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PubMed2002

Control of occupational exposure to hexavalent chromium and ozone in tubular wire arc-welding processes by replacement of potassium by lithium or by addition of zinc.

Hexavalent chromium [Cr(VI)] and ozone are produced in many arc-welding processes. Cr(VI) is formed when welding with chromium-containing alloys and is a suspected carcinogen. Ozone is formed by the action of ultraviolet light from the arc on oxygen and can cause severe irritation to the eyes and mucous membranes. Previous work has demonstrated that reduction of sodium and potassium in manual metal arc-welding electrodes leads to substantial reductions in Cr(VI) concentrations in the fume as well as a reduction in the fume formation rate. In this paper replacement of potassium by lithium in a tubular wire welding electrode (self-shielding flux-cored) is shown to give reductions in Cr(VI) concentrations and fume formation rates. Previous work has also demonstrated that use of a tubular wire (metal cored) containing 1% zinc can, under certain conditions, result in a reduction in Cr(VI) formation rate and in ozone concentration near the arc but with a rise in the total fume formation rate. The effects of different shield gases and different levels of zinc are examined. An experimental chromium-containing tubular wire with 1% zinc was used with the following shield gases: argon, Argoshield 5, Argoshield 20, Helishield 101, Ar + 2% CO2, Ar + 5% CO2, Ar + 1% O2 and Ar + 2% O2. The wire gave > 98% reduction in Cr(VI) formation rate compared to the control wire provided the shield gas contained no oxygen. When the shield gas did contain oxygen, 1% zinc enhanced Cr(VI) formation rate, resulting in more than double the rates measured when welding with the control wire. Experiments with zinc concentrations, from 0.018 to 0.9% using Helishield 101, gave results indicating that there is an optimum zinc concentration from the point of view of Cr(VI) reduction. Implications of the use of lithium or zinc on the overall exposure risk are discussed.

Chromium↗
PubMed1995

Influence of reducing compounds on the formation of DNA-protein cross-links in HL-60 cells induced by hexavalent chromium.

The influence of reducing compounds on the formation of DNA--protein cross-links induced by hexavalent chromium was studied in the human cell line HL-60. Analysis of cytoplasmic concentration of ascorbic acid and glutathione by HPLC in these cells showed that ascorbic acid was not detectable (detection limit: 0.1 nmol). The cellular content of glutathione was low (6 nmol/million cells). It could easily be depleted with diethylmaleate. The effect of glutathione, ascorbic acid and ascorbyl palmitate alone, or glutathione in combination with ascorbyl palmitate was investigated. It could be shown that glutathione increased DNA--protein cross-links in HL-60 cells by chromate significantly in a dose dependent manner, while pre-incubation with L-ascorbic acid and L-ascorbic acid-6-hexadecanate (ascorbyl palmitate) did not change the cross-linking activity of chromate significantly. Ascorbyl palmitate counteracted the increasing effect of glutathione on the concentration of DNA--protein cross-links in HL-60 cells after exposure to chromate. As ascorbic acid reacts much faster with hexavalent chromium at physiological pH than glutathione does, this suggests an influence of the reaction velocity of the redox reaction between hexavalent chromium and the reducing compounds on the toxification of Cr(VI) and formation of DNA--protein cross-links.

Antimutagenic Agents↗
PubMed1998

Elevated DNA single-strand breakage frequencies in lymphocytes of welders exposed to chromium and nickel.

DNA damage (alkaline filter elution) and sister chromatid exchange (SCE) frequencies were measured in lymphocytes of 39 welders and 39 controls. The welders showed a significantly higher rate of DNA single-strand breakages and significantly elevated SCE values. These results are not in accordance with those of a former study in which only DNA-protein cross-links were measured. The different results may be explained on the basis of different exposure levels for chromium(VI) and nickel. Both methods are not specific but sensitive enough to measure genotoxic damage after occupational exposure to chromium(VI) and nickel in the range of threshold values for the workplace on a collective basis. Additionally, the results indicate that DNA single-strand breakage and DNA-protein cross-links show different increases depending on the exposure levels for chromium and nickel.

Adult↗
PubMed1979

Mortality in chromium chemical production workers: a prospective study.

