Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Metals, Heavy”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,081 records · Page 60Linked to original sources

Neurosyphilis, or chronic heavy metal poisoning: Karen Blixen's lifelong disease.

BACKGROUND: Since the 1490s, the treatment of syphilis has consisted of heavy metals--first mercurial and later arsenic and bismuth preparations. Tabes dorsalis, as described by Duchenne in the 1850s, is made up of various characteristic neurologic symptoms. "Gastric crises," sudden stabbing pains followed by vomiting and diarrhea, was originally included by Duchenne, but later, syphilologists disputed its relevance to syphilis. Poisoning by heavy metals, including mercury, may produce similar pain reactions and tabes-like neurologic symptoms. METHODS: According to an earlier published pathography, the Danish author Karen Blixen (1885-1962), also known under the pseudonym Isak Dinesen, suffered from a lifelong disease described as tabes dorsalis. She got syphilis in 1914 and took mercury pills for a year, after which she experienced a severe mercurial intoxication. The Wassermann reaction (WR) in peripheral blood was positive only once, in 1915, before treatment with arsphenamine (Salvarsan), which she received during hospitalization in Copenhagen in 1915 to 1916. Her spinal fluid was examined several times from 1915 to 1956. Apart from an increased number of cells in 1915, the fluid remained unremarkable and the WR was always negative. RESULTS AND CONCLUSIONS: It was postulated that her illness, ending with a cachectic state, was the result of heavy metal poisoning from the various treatments and not a monosymptomatic tabes dorsalis with negative serology.

Arsenicals↗

Cellular localization of calcium, heavy metals, and metallothionein in lobster (Homarus americanus) hepatopancreas.

This investigation combines confocal microscopy with the cation-specific fluorescent dyes Fluo-3 and BTC-5N to localize calcium and heavy metals along the length of intact lobster (Homarus americanus) hepatopancreatic tubules and isolated cells. A metallothionein-specific antibody, developed in mollusks with cross-reactivity in crustaceans, showed the tissue-specific occurrence of this metal-binding protein in several organ systems in lobster and in single cell types isolated from lobster hepatopancreas. Individual lobster hepatopancreatic epithelial cell types were separated into pure single cell type suspensions for confocal and antibody experiments. Intact hepatopancreatic tubules showed high concentrations of both calcium and heavy metals at the distal tips of tubules where mitotic stem cells (E-cells) are localized. In addition, a concentrated distribution of calcium signal within isolated single premolt E-cells in solution was disclosed that might suggest an endoplasmic reticulum compartmentation of this cation within these stem cells. Both E- and R-cells showed significantly (P < 0.05) greater intracellular calcium concentrations in premolt than intermolt, suggesting the accumulation of this cation in these cells prior to the molt. Antibody studies with lobster tissues indicated that the hepatopancreas possessed 5-10 times the metallothionein concentration as other lobster organ systems and that isolated E-cells from the hepatopancreas displayed more than twice the binding protein concentrations of other cells of this organ or those of blood cells. These results suggest that crustacean hepatopancreatic stem cells (E-cells) and R-cells play significant roles in calcium and heavy metal homeostasis in this tissue. Interactions between the four hepatopancreatic cell types in this regulatory activity remain to be elucidated.

Aniline Compounds↗

Studies on the effects of some organic pollutants on the heavy metal transport in an Indian soil.

The translocation of some heavy metals, such as Hg, Cd, Cu, Co, Ni and Zn, as affected by organic pollutants, i.e. methanol, ethanol, propanol, formaldehyde, acetaldehyde, benzaldehyde, acetone, ethyl methyl ketone and cyclo-hexanone, was studied in an Indian red soil using soil thin layer chromatography. It was observed that an increase in the concentration of organic compounds in developer enhances the heavy metal mobility, except in the case of Cu and Hg which show a decreasing trend. The results are discussed in relation to the physico-chemical characteristics of the soil and adsorption/desorption phenomena.

Journal Article↗

Field reconnaissance and estimation of petroleum hydrocarbon and heavy metal contents of soils affected by the Ebocha-8 oil spillage in Niger Delta, Nigeria.

