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PubMedDate not supplied

[Heavy metal content of the hair of children in industrial cities].

Heavy metals are most common pollutants in large industrial cities. Differences were first shown in the distribution of concentrations of toxic and biogenic heavy metals in the hair of children. Zinc and copper had dispersion close to normal values, whereas lead, cadmium, and nickel had asymmetric dispersion. Scales were first developed for rating the levels of heavy metals in the children's hair in cities. A typology of microareas was also first developed by the level of metal pollution. The permanent stay of children in the highly polluted areas causes a high accumulation of lead in the hair and it is a risk factor of morphofunctional abnormalities and chronic diseases.

Age Factors↗

PubMed2005

Differential gene expressions in arbuscular mycorrhizal-colonized tomato grown under heavy metal stress.

When tomato was grown in either "Breinigerberg" soil, which has a high content of Zn and of other heavy metals or in non-polluted soil enriched with up to 1 mM CdCl2, plants colonized with the arbuscular mycorrhizal fungus (AMF) Glomus intraradices grew distinctly better than non-mycorrhizal controls. An analysis of differential mRNA transcript formations was performed on several plant genes coding for products potentially involved in heavy metal tolerance. Northern blot analyses indicated that the mRNA from either roots or leaves was not differentially expressed in the case of LePCS1 (coding for phytochelatin synthase), Lemt1, Lemt3 and Lemt4 (for metallothioneins) or LeNramp2 (for a broad range heavy metal transporter) in both mycorrhizal and non-mycorrhizal plants, grown either with or without heavy metals. In contrast, Lemt2 was strongly expressed only in non-AMF-colonized roots, and only after growth in the Breinigerberg soil or in the presence of high CdCl2-concentrations. AMF colonization distinctly reduced the level of Lemt2 transcripts. This was also the case for the root specific LeNramp1 transporter, however, only after growth in the Breinigerberg soil, but not under Cd-stress. Likewise, the levels of LeNramp3 transcripts were reduced by the AMF colonization in roots, but not in leaves. Quantitative Real-Time RT-PCR-experiments performed with Lemt2, LeNramp1 and LeNramp3 largely corroborated the Northern analysis data. In situ hybridization experiments with Lemt2 and LeNramp1 showed that both genes were strongly expressed throughout the plant cells in non-colonized roots, whereas colonized roots revealed only few signals restricted to some parenchyma cells. All the data suggest that the transcript levels of some, but not all genes of the Nramp or mt family are elevated under heavy metal stress. AMF colonization results in a down-regulation of these genes, presumably due to the fact that the content of heavy metals is lower in mycorrhizal than in non-colonized roots. A suppression subtractive hybridization (SSH) Library from hyphae of the AMF G. intraradices grown in high versus low Zn++ provided none of the genes which were down-regulated at the plant side (mt or Nramp genes). In contrast, several gene sequences coding for enzymes potentially catalysing the detoxification of reactive oxygen species were found. Thus the fungal cells in the symbiosis may primarily have to cope with the heavy metal-induced oxidative stress.

Cadmium Chloride↗

PubMed2006

Sorption of phenanthrene by soils contaminated with heavy metals.

The fate of polycyclic aromatic hydrocarbons (PAHs) in soils with co-contaminants of heavy metals has yet to be elucidated. This study examined sorption of phenanthrene as a representative of PAHs by three soils contaminated with Pb, Zn or Cu. Phenanthrene sorption was clearly higher after the addition of heavy metals. The distribution coefficient (K(d)) and the organic carbon-normalized distribution coefficient (K(oc)) for phenanthrene sorption by soils spiked with Pb, Zn or Cu (0-1000 mg kg(-1)) were approximately 24% larger than those by unspiked ones, and the higher contents of heavy metals added into soils resulted in the larger K(d) and K(oc) values. The enhanced sorption of phenanthrene in the case of heavy metal-contaminated soils could be ascribed to the decreased dissolved organic matter (DOM) in solution and increased soil organic matter (SOM) as a consequence of DOM sorption onto soil solids. Concentrations of DOM in equilibrium solution for phenanthrene sorption were lower in the case of the heavy metal-spiked than unspiked soils. However, the decreased DOM in solution contributed little to the enhanced sorption of phenanthrene in the presence of metals. On the other hand, the sorbed DOM on soil solids after the addition of heavy metals in soils was found to be much more reactive and have far stronger capacity of phenanthrene uptake than the inherent SOM. The distribution coefficients of phenanthrene between water and the sorbed DOM on soil solids (K(ph/soc)) were about 2-3 magnitude larger than K(d) between water and inherent SOM, which may be the dominant mechanism of the enhanced sorption of phenanthrene by soils with the addition of heavy metals.

