Determination of selected elements in different pharmaceutical forms of some Polish herbal medicinal products

In the present work, the following microelements and heavy metals were determined in the Willow bark (Cortex Salicis), in the St. John's wort (Herba Hyperici), in the infusions from these raw materials and in the tablets containing these herbs: Cr, Cu, Fe, Ni, Zn and Ba, Cd, Pb. The concentration of the metals were determined by means of the GFAAS and ICP-MS methods. Considering the examined two herbs as a source of toxic metals, the occurrence of high levels (exceeding the European Pharmacopoeia limits) of Cd should be emphasized. The level of cadmium was low in the infusions because of a low extraction efficiency of this metal, so that the infusions can be found as a rather safe form of herbal medicine. In the tablets, the Cd contents were similar to the levels found in the raw materials. Because the total heavy metal content can be accessible, it may cause a potential health risk for human.     

Concentrations and solubility of selected trace metals in leaf and bagged black teas commercialized in Poland

The objective of this study was to determine the concentrations of heavy metals in bagged and leaf black teas of the same brand and evaluate the percentage transfer of metals to tea infusion to assess the consumer exposure. Ten leaf black teas and 10 bagged black teas of the same brand available in Poland were analyzed for Zn, Mn, Cd, Pb, Ni, Co, Cr, Al, and Fe concentrations both in dry material and their infusion. The bagged teas contained higher amounts of Pb, Mn, Fe, Ni, Al, and Cr compared with leaf teas of the same brand, whereas the infusions of bagged tea contained higher levels of Mn, Ni, Al, and Cr compared with leaf tea infusions. Generally, the most abundant trace metals in both types of tea were Al and Mn. There was a wide variation in percentage transfer of elements from the dry tea materials to the infusions. The solubility of Ni and Mn was the highest, whereas Fe was insoluble and only a small portion of this metal content may leach into infusion. With respect to the acceptable daily intake of metals, the infusions of both bagged and leaf teas analyzed were found to be safe for human consumption.     

Speciation and distribution characteristics of heavy metals and pollution assessments in the sediments of Nashina Lake,Heilongjiang, China

Sediment core samples from Nashina Lake, Heilongjiang, China were collected using a gravity sampler. The cores were sliced horizontally at 1 cm each to determine the particle size, total concentrations and speciation of Cd, Cr, Cu, Mn, Ni, Pb, and Zn. Total concentrations of heavy metals were extracted using an acid mixture (containing hydro fluoric acid, nitric acid, and sulphuric acid) and analyzed using an inductively coupled plasma spectrometry. A sequential extraction procedure was employed to separate chemical species. Analysis of results indicate that the concentrations of heavy metals in the sediments of Nashina Lake in descending order are Mn, Cr, Zn, Pb, Ni, Cu, and Cd. The ratios of the average concentrations of four heavy metals (e.g.Cr, Cu, Ni, Zn) to their background values were >1; and those of Mn, Cd, and Pb were >1. Moreover, some toxic metals were mainly distributed in bioavailable fractions. For instance, both Cd and Mn were typically found in Acid-extractable species or Fe–Mn oxide species, and thus can be easily remobilized and enter the food chain. Finally, the analysis of geo-accumulation index showed that anthropogenic pollution levels of Cr, Cu, Mn, Ni, Zn were low, but those of Pb and Cd were at the moderate level. As both Pb and Cd are toxic metals, it is highly necessary to prohibit their transformation and accumulation in the sediments.     

Evaluation of heavy metals in cosmetic products and their health risk assessment

Heavy metals’ contamination in cosmetic products is a serious threat. Present study was conducted to evaluate the concentrations of heavy metals (HMs) in various brands of cosmetic products with special emphasis on their health risk assessment. Five heavy metals including Cd, Cr, Fe, Ni and Pb were quantified in different brands of lotions, foundations, whitening creams, lipsticks, hair dyes and sunblock creams using atomic absorption spectrometry. Risk to the consumer’s health was determined using systemic exposure dosage (SED), margin of safety (MoS), hazard quotient (HQ), hazard index (HI) and lifetime cancer risk (LCR).On comparative basis, different brands of sunblock creams depicted highest concentration of Ni, Pb and Cr (7.99 ± 0.36, 6.37 ± 0.05 and 0.43 ± 0.01 mg/kg, respectively), whereas lipsticks had elevated levels of Fe at 12.0 ± 1.8 mg/kg, and Cd was maximum in lotions (0.26 ± 0.02 mg/kg). Multivariate analysis revealed strong associations among Cr, Ni and Pb, while Cd and Fe showed disparity in distribution and sources of contamination. MoS, HQ and HI values were within the permissible limit apart from for lotions and sunblock creams, while LCR value was higher than the permissible limit in all cosmetic products except lipsticks. Regular use of these products can cause serious threat to human health, particularly skin cancer on long time exposure. Therefore, continuous monitoring of cosmetic products, particularly with reference to HMs adulteration should be adopted to ensure the human safety and security.     