Mortality among male employees was studied in a chromium chemical production plant, part of which was rebuilt in 1950-51 and the remainder in 1960, to reduce exposure to chromium bearing dusts. Of 2 101 employees initially employed between 1945 and 1974 and having worked at least 90 days, the vital status of 88% was ascertained, as of mid-1977. Lung cancer mortality for hourly workers initially employed between 1945 and 1959 was significantly higher than in the comparison Baltimore City population (SMR = 2.0), yet it was lower than that reported in previous studies of this industry. A dose response effect was evident from the relationship between duration of employment and mortality. The lung cancer mortality among those employed for three or more years exclusively in the new facility was similar to that observed for such long-term workers in other parts of the plant. Specific job positions were examined. A history of employment in the Bichromate and Special Products Department (production of chromic acid and other products), known as the 'wet end', was associated with the increased lung cancer mortality in contrast to the Mill and Roast Department, known as the 'dry end'. Because of the long latency period associated with chromium exposure and cancer, it was not possible to adequately assess the risk of cancer for workers initially employed after 1960. Methodological issues related to these findings are discussed.

Chemical Industry↗
PubMed1977

Analysis of chromium induced carbohydrate intolerance in the rat.

Carbohydrate tolerance was studied by intravenous glucose tolerance tests in normal and chromium deficient rats. A significant difference in glucose metabolism between chromium deficient and chromium supplemented rats was demonstrated only when the glucose decay constant was calculated from the line fitting the plotted logarithms of the excess plasma glucose concentrations. Calculation of the glucose decay constant from the line fitting the logarithms of the total plasma glucose concentrations showed no significant difference between the two groups. This finding suggests that either the first method is more sensitive to mild changes in intravenous glucose tolerance in the rat, or the observed difference is a methodological artifact.

Animals↗
PubMed1999

Oxidative damage of DNA by chromium(V) complexes: relative importance of base versus sugar oxidation.

Chromium(V)-mediated oxidative damage of deoxy-ribonucleic acids was investigated at neutral pH in aqueous solution by utilizing bis(2-ethyl-2-hydroxy-butanato)oxochromate(V) (I) and bis(hydroxyethyl)-amino-tris(hydroxymethyl)methane)oxochromate(V) (II). Single-stranded and double-stranded (ds) calf thymus and human placenta DNA, as well as two oligomers, 5'-GATCTAGTAGGAGGACAAATAGTGTTTG-3' and 5'-GATCCAAGCAAACACTATTTGTCCTCCTACTA-3', were reacted with the chromium(V) complexes. Most products were separated and characterized by chroma-tographic and spectroscopic methods. Polyacrylamide gel electrophoresis experiments reveal more damage at G sites in comparison to other bases. Three primary oxidation products, 5-methylene-2-furanone (5-MF), furfural and 8-oxo-2'-deoxyguanosine, were characterized. A minor product, which appears to be thymine propenal, was also observed. The dsDNA produces more furfural than furanone. The formation of these two products resulted from hydrogen ion or hydride transfer from C1' and C5' positions of the ribose to the oxo-chromium(V) center. Since no enhancements of these products (except propenal) were observed in the presence of oxygen, mechanisms pertaining to the participation of activated oxygen species may be ruled out. The oxidation of the G base is most likely associated with an oxygen atom transfer from the oxo-metallates to the double bond between C8 and N7 of the purine ring. The formation of the propenal may be associated with an oxygen-activated species, since a marginal enhancement of this product was observed in the presence of oxygen. The formation of furfural in higher abundance over 5-MF for dsDNA was attributed to the ease of hydrogen ion (or hydride transfer) from the C5' compared to C1' position of the ribose within a Cr(V)-DNA intermediate in which the metal center is bound to the phosphate diester moiety.

Animals↗
PubMed2002

Respiratory health effects of long-term exposure to different chromium species in stainless steel production.

