Toxicity of metals to tadpoles of the common Sunda toad,Duttaphrynus melanostictus

Tadpoles of the common freshwater Sunda toad, Duttaphrynus melanostictus (Amphibia, Bufonidae), were exposed for a 4-day period under laboratory conditions to copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminum (Al), and manganese (Mn) at various concentrations. Mortality was assessed and median times of death (LT₅₀) and lethal concentrations (LC₅₀) were calculated. LT₅₀ and LC₅₀ increased with the decrease in mean exposure times and concentrations for all metals. LC₅₀ (96?h) for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.03, 0.3, 4.2, 1.5, 8.8, 0.4, 1.9, and 39?mg?L^?1, respectively. Cu was the most toxic to D. melanostictus, followed by Cd, Fe, Al, Pb, Zn, Ni, and Mn (Cu?>?Cd?>?Fe?>?Al?>?Pb?>?Zn?>?Ni?>?Mn). Duttaphrynus melanostictus is similarly sensitive to these metals as other amphibian tadpoles.     

Concentrations of selected metals in chicken eggs from commercial farms in Southern Nigeria

This work presents the results of the determination of concentrations of the trace metals Ni, Zn, Mn, Pb, Cd, Cr, Co, Cu, and Fe in eggs from farms in Southern Nigeria. The mean concentrations (µg?g^?1 fresh weight) ranged from 0.6 to 1.2 for Ni, 3.1 to 8.9 for Zn, 0.45 to 0.65 for Mn, 0.4 to 1.2 for Pb, <0.09 to 0.3 for Cr, 0.1 to 0.3 for Cd, 0.26 to 0.34 for Co, 0.9 to 1.2 for Cu and 19.5 to 24.0 for Fe. The concentrations and estimated dietary intakes of these metals were below the respective statutory limits. The Target Hazard Quotient (THQ) values for the individual metals in all zones are less than 1, i.e., within safe levels. The combined THQ values for the different zones were greater than 1but less than 2, with a significant contribution of cobalt.     

Physicochemical characteristics and distribution of some metals in the ecosystem of Lake Nasser,Egypt

To know the interrelationship between some metals in different ecosystem components (water, sediment, aquatic plant and fish), many samples from these components were collected from four bights at the Nasser Lake, Egypt, and analyzed for Fe, Mn, Zn, Ca, Mg, Pb, Cd, Ni, Co, Cu and Cr using atomic absorption spectrophotometer. Different distribution factors (bioaccumulation factor – BF, discrimination factor – DF and enrichment factor – EF) were applied on the results of analysis. Data showed that the relatively high concentration of measured metals in water samples are derived from fish farms, and discharge of tourism and trade ships. Applying single leaching sequential technique on sediment samples, using different extracting solutions, revealed a strong ability of trace metals to adsorb on or co-precipitate with amorphous Fe/Mn oxides. High concentrations of Fe, Mn, Co and Ni were measured in the intestine while high Cd and Cr concentrations were recorded in the stomach in both Tilapia (nilotica and galilea). Tilapia galilea accumulated high Pb, Cu and Zn concentrations in their stomach, while in nilotica high concentrations of Pb, Cu and Zn were measured in the intestine, liver and muscles, respectively. Myriophyllum spicatum (an aquatic plant) in the lake recorded high concentrations of Fe, Mn and Zn. Bioaccumulation factors of studied elements in the different bights components indicate that the elevated concentration of measured elements in the aquatic plant and Tilapia (nilotica and galilea) are derived from water, reflecting the increase of human activities in Nasser Lake in recent years. However, the present study concluded that all the elements studied were still below the natural back-ground levels, except Zn and Cu.     

Biochemical responses and accumulation of cadmium in Spirodela polyrhiza

The present study focused on biochemical responses of Spirodela polyrhiza to cadmium stresses and its accumulation. The laboratory experiments were conducted for the assessment of biochemical responses and accumulation of cadmium in plants at its various concentrations (0.1, 0.5, 1.5 and 2.0 ppm) at the regular interval for twelve days exposure. Spirodela showed visible symptoms like withering of roots and chlorosis at higher concentration (2.0 ppm), however the plant showed normal growth at lower concentration (0.1 ppm). The estimation of biochemical parameters (total chlorophyll, protein and carbohydrate) of test plants showed a significant increase at lower concentration (0.1 ppm) of cadmium. The biochemical changes decrease with increase in exposure concentration and duration. The toxic effect of cadmium is directly proportional to its concentration and duration. The accumulation of cadmium by Spirodela polyrhiza was maximum at four days exposure duration and gradually decreases.     

