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PubMed1989

Studies with nonradioisotopic sodium chromate. I. Development of a technique for measuring red cell volume.

A nonradioisotopic method for measuring red cell volume that involves the use of 52Cr-sodium chromate as the red cell label and of graphite furnace atomic absorption analysis of chromium is described. The technique allows the labelling of 20 mL of packed red cells with 40 to 50 micrograms of sodium chromate (Na2CrO4) in 30 minutes at 22 degrees C with 94 +/- 6 percent uptake. Approximately 40 micrograms of Na2CrO4 was injected for in vivo studies. This results in posttransfusion in vivo red cell chromium levels after sample processing in the range of 1 to 7 micrograms per L, which could be quantitated accurately (coefficient of variation = 4.7%) by Zeeman electrothermal atomic absorption spectrophotometry. The labeling concentration of chromium did not cause increased hemolysis, and the labeled cells exhibited an osmotic fragility curve similar to that of unlabeled, fresh ACD red cells. Red cell glutathione peroxidase was unaffected by labeling, although glutathione reductase was reduced by approximately 13 percent (p less than 0.05). The 52Cr red cell volume-measuring method was evaluated by concurrent in vivo studies with the standard 51Cr and 125I-albumin methods for that procedure. Simultaneous measurement of red cell volumes in seven volunteers by the 51Cr, 52Cr, and 125I-albumin techniques correlated highly with each other (r greater than 0.76), with mean values of 2294 +/- 199, 2191 +/- 180, and 2243 +/- 291 mL, respectively. The standard deviations of the differences were small: 134 mL for 52Cr versus 51Cr and 183 mL for 52Cr versus 125I.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromates↗
PubMed1990

Direct radioimmunoassay of rat cystatin C: increased urinary excretion of this cysteine proteases inhibitor during chromate nephropathy.

Rat cystatin C was purified to apparent homogeneity from rat urine after induction of a tubular dysfunction with sodium chromate. The two-steps purification procedure included a Carboxymethyl-papain affinity chromatography and anion exchange chromatography. The purified protein was identified as rat cystatin C by the following criteria: firstly retained on a Cm-papain affinity column, secondly an apparent molecular weight of 15 kDa and pI of 10.2. Antisera raised in rabbits against our purified rat cystatin C did not cross-react with other urinary proteins such as rat albumin and rat kallikrein, but partially cross-reacted with human cystatin C. A direct radioimmunoassay was developed and it enabled 8.32 fmol/ml of rat cystatin C to be detected. The detection range was between 0.125 and 62.5 ng/ml, with 10% intra-assay variation and 14% inter-assay variation. Physiological rat cystatin C excretion (40 +/- 18 micrograms/24 h) was found by the direct assay. In the chromate-intoxicated rat, urinary excretion increased twenty-fivefold (1017 +/- 391 micrograms/24 h) and returned to normal level one week after intoxication. This RIA will allow the study of rat cystatin C metabolism particularly during renal dysfunction.

Acute Kidney Injury↗
PubMed2005

Beneficial role of hydrophytes in removing Cr(VI) from wastewater in association with chromate-reducing bacterial strains Ochrobactrum intermedium and Brevibacterium.

This study deals with the use of three chromium-resistant bacterial strains (Ochrobactrum intermedium CrT-1, Brevibacterium CrT-13, and CrM-1) in conjunction with Eichornia crassipes for the removal of toxic chromium from wastewater. Bacterial strains resulted in reduced uptake of chromate into inoculated plants as compared to noninoculated control plants. In the presence of different heavy metals, chromium uptake into the plants was 28.7 and 7.15% less at an initial K2CrO4 concentration of 100 and 500 microg ml(-1) in comparison to a metal free chromium solution. K2CrO4 uptake into the plant occurred at different pHs tested, but maximum uptake was observed at pH 5. Nevertheless, the bacterial strains caused some decrease in chromate uptake into the plants, but the combined effect of plants and bacterial strains conduce more removal of Cr(VI) from the solution.

Brevibacterium↗
PubMed2004

Size distribution of chromate paint aerosol generated in a bench-scale spray booth.

