Exposure to hexavalent chromium does not increase 8-hydroxydeoxyguanosine levels in Korean chromate pigment workers.

This study was performed to determine whether chromium exposure increased 8-hydroxydeoxyguanosine levels in respiratory epithelial and white blood cells of chromate pigment workers. The subjects of this study were 22 chromium pigment workers and 16 controls in a chromate pigments factory. To estimate the level of exposure, hexavalent chromium concentrations in the factory air were measured. Chrominum concentrations of venous blood and spot urine, and 8-hydroxydeoxyguanosine levels in DNA extracted from sputum and white blood cells were determined. Correlation coefficients were calculated between them and their statistical significance was tested. Hexavalent chromium concentration in the factory air ranged from below limit of detection to 0.5150 mg/m3. Chromium levels in blood and 8-hydroxydeoxyguanosine levels in DNA extracted from venous blood and sputum were not statistically different between the two groups. Urine chromium level was significantly higher among workers. Among the correlation coefficients between blood chromium concentration, urine chromium concentration, blood 8-OH-dG level, and sputum 8-OH-dG level, none was statistically significant for workers, controls, and total subjects. Duration of employment did not show any significant correlation with those four variables, either. These results suggest that neither the hydroxyl radical nor 8-hydroxydeoxyguanosine is formed by the reduction of hexavalent chromium, or that one or both of these is formed and then effectively removed by oxygen free radical scavengers or 8-hydroxydeoxyguanosine repair enzymes. Since increased exposure to hexavalent chromium did not result in increased 8-hydroxydeoxyguanosine levels, it is unlikely that hexavalent chromium induces lung cancer through 8-hydroxydeoxyguanosine formation.     

Relationship between clinical and electromyographic findings and exposure to solvents, in shoe and leather workers.

A very high prevalence of polyneuropathy was observed in shoe and leather workers from the area of Florence. In addition, normal workers showed abnormally low maximal nerve motor conduction velocity. A linear decrease of motor conduction velocity was observed as a function of age and of the length of exposure to solvents. The worker population showed a steeper decrease with age than controls. A higher prevalence of polyneuropathy was observed when the amount of glue used by each worker per day was higher, and when the air volume of the plant was smaller. The subjective symptoms most frequently associated with polyneuropathy were muscle spasms, leg weakness and pain, and arm paresthesiae. Cases of polyneuropathy were more frequent in the workers exposed to solvents and in the older age group. A solvent aetiology of the disease is suggested, and glue substitution and proper hygienic conditions are recommended.     

Relationship between clinical and electromyographic findings and exposure to solvents, in shoe and leather workers

A very high prevalence of polyneuropathy was observed in shoe and leather workers from the area of Florence. In addition, normal workers showed abnormally low maximal nerve motor conduction velocity. A linear decrease of motor conduction velocity was observed as a function of age and of the length of exposure to solvents. The worker population showed a steeper decrease with age than controls. A higher prevalence of polyneuropathy was observed when the amount of glue used by each worker per day was higher, and when the air volume of the plant was smaller. The subjective symptoms most frequently associated with polyneuropathy were muscle spasms, leg weakness and pain, and arm paresthesiae. Cases of polyneuropathy were more frequent in the workers exposed to solvents and in the older age group. A solvent aetiology of the disease is suggested, and glue substitution and proper hygienic conditions are recommended.     

Sister chromatid exchange analysis in lymphocytes of workers exposed to hexavalent chromium.

To investigate the usefulness of sister chromatid exchange (SCE) analysis in lymphocytes as an indicator for mutagenic effects after in vivo exposure to hexavalent chromium (Cr), SCE frequency was analysed in lymphocytes of 44 Cr platers occupationally exposed to hexavalent Cr and 47 controls. Although urinary Cr analysis confirmed that the Cr platers were exposed to Cr, no effects of the exposure on SCE frequency were found. Smokers, both Cr platers and controls, had a significantly higher SCE frequency than non-smokers. These results suggest that SCE analysis in human lymphocytes is not a good indicator of possible mutagenic effects of exposure to hexavalent Cr.     

Normal chromium levels in urine and blood of Japanese subjects determined by direct flameless atomic absorption spectrophotometry, and valency of chromium in urine after exposure to hexavalent chromium

Two hundred and thirty one urine and 20 blood samples of Japanese subjects from 4 geographic areas without known chromium pollution were assayed for chromium by direct flameless atomic absorption spectrophotometry. Normal chromium level in urine of Japanese subjects was 0.41 microg/L on an average. Urine level was less than 0.8 microg/L for all age and sex groups. Chromium levels in 2 hour urines did not correlate with those in 24 hours urine. Blood level of chromium was 2.9 ng/mL. A rabbit given an oral administration of 100 mg hexavalent chromium excreted 8.2 mg in 15 days after administration. No hexavalent chromium could be detected in urine. Ninety percent of the urinary excretion occurred within 2 days of administration.     