Adsorption↗

PubMed2006

Analysis of heavy metals in the endometrial tissue using electron microscope.

OBJECTIVE: This study was done to estimate whether heavy metals in the air may affect endometrial chemical composition. MATERIALS AND METHODS: A total of 30 albino Wistar rats were employed and randomly divided into three groups. The rats of Group 1 and 2 were acutely and sub-chronically exposed to the gas form of heavy metals, respectively. Group 3 was used as a control group. Endometrial tissue worth of heavy metals of the groups was measured in through using scanning electron microscope. RESULTS: A statistically no significant difference was found for endometrial chemical composition of all of the heavy metals (chrome, manganese, iron, cobalt, nickel, zinc and lead) between group 1 and 2 (p>0.05). On the other hand, there was statistically significant difference for all of the heavy metals between group 1 and group 3 (p<0.05), while there was statistically significant difference for chrome, manganese, iron, cobalt and nickel (p<0.05), but zinc and lead (p>0.05) between group 2 and 3. CONCLUSION: Air pollutants of Pb and Zn resulting mostly from combustion of fossil fuels and certain special industrial process in Kirikkale may be a risk factor for the high pregnancy loses by changing endometrial homeostasis.

Albinism↗

PubMed1997

Indicators of the sustainability of heavy-metal management in agro-ecosystems.

The aim of sustainable heavy-metal management in agro-ecosystems is to ensure that the soil continues to fulfil its function in agricultural production, in environmental processes such as the cycling of elements, and as a habitat of numerous organisms. Assessment of sustainability has to be carried out in time, since metal accumulation in soil is largely irreversible and may cause problems if certain concentration levels are exceeded. In this study, we provide a concept to assess the sustainability of current metal cycles in agro-ecosystems based on dynamic heavy-metal balances for the plough layer. After presenting some general aspects of dynamic metal balances, we introduce 'sustainability indices'. These characteristic numbers can be used as indicators for potentially adverse effects of current agricultural practices, since they account for (ecotoxicologically founded) soil quality standards and for quality standards for produce, groundwater and surface water. They can also be used to assess the effects of different management options that aim to prevent quality standards from being exceeded as they provide insight in the dynamics governing input-output relationships. This is illustrated with a case study on heavy-metal flows in different arable farming systems.

Agriculture↗

PubMed1979

Studies on urea hydrolysis. Part 2. Effects of some heavy metals on urease activity.

The effect of some heavy metals on the urease activity was studied in a pure system using jack bean urease (JBU). While Mn showed no effect, copper reduced the enzyme activity more than did Zn or Fe at high concentrations (100 ppm). At a low concentration, iron reduced the enzyme activity more than at a high concentration. Inhibition of the urease activity was induced by less than 0.1 ppm Fe, 0.5 ppm Cu, and 10.0 ppm Zn. In the soil, these heavy metals inhibited the JBU in this order: Fe++ greater than Cu++ greater than Zn++. The possibility is discussed of using heavy metals to delay urea hydrolysis in soils.

Copper↗

PubMedDate not supplied

[Effect of heavy metals on the growth of soil streptomyces].