大宝山矿水外排的环境影响:Ⅰ.下游水生生态系统

通过水质生物检测、理化分析及野外水生大型无脊椎动物多样性实地调查等综合方法，就广东大宝山矿区南侧拦泥库溢出的酸性矿水对下游横石水河生态系统的影响进行了系统研究。结果表明，大宝山矿区拦泥库溢出的酸性矿水对隆线溞具有较强的急性生物毒性，酸性矿水24h，48h及96h对水溞的半致死体积分数LC50分别为13．55%、10．30％、6．20％；安全体积分数为0．06％。通过在暴雨期间对拦泥库上游洪水的各项指标的分析结果表明，拦泥库溢出的酸性矿水pH值可低至2．15，其中铁及重金属的质量浓度分别为：铁216．79mg/L、锌73．23mg/L、铜32．63mg/L、铅1．82mg/L、镉0．87mg/L。在尾矿坝下游3．5km处，重金属质量浓度分别为：铁51．63mg／L、锌2．83mg/L；铜1．64mg／L、铅2．67mg／L、镉0．1mg／L，和锰20．50mg／L。从矿水排放口到受矿水影响的下游50km范围内，河水pH的变化幅度为3．36-7．42。大型无脊椎动物多样性的调查显示，从尾矿坝到受矿水影响的下游25km范围内，未发现任何底栖动物，而在横石水河上游未受矿水影响的对照点中至少有36利底栖动物存在。可见由大宝山矿区排出的酸性矿水对下游溪流的水生生物多样性和河流生态系统造成了严重的破坏。     

Effect of mixtures of metals on the spotted Babylon snail (Babylonia areolata) under different temperature conditions

A study was conducted on the Babylon snail (Babylonia areolata) to examine the effects of copper (Cu), cadmium (Cd), nickel (Ni), and zinc (Zn) on different life stages of this gastropod. Metal toxicity significantly varied according to the life stage of the snail. The different LC₅₀ values obtained were 0.51, 5.49, 0.31, and 0.2 ppm for Cu, Zn, Cd, and Ni for the larval stage and 4.98, 15.19, 0.91, and 1.21 ppm at the juvenile stage and 8.54, 17.52, 1.14, and 1.44 ppm in the adult stage. Studies were also conducted on the effects of dual metal concentrations and experiments were repeated with temperature as a variable. Results demonstrated that metal toxicity values were altered depending on the metals involved in the combination as well as temperature under which the experiment was conducted.     

Toxicity evaluation of a complex metal mixture to the softshell clam Mya arenaria

Adults of the softshell clam Mya arenaria were continuously subjected to a flowing raw seawater solution containing a mixture of salts of manganese, zinc, lead, nickel, copper, and cadmium. Final calculated concentrations, in g l^-1, of the toxicant solution were 7200 Mn, 2500 Zn, 70 Pb, 50 Ni, 50 Cu and 1 Cd; these concentrations approximated highest measured levels within surficial interstitial sediment waters from mid-Narragansett Bay, Rhode Island. M. arenaria were also subjected to a 20% solution, i.e., 1440 Mn, 500 Zn, 14 Pb, 10 Ni, 10 Cu, and 0.2 g l^-1 Cd. One study was conducted for 112 days in winter at 0° to 10°C and another for 16 days in summer at 16° to 22°C. In the winter study, all clams exposed to a 100% solution died between the 4th and 10th week; soft parts of survivors at 6 weeks contained about 19 times more Pb, 15 x more Zn, 12 x more Cu, 10 x more Mn, 3 x more Ni and 0.1 x more Cd than controls; relatively minor changes in whole body elemental content of Ca, Cr, Fe, K, Mg, Na, Sr, and V were observed. Clams exposed to a 20% solution during winter survived the 112 day study; at that time these contained about 5 x more Cu, 4 x more Mn, 3 x more Zn and about 2 x more Pb than controls; comparatively minor changes were observed in other elements examined. In the summer study, all M. arenaria subjected to the 100% solution died between 6 and 14 days; survivors from this group at 7 days contained about 25 x more Pb, 13 x more Cu, 11 x more Zn, 7 x more Mn, and 3 x more Ni than controls; other changes in elemental content were not as pronounced. Mortality in the 20% group during summer was slightly higher than controls during the 16 day study; at 14 days survivors from this group contained about 12 x more Mn, 7 x more Pb, 7 x more Zn, 4 x more Cu, and 3 x more Ni than controls. Survival and bioaccumulation patterns were not altered through feeding a supplemental diet of algae. The significance of these findings are discussed in terms of potential environmental perturbations, especially local dredging practices.     