Field reconnaissance of the Ebocha-8 oil spill-affected site at Obiobi/Obrikom in the Niger Delta region of Nigeria was carried out to assess the extent of damage to the terrestrial ecosystem and delimit the epicenter of oil spillage. Following three successive reconnaissance surveys, the area to be sampled was delimited (200 x 200 m2), and soil samples were collected using the grid method from three replicate quadrats at two depths, surface (0-15 cm) and subsurface (15-30 cm). A geographically similar area located 50 m adjacent to the oil-polluted area was used as a reference (control) site. Total hydrocarbon content (THC) and heavy metal concentrations were later determined in the laboratory by extraction and spetrophotemetric techniques. Generally, the THC of soils at surface and subsurface depths of the oil-polluted plots was 2.06 x 10(4) +/- 4.97 x 10(3) mg/kg and 1.67 x 10(3) +/- 3.61 x 10(2) mg/kg soil, respectively, (no overlap in standard errors at 95% confidence limit) while concentrations of heavy metals(Pb, Cd, V, Cu and Ni) were enhanced, especially at the surface. The high levels of THC and heavy metals may predispose the site, which hitherto served as arable agricultural land, to impaired fertility and possible conflagration. When concentrations of heavy metals reach the levels obtained in this study, they may become toxic to plants or possibly bio-accumulate, thus leading to toxic reactions along the food chain. While the spilled-oil may have contributed to the enhanced levels of the metals in the affected soils, physico-chemical properties of the soils, mobility of metals, and the intense rainfall and flooding that preceded the period of study may have also contributed in part to their enhanced concentrations. The presence of high hydrocarbon content may cause oxygen deprivation, which may result in the death of soil fauna by asphyxiation. There is, therefore, an urgent need to clear the affected site of these excess hydrocarbon deposits so as to enhance the rehabilitation process of the affected mat layer of soils. Other appropriate mitigating measures, such as subsequent monitoring of hydrocarbon levels at suitable intervals after the clean up activities, are also recommended, with reference to the findings of this study, for effective management of the affected area.

Accidents↗

Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) beads for heavy metal removal.

Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150-200 microm) was prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). The copolymer hydrogel bead composition was characterized by elemental analysis and found to contain 5 EGDMA monomer units each VIM monomer unit. Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m2/g. Poly(EGDMA-VIM) beads were characterized by swelling studies and scanning electron microscopy (SEM). These poly(EGDMA-VIM) beads with a swelling ratio of 78% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Cd(II), Hg(II) and Pb(II) were investigated in aqueous media containing different amounts of these ions (10-750 mg/l) and at different pH values (3.0-7.0). Chelation rate was very fast. The maximum chelation capacities of the poly(EGDMA-VIM) beads were 69.4 mg/g for Cd(II), 114.8 mg/g for Pb(II) and 163.5 mg/g for Hg(II). The affinity order on molar basis was observed as follows: Hg(II) > Cd(II) > Pb(II). Chelation behavior of heavy metal ions could be modelled using both the Langmuir and Freundlich isotherms. pH significantly affected the chelation capacity of VIM incorporated beads. Chelation of heavy metal ions from synthetic wastewater was also studied. The chelation capacities are 45.6 mg/g for Cd(II), 74.2 mg/g for Hg(II) and 92.5 mg/g for Pb(II) at 0.5 mmol/l initial metal concentration. Regeneration of the chelating-beads was easily performed with 0.1 M HNO3. These features make poly(EGDMA-VIM) beads potential candidate adsorbent for heavy metal removal.

Acrylates↗

Trends in heavy metal levels in the dissolved and particulate phase in the Dutch Rhine-Meuse (Maas) Delta.