Heavy metals in agricultural soils and crops and their health risks in Swat District,northern Pakistan

This study assessed the concentrations of heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni) and zinc (Zn) in agricultural soils and crops (fruits, grains and vegetable) and their possible human health risk in Swat District, northern Pakistan. Cd concentration was found higher than the limit (0.05 mg/kg) set by world health organization in 95% fruit and 100% vegetable samples. Moreover, the concentrations of Cr, Cu, Mn, Ni and Zn in the soils were shown significant correlations with those in the crops. The metal transfer factor (MTF) was found highest for Cd followed by Cr > Ni > Zn > Cu > Mn, while the health risk assessment revealed that there was no health risk for most of the heavy metals except Cd, which showed a high level of health risk index (HRI ⩾ 10E-1) that would pose a potential health risk to the consumers.     

Assessment of environmental contamination using feathers of Bubulcus ibis L., as a biomonitor of heavy metal pollution, Pakistan

Concentrations of metals such as Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, Pb, and Zn were analyzed in the feathers of cattle egret (Bubulcus ibis) from three breeding colonies in the Punjab province, Pakistan. The mean concentrations of Ca, Cd, Fe, Pb and Mn were significantly different between the three study sites (River Chenab, River Ravi and Rawal Lake Reservoir). The mean concentrations of Ca, Cd, Fe and Mn were significantly greater at the River Chenab heronry and Cr, Co, Zn, and Pb concentrations at the River Ravi heronry. The feathers of cattle egrets collected from the Rawal Lake Reservoir heronry were least contaminated. Multivariate statistical methods viz., Factor Analysis based on Principal Component Analysis (FA/PCA); Hierarchical Cluster analyses (HACA), and Correlation Analyses identified relatively similar associations of metals and their sources of input. Metals such as Ca, Mg, and K were related with natural input from parent rock material whereas trace metals viz., Cu, Cd, Co, Pb, Ni, and Zn were associated mainly with anthropogenic processes. Metals such as Fe, Mn, and Li were either correlated with natural input or with anthropogenic activities. Concentration of heavy metals such as Cd, Pb, and Cr were well above the threshold level that can cause adverse effects in birds and pose menace to the cattle egrets population in Pakistan. The study suggested that the feathers of cattle egret could be used as a bio-monitor of the local heavy metals contamination.     

不同生长环境灰毡毛忍冬中微量元素的含量比较

目的:比较4个不同生长环境的灰毡毛忍冬中9种微量元素的含量,为GAP基地建设及饮片质量控制提供依据。方法:采用湿法消解法处理灰毡毛忍冬样品,利用火焰原子吸收光谱法测定样品中Cu、Zn、Fe、Mn、Pb、Cr、Ni、Cd的含量,用原子发射光谱法测定Se的含量。结果:Cu、Zn、Fe、Mn、Pb、Cr、Ni、Cd的回收率在96%～105%之间(n=9),Se的回收率在97%～102%之间(n=9),9种微量元素的RSD分别是1.19%、1.89%、3.49%、6.12%、6.08%、6.58%、3.53%、2.48%、3.41%(n=6)。A、B、C、D4个产地的灰毡毛忍冬中有益元素Fe含量较高,而重金属元素Pb、Cr、Ni、Cd的含量较低;B地区灰毡毛忍冬中有益元素Zn、Mn的含量较其他3个地区高。结论:本方法简便、准确,适合分析测定灰毡毛忍冬的微量元素;B地区所产灰毡毛忍冬药材质量更优。     