Spray painters are potentially exposed to aerosols containing hexavalent chromium [Cr(VI)] via inhalation of chromate-based paint sprays. Evaluating the particle size distribution of a paint spray aerosol, and the variables that may affect this distribution, is necessary to determine the site and degree of respiratory deposition and the damage that may result from inhaled Cr(VI)-containing paint particles. This study examined the effect of spray gun atomization pressure, aerosol generation source and aerosol aging on the size distribution of chromate-based paint overspray aerosols generated in a bench-scale paint spray booth. The study also determined the effect of particle bounce inside a Marple personal cascade impactor on measured size distributions of paint spray aerosols. Marple personal cascade impactors with a modified inlet were used for sample collection. The data indicated that paint particle bounce did not occur inside the cascade impactors sufficiently to affect size distribution when using uncoated stainless steel or PVC substrate sampling media. A decrease in paint aerosol mass median aerodynamic diameter (MMAD) from 8.2 to 7.0 mum was observed as gun atomization pressure increased from 6 to 10 psi. Overspray aerosols were sampled at two locations in the spray booth. A downstream sampling position simulated the exposure of a worker standing between the painted surface and exhaust, a situation encountered in booths with multiple workers. The measured mean MMAD was 7.2 mum. The distance between the painted surface and sampler was varied to sample oversprays of varying ages between 2.8 and 7.7 s. Age was not a significant factor for determining MMAD. Overspray was sampled at a 90 degrees position to simulate a worker standing in front of the surface being painted with air flowing to the worker's side, a common situation in field applications. The resulting overspray MMAD averaged 5.9 mum. Direct-spray aerosols were sampled at ages from 5.3 to 11.7 s. Overspray and direct-spray results indicated that most of the change in aerosol size distribution occurred between the time the paint aerosol impacted the painted surface and the time the overspray became 2.8 s old. The overall mean MMAD of overspray in the study was 6.4 mum and may have been underestimated due to sampling efficiency biases. If inhaled by a worker, the overspray aerosols evaluated in this study would mostly deposit in the head airways region of the respiratory tract. Paint overspray aerosols contained Cr primarily in the Cr(VI) state.

Aerosols↗
PubMed1995

The formation of both apurinic/apyrimidinic sites and single-strand breaks by chromate and glutathione arises from attack by the same single reactive species and is dependent on molecular oxygen.

The induction of apurinic/apyrimidinic sites (AP sites) and DNA single-strand breaks (SSB) by chromate and glutathione in isolated DNA was investigated using agents that cleave the DNA at AP sites (putrescine and exonuclease III). It was found that chromate/glutathione-induced AP sites contain free aldehyde groups, as cleavage by putrescine could be prevented by treatment with sodium borohydride. The formation of AP sites and SSB followed a very similar temporal pattern, suggesting that both lesions arise from attack by the same single reactive species deriving from chromate and glutathione. Furthermore, the induction of both lesions was found to be dependent on the presence of molecular oxygen.

Apurinic Acid↗
PubMed2006

Membrane topology of the chromate transporter ChrA of Pseudomonas aeruginosa.

The membrane topology of the plasmid-encoded Pseudomonas aeruginosa ChrA protein, which effluxes chromate ions, was determined by the analysis of translational fusions with reporter enzymes alkaline phosphatase and beta-galactosidase. A novel 13-TMS (transmembrane segments) topology, with the N-terminus located in the cytoplasm and the C-terminus in the periplasmic space, was consistent with the enzyme activities determined in both Escherichia coli and P. aeruginosa. Alignment of the two halves of ChrA showed significant sequence homology, with TMS I, II, III, IV, V and VI displaying similarity to TMS VIII, IX, X, XI, XII and XIII, respectively, although with opposite membrane orientations. This suggests that ChrA arose from the duplication of a gene encoding a 6-TMS ancestral protein, followed by the insertion of extra TMS VII. These data also suggest that the two halves of ChrA may carry out distinct functions for the transport of chromate.

Amino Acid Sequence↗
PubMed1977

Relapse of chromate dermatitis from sheet metal.

Galvanised sheet metal has previously been described as a source of chromate dermatitis (Fregert et al. 1970). We report a patient who appears to have been sensitised many years previously by an entirely different source of chromate, but whose resulting hand eczema has relapsed while handling galvanised sheet metal at work.

Adult↗
PubMed1977

Chromate dermatitis from a boiler lining.

Chromate dermatitis is described in a mechanical fitter working inside boiler combustion chambers. A source of hexavalent chromate is traced to the action of the heat and alkaline fuel ash on trivalent chrome ore in parts of the refractory lining. Removal of the patient from this contact has resulted in almost complete clearing of his dermatitis, without any relapse, during a 9-month follow-up period.

Chromates↗
PubMed1980

Eau de Javel and prevention of chromate allergy in France.

"Eau de Javel" (liquid bleach) is a common cause of chromate contact allergy. A historical review explains the reasons for the addition of sodium dichromate after the First World War. The chromium content in different brands of eau de Javel has been determined by flameless atomic absorption spectrophotometry. The results indicate that the chromium content is very low (0.03--3.65 mg/l) in French brands, whereas it is still important (7.06--82.9 mg/l) in Belgian brands, such an observation indicates that the almost complete removal of chromate in most brands of French eaux de Javel is a good example of prevention in the field of contact dermato-alllergology.