Levels of the heavy metals Cd, Cr, Cu, Pb and Zn, in both the dissolved and particulate phase, were determined in two sampling campaigns in August 1978 and August 1984 in the Dutch Rhine-Meuse (Maas) Delta. Besides the heavy metal concentrations, other important parameters were determined, such as the concentrations of seston, chlorophyll and nutrients. The concentrations of dissolved Cd and of Cd, Pb and Cu in particulate matter were much higher in 1978 than in 1984, especially for Cd. This may be due to the strict regulations implemented in Germany to reduce the pollution of natural waters by heavy metals. The correlation between the high Cd content and the chlorophyll content is explained by the binding of Cd to living and dead organisms. The distribution of the metals between the dissolved and the particulate phase, indicated by the distribution quotient Kd, increases from low values of Kd for Cu and Zn, to higher values for Cd and Cr, and the highest values for Pb. The differences are explained by various binding forms of each of these metals in natural waters.

Fresh Water↗

[Eco-toxicology of heavy metals on the inhibition of seed germination and root elongation of wheat in soils].

The eco-toxicity of Cu, Zn, Pb, and Cd in the single form was tested with four types of soils(red loam soils, meadow brown soils, chestnut soils, and dark brown soils) and their combined effect was determined with meadow brown soils. The results showed that with the same content of heavy metals, the root elongation was strongly inhabited than the seed germination, and it indicated that root was more sensitive to heavy metals pollution. The inhibition rate of heavy metals pollution on the root elongation (IRHMRE) of wheat was significantly related with the contents of organic matter (OR) and Kjedahl-nitrogen (K-N) in soils (R2OR = 0.91, R2K-N = 0.92). However, IRHMRE was not significantly related with soil pH as did with OR and K-N, so does the content of CEC (R2pH = 0.62, R2CEC = 0.60). Whether under the low concentration of Cu, Zn, Pb, and Cd resulted in an irritated effect in root elongation, or under high concentration resulted in an inhibition effect in the single form, an synergistic effect occurred in the combined form.

Cadmium↗

Heavy metals in water, sediment and tissues of Leuciscus cephalus from a stream in southwestern Turkey.

Concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn) were measured in water, bottom sediment and tissues (muscle and gills) of Leuciscus cephalus from the Dipsiz stream in the Yatagan basin (southwestern Turkey), the site of a thermal power plant. Results for levels in water were compared with national and international water quality guidelines, as well as literature values were reported for streams and rivers. Comparisons were made of metal concentrations in water and sediment with those in the muscle and gills of L. cephalus caught from the Dipsiz stream. We found that there was metal accumulation in the gills compared to the muscle. Concentrations of Cd, Pb, Zn and Cr in the gills were higher than that in the muscle; however, Cu levels were higher in muscle than that in gills. Concentrations of heavy metals in L. cephalus muscle were below the legal limits for human consumption, although Cr, Pb and Zn levels in the gills were above the limits in the fish taken from the Dipsiz stream. On the other hand, no correlation was found between metal concentrations in water and sediment or between metal concentrations in water and muscle and gills of L. cephalus. A positive correlation was found between concentrations of Cu and Zn in the sediment and in fish tissue, whereas there was no relationship between other metal concentrations in the sediment and water, and muscle and gills of L. cephalus. As with water, Pb and Cd concentrations in particular were higher in sediment than that in background levels. The results show that the pollutants from the thermal power plant may be a source of these elements.

Animals↗

Toxic effect of heavy metals on cells isolated from the rat adrenal and testis.

Heavy metals including mercury, cadmium, cobalt, and copper (100 microM) exerted an adverse effect on the viability of isolated rat adrenal capsular (zona glomerulosa), adrenal decapsular (fasciculata and reticularis), and Leydig cells of the testis, with mercury being the most potent. Due to the decreased cell viability there was a parallel reduction in corticotropin-stimulated corticosterone production by adrenal decapsular cells and luteinizing hormone-stimulated testosterone production by Leydig cells. The results indicated a direct toxic action of these heavy metals on steroid-producing cells in the adrenal gland and the testis. Other metals tested, including lead, zinc, aluminum, chromium, iron, nickel, and lithium, did not exert any deleterious effect on cell viability or hormone-induced steroidogenesis in adrenal and Leydig cells when tested up to a concentration of 100 microM.

Adrenal Glands↗

Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina.

The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n=38) were chosen in the province of Córdoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies.

