Hexavalent chromium and lung cancer in the chromate industry: a quantitative risk assessment.
ABSTRACT The purpose of this investigation was to estimate excess lifetime risk of lung cancer death resulting from occupational exposure to hexavalent-chromium-containing dusts and mists. The mortality experience in a previously studied cohort of 2,357 chromate chemical production workers with 122 lung cancer deaths was analyzed with Poisson regression methods. Extensive records of air samples evaluated for water-soluble total hexavalent chromium were available for the entire employment history of this cohort. Six different models of exposure-response for hexavalent chromium were evaluated by comparing deviances and inspection of cubic splines. Smoking (pack-years) imputed from cigarette use at hire was included in the model. Lifetime risks of lung cancer death from exposure to hexavalent chromium (assuming up to 45 years of exposure) were estimated using an actuarial calculation that accounts for competing causes of death. A linear relative rate model gave a good and readily interpretable fit to the data. The estimated rate ratio for 1 mg/m3-yr of cumulative exposure to hexavalent chromium (as CrO3), with a lag of five years, was RR=2.44 (95% CI=1.54-3.83). The excess lifetime risk of lung cancer death from exposure to hexavalent chromium at the current OSHA permissible exposure limit (PEL) (0.10 mg/m3) was estimated to be 255 per 1,000 (95% CI: 109-416). This estimate is comparable to previous estimates by U.S. EPA, California EPA, and OSHA using different occupational data. Our analysis predicts that current occupational standards for hexavalent chromium permit a lifetime excess risk of dying of lung cancer that exceeds 1 in 10, which is consistent with previous risk assessments.
Full-textDOI: · Available from: Herman Gibb, Aug 12, 2015
- SourceAvailable from: Hamidreza Mohammadi
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- "To estimate excess lifetime risk of lung cancer death, some authors challenged cumulative exposure to hexavalent chromium (Park et al., 2004). Throughout recent years; a variety of biomarker concentration has been developed in a risk assessment (Bailer & Hoel, 1989; Calafat & McKee, 2006; Cox Jr, 1996). "
ABSTRACT: Abstract Oxidative stress is the main cause of hexavalant chromium-induced damage in chrome electroplating workers. The main goal of this study is toxicity analysis and the possibility of toxicity risk categorizing in the chrome electroplating workers based on oxidative stress parameters as prognostic variables. We assessed blood chromium levels and biomarkers of oxidative stress such as lipid peroxidation, thiol (SH) groups and antioxidant capacity of plasma. Data were subjected to principle component analysis (PCA) and artificial neuronal network (ANN) to obtain oxidative stress pattern for chrome electroplating workers. Blood chromium levels increased from 4.42 ppb to 10.6 ppb. Induction of oxidative stress was observed by increased in lipid peroxidation (22.38 ± 10.47 μM versus 14.74 ± 4.82 μM, p < 0.0008), decreased plasma antioxidant capacity (3.17 ± 1.35 μM versus 7.74 ± 4.45 μM, p < 0.0001) and plasma total thiol (SH groups) (0.21 ± 0.07 μM versus 0.45 ± 0.41 μM, p < 0.0042) in comparison to controls. Based on the oxidative parameters, two groups were identified by PCA methods. One category is workers with the risk of oxidative stress and second group is subjects with probable risk of oxidative stress induction. ANN methods can predict oxidative-risk category for assessment of toxicity induction in chrome electroplaters. The result showed multivariate modeling can be interpreted as the induced biochemical toxicity in the workers exposed to hexavalent chromium. Different occupation groups were assessed on the basis of risk level of oxidative stress which could further justify proceeding engineering control measures.Drug and Chemical Toxicology 06/2014; DOI:10.3109/01480545.2014.922096 · 1.10 Impact Factor
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- "Cr(III) and Cr(VI) are the two common oxidation states of chromium in the environment. Cr(VI) is toxic and exposure to Cr (VI) may lead to cancer, nasal damage, asthma, bronchitis, pneumonitis, dermatitis, and skin allergies (Barceloux, 1999; Park et al., 2004). In contrast, Cr(III) is a trace element essential for the proper function of living organisms (Independent Environmental Technical Group [IETEG], 2005). "
ABSTRACT: Hexavalent chromium (Cr(VI)) and trivalent chromium (Cr(III)) are the primary chromium oxidation states found in ambient atmospheric particulate matter. While Cr(III) is relatively nontoxic, Cr(VI) is toxic and exposure to Cr(VI) may lead to cancer, nasal damage, asthma, bronchitis, and pneumonitis. Accurate measurement of the ambient Cr(VI) concentrations is an environmental challenge since Cr(VI) can be reduced to Cr(III) and vice versa during sampling. In the present study, a new Cr(VI) sampler (Clarkson sampler) was designed, constructed, and field tested to improve the sampling of Cr(VI) in ambient air. The new Clarkson Cr(VI) sampler was based on the concept that deliquescence during sampling leads to aqueous phase reactions. Thus, the relative humidity of the sampled air was reduced below the deliquescence relative humidity (DRH) of the ambient particles. The new sampler was operated to collect total suspended particles (TSP), and compared side-by-side with the current National Air Toxics Trends Stations (NATTS) Cr(VI) sampler that is utilized in the US. Environmental Protection Agency (EPA) air toxics monitoring program. Side-by-side field testing of the samplers occurred in Elizabeth, NJ during the winter and summer of 2012. The average recovery values of Cr(VI) spikes after 24-hr sampling intervals during summer and winter sampling were 57 and 72%, respectively, for the Clarkson sampler while the corresponding average values for NATTS samplers were 46% for both summer and winter sampling, respectively. Preventing the ambient aerosol collected on the filters from deliquescing is a key to improving the sampling of Cr(VI).Journal of the Air & Waste Management Association (1995) 11/2013; 63(11):1313-23. DOI:10.1080/10962247.2013.823894 · 1.17 Impact Factor
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- "However, lots of efforts have been made in order new techniques to be found for the replacement of hexavalent chromium. Alternative protection of AA is urgent since hexavalent chromium provokes human disease . The new techniques are based on sol–gel coatings, hybrid organic–inorganic coatings and on coatings with conductive copolymers. "
ABSTRACT: a b s t r a c t The development of new technology that prevents corrosion of aluminium alloys (AA) 2024-T3 was made. AA 2024-T3 panels were coated with two layers the first one consists of conductive polymers (CP) and the second one, on the top, is made of sol–gel coatings. Ceramic nanocontainers loaded with cor-rosion inhibitors were incorporated into the CP coatings. Studies on the corrosion resistance of these coatings demonstrated that the presence of loaded nanocontainers into the CP coatings improved the cor-rosion protective properties of the films by increasing the total impedance values, and decreasing both anodic and cathodic currents relatively to coatings without nanocontainers.Corrosion Science 04/2012; 57. DOI:10.1016/j.corsci.2011.12.034 · 3.69 Impact Factor