Belgium↗
PubMed1989

Cloning and expression of plasmid genes encoding resistances to chromate and cobalt in Alcaligenes eutrophus.

Resistances to chromate and cobalt were cloned on a 30-kilobase-pair (kb) DNA region from the large Alcaligenes eutrophus plasmid pMOL28 into the broad-host-range mobilizable cosmid vector pVK102. A restriction nuclease map of the 30-kb region was generated. The resistances expressed from the hybrid plasmids after transfer back into A. eutrophus were inducible and conferred the same degree of resistance as the parent plasmid pMOL28. Resistances were expressed in metal-sensitive Alcaligenes strains and related bacteria but not in Escherichia coli. Resistance to chromate was further localized on a 2.6-kb EcoRI fragment, and resistance to cobalt was localized on an adjoining 8.5-kb PstI-EcoRI fragment. When the 2.6-kb EcoRI fragment was expressed in E. coli under the control of a bacteriophage T7 promoter, three polypeptides with molecular masses of 31,500, 21,000, and 14,500 daltons were visible on autoradiograms. The 31,500- and 21,000-dalton polypeptides were membrane bound; the 14,500-dalton polypeptide was soluble.

Alcaligenes↗
PubMed1981

Health of workmen in the chromate-producing industry in Britain.

In a follow-up study of 2715 men who had worked for at least one year at the three chromate-producing factories in Britain between 1948 and 1977 only 298 were lost to follow-up, and the average number of person-years in the study was 16.3. One hundred and sixteen deaths from lung cancer occurred in these men, with only 48.0 expected (O/E = 2.4; p less than 0.001). For men employed at the factory, which is still in operation, the relative risk of lung cancer has decreased from over 3.0 before plant modification to about 1.8 in those who have worked only since plant modification. A multivariate analysis was used in an attempt to unravel the overlapping influence of duration of employment, length of follow-up, plant modification, factory, age at entry to work, and estimated degree of chromate exposure. The major dependent factor appeared to be duration of employment; in addition the analysis suggested that modifications in the plant and work environment had been associated with an appreciable reduction of the excess risk from lung cancer.

Adult↗
PubMed1991

Mortality from respiratory cancer and other causes in United Kingdom chromate production workers.

This report updates a 1981 study of mortality at three United Kingdom chromate producing factories, and pays special attention to workers engaged after major plant and process changes were completed during 1958-60. The study covers 2298 payroll workers in post on 1 January 1950 or entering employment up to 30 June 1976 and remaining at least one year, with mortality observed up to 31 December 1988. Expected numbers of deaths were calculated from national death rates adjusted for social class and area differences. At the two largest factories 1422 men starting work before the process changes showed a highly significant excess of deaths from lung cancer (observed deaths/adjusted expected deaths (obs/expA) 175/88.97, adjusted standardised mortality ratio (SMRA) 197). They also had a significant excess of deaths from nasal cancer (obs/expA 4/0.26, SMRA 1538); the four affected men all had over 20 years of employment. Six hundred and seventy seven men starting work after the completion of process changes showed no excess of lung cancer deaths (obs/expA 14/13.7, SMRA 102, 95% confidence interval (95% CI) 56-171), but the possibility of the risk persisting at a reduced level cannot be excluded. The risk among earlier entrants affected men with two or more years of employment and was highest among those working for 10 years or longer (SMRA 225). The relative risk was already raised 5-14 years after first employment; it was highest in the 25-40 year period, but was still raised 50 years after first exposure. The risk showed most clearly at young ages, with a SMRA of 355 for ages under 50 (obs/expA 21/5.91). The excess was greater among men in jobs with high exposure to chromates (obs/expA 151/61.73, SMRA 245) than among men in less exposed jobs (obs/expA 21/19.57, SMRA 107). Less evidence of a lung cancer excess was found among 199 men employed at a third small factory (obs/expA 12/9.91, SMRA 121). No risk was apparent in further groups of 214 salaried works staff (obs/expA 1/2.53), or 95 workers at an adjacent fertiliser plant (obs/expA 3/3.95). No significant excesses of deaths from cancers of other sites were found.

Adult↗
PubMed1978

Lung cancer in Japanese chromate workers.

We have treated ten patients with lung cancer among workers in a chromate factory between 1972 and 1976. Four further cases were also found through death certificates and medical records. Most were smokers and all were men. The average duration of exposure to chromate was 24 years (range 10 to 36). The cell type in our ten patients was squamous in seven and small anaplastic type in three. The primary sites were all in large bronchi. The incidence (person per year) calculated from the number of employees, duration of factory activity, number of cancer patients, and shortest duration of labour period among the patients was 657.9 per 100,000 compared to 13.3 per 100,000 in Japan as a whole.