Comparison of Eleven Heavy Metals in Moringa Oleifera Lam. Products

Eleven heavy metals in various products of Moringa oleifera were analyzed to determine eleven heavy metals (Al, As, Cd, Cr, Cu, Fe, Pb, Mn, Hg, Ni, and Zn) using Inductively Coupled Plasma-Mass Spectrometry. The products of M. oleifera were purchased in Nakhon Pathom, Thailand. All products were digested with nitric acid solution before determining the concentrations of heavy metals. The recoveries of all heavy metals were found to be in the range of 99.89-103.05%. Several criteria such as linearity, limits of detection, limits of quantification, specificity, precision under repeatability conditions and intermediate precision reproducibility were evaluated. Results indicate that this method could be used in the laboratory for determination of eleven heavy metals in M. oleifera products with acceptable analytical performance. The results of analysis showed that the highest concentrations of As, Cr, Hg, and Mn were found in tea leaves while the highest concentrations of Al, Cd, Cu, Fe, Ni, Pb, and Zn were found in leaf capsules. Continuous monitoring of heavy metals in M. oleifera products is crucial for consumer health.     

Biomonitoring of heavy metals using Mytilus galloprovincialis in Safi coastal waters, Morocco

Heavy metal concentrations of mercury, cadmium, lead, zinc, cooper, nickel, manganese, and chromium in Mytilus galloprovincialis were investigated to provide information on pollution of Safi coastal area, since these metals have the highest toxic potential. The concentration of Hg and Pb was determined by AFS and ICP-MS methods, respectively, whilst the remaining metals (Cd, Cr, Cu, Mn, Zn, and Ni) were quantified by AAS. High lead, cadmium, chromium, and mercury levels were registered in tissue samples collected from two stations near the Jorf Lihoudi and Safi city, while elevated concentration of manganese and zinc (14.70-25.30 mg kg(-1) and 570-650 mg kg(-1) dry wt, respectively) were found in mussel specimens from Cap Cantin. The high levels of nickel found respectively in the areas near the industrial area being of concern in terms of environmental health need frequent monitoring. The metal concentrations recorded at the clean stations may be considered as useful background levels to which to refer for comparison within the Atlantic coast. M. galloprovincialis are suitable biomonitors to investigate the contamination levels of heavy metals pollution face a different human activity in this coastal area of the Atlantic coast.     

Evaluation of some pollutant levels in conventionally and organically farmed potato tubers and their risks to human health

A total of 144 kg of potato tuber samples, representing two different types of farming production [e.g., conventional (C) and organic (O)], were collected from different locations in Giza governorate (Egypt), and subjected to pesticide residue and heavy metal analyses. Residues of some organochlorine pesticides (OCPs), such as HCB and heptachlor as well as some organophosphorus pesticides (OPPs), such as methamidophos, thiometon, profenofos, phorate and pirimiphos-methyl were found in a number of samples at concentration levels exceeding their MRLs. The majority of the analyzed samples contained detectable concentrations of Zn, Cu, Mn, Fe, Cd, Pb, Cr, Ni and Co. Specifically, Pb and Fe were found in a number of samples at concentrations exceeding their MLs. Contamination among the two types of potatoes varied from a season to another and contamination of C potatoes was nearly 2 times that of O potatoes either by pesticides or heavy metals. Estimation of dietary intake of pesticides and heavy metals by potatoes revealed that only phorate residues either in conventional or organic potatoes may pose risks to human health. None of the studied heavy metals showed to cause dietary intake risks to human health. The study shed light to the problem of multi toxicants in potatoes.     

Combined toxicity of heavy metal mixtures in liver cells

With rapid industrialization, China is now facing great challenges in heavy metal contamination in the environment. Human exposure to heavy metals through air, water and food commonly involves a mixture consisting of multiple heavy metals. In this study, eight common heavy metals (Pb, Cd, Hg, Cu, Zn, Mn, Cr, Ni) that cause environmental contamination were selected to investigate the combined toxicity of different heavy metal mixtures in HL7702 cells. Toxicity (24 h LC₅₀) of each individual metal on the cells ranked Hg > Cr = Cd > Cu > Zn > Ni > Mn > Pb; toxicity of the different mixtures ranked: M5 > M3PbHgCd > M5+Mn > M5+Cu > M2CdNi > M4A > M8‐Mn > M8 > M5+Zn > M4B > M8‐Cr > M8‐Zn > M8‐Cu > M8‐Pb > M8‐Cd > M8‐Hg > M8‐Ni > M3PbHgNi > M3CuZnMn. The cytotoxicity data of individual metals were successfully used to build the additive models of two‐ to eight‐component metal mixtures. The comparison between additive model and combination model or partly additive model was useful to evaluate the combined effects in mixture. Synergistic, antagonistic or additive effects of the toxicity were observed in different mixtures. These results suggest that the combined effects should be considered in the risk assessment of heavy metal co‐exposure, and more comprehensive investigations on the combined effects of different heavy metal mixtures are needed in the future. Copyright © 2016 John Wiley & Sons, Ltd.     