Heavy metals in water of the rivers Hooghly and Haldi at Haldia and their impact on fish

The paper deals with the measurement of five heavy metals viz., Cd, Cu, Mn, Pb and Zn in water of the rivers Hooghly and Haldi at Haldia during June 1999 to October 2002. The industrial effluent out fall (OF) at Patikhali, Haldia was also taken as sampling site along with above out fall (AOF) and below out fall (BOF) sites. Most of the metals exhibited their least concentration at the sampling site above the Haldia industrial area of river Hooghly. The average concentrations of the studied metals were Cd 2-14, Cu 5-19, Mn 8-88, Pb 17-41 and Zn 22-37 microg l(-1). Comparison of the data with the Criterion Continuous Concentration (CCC) of USA revealed that Cd, Cu and Pb were the pollutants present at alarming level to disturb the aquatic life process in the zone. The effect was found to reflect on the tissue level aberrations in the residential fishes. The other two metals viz., Mn and Zn were probably less harmful to the aquatic ecosystem. In India, necessity is felt to develop the CCC values, which will be more appropriate for protection of aquatic environment than comparing with drinking water standards.     

Bioaccumulation of heavy metals in flora and fauna of Hooghly estuary,east coast of India

Spectroscopic determinations of Fe, Zn, Mn, Cu, Co and Ni were carried out in 23 organisms including seaweeds, zooplankters, molluscs and fishes from Hooghly estuary at the confluence of Bay of Bengal. Seaweeds and gastropods were more efficient in accumulating levels while zooplankters bivalves and fishes showed intermediate levels. Analyses were performed on the sediment, water and on the individual dissected organs of a mussel, oyster and teleost fish. Bioaccumulation of Fe, Zn, Mn and Cu in the soft body parts (gills, mantle, liver etc.) of the three species showed a high degree of organ specificity in some cases. Major sources of the micropollutants include natural weathering, catchment runoff, urban and industrial discharges that may pose an ecological risk to the local estuarine ecosystem.     

Metal accumulation in sediment,water, and freshwater fish in a Dam Lake

Metal concentrations were determined in water, sediment, and freshwater fish samples (Squalus cephalus, Barbus esocinus, and Barbus xanthopterus) collected from Karakaya Dam Lake, Turkey, to estimate the risk of human consumption and pollution. Metal concentrations differed between the species (p??Zn?=?Cu in water and Fe?>?Zn?>?Mn?>?Ni?>?Cu in sediment. In general, the accumulation order of elements in the tissues all of the species sampled were found as Fe?>?Zn?>?Se?>?Mn?>?Cu?>?Ni?>?Cd in muscle, Zn?>?Fe?>?Mn?>?Se?>?Cu?>?Ni?>?Cd in gills, Fe?>?Zn?>?Se?>?Mn?>?Cu?>?Ni?>?Cd in liver and gonad, and Zn?>?Fe?>?Cu?>?Mn?>?Se?>?Ni?>?Cd in kidney. It was concluded that the fish from the dam lake are not heavily burdened with metals, but they should be controlled periodically to avoid excessive intake of trace metals by humans, and to monitoring the pollution of aquatic environment.     

The Sagamu cement factory,SW Nigeria: Is the dust generated a potential health hazard?