The effect of heavy metals on the streptomycete pure cultures under solid and liquid nutrient media has been studied. There were revealed streptomycete forms sensitive and resistant to heavy metals. Streptomyces versipellis strain 1, S. griseoalbus strain 6, and S. viridogenes strain 570 belong to the first group. The increase of metal content in the agarized medium caused the decrease of the number and dimension of colonies, capacity for sporulation and loss of aerial mycelium, soluble pigment, and, at last, death. These cultures may be used as indicators of the soil heavy metal pollution in the future. The resistant streptomycete forms had good growth under experimental conditions and could accumulate the metals in the liquid media: S. flavovirens, strain 12,--about 230 micrograms of copper ions, S. albaduncus, strain 279,--209 micrograms of cadmium ions and S. alboviridis, strain 141-653 micrograms of lead ions per 1 g of dry mycelium. It is supposed that these streptomycetes, when assimilating the above metals in amounts required for life about can exclude them from the circulation and can decrease the metal negative influence on plants.

Cadmium↗

PubMed1994

Evaluation of a microplate assay specific for heavy metal toxicity.

A rapid, quantitative microbial assay, which is specific for heavy metal toxicity, has been developed. The assay (MetPLATE) is in a 96-well microtitration plate format and is suitable for determining toxicity characteristics such as median inhibitory concentrations. The sensitivity of MetPLATE to heavy metals [Cu, Zn, Cd, Pb, Hg, Cr(III)] was generally higher than Microtox and was of the same order as or better than Daphnia and fish bioassay. MetPLATE was insensitive to organic compounds at concentrations higher than those found in the environment. Six out of 10 industrial wastewaters or process waters surveyed were toxic. Heavy metal analysis of these waters confirmed the presence of heavy metals in the toxic samples. MetPLATE can be run concurrently with other assays for general toxicity to help determine the nature of chemicals causing toxicity.

Animals↗

PubMed2001

Retention of selected heavy metals: Cd, Cu, Pb in a hybrid wetland system.

The budget of heavy metals was investigated in a constructed wetland in a hybrid wetland system near Gdańsk. It is a pilot wastewater treatment plant (WWTP) designed for 150 PE (person equivalent). The system consists of two sections: a vegetated submerged bed (VSB) with horizontal flow of sewage and a cascade filter situated on a slope of a hill. Total area of the constructed wetland is about 870 m2. Domestic sewage, after a conventional pretreatment (consisting of an Imhoff tank and a trickling filter) is pumped to the VSB filter located on the top of the hill and then flows through subsequent segments of the constructed wetland. In the period 1995-98 the measurements of several heavy metals (Cd, Cu, Pb) were carried out in sewage inflowing, outflowing and collected from the in between sections of the system. Moreover analysis of sediment collected in ditches of the cascade filter, VSB filter and reed were carried out. The content of heavy metals in suspended solids decreased along the course of treatment, starting from VSB filter, through the first ditch to the last ditch. Measurable concentrations of dissolved heavy metals were found in sewage collected from several subsequent ditches. Sorption was deemed the main mechanism of dissolved metals removal in subsequent ditches.

Adsorption↗

PubMed2004

A novel response of wild-type duckweed (Lemna paucicostata Hegelm.) to heavy metals.

The responses of wild-type Lemna paucicostata, used as the experimental stock, to seven heavy metals were investigated with a hydroponic culture in a culture facility. The results showed that six of the metals could induce L. paucicostata to release daughter fronds from the mother frond before maturity, resulting in breakup of the colony. This phenomenon is novel and has not been reported before. Six of the heavy metals investigated-copper, cadmium, nickel, zinc, mercury, and chromium-could induce this response, but sensitivity and response of the plant varied. When Cu(2+) at a concentration of 0.2 micromol/L was added, the response was significantly different from that of the control after a 2-h exposure. The response to cadmium (0.8 micromol/L) was significantly different after a 6-h exposure; to zinc (10 micromol/L) and nickel (5 micromol/L), after 5 and 7 h, respectively. But for lead, even at a concentration of 80 micromol/L for 96 h, no colony breakup was induced. The response to heavy metals occurred within 24 h; increasing the exposure by another 24 h had nearly no additional effect on the colony breakup. When the response was over, the number of colonies with fronds varied with the inducement capacity of the metal. Nutrients could affect the sensitivity of L. paucicostata to some heavy metals, such as mercury, chromium, zinc, and nickel, but not to copper and cadmium. Sensitivity was also changed when CuCl(2) was used as the copper source instead of CuSO(4). These results indicate that some heavy metals could serve as a toxicant for inducing L. paucicostata to release daughter fronds in advance. This change might involve a stress response such as ethylene production. Also discussed is the possibility of this response as a biomarker in a bioassay.

