different analysis processes. The three species of Cu, Pb, Cd and Zn in seawater samples collected in different locations across Sishili Bay, North Yellow Sea, China were studied. The relative concentration of the dissolved active Cu, Pb, Cd and Zn in the total dissolved concentrations is 59.0%, 69.6%, 87.3% and 84.1%, respectively. The concentrations of different HMs species in Sishili Bay could be affected by the discharged effluent, sea current, and uptake of marine organism.     

Heavy Metals in Sediments and Lobster (<Emphasis Type="Italic">Panulirus gracilis</Emphasis>) from the Discharge Area of the Submarine Sewage Outfall in Mazatlán Bay (SE Gulf of California)

Concentrations of selected heavy metals in lobster (Panulirus gracilis) tissues and sediments (bulk and bioavailable fractions) from an area influenced by sewage discharge in Mazatlán Bay were determined. Cd, Cu, Fe, Pb, and Zn in the sediments showed enrichment factors higher than one related to the discharge and were higher than the lower values of the sediment quality guidelines proposed by NOAA and CCME. In addition to the high levels, relatively high bioavailability in the sediments was estimated for Cd, Cu, Mn, Pb, and Zn, suggesting a possible adverse effect on the associated benthic organisms. A high concentration of Cr, Fe, Mn, and Ni was found in the exoskeleton of P. gracilis. The hemolymph, hepatopancreas, gills, and gonads concentrate Cu, Cd, and Zn to levels higher than the available concentration in the sediments (BCF > 1). However, most of the metals studied in the edible muscle tissue in P. gracilis ranged within the recommended limits for human consumption, except Pb, which was found to be above the acceptable level for shellfish and represents a health risk.     

Uptake of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe, Zambia

Concentrations of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe (Zambia), which is ranked among the 10 worst polluted places on earth, were compared with other Zambian towns. Metal concentrations were measured in the liver and kidneys of 51 cattle from Kabwe and other Zambian towns. The maximum metal concentrations, expressed in mg/kg and dry weight, in the liver or kidneys were 398.4 (Cu), 252.6 (Zn), 77.81 (Cr), 19.37 (Cd), 7.57 (Ni), 1.8 (Pb), 1.04 (Co), 0.112 (Hg), and 0.05 (As). Concentrations of Pb and Cd in Kabwe cattle were higher than levels in other Zambian towns. The mean concentration of Cd exceeded benchmark values in offal destined for human consumption. Levels of Ni and Cr may also pose public health concerns. Concentrations of Pb and Cr, Pb and Cu, Cd and Zn, Cd and Hg, Zn and Cu, Cu and Co, as well as Co and Ni were positively correlated. The present study also highlighted the dangers of exposure of animals and humans to a mixture of toxic metals.     

公路旁土壤中重金属污染分布及潜在生态危害的研究

[目的]研究公路旁土壤中重金属污染的分布及潜在生态危害。[方法]以319国道龙岩市新罗区路段为研究区,对耕作土采样,用原子吸收光谱法和分光光度法分析土壤中重金属Cd、Pb、Cu、Zn和Cr含量,并与对照区比较,同时采用Lars Hakanson指数法评价重金属的潜在生态危害。[结果]研究区表层土壤cd[(1.48±0.60)mg/kg]、Pb[(160.17±55.99)mg/kg]、cu[(38.44±12.16)mg/kg]、Zn[(80.35±6.60)mg/kg]、Cr[(79.50±23.58)mg/kg]含量显著高于对照区(P<0.001),Cd和Pb为重度污染(100％),Cu和Cr为轻微污染(分别占监测点位的55.8％和35.3％);土壤对重金属元素的吸收及污染程度:Pb>Cd>Cu>Cr>zn。潜在生态危害综合指数为253.0,主要污染为Cd,达到很强的生态危害,其次是Pb、Cu、Cr和Zn,均为轻微生态危害;潜在生态危害地带自公路起向其两侧扩散范围约为150 m。[结论]公路旁土壤中重金属以Cd、Pb污染为主,属于中等生态危害,污染物主要来源于机动车辆燃料和轮胎中所含微量重金属成分。     

Bioaccumulation of heavy metals in mullet (Mugil cephalus) and oyster (Crassostrea madrasensis) from Pulicat lake, south east coast of India

The accumulation of six heavy metals (Cr, Cd, Cu, Zn, Pb and Ni) in sediment, water and in tissue parts of Mugil cephalus and Crassostrea madrasensis was studied in two locations of Pulicat lake, Southeast coast of India, which receives considerable quantity of effluents from industries located in North Chennai coastal region. The results reveal that the metal concentration in water is decreasing in the following order of Zn > Ni > Cu > Cr > Pb > Cd both in lake and barmouth and highest concentration was observed for Zn (32.5 μg L(-1) in lake and 25.2 μg L(-1) in bar mouth). Metals were highly concentrated in sediments when compared to water and biota. Metals abundance in sediments has following sequential order of Cr > Ni > Zn > Cu > Pb > Cd and the accumulation pattern in barmouth showed minor variation indicating the following pattern of Zn > Ni > Cr > Cu > Pb > Cd. The geoaccumulation index (I(geo)) for Pulicat lake sediments indicate that the sediments are extremely contaminated with Cd and moderately contaminated with Cu and Ni. Bioaccumulation of heavy metals in Mugil cephalus and Crassostrea madrasensis showed marked differences in the accumulation patterns. It is observed that Zn, Cu and Pb are accumulated in elevated concentrations in various parts of the fish and oyster when compared with other metals.     

Concentrations of Metals in Water,Sediment, Biofilm,Benthic Macroinvertebrates,and Fish in the Boulder River Watershed,Montana, and the Role of Colloids in Metal Uptake

To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 μg/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 μg/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for Pb into biological components seems to begin with sediment because concentrations of Pb in water were not significantly correlated with any other component and because concentrations of Pb in the water were often below detection limits.     

Acute Lethal Toxicity of Heavy Metals to the Seeds of Plants of High Importance to Humans

Laboratory experiments were conducted to assess the effects of highly toxic and dangerous metals (Pb, Cd, Hg) and essential microelements (Cr, Cu, Ni, Zn) on the seed germination process in vetch and eight plant species of major importance to human consumption. The degree of metal toxicity was determined on the basis of acute LC50 values calculated by means of two different methods. All the metals were found to inhibit the germination process, but in a varying, species-dependent degree. Of all the plant seeds under study, the most sensitive to the presence of the examined metals during germination were the seeds of cress (Cu, Pb, Hg), rye (Ni, Zn, Cd) and barley (Cr), while vetch (Cr, Ni, Zn, Cd, Pb, Hg), rape (Cr, Cu) and pea (Ni, Cd) were found to be least affected.