Adult↗
PubMed2006

Hexavalent chromium removal in vitro and from industrial wastes, using chromate-resistant strains of filamentous fungi indigenous to contaminated wastes.

Two chromate-resistant filamentous fungi, strains H13 and Ed8, were selected from seven independent fungal isolates indigenous to Cr(VI)-contaminated soil because of their ability to decrease hexavalent chromium levels in the growth medium. Morphophysiological studies identified strain H13 as a Penicillium sp. isolate and Ed8 as an Aspergillus sp. isolate. When incubated in minimal medium with glucose as a carbon source and in the presence of 50 microg/mL Cr(VI), these strains caused complete disappearance of Cr(VI) in the growth medium after about 72 h of incubation. Total chromium concentration in growth medium was constant during culture growth, and no accumulation of chromium in fungal biomass was observed. Quantitative determinations of oxidized and reduced chromium species during the reduction process revealed stoichiometric conversion of Cr(VI) to Cr(III). A decrease in Cr(VI) levels from industrial wastes was also induced by Ed8 or H13 biomass. These results indicate that chromate-resistant filamentous fungi with Cr(VI)-reducing capability could be useful for the removal of Cr(VI) contamination.

Aspergillus↗
PubMed2003

Cellular phone dermatitis with chromate allergy.

BACKGROUND: A patient with allergic contact dermatitis caused by hexavalent chromium plating on a cellular phone has already been reported. OBJECTIVES: This study described the clinical characteristics and results of patch tests in 8 patients with contact dermatitis possibly caused by handling a cellular phone. PATIENTS: The 8 patients were 4 males and 4 females aged from 14 to 54 years. They each noticed skin eruptions after 9-25 days of using a cellular phone. All patients had erythema, and 7 had papules on the hemilateral auricle or in the preauricular region. Three of 8 patients had a history of metal allergy. Chromate, aluminium and acrylnitrile-butadiene-styrene copolymer were used as plating on the cellular phones used by these patients. METHODS: Closed patch tests and photopatch tests were performed using metal standard antigens. RESULTS: The patch test was positive for 0.5, 0.1 and 0.05% potassium dichromate in all 8 patients. The photopatch test showed the same results. One patient was positive for 2% cobalt chloride and one for 5% nickel sulfate. CONCLUSION: It is important to consider the possibility of contact dermatitis due to a cellular phone, possibly caused by chromate, when the patients have erythema and papules on the hemilateral auricle or in the preauricular region.

Adolescent↗
PubMedDate not supplied

Removing UV-A and UV-C radiation from UV-B fluorescent lamp emissions. Differences in the inhibition of photosynthesis in the marine alga Dunaliella tertiolecta using chromate versus cellulose acetate-polyester filters.

Ultraviolet-B (UV-B; 280-320 nm)-emitting lamps unavoidably emit ultraviolet-A (UV-A; 320-400 nm) and ultraviolet-C (UV-C; <280 nm) radiation. Short-wavelength-blocking filters are generally used to limit the wave bands of UV under investigation. The widespread use of such filters means that all exposures to UV-B radiation will have a significant UV-A component. Therefore, the physiological effects unique to UV-B exposure are difficult to clearly isolate. This study presents a method to remove the UV-A and UV-C "contamination" using a liquid potassium chromate (K(2)CrO(4)) filter, thus allowing more direct assessment of the effects of UV-B exposure. Cultures of the green marine alga Dunaliella tertiolecta were grown in the absence of UV radiation. Sunlamps supplied the UV radiation for a 24 h exposure (solar radiation was not used in this study). The UV radiation was filtered either by the standard method (i.e. cellulose acetate (CA) with polyester = Mylar controls) or by a liquid filter of potassium chromate. Photosynthetic responses were compared. Major decreases in the ratio of variable to maximal fluorescence in dark-adapted cells and photosynthetic capacity were observed in CA-filtered cultures, whereas no change was observed in cells exposed to the same UV-B flux with the UV-A removed by K(2)CrO(4). The use of a CA filter with a Mylar control does not link results unequivocally to UV-B radiation. Such results should be interpreted with caution.

Cellulose↗
PubMed1980

Chelation in metal intoxication. VIII. Removal of chromium from organs of potassium chromate administered rats.

Some polyaminocarboxylic acids were examined for their ability to mobilize chromium from certain vital organs, their subcellular fractions, and blood cells of potassium chromate administered rats. Hexamethylene 1,6-diamino tetraacetic acid (TDTA), triethylene tetramine hexaacetic acid (TTHA), and ethylene diamine di (O-hydroxylphenyl acetic acid) (EDDHA) may be useful in preventing or reducing chromate toxicity. No definite relationship could be observed between the structure of the chelating agents and their chromium-removing capacity.

Animals↗