Hexavalent Chromium and Lung Cancer in the Chromate Industry: A Quantitative Risk Assessment

US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, MS C-15, Cincinnati, OH 45226-1998, USA.
Risk Analysis (Impact Factor: 2.5). 11/2004; 24(5):1099-108. DOI: 10.1111/j.0272-4332.2004.00512.x
Source: PubMed


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.

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    • "Fe is considered a nuisance dust with little likelihood of causing chronic lung disease, while Mn has been associated with neurological diseases (McMillan 1999; Antonini 2003; NIOSH 2007). Welding on stainless steel presents added occupational hazards compared to mild steel due to exposure to hexavalent chromium (Cr(VI)) and Ni, two known carcinogens also associated with asthma (Gibb et al. 2000; Park et al. 2004b; NIOSH 2007). The particle size distribution of welding fumes has significance to the deposition in the respiratory tract and the Received 20 August 2014; accepted 20 October 2014. "
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    ABSTRACT: A laboratory study was conducted to determine the mass of total Cr, Cr(VI), Mn, and Ni in 15 size fractions for mild and stainless steel gas-metal arc welding (GMAW) fumes. Samples were collected using a nano multi orifice uniform deposition impactor (MOUDI) with polyvinyl chloride filters on each stage. The filters were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography. Limits of detection (LODs) and quantitation (LOQs) were experimentally calculated and percent recoveries were measured from spiked metals in solution and dry, certified welding-fume reference material. The fraction of Cr(VI) in total Cr was estimated by calculating the ratio of Cr(VI) to total Cr mass for each particle size range. Expected, regional deposition of each metal was estimated according to respiratory-deposition models. The weight percent (standard deviation) of Mn in mild steel fumes was 9.2% (6.8%). For stainless steel fumes, the weight percentages were 8.4% (5.4%) for total Cr, 12.2% (6.5%) for Mn, 2.1% (1.5%) for Ni and 0.5% (0.4%) for Cr(VI). All metals presented a fraction between 0.04 and 0.6 μm. Total Cr and Ni presented an additional fraction p-value = 0.19), hence our analysis does not show that particle size affects the contribution of Cr(VI) to total Cr. The predicted total respiratory deposition for the metal particles was ∼25%. The sites of principal deposition were the head airways (7–10%) and the alveolar region (11–14%). Estimated Cr(VI) deposition was highest in the alveolar region (14%).
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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). "
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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). "
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