Evaluation of the genetic alterations in direct and indirect exposures of hexavalent chromium [Cr(VI)] in leather tanning industry workers North Arcot District, South India

Purpose  

The focal aim of the present study was to identify the genetic alterations occurring in the tannery workers and surrounding inhabitants chronically exposed to hexavalent chromium [Cr(VI)].     

Evaluating chromosomal damage in workers exposed to hexavalent chromium and the modulating role of polymorphisms of DNA repair genes

Purpose

Welders have been chronically exposed to hexavalent chromium with potential consequences on chromosomal integrity. Our study is focused on the extent of any such chromosomal aberrations with respect to chromium levels in the blood of welders as well as on the tentative modulating role of polymorphisms in DNA repair genes XPD Lys751Gln, XPG Asn114His, XPC Lys939Gln, hOGG1 Ser326Cys and XRCC1 Arg399Gln on chromosomal damage.

Methods

The study was conducted on 144 individuals consisting of 73 welders exposed to chromium for 10.2?±?1.67?years and 71 control individuals without known exposures. Chromosomal aberrations, their chromatid-type and chromosome-type aberrations were detected by conventional cytogenetic analysis. XPD, XPG, XPC, hOGG1 and XRCC1 gene polymorphisms were assayed for by Taqman SNP genotyping assay (“Assay-by-Demand”) using Real-Time allelic discrimination on AB 7500 equipment. Chromium concentration in the blood was determined by atomic absorption spectrophotometry.

Results

The level of chromium in the blood of welders ranged between 0.032 and 0.182?μmol?l^?1 and was significantly higher than that in controls (0.07?±?0.04?μmol?l^?1 vs. 0.03?±?0.007?μmol?l^?1). Parameters of chromosomal damage were similar in both the exposed and the control individuals (1.89% vs. 1.70% for total chromosomal aberrations, 0.97% vs. 0.88% for chromosome-type and 0.92% vs. 0.80% for chromatid-type, respectively). Chromatid-type of aberrations positively correlated with the level of chromium in the blood (r?=?0.28; P?=?0.02). Significantly higher total chromosomal aberrations were detected in individuals with homozygous variant polymorphism in XRCC1 Arg399Gln gene as compared to those with heterozygous and homozygous wild-type genotypes (2.20, 1.89 and 1.48%, respectively; P?=?0.01). A similar tendency was found for chromatid-type aberrations (1.30% for homozygous variant genotype bearers, 0.94% for those with heterozygous genotype and 0.75% for carriers of homozygous wild-type genotype, respectively; P?=?0.04).

Conclusions

Although no apparent increase in chromosomal damage was recorded in chromium-exposed welders in comparison with controls, genetic make-up in DNA repair genes may increase susceptibility toward adverse effect of chromium.     

Waiting time to pregnancy and pregnancy outcome among Danish workers in the textile, clothing, and footwear industries.

The relationship between time from planned to achieved pregnancy and pregnancy outcome has been studied in a group of 18,658 workers in the textile, clothing and footwear industries. Information on pregnancy outcome and delay in conception in the period 1979-84 was collected by self administered questionnaires in 1985. The response rate was 70.3%. During the study period there had been 5,171 live births and 708 spontaneous abortions. Information on delay in conception was collected in broad categories. The data were analysed by means of a newly developed statistical parametric model in order to collect all possible information from the highly grouped data. Median waiting time before a pregnancy which ended in spontaneous abortion was 1.68 times longer than median waiting time before a pregnancy leading to a live birth. There seems to be a correlation between the length of the waiting time and abortion.     

Aplastic anemia, leukemia and other cancer mortality in a cohort of shoe workers exposed to benzene

Benzene is a well documented carcinogen for the hematic and lymphopoietic system, and experimental research confirms its carcinogenicity for tumors of other sites. This report presents the results of a historical cohort study in a shoe manufacturing plant in Florence where cases of aplastic anemia and leukemia were reported in the 1960s. A total of 1008 men and 1005 women were considered eligible members of the cohort. For total mortality, comparing the rates of the cohort with the national rates, the standardized mortality ratio (SMR) was 79 for the women and 95 for the men. For the men excesses of risk for aplastic anemia [SMR 1566; 95% confidence interval (95% CI) 547-3264] and leukemia (SMR 400, 95% CI 146-870) were observed. The increased risk occurred among workers first employed during the period in which benzene was used, but the expected number of cases in the subsequent period was too small to evaluate whether any reduction in risk had occurred. No increasing pattern with duration of employment was discernible.     

Individual mercury exposure of chloralkali workers and its relation to blood and urinary mercury levels.

