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PubMed1983

[Levels of lead, cadmium and mercury in the hair of inhabitants of the Nantes and Grenoble areas].

Lead, cadmium and mercury were measured in the air of 398 inhabitants of the Grenoble area and 341 inhabitants of the Nantes area. The hair was washed with hor solution of EDTA, dissolved in nitric acid and analyzed by electrothermal atomic absorption spectrometry. The average concentrations are 6,23 micrograms/g for lead, 0,40 microgram/g for cadmium and 1,06 microgram/g for mercury. There is no difference between found data of the two areas for lead and cadmium. Mercury levels are higher in the Nantes area. Lead content is higher in male hair than in female hair, but the difference is not significant. In the Grenoble area, mercury levels are higher in males than in females; the process is reversed in the Nantes area. We have found no relation between metal levels and age of persons, but lead content is high in the hair of people under ten. Artisans and mechanics have lead content higher than the general people, though exposed people to occupational risks is excluded. We have found to relation between metal in the hair and the size of the town. It seems that the use of tobacco is without influence. Mercury content is related to the eating of fish. It is not increased in the population because of dental amalgams.

Adolescent↗
PubMed1985

Asbestos exposure, smoking habits, and cancer incidence among production and maintenance workers in an electrochemical plant.

The incidence of cancer was studied in a cohort of 287 men who were exposed to asbestos at a nitric acid production plant from 1928 onwards. During the observation period from 1953 through 1980 all cancer cases among the cohort members were identified in The Cancer Registry. For the whole cohort 42 cases of cancer were observed versus 30.6 expected. The figures for cancer of the lungs and pleura combined were 17 observed versus 3.7 expected. The corresponding figures for a heavily exposed subcohort were 11 observed and 1.2 expected. In that group there was also an increased incidence of colon cancer with 3 cases observed against 0.8 cases expected. Within the whole cohort four cases of pleural and one case of peritoneal malignant mesothelioma were found. There was also an increased incidence of malignant melanoma of the skin with 3 cases observed against 0.6 expected. For cancer cases that were registered as of unknown origin there were 7 cases observed and 1.4 expected. There was no increased rate ratio for cancer at any site before 20 years after the first asbestos exposure. The smoking habits of all cohort members were recorded and the relative rates for lung cancer were calculated in relation to smoking habits. In common with previous studies the results indicate a multiplicative model for the interaction between asbestos exposure and smoking in regard to lung cancer risk.

Asbestos↗
PubMedDate not supplied

Determination of iodine in seafood by inductively coupled plasma/mass spectrometry.

A method was developed for determination of total iodine content in different standard reference materials (SRMs) and seafood products by inductively coupled plasma/mass spectrometry (ICP/MS). If iodine is present as iodide and nitric acid is used in the wet digestion system, the observed signal is not stable when iodine is measured by ICP/MS at m/z 127. To stabilize the iodine signal, 3% ammonia solution (1 + 1, v/v) was added to the digest. The limit of quantitation of the method, defined as 6 times the standard deviation in the blank solution (n = 20) was estimated to be 15 mg/kg (using 0.2 g dry mass and a dilution factor of 50). The precision, expressed as repeatability of the iodine concentration, varied between 3.2 and 12% in SRMs, with concentrations of 4.70-0.17 mg/kg dry matter. The described method was compared with a method using tetramethylammonium hydroxide extraction. Both methods showed good precision and trueness by analyses of SRMs. The 2 methods were used to determine iodine in seafood from the Barents Sea, the Norwegian Sea, and the North Sea. The results showed great variation between different fish species as well as between individuals within a species. The lowest values of iodine were recorded in muscle of ling (Molva molva) with a mean of 0.07 mg/kg fresh weight and a variation between 0.03 and 0.11 mg/kg fresh weight. The highest values were found in cod (Gadus morhua) from the Barents Sea, with a mean of 2.5 mg/kg and a variation between 0.7 and 12.7 mg/kg fresh weight.

Ammonia↗
PubMed2005

Absorption spectroscopic study of synergistic extraction of praseodymium with benzoyl acetone in presence of crown ether.