The aim of this study was to assess the heavy metal content of the dust generated by the Sagamu cement factory and its attendant health hazards on the immediate environment, especially on the inhabitants of the area. A total of 25 samples were collected and analyzed using inductively coupled plasma-optical emission spectrometry. Records of medical ailments associated with heavy metal toxicity were also compiled from the Obafemi Awolowo Teaching Hospital situated in the town.The results for some of the selected heavy metals showed the following pattern: limestone: Cd (n.d.-1.7 ppm), Pb (42–48 ppm), Cu (3.0–11 ppm), Zn (7.0–53 ppm) and Ni (3.0–8.0 ppm); shale: Cd (0.3–1.1 ppm), Pb (17–22 ppm), Cu (2.0–11 ppm), Zn (17–147 ppm) and Ni (3.0–18 ppm); dusts: Cd (0.5–0.7 ppm), Pb (32–52 ppm), Cu (2–16 ppm), Zn (5–152 ppm) and Ni (2–17 ppm); soils: Cd (0.5–1.1 ppm), Pb (28–49 ppm), Cu (22–35 ppm), Zn (43–69 ppm) and Ni (13.0–17 ppm). High levels of heavy metals were found in the rocks and soils. We propose that the high levels of metals in the dust and soil were acquired from the raw materials used by the cement factory and from active industrial discharge from this same factory. Medical records and the current health situation of the local residents in the study area reveal that there have been increases in the prevalence of diseases linked to heavy metal toxicity in the environment, especially those related to dust generation.     

宝鸡城市街尘、土壤及河流沉积物重金属形态迁移特征

在宝鸡城市街尘、土壤及河流沉积物基本理化性质和重金属元素含量分析的基础上,重点研究了重金属元素在街尘、土壤及河流沉积物中的赋存形态和迁移特征.结果表明:在街尘中Cu主要以可氧化态和残余态形式存在,Pb主要以可还原态和可氧化态形式存在,Zn和Cd主要以乙酸可提取态形式存在,Mn、Fe、Co、Ni和Cr主要以残余态形式存在...     

Geochemical speciation of trace metals in sediments of the northern Nile Delta Lake by sequential extraction technique

ABSTRACT

The present study was performed to investigate surface sediment samples from Lake Edku of the Nile Delta Lagoons, Egypt. The Lake is important for fishing in the region. The importance of research is to understand the mobility and bioavailability of each studied metal. The study was carried out on 10 sampling sites during 2017. The sediments were subjected to the technique of sequential extraction to examine the chemical forms of some trace metals (Fe, Mn, Zn, Cu, Pb and Ni). Five stage extractions were done as the following order: soluble and exchangeable, carbonate, iron and manganese oxides, organic matter fraction and residual fraction. Attained results from the five fractions showed variations in the concentrations of metal contents of different sites under study. The overall metal concentrations (%) in the initial four extractable fractions (exchangeable, carbonate, oxides and organic matter fractions) were assessed to configure the mobility of each studied metal. The risk assessment code (RAC) represents the summation of exchangeable and carbonate fractions, it was between low and medium risk for aquatic environment. The range percentage of RAC for the metals was in the following order: 1.8–13, 4–23.5, 15–26, 5.7–19.5, 9–25 and 4.8–18.2 for Fe, Mn, Zn, Cu, Pb and Ni, respectively. Approximately 30% of the total copper was associated to the organic fraction, which may represent a high mobility of copper in these sediments. The highest mobility of metals in the sediments could be confirmed by its bioavailability factor (BF), which was within the ranges of 0.32–0.61, 0.36–0.59, 0.64–0.83, 0.36–0.72, 0.37–0.62 and 0.52–0.78 for Fe, Mn, Zn, Cu, Pb and Ni, respectively. The BF exhibited the following order: Zn > Ni > Cu > Pb ≈ Mn?>?Fe. The high levels of BF for the studied metals may represent the potentiality for toxic metals to be easily released into the aquatic environment.     

