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At least 19 recordsLinked to original sources

Nasal septum lesions caused by chromium exposure among chromium electroplating workers.

A chromium electroplating worker, suffering from epistaxis during work, was found to have nasal septum perforation. To determine the etiology and prevalence of nasal septum lesions, we conducted a survey of seven chromium electroplating factories and examined 79 workers. Forty workers from three aluminum electroplating factories were also enrolled as the reference group. Subjects were thoroughly examined by an otolaryngologist and each of them provided a blood and urine sample. A questionnaire interview regarding symptoms of the upper respiratory tract, past medical history, life style, and work history was also conducted. Air chromium concentrations were measured by taking area samples for 4-6 hours. Based on field observation and chromium measurements, we divided chromium electroplating into three different exposure zones: workers directly dealing with electroplating tanks (n = 31), other process workers (n = 29), and office workers and drivers (n = 19). Among the 79 chromium electroplating workers, there were 16 cases of nasal septum perforation, and 42 with either scar formation or ulceration; 10 chromium electroplating workers developed skin ulcers after performing chrome plating. No workers from aluminum electroplating factories had any nasal septum or skin abnormalities. There was a consistent trend between the degree of chromium exposure and the signs and symptoms related to the nose, throat, and skin. Immediate improvement of occupational hygiene is warranted.

Adult↗

Copper electroplating of non-aqueous elastomeric impression materials: a subjective appraisal of their platability.

Electroplating of non-aqueous elastomeric impression materials is a well-documented technique. Electroplated silver or copper plated dies have many clinical advantages compared to other die systems. Silver electroplating appears to be used more frequently than copper electroplating. Utilization of silver for electroplating requires an appreciation of financial and biohazard considerations. Research on compatibility of copper electroplating with current non aqueous elastomeric impression materials is lacking. Samples of currently used non aqueous elastomeric impression materials were used to register impressions of conventional crown preparations on a typodont. These impressions were electroplated to form copper plated dies. The surface qualities of the dies were evaluated. Not all impression materials produced visually acceptable or workable copper plated dies.

Color↗

The effect of tin-electroplating on the bond of four dental alloys to resin cement: an in vitro study.

STATEMENT OF THE PROBLEM: Nickel-chromium alloys are indicated for the construction of resin-bonded fixed partial dentures; however, the potential toxicity of nickel has been a source of concern. Composite cements do not develop an adequate bond to air abraded noble alloys, which cannot be electrolytically etched. Tin-electroplating of noble alloys appears to be an alternative treatment for resin bonding. PURPOSE: This in vitro study investigated the effect of tin-electroplating on the bond of a composite cement to base and noble alloys. MATERIAL AND METHODS: Tensile tests were made with disks of four alloys that were cemented to each other with an adhesive composite cement after (1) air abrasion with 50 microns aluminum oxide and (2) air abrasion plus tin-electroplating. RESULTS: Tin-electroplating increased the bond strength of metal-ceramic gold alloy (Au,Pd,Pt) to a level comparable to the nickel-chromium alloy, but had a harmful effect on type IV gold alloy. CONCLUSIONS: Despite the recommendation for tin-electroplating of type IV gold alloys, this procedure did not improve bond strength to composite in this study.

Analysis of Variance↗

[Corrosion and haemocompatibility of 316L stainless steel with electroplated Rh film].

In this study, surface modification by electroplating Rh on 316L stainless steel was carried out in order to improve the corrosion resistance and blood compatibility of implants. XPS was used to characterize the Rh film. The corrosion behavior of 316L stainless steel with electroplated Rh and non-treated was studied in Tyrode's biological solution. Additionally, the haemocompatibility of 316L stainless steel with electroplated Rh was evaluated by preliminary hemolysis test. The results showed that the corrosion resistance of 316L stainless steel with electroplated Rh was improved, and hemolysis decreased, which indicated that electroplating Rh can improve the blood compatibility of 316L stainless steel.

Animals↗

Nasal septum lesions and lung function in workers exposed to chromic acid in electroplating factories.