The extraction behaviour of Pr(III) from aqueous nitric acid medium employing benzoylacetone has been studied in presence of two crown ethers, viz., 15-crown-5 and benzo-15-crown-5 in chloroform medium using UV-vis absorption spectroscopy. The binary equilibrium constant (logk(ex)) for the complex [Pr(benzoylacetonate)(NO3(-))2(H(2)O)] in organic phase was found to be 1.170. The overall equilibrium constants (logK) for the ternary species [Pr(benzoylacetonate)(crown ether)(NO3(-))(2)] were estimated to be 4.01 and 4.41 for 15-crown-5 and benzo-15-crown-5, respectively. The trend in the equilibrium constant values were very much in accordance with the nature of substitution of the donor moiety. The extraction of Pr(III) by the benzoylacetone-crown ether combination was maximum at pH 3.0 and extraction decreases with increase in pH. It has been found that the extent of extraction of Pr(III) in organic phase as the binary as well as ternary complex [Pr(benzoylacetonate)(NO3(-))(2)(H(2)O)] and [Pr(benzoylacetonate)(crown ether)(NO3(-))(2)] increases with increase in concentration of the ligand. Similar trend is observed in the extraction by only donors. Enthalpies and entropies of formation for the ternary extraction process have been estimated. In addition, the effect of NaNO(3) as foreign salt was also studied and it was observed that with increase in ionic strength, percentage extraction increases.

Butanones↗
PubMed2001

Ultrasonic extraction and field-portable anodic stripping voltammetric measurement of lead in dust wipe samples.

Dust wipe samples were subjected to ultrasonic extraction (UE) in diluted nitric acid, and then analyzed for lead content using field-portable anodic stripping voltammetry (ASV). Recoveries of lead were determined from wipe materials which were spiked with certified reference materials (CRMs) containing known quantities of lead. Four different wipe materials and four different CRMs were tested, with and without filtration of aliquots of sample extract through 0.45 microm hydrophilic polytetrafluoroethylene filters. The CRMs consisted of paint, soil, particulate, and dust matrices. Wipe materials were chosen from those which have been found to meet the performance aspects of an ASTM standard specification. UE/ASV experiments were carried out in accordance with newly published ASTM procedures for on-site extraction and electroanalysis. Recoveries were found to vary for different wipe materials and CRMs. For several CRMs, quantitative (80--120%) recoveries for UE/ASV were observed for one wipe material whether filtration was used or not, while other wipe materials required filtration for quantitative recovery. In the case of one wipe material which contained detergents, quantitative recoveries could not be achieved whether filtration was used or not. The total analysis time for a sample set of 6--12 samples was 60--90 min, including extraction time and sample manipulation. The results of this work have provided information on the choice of wipe materials that can be used for quantitative lead measurements by UE/ASV in materials that are representative of sources of lead in surface dust.

Dust↗
PubMed1990

The in-vitro response of pollen germination and tube length to different types of acidity.

Pollen germination and tube growth are among the most sensitive responses to atmospheric pollution. Both these are inhibited by the acidity of the growth medium. Pollen grains from two species (Pinus cembra L. and Sambucus nigra L.) were germinated in media over a range of pHs (5.0, 4.5, 4.0, 3.5, 3.0 and 2.5) and six types of acidity (H(2)SO(4), HNO(3), H(2)SO(4): HNO(3) in 1:1, 2:1, 3:1 and 5:1 ratio). Pollen of the Gymnosperm is shown to be more resistant to acidity in the medium. Sulphuric acid alone and the ratio 2:1 with nitric acid are demonstrated to be the more harmful for P. cembra and S. nigra, respectively. The latter species was sensitive to all mixtures, particularly in respect to germination percentage.

Journal Article↗
PubMed2005

Potentially toxic metals in ombrotrophic peat along a 400 km English-Scottish transect.

Four samples of ombrotrophic peat were collected from each of 10 upland locations in a transect from the southern Pennines to the Highland Boundary Fault, a total distance of ca. 400 km. Bulk compositions and other properties were determined. Total contents of Al and heavy metals (Ni, Cu, Zn, Cd, Pb) were determined following digestion with hydrofluoric acid, and concentrations of metals extractable with dilute nitric acid were also measured. Supernatants obtained from aqueous extractions of the peat samples were analysed for pH, major cations and anions, dissolved organic carbon and dissolved metals, and concentrations of free metal ions (Al(3+), Ni(2+), etc.) were estimated by applying a chemical speciation model. Both total and HNO(3)-extractable metal concentrations varied along the transect, the highest values being found at locations close to industrial and former mining areas. The HNO(3)-extractable soil metal contents of Ni, Cu and Cd were appreciably lower than lowest-observed-effect-concentrations (LOEC) for toxicity towards microorganisms in acid, organic rich soils. However, the contents of Zn at two locations, and of Pb at five locations exceeded LOECs, suggesting that they may be exerting toxic effects in the peats. Soil solution concentrations of free heavy metal ions (Cu(2+), Zn(2+), Cd(2+), Pb(2+)) were substantially lower than LOECs for toxicity towards vascular plants, whereas concentrations of Al(3+) were near to toxic levels at two locations.