On two occasions, chloralkali workers were investigated with regard to personal air mercury exposure, blood mercury and urinary mercury. The first investigation (13 workers, 2 weeks) was made at an exposure above the threshold limit value (64 microgram/m3, range 36--112), the second (16 workers, 8 weeks) at a lower exposure (23 microgram/m3, range 15--43). At the higher level of exposure, good correlations were found between air exposure and blood or urinary mercury for the group, but not for individuals. At the lower level, the correlations were less pronounced for the group. For individuals, the best correlation was found between mean air exposure during one week and blood mercury about half a week later. Other individuals, mainly the least exposed, showed no such correlation. Corresponding correlations were not found for urinary mercury. The urinary excretion rate was determined only for the last few hours of the workday, but the results agree with earlier investigations of 24-h excretion on a group basis. The threshold limit value for mercury in air (50 microgram/m3) corresponds to 150--175 nmol Hg/1 blood (= 30--35 microgram/1) for the group, with large individual variation.     

HLA Gm systems and susceptibility to alcoholic cirrhosis: a study of mixed-race subjects.

The fact that only a small percentage of excessive drinkers develop cirrhosis may be due to a genetic susceptibility to the disease. In order to identify possible genetic risk factors for cirrhosis, we studied mixed-race (Negroid-Caucasian) inhabitants of the French West Indies and compared: (1) the frequency of 51 HLA-A, -B, -C and -DR antigens in 41 subjects with alcoholic cirrhosis and in two control groups consisting of 41 excessive drinkers free of liver disease and 51 healthy non-drinkers; and (2) the frequency of Gm and Km haplotypes in the same groups. Analysis of the Gm system also determined the patients' ethnic origins. The frequency of the HLA-A2 antigen was significantly higher in the cirrhotic patients than in the control group of excessive drinkers (chi 2 = 4.47; P less than 0.05), while that of the HLA-B15 antigen was significantly lower (chi 2 = 5.14; P less than 0.05). The frequency of the Cw4 antigen was significantly higher in the cirrhotics than in the non-drinkers (chi 2 = 5.59; P less than 0.05). However, these differences did not persist when the number of comparisons was taken into account. The frequency of Gm and Km haplotypes was not significantly different in the three groups. In conclusion, complementary studies are required to determine the value of the Gm-Km system as a marker of susceptibility to alcoholic cirrhosis. Our results do not identify an association between HLA antigens and cirrhosis specific to a negroid ethnic group and support the notion that such an association is weak.     

Characterization of exposures among cemented tungsten carbide workers. Part II: Assessment of surface contamination and skin exposures to cobalt, chromium and nickel

Cobalt, chromium and nickel are among the most commonly encountered contact allergens in the workplace, all used in the production of cemented tungsten carbides (CTC). Exposures to these metal-containing dusts are frequently associated with skin sensitization and/or development of occupational asthma. The objectives of this study were to assess the levels of cobalt, chromium and nickel on work surfaces and on workers' skin in three CTC production facilities. At least one worker in each of 26 work areas (among all facilities) provided hand and neck wipe samples. Wipe samples were also collected from work surfaces frequently contacted by the 41 participating workers. Results indicated that all surfaces in all work areas were contaminated with cobalt and nickel, with geometric means (GMs) ranging from 4.1 to 3057 microg/100 cm(2) and 1.1-185 microg/100 cm(2), respectively; most surfaces were contaminated with chromium (GM=0.36-67 microg/100 cm(2)). The highest GM levels of all metals were found on control panels, containers and hand tools, whereas lowest levels were on office and telecommunication equipment. The highest GM levels of cobalt and nickel on skin were observed among workers in the powder-handling facility (hands: 388 and 24 microg; necks: 55 and 6 microg, respectively). Levels of chromium on workers' skin were generally low among all facilities. Geometric standard deviations associated with surface and skin wipe measurements among work areas were highly variable. Exposure assessment indicated widespread contamination of multiple sensitizing metals in these three facilities, suggesting potential transfer of contaminants from surfaces to skin. Specific action, including improved housekeeping and training workers on appropriate use and care of personal protective equipment, should be implemented to reduce pathways of skin exposure. Epidemiologic studies of associated adverse health effects will likely require more biologically relevant exposure metrics to improve the ability to detect exposure-response relationships.     

三硝基甲苯作业工人和HBsAg阳性者血清铜蓝蛋白和谷胱甘肽过氧化物酶活性的变化

对河南省某化工厂职业接触ＴＮＴ作业工人现场劳动卫生学调查和健康监护结果表明，车间空气中ＴＮＴ浓度绝大多数超过ＭＡＣ（１ｍｇ／ｍ３），作业工人皮肤污染严重。ＴＮＴ接触组与对照组血清ＧＰＴ活性升高和ＨＢｓＡｇ阳性检出率两组间无显著性差异，表明这两组人群肝功能属于正常范围。同时发现，ＴＮＴ接触组和ＨＢｓＡｇ阳性组血清铜蓝蛋白和谷胱甘肽过氧化物酶活性均极显著低于对照组（Ｐ＜０．０２，Ｐ＜０．００１）；ＨＢｓＡｇ阳性组这两项指标极显著低于ＴＮＴ接触组（Ｐ＜０．０５，Ｐ＜０．０２）。表明ＴＮＴ和ＨＢＶ诱发的肝损伤机理可能部分归因与活性氧生成有关。