The objective of this study was to compare workers from chromium, nickel-chromium, and zinc electroplating factories with regards to nasal septum lesions and lung function. Also investigated was the relationship between chromium levels in air and urine. A total of 189 workers from 11 electroplating factories (three chromium, six nickel-chromium, two zinc) were chosen from central Taiwan. All subjects were interviewed by constructed-questionnaire, given a nasal examination by a certified otolaryngologist and a lung function test. In the chromium factories 30.8% of the workers showed evidence of nasal septum perforations and 38.5% showed evidence of nasal septum ulcers. A Mantel extension test for trend showed that workers in the chromium factories were 31.7 times more likely to experience nasal ulcers than nickel-chromium and zinc factory workers. Those who worked in the electroplating tank area were 4.2 times more likely to experience ulcers and those with over 9 years' experience were 30.8 times more likely. A comparison of lung function adjusted for age, gender and smoking habit among workers showed that vital capacity (VC), forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1) were all significantly decreased among chromium factory workers. Because the results showed that the workers' health is being severely damaged by the harmful environment of chromium electroplating factories, the authors wish to suggest improvements in the workplace are vitally needed to ensure the safety of the workers.

Adult↗

Urinary N-acetyl-beta-glucosaminidase as an indicator of renal dysfunction in electroplating workers.

OBJECTIVES: To investigate chromium-induced renal dysfunction in electroplating workers. METHODS: A cross-sectional study was used to evaluate four biochemical markers of renal function. A total of 178 workers were divided into 3 comparable groups consisting of 34 hard-chrome plating workers, 98 nickel-chrome electroplating workers. and 46 aluminum anode-oxidation workers, who represented the reference group. Ambient and biological monitoring of urinary chromium were performed to measure exposure concentrations. RESULTS: Overall, urinary chromium concentrations were highest among hard-chrome plating workers (geometric mean 2.44 microg/g creatinine), followed by nickel-chrome electroplating workers (0.31 microg/g creatinine) and aluminum workers (0.09 microg/g creatinine). Airborne chromium concentrations were also highest in the hard-chrome plating area (geometric mean 4.20 microg/m3), followed by the nickel-chrome electroplating area (0.58 microg/m3) and the aluminum area (0.43 microg/m3). A positive correlation was found between urinary chromium and airborne concentrations (r=0.54, P < 0.01). Urinary concentrations of N-acetyl-beta-D-glucosaminidase (NAG) were also highest among hard-chrome plating workers (geometric mean 4.9 IU/g creatinine), followed by nickel-chrome workers (3.4 IU/g creatinine) and aluminum workers (2.9 IU/g creatinine). The prevalence of "elevated" NAG (>7 IU/g creatinine) was significantly highest among hard-chrome plating workers (23.5%), then among nickel-chrome workers (7.1%) and aluminum workers (8.7%). Differences in beta2-microglobulin, total protein, and microalbumin were not significant. CONCLUSION: The author's evidence indicates that NAG is an early indicator of renal dysfunction in hard-chrome plating workers.

Acetylglucosaminidase↗

Concentration and size distribution of airborne hexavalent chromium in electroplating factories.

Studies have shown that chromium from electroplating factories can cause respiratory problems to workers after prolonged exposure. Since Taiwan has a relatively high number of electroplating factories and minimal data regarding chromium's effect on workers, the authors undertook this study focusing on the size distribution of airborne hexavalent chromium and its concentration levels within the factory. Both area and personal sampling were conducted using a particle fractionating sampler. Samples were analyzed using visible spectrophotometry. A comparison of three types of factories-chromium, nickel-chromium, and zinc-showed that the highest concentrations were found in chromium electroplating factories near the electroplating tank. Hexavalent chromium particles obtained from area sampling had mass median diameters between 1.67-6.38 microns and 0.75-4.73 microns for personal sampling. Particles of this high concentration and small size can enter and cause considerable damage to the respiratory tract.

Air Pollutants, Occupational↗

Fluctuations of nickel concentrations in urine of electroplating workers.