The aim of this study was to determine whether occupational exposure to chromite, trivalent chromium (Cr(3+)) or hexavalent chromium (Cr(6+)) causes respiratory diseases, an excess of respiratory symptoms, a decrease in pulmonary function or signs of pneumoconiosis among workers in stainless steel production. Altogether, 203 exposed workers and 81 referents with an average employment of 23 years were investigated for indicators of respiratory health on two occasions, in 1993 and in 1998. Data collection with a self-administered questionnaire, flow volume spirometry, measurement of diffusing capacity, chest radiography and laboratory tests were carried out by a mobile research unit. Exposure to different chromium species and other metals was monitored regularly and studied separately. No adverse respiratory health effects were observed in the group exposed to Cr(6+), either in comparison with the control group in the first cross-sectional study or during the additional 5 year follow-up. Among the Cr (3+) exposed people, the production of phlegm, shortness of breath and breathlessness on exertion were significantly more frequent than in the control group, but the frequency of the symptoms did not increase during the follow-up; no differences were observed in the lung function tests and the radiographic findings did not progress. In the chromite group, the prevalence of breathlessness on exertion was higher than in the control group. However, in the follow-up, the occurrence of symptoms did not differ from 1993 to 1998. In the first study, most parameters of lung function were lower among the smokers in the chromite group than among the smoking controls, but in 1998 the difference was less marked. An average exposure time of 23 years in modern ferrochromium and stainless steel production and low exposure to dusts and fumes containing Cr(6+), Cr(3+), nickel and molybdenum do not lead to respiratory changes detectable by lung function tests or radiography. The workers exposed to Cr(3+) had more respiratory symptoms than those in the control group. The workers in the chromite mine had lower lung function test results than the control group due to earlier exposure to higher dust concentrations.

Adult↗
PubMed1999

A study of leukaemia in Glasgow in connection with chromium-contaminated land.

BACKGROUND: In 1991, soil pollution was found around the site of a former chromium-processing factory in Glasgow, Scotland. Levels of chromium in soil were above limits considered as safe, although a risk assessment concluded that population exposure was likely to be below occupational levels. As an excess incidence of leukaemia has been suspected in the area, it was decided to investigate a possible relationship between the pollutant and the illness. METHODS: The ensuing study was descriptive-geographical. In the absence of better data, levels of exposure were assumed to decrease with distance from the centre of the polluted area. Leukaemia and population figures were obtained for each of nine concentric rings by aggregation of data available at the Enumeration District level. The null study hypothesis was that relative risk (as measured by Poisson regression) would not follow a definite trend with distance from the centre. Sex, age and levels of deprivation were taken into account. RESULTS: Relative risks by variables other than distance followed previously known patterns for leukaemia. No evident pattern by distance was found. After regroupings inside the variables, a significant excess of leukaemia was found for intermediate distances from the pollutant. CONCLUSIONS: No evidence was found of a possible relationship between soil pollution by chromium and leukaemia in the general population. Nonetheless, the excess noticed by the study warrants further research.

Adolescent↗
PubMed2000

Congenital anomalies in Glasgow between 1982 and 1989 and chromium waste.

BACKGROUND: The former site of a factory in Glasgow and nearby areas were found to be heavily polluted by chromium waste. This gave rise to local concern on possible health effects. As part of a wider study answering this concern, congenital malformations were investigated. METHODS: A descriptive geographical study was carried out. A 10 km circle centred on the factory site was designated as the study area and subdivided into one circle of 2 km radius and eight 1 km wide rings. Significant differences in relative risk between the circle and rings and a decreasing trend of risk with distance from the centre would point towards a teratogenic role of the chromium waste. Relative risks by rings were obtained by Poisson regression. Relative risks by deprivation categories were also obtained, with most results adjusted by these categories. RESULTS: Significant differences in risk appeared, with the area containing the polluted soil having the lowest risk. Aggregations of rings showed a central area with a relatively low risk, followed by an intermediate one with the highest risk and an external area with risk also high. Relative risk appeared to increase sharply between the most affluent category and the rest, then growing steadily with increasing deprivation but decreasing slightly for the most deprived. CONCLUSIONS: Relative risk shows a significant peak in an area 2-4 km away from the pollutant, which does not point towards a possible teratogenic effect of the chromium waste. Relative risk of congenital malformations for the more affluent sector of the population appeared to be markedly lower than that for the rest.

Chromium↗
PubMed1994

Sinus histiocytosis of pelvic lymph nodes after hip replacement. A histiocytic proliferation induced by cobalt-chromium and titanium.