Evaluation of metal concentration and antioxidant activity of three edible mushrooms from Mugla,Turkey

This study is designed for the determination of metal concentrations, antioxidant activity potentials and total phenolics of Amanita caesarea, Clitocybe geotropa and Leucoagaricus pudicus. Concentrations of four heavy metals (Pb, Cd, Cr, Ni) and five minor elements (Zn, Fe, Mn, Cu, Co) are determined. In the case of A. caesarea, Cr and Ni concentrations are found in a high level. Concentrations of the metals are found to be within safe limits for C. geotropa. In β-carotene/linoleic acid test, L. pudicus showed the highest activity potential. In DPPH system, A. caesarea showed 79.4% scavenging ability. Additionally, reducing power and chelating capacity of the mushrooms increased with concentration. The strongest super-oxide anion scavenger was A. caesarea. In the case of total phenolics, L. pudicus found to have the highest content.     

Heavy metals levels in fish from aquaculture farms and risk assessment in Lhasa,Tibetan Autonomous Region of China

Fish is consumed as a common food by humans due to its nutritional and therapeutic benefits. However, they can accumulate toxic chemicals (such as heavy metals, persistent organic pollutants) from water and food chain. Very few studies have been investigated on heavy metal contents in fish from Tibetan Autonomous Region of China. In order to study heavy metals levels in fish from aquaculture farms and evaluate the risk that human consume fish in this area, we collected four types of aquaculture fish species (6 big-head carps, 5 grass carps, 5 carps and 5 tilapias) from fisheries around Lhasa city in this study. 9 heavy metals (Cr, As, Cd, Pb, Cu, Ba, Co, Mn and V) in different tissues of fish were determined by an inductively coupled plasma mass spectrometer. Cr, Ba, Co, Mn and V could easily accumulate in the gill, and Cu was detected in the hearts of all the fishes. Toxic metal (As, Cd and Pb) contents were higher in the liver than those in other tissues, heavy metal levels were the lowest in the muscle among all tissues. Most of heavy metal concentrations in the tilapia tissues were higher than those in other fish tissues, especially arsenic. Arsenic content in the tilapia samples was ~2–4 times higher than the maximum levels (MLs) of contaminants in the national standard, and other metals were all lower than the MLs. Compared the estimated daily intake of heavy metals through fish consumption with tolerable daily intakes recommended by FAO, the metals daily intake of As, Cd and Pb from fish consumption might not pose serious health risk to the local inhabitants. It is therefore necessary to determine the dose level for human, which is considered to be taken daily over a lifetime without adverse effects.     

Ecological risk of heavy metals in sediments of the Luan River source water

Distribution and characteristics of heavy metals enrichment in sediment were surveyed including the bio-available form analyzed for assessment of the Luan River source water quality. The approaches of sediment quality guidelines (SQG), risk assessment code and Hakanson potential ecological risk index were used for the ecological risk assessment. According to SQG, The results show that in animal bodies, Hg at the sampling site of Wuliehexia was 1.39 mg/kg, Cr at Sandaohezi was 152.37 mg/kg and Cu at Hanjiaying was 178.61 mg/kg exceeding the severe effect screening level. There were 90% of sampling sites of Cr and Pb and 50% sites of Cu exceeded the lowest effect screening level. At Boluonuo and Wuliehexia, the exchangeable and carbonate fractions for above 50% of sites were at high risk levels and that for above 30% of sites at Xiahenan and Wulieheshang were also at high risk levels. Other sites were at medium risk level. Compared to soil background values of China, Hg and Cd showed very strong ecological risk, and the seven heavy metals of Hg, Cd, Cu, As, Pb, Cr, Zn at ecological risk levels were in the descending order. The results could give insight into risk assessment of environmental pollution and decision-making for water source security.     