Nickel analyses were performed by electrothermal atomic absorption spectrometry upon urine specimens obtained from electroplating workers at the beginning, middle and end of the work-shift. The means (+/- S.D.) for nickel concentrations in urine specimens from seven electroplating workers on three regular workdays were: 34 +/- 32 micrograms/L (pre-shift); 64 +/- 63 micrograms/L (mid-shift) and 46 +/- 32 micrograms/L (end-shift), compared to 2.7 +/- 1.6 micrograms/L (pre-shift) in 19 controls (hospital workers). Nickel concentrations in urine specimens from six electroplating workers on the first workday after a two-week vactation averaged: 5 +/- 3 micrograms/L (pre-shift); 9 +/- 6 micrograms/L (mid-shift), and 12 +/- 6 micrograms/L (end-shift). Nickel concentrations in personal air samples (seven hours) collected from the breathing zones of five electroplating workers on three regular workdays averaging 9.3 +/- 4.4 micrograms/m3. Nickel concentrations in the air samples were correlated with nickel concentrations in end-shift urine specimens (corr. coef. = 0.70; P less than 0.05), but were not correlated with nickel concentrations in pre-shift or mid-shift urine specimens. In view of the fluctuations of urine nickel concentrations that occur during the work-shift, the authors recommend that nickel analyses of eight hour urine specimens be used routinely to monitor occupational exposures to nickel. In situations where timed urine collections are impractical, analyses of end-shift urine specimens are the best alternative.

Adult↗

Effects of chromic acid exposure on immunological parameters among electroplating workers.

OBJECTIVE: To investigate the immunological parameters of chromic acid exposure among electroplating workers. METHODS: Forty-six subjects were selected from five electroplating plants in central Taiwan. Each subject was interviewed by questionnaire, and urine chromium (urine-Cr) concentration was assessed. Immunological parameters were evaluated by interleukin (IL-2, IL-4, IL-6, IL-8, IL-10, TNF-alpha, IFN-gamma) and levels of lymphocyte subsets (T-cell, B-cell, T4, T8 and T4/T8). RESULTS: Levels of IL-6 and IL-8 significantly increased in subjects with high urine Cr concentration, but TNF-alpha levels decreased. IL-2, IL-4, IL-10 and IFN-gamma were undetected. Flow cytometry was used to determine levels of lymphocyte subsets: only B-cells percentage had a negative correlation with urine-Cr. Smoking was an important factor that influenced levels of lymphocyte subsets. CONCLUSION: Exposure to Cr has a detrimental effect on the immune system, so it is evident that worker exposure to chromic acid in the electroplating workplace must be reduced to a minimum.

Adult↗

Controlling emissions from electroplating by the application of ultrasound.

Ultrasonic irradiation applied either above the surface of a chromic acid plating bath or through the plating bath itself during the process of chromium electroplating reduces the emissions of hazardous chromic acid mist The use of ultrasound is particularly effective at high current densities. The results suggest that sonication during the electroplating of chromium may provide a useful method of controlling chrome mist emission without the need for a chemical additive (mist suppressant). In conjunction with lip extraction this could lead to a more efficient process since the use of ultrasound has been shown to be of benefit in the electroplating process itself.

Air Pollution↗

Treatment of alloy-electroplating wastewater by an automated solvent extraction technique.

Electroplating with highly toxic metals is being gradually replaced by alloy or mixed-metal electroplating. We developed a solvent extraction method for the treatment of waste rinsewater generated in Zn-Co alloy electroplating, based on the studies of the extraction properties. An alkyl ester of an alkylphosphonic acid (PC-88A) or a dialky phosphinic acid (Cyanex 272) was used as the extractant. The two metals were co-extracted into the organic solvent and then separately recovered in a simple process. The feasibility of the process was demonstrated with automated mixer-settler solvent extraction units.

Automation↗

Occupational asthma due to chrome and nickel electroplating.

BACKGROUND: Exposure to chromium during electroplating is a recognised though poorly characterised cause of occupational asthma. The first series of such patients referred to a specialist occupational lung disease clinic is reported. METHODS: The diagnosis of occupational asthma was made from a history of asthma with rest day improvement and confirmed by specific bronchial provocation testing with potassium dichromate and nickel chloride. RESULTS: Seven workers had been exposed to chrome and nickel fumes from electroplating for eight months to six years before asthma developed. One subject, although exposed for 11 years without symptoms, developed asthma after a single severe exposure during a ventilation failure. This was the only subject who had never smoked. The diagnosis was confirmed by specific bronchial challenges. Two workers had isolated immediate reactions, one a late asthmatic reaction, and four a dual response following exposure to nebulised potassium dichromate at 1-10 mg/ml. Two of the four subjects were also challenged with nebulised nickel chloride at 0.1-10 mg/ml. Two showed isolated late asthmatic reactions, in one at 0.1 mg/ml, where nickel was probably the primary sensitising agent. Four workers carried out two hourly measurements of peak expiratory flow over days at and away from work. All were scored as having occupational asthma using OASYS-2. Breathing zone air monitoring was carried out in 60 workers from four decorative and two hard chrome plating shops from workers with similar jobs to those sensitised. No measurement exceeded the current occupational exposure standard for chromate or nickel, the mean levels of chromate exposure for jobs similar to those of the affected workers were 9-15 micrograms/m3. CONCLUSION: Chrome used in electroplating is a potential cause of occupational asthma. Sensitivity to chrome in electroplaters may occur in situations where exposure levels are likely to be within the current exposure standards. There may be cross reactivity with nickel. Inhalation challenge with nebulised potassium dichromate solution is helpful in making the specific diagnosis where doubt exists.