Analysis of Variance↗

PubMed2004

[Characters of greening tree species in heavy metal pollution protection in Shanghai].

In this paper, the stream banks nearby Qibao town and the factory area of Shanghai Baoshan Steel Company were selected as the typical areas contaminated by heavy metals. The polluted status was investigated by measuring the heavy metal concentrations of the sampled soils. The results showed that the heavy metal concentrations in the soils of stream banks were a little higher than the control, but obviously higher in the factory area of Shanghai Baoshan Steel Company. The growth status of the greening trees was recorded, and their heavy metal concentrations were measured by ICP. According to the research results and historic data, the excellent greening tree species mainly applied in polluted factory area were Viburnum awabuki, Lagerstroemia indica, Hibiscus mutabilis, Ligustrum lucidum and Sabina chinensis, which could grow well on contaminated soil, and accumulate high concentrations of heavy metal elements. The other tree species such as Distylium racemosum, Nerium indicum, and Photinia serrulata might be also available in greening for heavy metal pollution protection.

Cadmium↗

PubMed2003

Consequences and implication of heavy metal spatial variations in sediments of the Keelung River drainage basin, Taiwan.

A great deal of effort was enforced to reduce the pollution of the Keelung River in the past 20 years. A set of sediments covering most of the Keelung River drainage basin was analyzed for bulk sediment heavy metal concentrations, grain size content and Pb-210 dating in order to understand the spatial variations of sediment heavy metal contents as well as to evaluate the effectiveness of pollution control. The results showed that anthropogenic pollution and grain size are two of the most important factors in controlling spatial variations of metals in the Keelung River sediments. In addition, little reduction of sediment heavy metal concentrations was observed in the Keelung River drainage basin. Large spatial variations of metals and grain size were observed. High concentrations of zinc, copper, lead and cadmium were found in sediments near the main outlets of the adjacent Da-Wu-Lun Industrial Park and municipal waste drainage systems. Anthropogenic sources of heavy metal have altered the natural sediment heavy metal distributions. Positive linear relationships between aluminum, iron and fine-grained sediments showed that spatial grain size variations controlled the natural aluminum and iron concentrations in sediments. Zinc, copper, lead and cadmium contents were much higher than those measured 15 years ago. The unusually high concentrations of heavy metals, high enrichment factors and their rapid increases with time in Pb-210 dated core showed that the efforts in heavy metal reduction were futile. A proper regulation to prevent further heavy metals from entering into the river is urgently needed.

Environmental Monitoring↗

PubMed2006

[Assessment on heavy metal pollution in the sediment of Poyang Lake].

In order to know the heavy metals content and the degree of the potential ecological risk in the sediment of Poyang Lake in high-water period and low-water period, based on the detailed survey and analysis of the current state of pollution in Poyang Lake, using the Index of Geoaccumulation and the Potential Ecological Risk Index evaluate the heavy metals pollution of Poyang Lake. The results indicate that Poyang Lake has been polluted by heavy metals in various degrees. According to the Index of Geoaccumulation, the order of the analyzed heavy metals, arranged from highest to lowest pollution degree, is as follows: Cu > Pb > Zn > Cd; The ecological risk to Poyang Lake is: Cd>Pb> Zn>Cu;And the pollution is different from space and time, the pollution degree of each sampling site is arranged in the following order: Rao River> Longkou > Nanji shan > Dongku shan > Yumin village, and the degrees in low-water season are bigger than the degrees that in the high-water period commonly.