Aluminum↗
PubMed2004

Measurement and analysis of the relationship between ammonia, acid gases, and fine particles in eastern North Carolina.

An annular denuder system, which consisted of a cyclone separator; two diffusion denuders coated with sodium carbonate and citric acid, respectively; and a filter pack consisting of Teflon and nylon filters in series, was used to measure acid gases, ammonia (NH3), and fine particles in the atmosphere from April 1998 to March 1999 in eastern North Carolina (i.e., an NH3-rich environment). The sodium carbonate denuders yielded average acid gas concentrations of 0.23 microg/m3 hydrochloric acid (standard deviation [SD] +/- 0.2 microg/m3); 1.14 microg/m3 nitric acid (SD +/- 0.81 microg/m3), and 1.61 microg/m3 sulfuric acid (SD +/- 1.58 microg/m3). The citric acid denuders yielded an average concentration of 17.89 microg/m3 NH3 (SD +/- 15.03 microg/m3). The filters yielded average fine aerosol concentrations of 1.64 microg/m3 ammonium (NH4+; SD +/- 1.26 microg/m3); 0.26 microg/m3 chloride (SD +/- 0.69 microg/m3), 1.92 microg/m3 nitrate (SD +/- 1.09 microg/m3), and 3.18 microg/m3 sulfate (SO4(2-); SD +/- 3.12 microg/m3). From seasonal variation, the measured particulates (NH4+, SO4(2-), and nitrate) showed larger peak concentrations during summer, suggesting that the gas-to-particle conversion was efficient during summer. The aerosol fraction in this study area indicated the domination of ammonium sulfate particles because of the local abundance of NH3, and the long-range transport of SO4(2-) based on back trajectory analysis. Relative humidity effects on gas-to-particle conversion processes were analyzed by particulate NH4+ concentration originally formed from the neutralization processes with the secondary pollutants in the atmosphere.

Acids↗
PubMed2006

Assessment of skin exposure to nickel, chromium and cobalt by acid wipe sampling and ICP-MS.

There is a great need to accurately assess skin exposure to contact allergens. We have developed a technique for assessment of skin exposure to nickel, chromium and cobalt using acid wipe sampling by cellulose wipes with 1% nitric acid. Chemical analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS). The recovery of nickel, chromium and cobalt from arms and palms was 93%. The analytical result is expressed in terms of mass per unit area (microg/cm(2)). The developed acid wipe sampling technique is suitable for determination of nickel, chromium and cobalt deposited on the skin. The technique may be used in workplace studies, in studies of individuals in the general population, in dermatitis patients, in identification of risk groups, as well as in developing preventive strategies and in follow-up after intervention.

Allergens↗
PubMed2004

A novel separation and preconcentration method for traces of manganese, cobalt, zinc and cadmium using coagulation of colloidal silica.

A separation and preconcentration method has been developed for traces of heavy metals using coagulation of colloidal silica. An appropriate amount of colloidal silica was added to a sample solution, the pH was adjusted to 11 with tetramethylammonium hydroxide solution and calcium chloride solution was then added to coagulate the silica. The coagulated silica and solution were separated by centrifugation, and the silica was then treated with hydrofluoric and perchloric acids. The residue was taken up in dilute nitric acid and subjected to ICP-AES to determine manganese, cobalt, zinc and cadmium. The proposed method was successfully applied to analysis of river-water.

Journal Article↗
PubMed1997

Overexpression of protein kinase C-zeta isoform increases cyclooxygenase-2 and inducible nitric oxide synthase.