Air Pollutants↗

Heavy metals pollution in poultry and livestock feeds and manures under intensive farming in Jiangsu Province, China.

The heavy metals pollution in poultry and livestock feeds and manures under intensive farming in Jiangsu Province was investigated. 97 feed and manure samples were sampled from 31 farming plants in 10 major cities of Jiangsu. 14 metals, including Zn, Cu, Pb, Cd, Cr, Ni, Mo, Mn, Ba, Co, Sr, Ti, As and Hg, were analyzed after samples acid digestion. The results showed that the most feed samples contained high concentration of metals exceeding National Hygienical Standard for Feeds. Meanwhile, it was found that Cu, Zn, Pb, Cd and Cr concentrations in animal manures were also high, for example, Cu concentration in a manure sample reached to as much as 1726.3 mg/kg. Heavy metals loading quantities in soil per year were then calculated when metals contaminated organic fertilizers were applied, and its effects on soil environmental quality were further evaluated.

Animal Feed↗

In situ microcosms to study the impact of heavy metals resuspended by dredging on periphyton in a tropical estuary.

Ponggol estuary, located on the northeastern coast of Singapore, is heavily impacted by reclamation, dredging, construction and shipping. Tin, lead, nickel, cadmium, copper and zinc in the particulate and dissolved fraction and in sediments were monitored biweekly in the estuary from July 1999 to June 2000. The concentrations of tin, lead, nickel, cadmium, copper and zinc were observed to range from ND-92 ppm, ND-303 ppm, ND-2818 ppm, ND-74 ppm, ND-1117 ppm and ND-137000 ppm, respectively, in the dissolved, particulate and sediments fractions. Intensive dredging activity occurred during the monitoring period, and this may have led to the resuspension and increased bioavailability of particulate metals. Periphytic algae were established on glass slides and exposed to previously measured environmental levels of heavy metals using in situ estuarine microcosms. The toxicity of heavy metals in various fractions to periphytic algae was assessed from the changes in their chlorophyll a content. Cadmium had the least significant effect followed by lead, zinc, nickel, tin and copper at all concentrations tested. A reduction in periphyton biomass (with respect to controls) of 95-100% was observed for treatments with metals in particulate form. In addition, exposure to contaminated sediments for 3 days significantly decreased chlorophyll a by 90-99% compared to controls. High concentrations of zinc (9893-17240 mg l(-1)), copper (5-11 mg l(-1)) and cadmium (1-1.8 mg l(-1)) recorded in the aqueous phase of treatment microcosms, and attributed to release from the contaminated sediments, could account for the toxicity to periphyton.

Analysis of Variance↗

The relationship between heavy metal and rap music and adolescent turmoil: real or artifact?

Adolescents and their parents were surveyed to investigate the association between heavy metal and rap music and adolescent psychosocial turmoil. Subjects were asked about current and past psychosocial functioning, as well as their music preferences. Adolescents who preferred heavy metal and rap music were compared with those who preferred other types of music. Results indicated that adolescents who preferred heavy metal and rap had a higher incidence of below-average school grades, school behavior problems, sexual activity, drug and alcohol use, and arrests. However, when gender was controlled, only below-average current and elementary school grades and a history of counseling in elementary school for school problems remained significant. Implications of these findings are discussed.

Adolescent↗

Cytotoxicity and bioaccumulation of heavy metals by ciliated protozoa isolated from urban wastewater treatment plants.

We studied the cytotoxic effect of the heavy metals Cd, Zn and Cu on three different species of ciliated protozoa isolated from an urban wastewater treatment plant. The order of toxicity was Cd>Cu>>Zn or Cu>Cd>>Zn, depending on the microbial species. In bimetallic (Cd+Zn) treatments, results indicated that, in general, the presence of Zn in the same medium decreased Cd cytotoxicity. Both cellular assays and microscopic observations showed that bioaccumulation is an important mechanism of resistance to these toxic environmental pollutants in such eukaryotic microorganisms. However, bioaccumulation might not be the main mechanism involved in Cu resistance. For the first time, fluorescence methodology was applied for revealing metal deposits in the cellular cytoplasm. This microscopic method is only useful when cell cultures can be exposed to rather high metal concentrations, as in the case of Zn. Inside the ciliated protozoa exposed to sublethal concentrations of Cd or Zn, it is possible to observe diverse electron-dense granules by TEM which are not seen in controls. Problems in comparing our results on heavy metal cytotoxic effects on ciliates with already published data are exposed and discussed. The use of these eukaryotic microorganisms as potential whole cells or molecular (ciliate metallothioneins) biosensors seems to be a reasonable useful alternative for assessing metallic pollution.