肠道微生物对土壤中铜、锌、锰生物可给性的影响

为了更全面、准确地评价土壤中金属元素对人体的健康风险,研究土壤中金属元素在结肠阶段的生物可给性具有重要意义。通过采集我国一些地区的6种土壤,利用in vitro方法(PBET和SHIME联用)研究土壤中Cu、Zn、Mn在胃、小肠、结肠阶段的生物可给性。研究显示,土壤中Cu、Zn、Mn在胃阶段的生物可给性分别为23.8%~63.0%、21.2%~64.4%、11.7%~35.6%;从胃阶段到小肠阶段,土壤中Cu的生物可给性提高了0.4%~14.4%,而土壤中Zn在小肠阶段的生物可给性降低了6.7%~38.7%。结肠阶段,土壤中Cu、Zn、Mn的生物可给性分别为2.4%~12.9%、5.7%~18.7%、6.2%~18.9%,与小肠阶段相比,分别降低了21.7%~56.9%、0.4%~36.8%、4.5%~19.1%。结果表明,在肠道微生物存在的情况下,土壤中Cu、Zn、Mn在结肠阶段有较低的人体健康风险。     

Combined effect of iron and zinc on micronutrient levels in wheat (Triticum aestivum L.)

A nutrient solution experiment was conducted to investigate the effect of Fe and Zn supply on Fe, Zn, Cu, and Mn concentrations in wheat plants. The experiment used a factorial combination of two Fe levels (0 and 5 mg l(-1)) and three Zn levels (0, 0.1 and 10 mg I(-1)). The supply of Fe (5 mg l(-1)) and Zn (0.1 mg l(-1)) increased plant dry weight and leaf chlorophyll content compared to the Fe or Zn deficient (0 mg 11) treatments. However, excess Zn supply (10 mg l(-1)) reduced plant dry weights and leaf chlorophyll content. Iron supply (5 mg l(-1)) reduced wheat Zn concentrations by 49%, Cu concentrations by 34%, and Mn by 56% respectively. Zinc supply (10 mg l(-1)) reduced wheat Fe concentrations by an average of 8%, but had no significant effect on Cu and Mn concentrations. Stepwise regression analyses indicated that Zn, Cu, and Mn concentrations were negatively correlated with root- and leaf-Fe concentrations, but positively correlated with stem-Fe concentrations. Leaf-Mn concentrations were negatively correlated with root-, stem- and leaf-Zn concentrations.     

Risk assessment of potentially toxic elements in smaller than 100-μm street dust particles from a valley-city in northwestern China

Concentrations of potentially toxic elements (PTEs As, Ba, Co, Cr, Cu, Mn, Ni, Pb, Sr, V, Zn and Mo) in smaller than 100-μm street dust particles from Xining, a typical valley-city in northwestern China, were determined using X-ray fluorescence spectrometry, and their potential risks to local ecosystem and human health were assessed using potential ecological risk index and health risk model. The results indicate that the concentration of As, Ba, Co, Cr, Cu, Mn, Ni, Pb, Sr, V, Zn and Mo in the smaller than 100-μm street dust particles from Xining ranges from 0.8 to 11.1, 339.4 to 767.7, 27.2 to 110.2, 185.7 to 5134.5, 15.1 to 115.2, 150.1 to 623.5, 16.8 to 74.1, 24.4 to 233.0, 169.9 to 475.7, 47.4 to 96.8, 33.1 to 231.1 and 0.2 to 4.3 mg kg^?1, with an arithmetic mean of 3.6, 415.6, 50.1, 573.0, 40.6, 409.1, 22.6, 52.7, 257.8, 57.1, 108.6 and 2.5 mg kg^?1, respectively. Compared to the background value of local soil, the smaller than 100-μm street dust particles from Xining have elevated concentrations of Co, Cr, Cu, Pb, Zn, Sr and Mo. The contamination levels of Ba, Co, Cr, Cu, Pb, Zn, Sr and Mo are higher than As, Mn, Ni and V. The comprehensive potential ecological risk levels of PTEs were moderate to considerable. The non-carcinogenic risks of PTEs studied on children and adults due to dust exposure are limited except for Cr to children. Cr in the dust may pose a potential health risk to children; this should draw more attention.     