Adult↗

[Effects of chromium compounds on the respiratory system. Part 4. Long-term inhalation of chromic acid mist in electroplating to ICR female mice].

In order to determine the effect on the respiratory system of long-term inhalation of chromic acid in electroplating, histopathological examination was performed on mice (ICR, female, n = 50) exposed to chromic acid mist for 12 months (30 min/d, 2 d/wk), by using the authors' miniaturized chromium electroplating system. After 12 months' exposure, the mice were kept for 6 months without exposure. In the upper respiratory tract, round perforations were found in the nasal septum in 6 mice that were sacrificed or died after 10 months' exposure. The perforations were located near the point of the septum, the thinnest part of the nasal septum, and were of pin-hole sige. On the epithelium of the trachea and bronchus, loss of cilia, proliferation of goblet cells or basal cells, and squamous metaplasia were observed in almost all of the exposed mice. These changes appeared to be more advanced in mice exposed for a longer period. In the lung, development of benign adenoma was observed in one mouse in the 6- to 9-months' exposure group, in three in the 10- to 14-months' exposure group and in one in the group examined after 15 to 18 months. Furthermore, adenocarcinomas were found in two mice, one of which died at 17 months and the other was sacrificed 18 months after initiation of exposure. In conclusion, the finding that adenomas and adenocarcinomas were observed in mice exposed to chromic acid mist suggests the need to give careful attention to the possibility of respiratory cancers in chromium electroplating workers.

Adenocarcinoma↗

[Effects of chromium compounds on the respiratory system. 5. Long term inhalation of chromic acid mist in electroplating by C57BL female mice and recapitulation of our experimental studies].

Long term inhalation of CrO3 mist by C57BL mice The effects of the chromic acid mist used in electroplating on the respiratory system of C57BL mice (female; n = 43) were examined histopathologically after exposure for 12 months to the mist (1.81 mgCr/m3-120 min, twice a week). Among the 23 mice sacrificed at 12 months after the first exposure, three cases of perforation in the nasal septs, a case of proliferative change of the tracheal epithelium, nine cases of emphysema and four of adenomatous metaplasia of the lungs were observed on antopsy. Among the 20 mice which were sacrificed six months after the last exposure, the same changes as the 12-month exposure group were also observed in the nasal septum, trachea and lungs, but papillomas observed in the nasal epithelia of six mice and adenoma in the lung of a mouse were new findings not seen in the 12-month exposure group. These results suggest that, in view of the low incidence of spontaneous lung tumor in C57BL mice, inhalation of chromic acid mist in electroplating might be a risk factor of lung cancer. Additionally, the occurrence of papillomas in the nasal epithelium demonstrates the need of directing attention to the possible development of cancer of the upper respiratory tract in chromium electroplating workers. Recapitulation on our experimental studies Upon completion of our five reports on the effects of chromium compounds on the respiratory system, a recapitulation of our experimental studies was made and compared with the findings of a number of reports on chromium. It was experimentally and epidemiologically confirmed that hexavalent chromium compounds act as carcinogens and cause specific biological effects on the respiratory system. These characteristics of hexavalent compounds might be attributable to the strong oxidizing potency and/or high permeability through the cell membrane. Furthermore, hexavalent compounds might be entirely different in biological action from trivalent compounds which are chemically most stable.

Aerosols↗

Adsorption Equilibrium of Polyethylene Glycol in the Copper Electroplating Solution on Activated Carbon.