Removal of heavy metals by conventional water treatment plants using poly aluminum chloride

In this study, trace heavy metals, such as aluminum (Al), barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mn), nickel (Ni), lead (Pb), antimony (Sb), vanadium (V), and zinc (Zn) were investigated in the water of the Karun River that enters the water treatment plants (WTP1 and WTP2) in Ahvaz City, Iran. Removal efficiency of these heavy metals was assessed in various units of WTP1 and WTP2, as well. For this purpose, water samples were collected from four different points of the WTP1 and WTP2, namely, the influent (raw water, RW), the effluent of the clarifier (clarifier effluent, CE), and the effluent of the filter (filter effluent, FE). A total of 72 water samples were collected and analyzed for heavy metals using ICP-OES apparatus. The results indicated that all RW samples contain Ba, Cd, Co, Cr, Cu, Ni, Pb, V, and Zn within the US EPA maximum contaminant levels (MCLs), except Al, Fe, Mn, and Sb that crossed the MCLs. High levels of Al (649.9 (±171.6) µg/L, 806.4 (±135.1) µg/L), Fe (484.95 (±127.05) µg/L, and 529.7 (±119.6) µg/L) were found in finished water of WTP1 and WTP2, respectively. Experimental results showed that level of all studied heavy metals except Al reduced in WTP1 and WTP2 effluent. From the observed data, it is found that effluent Al concentration was over influent Al concentration in both WTP1 and WTP2. It is concluded that using PACl as coagulant in WTP1 and WTP2 can increase concentration of aluminum.     

Multivariate analysis combined with GIS to source identification of heavy metals in soils around an abandoned industrial area,Eastern China

Heavy metals in soils polluted by industrial production are a meaningful topic worldwide. The purpose of this study is to understand the pollution status and spatial distribution of heavy metals in soils. The result can help decision-makers apportion possible soil heavy metals sources and formulate effective pollution control policies. In this paper, 155 soil samples (0–20 cm) were collected and analyzed for eight heavy metals (Cd, Hg, As, Cu, Pb, Cr, Zn, and Ni) from an abandoned industrial area of Tong County, located in Jiangsu Province of Eastern China. The multivariate analysis (including I_geo, E_i/RI, EF, PCA, and CA) and geostatistics (GIS) were used to assess the enrichment level and pollution level of soil heavy metals and identify their sources. The results indicated that eight heavy metals in soils had moderate variations, with CVs ranging from 19.63 to 63.34 %. The pollution level of I_geo of soil heavy metals decreased in the order of Cd~Zn > Cu > Hg~As~Pb~Cr~Ni. The enrichment level of soil heavy metals decreased in the order of Cd > Zn > Hg > Cu > Pb > Ni > As > Cr. According to the E_i, except Cd and Hg were in the significant and moderate ecological risk levels respectively, other soil heavy metals were in the clean or light ecological risk levels, the level of potential ecological risk (RI) of the whole industrial area was moderate. Finally, the source identification of soil heavy metals indicated that Cd and Zn were primarily controlled by human activities, and Hg and Cu were controlled by natural and anthropogenic sources, and As, Pb, Cr, and Ni were mainly controlled by soil parent materials.     

The essential and toxic elements in tissues of six commercial demersal fish from Eastern Mediterranean Sea

The essential elements and contaminants (Pb and Cd) were determined seasonally in the muscle and liver of six demersal fish species Sparus aurata, Chelidonichthys lucernus, Upeneus molluccensis, Solea solea, Merluccius merluccius and Saurida undosquamis from the ?skenderun Bay, Eastern Mediterranean Sea. The concentrations in muscles of fish species were 474–1534 mg/kg for Na, 574–3374 mg/kg for K, 72.7–496 m/kg Ca, 94.1–210 mg/kg for Mg. Muscle accumulated the lowest levels of elements. Trace element and contaminant levels in muscle were highest in the spring and winter. The Cu and Ni concentrations were highest in the winter. The Zn, Cr and Fe concentrations were highest in the spring. The maximum Pb concentrations in the muscle and liver of fish species was 0.58 and 0.89 mg/kg (wet wt) in the autumn. The maximum Cd concentration in the muscle and liver tissues of fish was 0.20 mg/kg and 0.63 mg/kg (wet wt) in the winter. The Cr, Pb, Cd, Cu and Zn levels in muscle were found to be lower than permissible limits. Estimated weekly and daily intake for Pb and Cd was far below the PTWI and PTDI values. The consumption of these species from this region is not problem on human health.     