Six men who had undergone hip replacements for degenerative joint disease or trauma subsequently had radical prostatectomies or cystoprostatectomies with bilateral pelvic lymph node dissections for adenocarcinoma of the prostate or transitional cell carcinoma of the urinary bladder. The hip prostheses implanted in three patients were known to contain cobalt-chromium alloy and titanium. The pelvic lymph nodes ipsilateral to the hip prosthesis in five patients and the bilateral pelvic nodes in the only patient with bilateral hip prosthesis had dark brown or black cut surfaces. These lymph nodes did not contain carcinoma but showed florid sinus histiocytosis characterized by large polygonal histiocytes filling and expanding sinuses and interfollicular regions. The foamy histiocytes contained cobalt-chromium and titanium microparticles by light microscopy, ultrastructure, and energy-dispersive x-ray microanalysis. The lymph nodes uninvolved by the histiocytic reaction lacked the heavy metal microparticles. Four cases were found to have a small number of polyethylene particles, which might have contributed to the histiocytic response. By immunohistochemistry, the foamy cells displayed immunoreactivity for lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, and cathepsin D, providing additional support for their histiocytic derivation. To our knowledge, this is the first time that microparticles of cobalt-chromium and titanium that migrate from hip prostheses to pelvic lymph nodes have been shown to elicit a distinctive type of florid sinus histiocytosis. Pathologists should be aware of this characteristic foreign-body tissue response to avoid confusion with other types of sinus histiocytosis or with metastatic carcinoma.

Aged↗
PubMed2001

Cancer mortality in relation to environmental chromium exposure.

From the 1950s to the 1980s, hexavalent chromium compounds were used as additives at certain water-cooling towers at three southern California gas compressor facilities. Claims of potential residential chromium exposure prompted the examination of age-adjusted mortality rates during 1989 to 1998 for lung cancer, all cancer, and all deaths for neighborhoods near versus distant from the plants. Differences in the rates between areas tended to be small and not statistically significant. The only significant difference was a lower, rather than higher, rate of total cancer among women in the potentially exposed areas. Study limitations preclude a definitive assessment of risk, but similar to previous investigations of cancer in relation to environmental chromium exposure in other locations, this study found no evidence of a cancer hazard among residents living near these California gas compressor facilities.

California↗
PubMed2005

Low-level hexavalent chromium exposure and rate of mortality among US chromate production employees.

OBJECTIVE: Although numerous studies have reported an elevated lung cancer risk among chromium chemical production employees, few studies have focused on employees hired after major process changes and enhanced industrial hygiene controls were implemented. METHODS: This study examines the mortality experience of two post-change cohorts of chromate production employees constituting the current US chromium chemical industry. RESULTS: Mortality among chromium chemical workers generally was lower than expected on the basis of national and state-specific referent populations. Lung cancer mortality was 16% lower than expected, with only three lung cancer deaths (3.59 expected). CONCLUSION: The absence of an elevated lung cancer risk may be a favorable reflection of the post-change environment. However, longer follow-up allowing an appropriate latency for the entire cohort will be needed to confirm this conclusion.

Carcinogens, Environmental↗
PubMed1990

Structures of the monohydrate and dihydrate of (bidentate pyrophosphato) trans-diammine cis-diaqua chromium (III).

(OC-6-32)-Diamminediaqua [pyrophosphato(3-)]chromium(III) monohydrate, [Cr(NH3)2-(H2O)2(HP2O7)]. H2O, Mr = 315.1, triclinic, P1, a = 7.127 (2), b = 8.390 (2), c = 9.619 (2) A, alpha = 72.14 (2), beta = 98.86 (2), gamma = 76.98 (3) degrees, V = 517.7 (3) A3, Z = 2, Dx = 2.02 g cm-3, lambda(Cu K alpha) = 1.5418 A, mu = 129 cm-1, F(000) = 322, T = 293 K. (OC-6-32)-Diamminediaqua[pyrophosphato(3-)]-chromium(III) dihydrate, 0.5( [Cr(NH3)2(H2O)2-(HP2O7)].2H2O), Mr = 0.5(333.1), monoclinic, C2/m, a = 13.118 (3), b = 12.101 (3), c = 7.436 (2) A, beta = 105.09 (2) degrees, V = 1139.7 (3) A3, Z = 8, Dx = 1.94 g cm-3, lambda(Cu K alpha) = 1.5418 A, mu = 118 cm-1, F(000) = 684, T = 293 K. The structures were solved by the multi-solution technique and refined by the method of least squares to yield a final R index of 0.057 for 986 reflections in the monohydrate and a final R index of 0.043 for 1030 reflections in the dihydrate. The six-membered chromium pyrophosphate chelate ring is in a boat conformation for the monohydrate with an intramolecular hydrogen bond between an ammonia proton and a pyrophosphate O atom. In the dihydrate, the chelate ring is bisected by the mirror plane resulting in an unusual planar chelate ring conformation which does not permit intramolecular hydrogen bonding.