Polyethylene glycol (PEG) used as a brightening and stabilization agent at the concentration of 30 mg dm(-3) is a major organic additive in the copper electroplating solution. Activated carbon, Calgon Filtrasob 400, is used as the adsorbent to remove the PEG from the used electroplating solution in order to broaden the appeal of recycling it. The equilibrium of adsorption is attained within 14 days. The effect of the temperature on the amount of PEG adsorbed on the activated carbon is insignificant for the temperatures ranged from 288 to 313 K. The adsorption isotherm of PEG conforms to the Langmuir isotherm, q(e)=Q(L)K(L)C(e)/(1+K(L)C(e)), with a high correlation coefficient of 0.9979. The large values of the monolayer adsorption capacity, Q(L), of 303 mg g(-1) and the equilibrium constant, K(L), of 0.273 dm(3) mg(-1) show a great adsorption potential of PEG on the activated carbon. A high removal efficiency would be expected at such a low original concentration of PEG. From the results mentioned above, it is feasible to use activated carbon for removing PEG from the electroplating solution, thereby achieving the appeal of recycling. Copyright 2000 Academic Press.

Journal Article↗

Disorganisation of quantal acetylcholine release by zinc at the Torpedo nerve-electroplate junction.

The effects of zinc (Zn2+) on quantal acetylcholine release at the Torpedo nerve-electroplate junction were analysed by using loose patch electrodes designed to record evoked and spontaneous electroplate currents in a delimited area (electrode diameter of 10-15 microm) of the synaptic region. Zn2+ reduced the amplitude, prolonged the synaptic delay and slowed down the rising phase of all-or-none electroplate currents (EPCs) generated in response to activation of Na+ channels in a preterminal nerve branch. In graded EPCs (generated in response to direct activation of terminal Ca2+ channels), Zn2+ caused a reduction of quantal content but no change in the quantal size or in the minimum synaptic delay. The rise time of graded EPCs was prolonged but their half-decay time was not affected. Miniature EPCs (MEPCs) in control preparations had a widely distributed amplitude distribution but a homogeneous and rapid time course. Conversely, MEPCs in Zn2+-treated tissue exhibited a homogeneous and small amplitude, but a prolonged and more variable time course. Zn2+ at 1 mM caused, by itself, a high occurrence of MEPCs under conditions (flat-edged electrodes) when MEPCs are normally very infrequent. It is concluded that Zn2+ can both activate and inhibit the release mechanism and Zn2+-induced quanta exhibit an abnormal time course. The activation of the release process by Zn2+ or by Ca2+ may result in the production of quanta with different kinetics.

Acetylcholine↗

The genotoxicity of iron and chromium in electroplating effluents.

Electroplating effluents were tested for their genotoxicity with the micronucleus test on newt larvae. The metallic content of the tested samples was responsible for the induction of micronuclei in red blood cells (RBC). Then, iron (Fe3+), chromium (Cr3+, Cr6+) and zinc (Zn2+) which were identified in these samples, were tested either separately or combined, at their concentrations in the electroplating effluents. Fe3+ induced a high level of micronuclei at 12.5 and 25 mg/l (nominal concentrations). Both soluble and non-soluble forms of iron were responsible for these genotoxic effects. At lower concentrations (0.6 and 4.5 mg/l) Fe3+ was not systematically genotoxic. Zinc could not be considered genotoxic on newt. Cr3+ gave negative responses, but exposure to Cr6+ (1 mg/l) could result in a significant number of micronucleated RBC in some cases. The most dramatic genotoxic effects were registered when Fe3+ and Cr6+ were combined. This study demonstrates that interactions between pollutants and the effects of non-soluble chemicals on aquatic vertebrates and invertebrates can no longer be neglected.

Animals↗

Removal and recovery of heavy metals from electroplating wastewater by using Kyanite as an adsorbent.

Kyanite, a commercial mineral has been utilized as an adsorbent for the removal of heavy metals, such as Ni(II), Zn(II), Cr(VI) and Cu(II) from electroplating wastewater. The effect of contact time, pH, concentration, adsorbent doses, particle size of the adsorbent, salinity and hardness, both in natural and wastewater on the adsorption of Cu(II) have been studied in detail. The adsorption of metal ions seems to be an ion exchange process. The adsorbed metals ions from electroplating wastewater were recovered by batch as well as column operation using dilute HCl solution. The column operation was found to be more effective compared to batch process.

Adsorption↗