芜湖市区土壤重金属污染评价及来源分析

对芜湖市区153个土壤样品中9种重金属的含量进行测定和评价,利用多元地统计方法进行污染来源分析。结果表明：芜湖市区土壤Zn、Fe、Mn、Cu、Pb、Co、Cd、Ni、Cr的平均含量分别为96.8、30600.1、466.1、35.0、29.1、16.7、1.2、26.3、78.3mg/kg;除Fe、Mn、Ni外,其他元素均高于相应土壤背景值,Zn、Cu、Pb、Co、Cd、Cr分别是背景值的1.26、1.09、1.17、1.20、6.11、1.29倍,说明这些元素出现了一定程度的积累。单因子评价结果表明Cd污染最为严重,Zn、Cu、Pb、Co和Cr为轻度污染,Fe、Mn和Ni没有污染。综合相关性、聚类及主成分分析可知,Fe和Mn为＂自然源因子＂,不同功能区分布主要受成土母质控制;Zn、Cu、Pb和Cd为＂交通及工业活动因子＂,Cu、Cd高值区均分布在开发区,Zn和Pb的高值区分布在镜湖区;Ni、Co和Cr为＂农业活动因子＂,其空间变异受成土母质及农业活动等因素影响。     

An assessment of contamination and ecological risk of metals in sediments of the Guaracara,Caparo and Couva rivers in Trinidad,West Indies

The presence of metals in an aquatic environment can serve as a biomarker for pollution and can be used to evaluate its contamination status. Rapid industrialisation in recent decades has propelled Trinidad and Tobago to be one of the most developed nations within the Caribbean region and has stimulated the awareness of potential ecological risks from various industrial activities affecting the rivers of Trinidad. Sediment samples from three rivers along the West coast of Trinidad were analysed for Cd, Cr, Cu, Mn, Ni, Pb and Zn. For all three rivers, the metal concentrations in sediments were in the range of 0.40–2.31?μg/g, 12.77–33.04?μg/g, 14.51–72.89?μg/g, 224.90–4472.83?μg/g, 8.20–43.08?μg/g, 22.63–38.34?μg/g and 92.0–5462.60?μg/g for Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. Assessment of the pollution status indicated that all three rivers were considered polluted, with significant contributions from Cr, Cu, Mn, Ni and Zn. The potential ecological risk for all three rivers, however, was low and multivariate statistics revealed that mainly anthropogenic sources contributed to the metal concentrations in sediments of all three rivers.     

温瑞塘河温州市区典型河段底泥重金属污染特征

通过对温瑞塘河温州市区典型河段44个表层沉积物样品重金属含量进行监测和分析,应用地积累指数法和生态因子富集法等对典型重金属元素Cu、Zn、Pb、Cr、Fe、Mn、Ni进行污染评价和空间特征对比,结果表明：各重金属污染程度从高到低依次为：Zn〉Cu〉Pb〉Ni〉Mn〉Fe〉Cr,其中Zn、Cu在多数样点呈现重污染状态,含量分别为126．19～4312．07mg／kg及18．64～635．54mg／kg,Pb呈中度污染状态,含量为51．30～252．76mg／kg,而Ni、Mn、Fe、Cr基本处于无污染或轻微污染状态。绝大多数采样点出现3种以上重金属元素的复合污染,两种评价方法得出的结论基本一致,山下河重金属污染明显比九山外河更为严重,城市功能结构调整成为城市河网水环境治理的基础。     

Remediation rates and translocation of heavy metals from contaminated soil through Parthenium hysterophorus

The potential translocation of heavy metals by Parthenium hysterophorus over 30 and 90 days and its effect on biomass, chlorophyll content and photosynthetic activity were studied on 0, 10, 25, 50 and 100% fly-ash-amended soil (FAS). The results showed a decrease in chlorophyll content and photosynthetic area on exposure to 50–100% FAS. Heavy metal reduction was in the order Pb>Cd>Zn>Fe>according to accumulation trends. The plant exhibited good biomass growth on exposure to 25–50% FAS, but this decreased at>100% FAS. Heavy metal concentrations in P. hysterophorus after 90 days of the experiment were in the order Fe>Zn>Cu>Pb>Cd>Ni. Parthenium hysterophorus was suitable for translocating Fe, Zn and Cu based on translocation factors (TF=1.5, 1.3 and 1.05), but was more efficient for Pb, Ni and Cd (TF=8.5, 4.3 and 3.3). Plant uptake of Pb, Ni and Cd was high, whereas translocation of Fe, Zn and Cu was poor. These results indicated that P. hysterophorus can efficiently reduce heavy metal pollution in soil.