Cadmium↗

PubMed2006

Competitive sorption and desorption of heavy metals by individual soil components.

Knowledge of sorption and desorption of heavy metals by individual soil components should be useful for modelling the behaviour of soils of arbitrary composition when contaminated by heavy metals, and for designing amendments increasing the fixation of heavy metals by soils polluted by these species. In this study the competitive sorption and desorption of Cd, Cr, Cu, Ni, Pb and Zn by humified organic matter, Fe and Mn oxides, kaolinite, vermiculite and mica were investigated. Due to the homogeneity of the sorbents, between-metal competition for binding sites led to their preferences for one or another metal being much more manifest than in the case of whole soils. On the basis of k(d100) values (distribution coefficients calculated in sorption-desorption experiments in which the initial sorption solution contained 100mgL(-1) of each metal), kaolinite and mica preferentially sorbed and retained chromium; vermiculite, copper and zinc; HOM, Fe oxide and Mn oxide, lead (HOM and Mn oxide also sorbed and retained considerable amounts of copper). Mica only retained sorbed chromium, Fe oxide sorbed cadmium and lead, and kaolinite did not retain sorbed copper. The sorbents retaining the greatest proportions of sorbed metals were vermiculite and Mn oxide, but the ratios of k(d100) values for retention and sorption suggest that cations were least reversibly bound by Mn oxide, and most reversibly by vermiculite.

Adsorption↗

PubMed2004

Element accumulation in boreal bryophytes, lichens and vascular plants exposed to heavy metal and sulfur deposition in Finland.

Macronutrient (N, P, K, Mg, S, Ca), heavy metal (Fe, Zn, Mn, Cu, Ni, Cd, Pb) and Al concentrations in understorey bryophytes, lichens and vascular plant species growing in Scots pine forests at four distances from the Harjavalta Cu-Ni smelter (0.5, 2, 4 and 8 km) were compared to those at two background sites in Finland. The aim was to study the relationship between element accumulation and the distribution of the species along a pollution gradient. Elevated sulfur, nitrogen and heavy metal concentrations were found in all species groups near the pollution source. Macronutrient concentrations tended to decrease in the order: vascular plants>bryophytes>lichens, when all the species groups grew on the same plot. Heavy metal concentrations (except Mn) were the highest in bryophytes, followed by lichens, and were the lowest in vascular plants. In general, vascular plants, being capable of restricting the uptake of toxic elements, grew closer to the smelter than lichens, while bryophytes began to increase in the understorey vegetation at further distances from the smelter. A pioneer moss (Pohlia nutans) was an exception, because it accumulated considerably higher amounts of Cu and Ni than the other species and still survived close to the smelter. The abundance of most of the species decreased with increasing Cu and Ni concentrations in their tissues. Cetraria islandica, instead, showed a positive relationship between the abundance and Cu, Ni and S concentrations of the thallus. It is probable that, in addition to heavy metals, sporadically high SO(2) emissions have also affected the distribution of the plant species.

Bryophyta↗

PubMed2003

Plant availability of heavy metals and phosphorus in the agricultural reuse of biological sludges.

Concerns about the agricultural use of sludges are usually associated with heavy metals. In this study, plant-availabilities of heavy metals and phosphorus (P) in different P amendments were investigated. The dewatered sludge from Paşaköy Biological Nutrient (N, P) Removal (BNR) Plant in Istanbul, a chemical fertilizer (Triple Superphosphate), and a P-deficient, alkaline soil were used in pot experiments. Unstabilized sludge (S), lime-stabilized sludge (LS), and triple superphosphate (TSP) were applied to pots in a manner to supply 0, 100, 200, 300, 400 ppm P. Lollium Perenne was grown on these soils to compare P and heavy metal (Cu. Ni, Zn) availabilities in terms of plant uptake. The results of plant analyses showed that P-recycling through the agricultural use of biological nutrient removal (BNR) sludges was possible. Plant availability of heavy metals in sludge amended soil samples was comparable with those in control samples (soil only) and chemical fertilizer amended samples. Lime stabilization reduced the plant-availability of P and heavy metals. The choice of lime stabilization must depend on the specific soil to be amended.