Cyclooxygenase (COX) catalyzes the formation of prostaglandins from arachidonic acid. Nitric oxide synthase catalyzes the production of nitric oxide, a short-lived messenger molecule involved in many diverse cellular processes. Both of these enzymes have inducible forms [COX-2 and inducible nitric oxide synthase (iNOS), respectively] that respond to environmental stresses, chemicals, and extracellular ligands such as interleukin-1, epidermal growth factor, and platelet-derived growth factor. The precise cascade of intracellular events that leads to the expression of either COX-2 or iNOS is not known. Protein kinase C (PKC) is a family of 11 serine-threonine kinases conserved throughout eukaryotic species that transduce a wide variety of signals critical for cellular functions. Using a retroviral vector to overexpress the zeta-isoform of PKC in rat mesangial cells, we demonstrate markedly increased COX-2, prostaglandin E2 (PGE2), iNOS, and altered cellular morphology compared with mesangial cells expressing a control retroviral vector and untransfected mesangial cells. NIH/3T3 cells overexpressing PKC-zeta showed no change in morphology, PGE2 production, COX-2 expression, or iNOS expression at basal conditions. This suggests a role for PKC-zeta in the expression of these enzymes in mesangial cells.

3T3 Cells↗
PubMed1996

Characterization of time course of spinal amino acids, citrulline and PGE2 release after carrageenan/kaolin-induced knee joint inflammation: a chronic microdialysis study.

Pharmacological studies have implicated the spinal activation of excitatory amino acids, nitric oxide, and prostaglandins systems in the development of tactile and thermal hypersensitivity and central sensitization after peripheral inflammation. In the present study, using a chronically placed loop dialysis catheter, we examined in the unanesthetized rat the effect of carrageenan/kaolin (C/K)-induced knee joint inflammation on the time course of spinal release of several active factors including excitatory amino acids (glutamate, aspartate), citrulline (a marker of nitric oxide formation), and prostaglandin E2 (PGE2) as well as the concomitant development of tactile and thermal hypersensitivity. Infection of C/K in the knee evoked a significant release of glutamate, with an initial peak seen immediately after knee C/K injection (179 +/- 22%) and with a progressive and consistent increase over a period of 24 h (153-186%). Comparable changes in the concentration of aspartate (123-179%) were observed. Citrulline was constantly above baseline for the 24-h period (121-158%). PGE2 was significantly increased at 10 min (146 +/- 11%) with no change observed between 3-5 h. At 24 h, PGE2 was again significantly (143 +/- 18%) increased. Behaviorally, a prominent thermal and tactile allodynia developed after injection with the peak seen by 1-3 h after induction of the inflammation. This hypersensitivity state, while diminished in its intensity, persisted for the entire observation period. These data suggest that increased spinal release of excitatory amino acids (EAA), nitric oxide and/or PGE2 is involved in the maintenance of the pain state initiated by acute peripheral inflammation.

Amino Acids↗
PubMed2001

Metal extraction from road sediment using different strength reagents: impact on anthropogenic contaminant signals.

Washoff of road deposited sediment into storm drain systems is one of the major contributors to nonpoint source pollution in urban fluvial networks. These sediments contain a variety of potentially toxic organic and inorganic contaminants. Road sediment from 13 locations in an urban (non-industrialized) drainage basin, and soil from 10 background (control) locations were collected to assess total and labile fractions of Al, Co, Cu, Fe, Mn, Ni, Pb and Zn. Four digestions, of varying strength, were used to assess contaminant levels, these included: a total four-acid digestion, a microwave-assisted digestion with concentrated nitric acid (USEPA Method 3051), a 0.5 M 'cold' HCl, and a 0.05 M EDTA (pH 7). Road sediment data indicate that Al, Co, Fe, Mn and Ni were primarily lithogenic in origin, while Cu, Pb and Zn showed very significant anthropogenic signals, most probably from vehicle-related sources. Median Pb concentration enrichment ratios for the EDTA extraction were about 42, indicating an extreme anthropogenic signal. The weak extractants (HCI and EDTA) are considered in this study to be superior in their ability to characterize the degree of anthropogenic contamination and should be utilized more widely in environmental contaminant studies.

Chelating Agents↗
PubMed2000

[The effect of temperature on the behavior of aminobenzoic acid on silver surface].

SERS spectra of p-Aminobenzoic Acid (PABA) and o-Aminobenzoic Acid (OABA) absorbed on a silver surface, roughened by nitric acid, have been measured with a Renishaw Raman microprobe spectrometer(lambda = 632.8 nm) at different temperature, which ranged from 30 degrees C to -190 degrees C and from -190 degrees C to 30 degrees C. Some reversible changes in some band positions have been observed. The results indicated that if the adsorbates were enhanced by chemical mechanism and the molecules lie flat on surface, e.g. p-Aminobenzoic Acid molecule, temperature had no effect on their orientation. However, the vibrational frequencies enhanced by electromagnetic mechanism shifted as temperature changed, e.g. the vibration of NH2 in o-Aminobenzoic. The fact was that temperature had effect on the orientation of the molecules.