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman,Turkey

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (< 0.05 and 0.1 microg/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as microg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulation's residue limits, the cadmium level determined in fish tissues was high (0.1 microg/g) and the lead level, especially in liver tissue, was high in August (1 microg/g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.     

Dose-response effects of various metal ions on rat liver metallothionein,glutathione, heme oxygenase,and cytochrome P-450

Adult male rats received ip injections of the maximum tolerable dose (MTD; μmol/kg/day, in parentheses following metal), or a fraction thereof, of Hg (5), Cd (20), Se (25), Ag (65), Cu (75), Co (100), Ni (120), Zn (200), Mn (250), Fe (300), Pb (400), or Cr (400) 36 and 12 hr before sacrifice. MTDs were estimated from previous studies, and at least three serial dilutions ($\text{1}\text{2}$, $\text{1}\text{4}$, $\text{1}\text{8}$, etc.) of the MTDs were tested for each metal. The effects of metal treatment on hepatic heme oxygenase activity (HO), cytochrome P-450, reduced glutathione (GSH) and metallothionein (MT), and renal MT and GSH were determined. Nine metals increased HO at the MTD, but only Cd, Se, Mn, and Pb increased HO at lower doses. These four metals plus Ag and Cr depressed cytochrome P-450 levels at the MTD, but only Cd, Mn, and Pb depressed cytochrome P-450 at a lower dose. Se increased hepatic GSH at the two highest doses, but all other metals had little or no effect. Kidney GSH was increased by all metals except Cd, Ag, Cu, and Cr, to a maximum level of only 150% of control (Pb). Cd and Zn induced hepatic MT in a dose-related manner to 420 and 580% of control, respectively. On a molar basis, Cd was about eight times more potent than Zn in increasing hepatic MT concentration. Hg, Ni, Mn, Fe, Pb, and Cr also significantly increased hepatic MT, but only to 150–200% of control. Pb had a slight but significant effect on hepatic MT at all doses down to 1/16th the MTD. This effect of PB, as well as other metals having a small effect on MT, may be the result of the effects of stress on MT rather than the metal ion per se. Renal MT was effectively induced by Hg, Cd, Cu, Ni, Zn, and Pb. Relatively small amounts of Hg (0.62 μmol/kg/day) significantly increased renal MT when compared to the minimum effective dose of Cd (10 μmol/kg/day) or Zn (50 μmol/kg/day). In conclusion, metals have a number of effects on potential hepatic and renal biochemical defense mechanisms. Most of the metals lacked specificity, affecting a number but not all of the parameters examined. However, of the 12 metals examined, Zn was the most selective in that it produced marked increases in MT and little or no effect on the other parameters, whereas Cd had the broadest effect, altering all parameters except GSH.     

Interactive toxic effect and bioconcentration between cadmium and chromium using continuous algal culture

Numerous studies have been conducted on the effects of toxic chemicals using algal batch culture. On the other hand, continuous culture research has the advantage of allowing optimal cell growth. Few studies on the interactive toxic effect between chemicals have been carried out either with batch culture or with continuous culture. The purpose of this study is to find the relationship between interactive toxic effects and the bioconcentration of heavy metals using continuous algal culture. The green alga Chlorella ellipsoidea was used as a test organism. As test substances cadmium and chromium were used. The amount of heavy metals both in algae and in the medium was determined after the cells had been exposed to heavy metals for 10 days. The amount of Cd taken up in the cells and the growth inhibition rates caused by Cd increased as the concentration of Cd in the medium became higher. The inhibition rates rose drastically but the amount of Cd in the cells remained at almost the same level even if Cr was added. The bioconcentration factors of Cd were ca. 10,000 in all the cases tested, regardless of the presence of Cr. The amount of Cr in the cell exposed to Cr was low, while that amount and the growth inhibition rates for all the concentrations tested increased when Cd was added to the medium containing Cr. The bioconcentration factors of Cr reached 156,000 as the concentration of Cd in the medium increased. It seems that the toxicity of Cr was enhanced because the presence of Cd in the medium raised the amount of Cr in the cell. © 1993 John Wiley & Sons, Inc.