Agriculture↗

PubMed1994

Effect of heavy metals and mineral nutrients on forest litter respiration rate.

Two hypotheses were tested: (1) heavy metals such as Zn, Pb and Cd can suppress the respiration rate of forest litter at low-moderate pollution levels, and (2) mineral nutrients such as K, Ca and Mg can counteract the toxicity of heavy metals when applied onto the polluted litter. In a completely randomised design, three doses of heavy metals were used: Cd-10, 50, 250; Pb-100, 500, 2500; Zn-200, 1000, 5000 microg/g dwt litter, respectively. For Ca, Mg and K, the doses corresponded to 100, 500 and 2500 microg/g. A significant decrease in cumulated CO2 evolution after 4 weeks of incubation was found for the litter samples treated with medium doses of Zn, Cd/Ca, Cd/Mg, Pb/Ca, Pb/Mg, Pb/K, Zn/Mg, Zn/Ca, Zn/K and for all the highest-dose treatments. The largest drop in respiration rate in both the medium and the highest doses was caused by additions of Zn either alone or in combination with K, Ca or Mg. The additions of mineral nutrients were found to decrease the litter respiration rate below the value measured for the respective heavy metal alone in the case of Cd/Ca, Cd/Mg, Pb/Ca, Pb/Mg and Pb/K in the medium-dose treatments, and for Cd/Ca, Cd/Mg, Cd/K, Pb/Ca and Pb/Mg in the highest-dose treatments. In all other cases, additions of the mineral nutrients did not influence the respiration rate significantly when compared to the effect of the respective heavy metal.

Journal Article↗

PubMed2005

Heavy metal contamination from mining sites in South Morocco: 1. Use of a biotest to assess metal toxicity of tailings and soils.

Our work was conducted to investigate the heavy metal toxicity of tailings and soils collected from five metal mines located in the south of Morocco. We used the MetPAD biotest Kit which detects the toxicity specifically due to the heavy metals in environmental samples. This biotest initially developed to assess the toxicity of aquatic samples was adapted to the heterogeneous physico-chemical conditions of anthropogenic soils. Contrasted industrial soils were collected from four abandoned mines (A, B, C and E) and one mine (D) still active. The toxicity test was run concurrently with chemical analyses on the aqueous extracts of tailings materials and soils in order to assess the potential availability of heavy metals. Soil pH was variable, ranging from very acidic (pH 2.6) to alkaline values (pH 8.0-8.8). The tailings from polymetallic mines (B and D) contained very high concentrations of Zn (38,000-108,000 mg kg(-1)), Pb (20,412-30,100 mg kg(-1)), Cu (2,019-8,635 mg kg(-1)) and Cd (148-228 mg kg(-1)). Water-extractable metal concentrations (i.e., soil extracts) were much lower but were highly toxic as shown by the MetPAD test, except for soils from mines A, E and site C3 from mine C. The soil extracts from mine D were the most toxic amongst all the soils tested. On this site, the toxicity of soil water extracts was mainly due to high concentrations of Zn (785-1,753 mg l(-1)), Cu (1.8-82 mg l(-1)) and Cd (2.0-2.7 mg l(-1)). The general trend observed was an increase in metal toxicity measured by the biotest with increasing available metal contents in tailings materials and soils. Therefore, the MetPAD test can be used as a rapid and sensitive predictive tool to assess the heavy metal availability in soils highly contaminated by mining activities.

Hydrogen-Ion Concentration↗