Animals↗

The relationship of the increased level of metallothionein with heavy metal levels in the tissue of the harbor seal (Phoca vitulina).

The relationship between age, heavy metal levels, and a heavy-metal binding protein, metallothionein (MT), in the liver and kidney of the harbor seal (Phoca vitulina) was studied. The cadmium (Cd) level in the liver and the Cd, inorganic mercury (I-Hg), and zinc (Zn) levels in the kidney were increased with body length, suggesting an age-related accumulation of these metals. The MT levels determined by an MT radioimmunoassay showed concentrations of 240 +/- 139 micrograms/g in the liver and 343 +/- 219 micrograms/g in the kidney. These MT levels were shown to be correlated with age. The statistically significant relationship of the MT levels with the levels of Cd and Zn in the liver and those of Cd, Zn, and I-Hg in the kidney suggested that the protein is responsible for the sequestration of these metals as already observed in terrestrial animals.

Animals↗

Effects of heavy metals on plant-associated rhizobacteria: comparison of endophytic and non-endophytic strains of Azospirillum brasilense.

The plant-associated nitrogen-fixing rhizobacterium Azospirillum brasilense attracts world-wide attention owing to its plant growth-promoting activities. Among hundreds of its strains known up to date, wild-type strain Sp245 has been proved to be capable of colonising both the plant-root interior and exterior (i.e. a facultative endophyte), whereas others are non-endophytes colonising the root surface only. Thus, the different ecological niches occupied by these strains in the rhizosphere suggest that their responses to environmental conditions might differ as well. In this study, responses of A. brasilense strains Sp245 and Sp7 to several heavy metals (Co2+, Cu2+, Zn2+), present in the medium at tolerable concentrations (up to 0.2 mmol/l) and taken up by the bacteria, were compared. Fourier transform infrared (FTIR) spectroscopy was used for controlling the compositional features of whole cells. The results obtained show that in strain Sp7 (non-endophyte) the heavy metals induced an enhanced accumulation of polyester compounds (poly-3-hydroxybutyrate; PHB). In contrast, the response of the endophytic strain Sp245 to heavy metal uptake was found to be much less pronounced. These dissimilarities in their behaviour may be caused by different adaptation abilities of these strains to stress conditions owing to their different ecological status. It was also found that adding 0.2 mmol/l Cu2+ or Cd2+ in the culture medium resulted in noticeably reducing the levels of indole-3-acetic acid (IAA, auxin) produced by both the strains of the bacterium. This can directly affect the efficiency of associative plant-bacterial symbioses involving A. brasilense in heavy-metal-contaminated soil.

Azospirillum brasilense↗

Effects of heavy-metal-contaminated soil on growth, phenology and biomass turnover of Hieracium piloselloides.

The effects of low levels of heavy metals on plant growth, biomass turnover and reproduction were investigated for Hieracium pilosella. Plants were grown for 12 weeks on substrates with different concentrations of heavy metals obtained by diluting contaminated soils with silica sand. To minimize effects of other soil factors, the substrates were limed, fertilized, and well watered. The more metal-contaminated soil the substrate contained, the lower the leaf production rate and the plant mass were, and the more the phenological development was delayed. Flowering phenology was very sensitive to metals. Leaf life span was reduced at the highest and the lowest metal levels, the latter being a result of advanced seed ripening. Even if the effect of low metal levels on plant growth may be small, the delayed and reduced reproduction may have large effects at population, community and ecosystem level, and contribute to rapid evolution of metal tolerance.

Agriculture↗