Chromium↗
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↗
PubMed1979

Roentgenological detection of casting defects in cobalt-chromium alloy frameworks.

A method for non-destructive X-ray investigation of casting defects in cobalt-chromium prosthetic frameworks has been developed and tested. The attenuation properties of a cobalt-chromium alloy were studied. A dental X-ray machine with a tube voltage working at 70 kVp and a focus-film distance of 45-50 cm on dental ultraspeed film made it possible to detect defects representing 10% or less of the thickness of cobalt-chromium details with dimensions between 0.6 and 3.0 mm. The frequency and site of internal defects in sixty-six frameworks were investigated. Of the sixty-six frameworks only two were without roentgenologically visible defects. In the other sixty-four frameworks 294 pores or cracks were recorded. The defects were mostly situated in the saddles. Porosities occurred in 53% of the saddlebar regions. The results confirmed the need for a non-destructive routine test of prosthetic frameworks.

Absorptiometry, Photon↗
PubMed1998

Effects of chromium supplementation on the growth and carcass quality of bulls fed a grain-based diet during the finishing period.

Two groups of 12 young bulls, as similar as possible with respect to age and weight, were fed a basic diet of hay and concentrates ad libitum for 170 days. The concentrate fed to one of the groups was supplemented with 0.20 mg of organic chromium per kg DM from a fodder yeast product so that the concentration of chromium in the total dry matter of their diet was 0.90 mg/kg, compared with 0.72 mg/kg in the diet of the control group. No significant differences were observed between the two groups of animals in terms of either their daily weight gain or any of the parameters of carcass quality examined. It is therefore concluded that in Sweden there is no reason to add chromium routinely to the diet of intensively fed, growing bulls.

Animal Feed↗
PubMed1985

Chromium-induced pulmonary cancer. Report of a case and a review of the literature.

A 57-year-old man, whose occupational history was that of a chromate worker for about 35 years, suffered nasal perforation during and died due to pulmonary cancer. In the autopsy materials, the concentration of chromium in the lung tissues was very high, being about 90 times the amount found in normal lungs. The chromium particles in the lung tissues could not be detected by analytical electron microscope, but they could be found in the anthoracotic lesions of the lungs by means of an X-ray microanalyser. The present case was judged to be a case of chromium-induced pulmonary cancer since all the pathologic data obtained were similar to those found in similar cases reported in the literature.

Adenocarcinoma↗
PubMed1992

Microenvironmental analysis of residential exposure to chromium-laden wastes in and around New Jersey homes.

The purpose of this study was to identify the significant microenvironments that can lead to chromium exposure in Hudson County, New Jersey residential settings near or on soil contaminated with chromium waste. Measurements were made in indoor air, outdoor air, and house dust. Surface dust was found to be the best index of potential Cr exposure. The values of Cr in Hudson County household dust ranged from 3.25-320 ng/cm2 in wipe samples and 1.0-12 ng/cm2 in vacuum samples. Elevated Cr in household dust was found to be related to residential locations near large chromium waste sites, household cleaning habits, and house renovation activities. Outdoor Cr air levels were similar to those obtained in other urban areas at these seasons of the year, approximately 5-7 ng/m3. Comparisons with measurements of the Cr levels in urine found that the elevated Cr in dust was associated with elevated excretion of Cr. Site-specific Cr differences in household dust suggest different sources and routes of exposure. Within the total group of homes in the present study, Cr in household dust was the major influence on household exposure.

Air Pollutants↗