Authors:M. Longjiang, F. Qiang, M. Duowen, H. Ke, and Y. Jinghong
The heavy metal contents and the contamination levels of the surface sediments of the Wuding River, northern China, were investigated.
Heavy metal concentration ranged in μg g−1: 50.15–71.91 for Cr, 408.1–442.9 for Mn, 20.11–43.59 for Ni, 17.51–20.1 for Cu, 68.32–89.57 for Zn, 0.2–0.38 for Cd and 15.08–16.14
for Pb in the Wuding River sediments. The enrichment factor (EF) and the geo-accumulation index (Igeo) demonstrated that the sediments of the Wuding River had been polluted by Cd, Cr and Ni, which mainly originated from
anthropogenic sources, whereas the sediments had not been polluted by Zn, Pb, Cu and Mn, which were derived from the crust.
In addition, the assessment results of EF and Igeo suggested that the sediments of the Wuding River was “moderately” polluted by Cd and “unpolluted to moderately” polluted
by Cr and Ni. The elevated urban sewage discharges and agriculture fertilizers usage in river basin are the anthropogenic
sources of these heavy metals in river.
Lead has been the bulwark of radiological shielding primarily because of its excellent attenuating properties, abundance, and cheapness as compared to other elements. Lead is now a federal regulated element under the Resource Conservation and Recovery Act and is potentially perilous material to deal with, expensive to decontaminate and stabilize, and environmentally difficult to bury at any approved sites. Leaded gloves are used in gloveboxes as a form of protection for the hands and arms from radioactive contamination and penetrating radiation from radioisotopes. The reduction of lead, mandated by United States Congress because of its hazardous and toxic characteristics, has required a substitute for the red lead oxide (Pb3O4) in the leaded-neoprene hand glove. We have performed heavy metal analysis on several proposed alternative materials using neutron activation analysis. To assess potential environmental impact the Toxicity Characteristic Leaching Procedure (TCLP) was also employed on the current leaded-neoprene glove. These TCLP results using ICP verified that lead leached out at a concentration higher than allowed by US EPA RCRA act. Other heavy metals that leached out were either below the US EPA limits or not on listed of regulated heavy metals.
The abundance and
diversity of indigenous
fungi were tested for correlations
with the natural colonization of symbiotic arbuscular mycorrhizal fungi (AMF)
in Cd-, Zn- and Ni-polluted soils. Infection frequency (F%) and arbusculum
richness (a%) of the mycorrhiza fungi were estimated on red clover grown in a
pot experiment set up with calcareous loamy chernozem soil contaminated with
Cd, Ni and Zn salts (in 0, 30, 90 and 270 mg kg
concentration) in the field, eight years prior to the pot experiment.
Correlation analyses were used to assess the effect of different heavy metal
loads on the interrelations of these two types of beneficial fungi. When the
test was performed for single variables, significant correlations could be
found with very close (r > 0.96 at p < 0.05) results. The rate and
direction (positive or negative) of correlations, however, varied with the type
of heavy metals. With the combinations of some
mycorrhiza parameters a significant model was obtained for the infection
frequency (R² = 0.9405 at p = 0.0062) and for arbusculum richness (R²
= 0.997 at p = 0.0007), which suggests a significant complex influence between
the symbiotic (AMF) and the free-living (
) beneficial fungi.
This interaction was altered by heavy metals. In the Ni treatments, the
correlation data were always negative between the two groups of beneficial
Heavy metals can be the most important toxic substances in welding environments. Their chemical behavior is related to welding aerosols; hence, reliable analysis of these aerosols is quite important. Activation analysis by fast neutrons (14 MeV), and radionuclidic X-ray fluorescence analysis (241-Am source) were used to determine selected metals (Fe, Mn, Cr, Ni, Mo) in aerosols produced during welding of high-alloy steels with MIG technology. Sampling was done by filtration using micro-pore filters. A multichannel analyzer (MCA S80 CANBERRA) and Si/Li, Ge/Li detectors were used to process the analytical signals. Appropriate statistical parameters were calculated.
Authors:P. Misaelides, A. Godelitsas, V. Charistos, D. Ioannou, and D. Charistos
The uptake of mercury, cadmium and silver from aqueous solutions by unpretreated and NaCl-pretreated clinoptilolite-bearing volcaniclastic rocks from Metaxades (Thrace, Greece) has been studied using a batch method with radioactive tracers (197Hg,115Cd and110mAg). The concentration of the solutions used varied between approximately 1000 and 17000 ppm. An improvement of the uptake ability was observed in the case of NaCl-pretreated material for all the investigated metals and especially for mercury at the upper part of the concentration range studied. The heavy metal uptake is attributed to different mechanisms taking place both at the rock grains and their individual mineral components.
This paper describes a simple, reasonably rapid, and accurate technique developed for the multielement analysis of heavy metals
in surface waters using ion exchange filter papers and cyanide complexing in conjunction with neutron activation analysis.
The method employs large water volume irradiation for improved sensitivity.130Te was used as an internal flux monitor to correct for neutron flux variations in the samples. Proof of the value of this
technique was obtained by the analysis of 10 surface water samples previously analyzed using conventional methods by the U.
S. Geological Survey of the U. S. Department of Interior. Good agreement resulted from this comparison.
Authors:Zsuzsanna Lengyel, Anita Lukács, Andrea Szabó, and L. Institóris
Three different insecticides: dimethoate, cypermethrin and amitraz were given, alone or combined with the heavy metals Pb, Hg and Cd, to male Wistar rats per os for 12 weeks from their 4th week of life. After the treatment period, the left hemisphere of the rats was exposed in urethane anaesthesia, and spontaneous and evoked cortical activity was recorded from the primary sensory areas. The effects of dimethoate on the spontaneous activity, and of dimethoate and amitraz on the evoked responses, were increased by the metal combination treatment, whereby the metals alone had no effect on the spontaneous and mild effect on the evoked activity. Finally, the animals were dissected, organ weights measured, and relative organ weights calculated. The weight gain of all treated groups was significantly retarded compared to the control. Several organ weights were also significantly reduced, mainly in groups receiving insecticide plus metal treatment. The toxic interactions observed in this work indicate that combined human exposure to environmental pesticide residues and heavy metals may have unexpectedly severe effects.