4-Aminobenzoic Acid↗
PubMed2003

Comparison of three sequential extraction procedures used to study trace metal distribution in an acidic sandy soil.

On an acid sandy soil contaminated with trace metals (Fe, Mn, Cu, Pb and Zn), three sequential extraction procedures were compared to determine the efficiency of the reagents used and the effects of the step order on the fractionation of metal species. In all cases, a magnesium nitrate solution (MgNIT) was previously used to extract exchangeable forms. In the first procedure (I), the next extraction step was performed with sodium acetate buffer (NaOAc), as used on calcareous soils, to dissolve active calcium carbonate. Then trace metals bound to different forms of oxi-hydroxides (NH(2)OH, TAMOx and TAMAs fractions) were extracted before organic matter/sulfide oxidation with hydrogen peroxide at pH 2.0 in nitric acid medium (OMHyd). Finally, residual bound metals (RESID) in each procedure were extracted with a nitric-hydrofluoric-perchloric acid mixture. The second procedure (II) was the same as I, but without the NaOAc step, because of the absence of carbonate in the study soil. In procedure III, the NaOAc step was omitted and the oxidizable organic/sulfide fraction was extracted with sodium hypochlorite at pH 8.5 (OMOCl) before the reducible fractions. This study first showed that NaOAc may remove considerable amounts of metals (especially Mn and Zn) in other forms than exchangeable ones. Procedures II and III give similar results for Fe, Mn and Zn forms, which were mainly found in fractions of inorganic soil components, but not for Cu and Pb. Copper distribution was affected by the position of the oxidation step in the sequence. In procedure II, where the oxidation step (OMHyd) ended the sequence, Cu was mainly recovered in the TAMOx fraction. However, in procedure III, where the oxidation step (OMOCl) preceded the NH(2)OH, TAMOx and TAMAs steps, Cu was found in both OMOCl and TAMOx fractions. Lead distribution varied with oxidation reagent: it was partly removed in the OMHyd fraction of procedures I and II, and to a much lower extent in the OMOCl fraction of procedure III, probably due to the alkaline pH of the reagent in the latter case.

Acids↗
PubMed1997

The initial reactions of TiO2 with blood.

The natural titanium oxide (TiO2) layer of commercial sheet titanium was dissolved in hydrofluoric acid. A new oxide layer was grown by oxidation in nitric acid or by annealing at 700 degrees C in air. At this temperature, reaction with nitrogen is unlikely. The purity of the oxidized sheet-titanium surfaces was investigated by Auger spectroscopy. The composition of both surfaces was TiO2 with carbon impurities. The carbon content of the acid-oxidized titanium was 20 +/- 2%, and the carbon content of the heat-oxidized titanium was 14 +/- 2% The initial reactions of the TiO2 surfaces with blood were investigated by short-time exposure to capillary blood and by detection of surface-adsorbed plasma proteins and cells with immunofluorescence. Antibodies specific to fibrinogen, complement factor C1q, prothrombin/thrombin, and platelet membrane antigen were used, and the fluorescence was quantitated by computer-aided image analysis. The results show that serine proteases are the dominating proteins adsorbed onto annealed titanium (C1q = 67 +/- 4.6; pt/t = 97 +/- 0.2; fib = 47 +/- 0.2). The adsorption of serine proteases was lower and the amount of fibrinogen was higher on the acid-oxidized surface (C1q = 46.3 +/- 2.6; pt/t = 25 +/- 2.9; fib = 64 +/- 0.7). Platelets adhered and spread on the annealed titanium surface within 5 sec of blood-material contact. The number of adhering platelets was higher on the acid-oxidized surface.

Biocompatible Materials↗
PubMed2005

Synthesis and ocular effects of imidazole nitrolic acids.

Novel 1-R-imidazole-2-nitrolic acids and 1-R-imidazole-5-nitrolic acids (R: H, Me, Bn) were synthesized from oximes by treatment with a mixture of fuming nitric acid and acetic acid. The effects of these potential nitric oxide-donating compounds were tested on ocular variables such as intraocular pressure and formation of cyclic guanosine-3,5'-monophosphate in the incubation of porcine iris-ciliary body.

Animals↗