A Nested Case-Control Study of Multiple Myeloma Risk and Uranium Exposure among Workers at the Oak Ridge Gaseous Diffusion Plant

Abstract

The primary risk factors of multiple myeloma are age, race and sex, but several studies have found an association between radiological hazards and multiple myeloma. The purpose of this nested case-control study was to investigate whether workers with chronic low-level exposure to internally deposited uranium at the Oak Ridge Gaseous Diffusion Plant in eastern Tennessee were at higher risk of dying of multiple myeloma than those without occupational exposure to uranium, with the consideration of potential confounders of external ionizing radiation and occupational chemical hazards such as mercury, nickel and trichloroethylene. The main analyses were carried out using conditional logistic regression on 98 cases and 490 controls (five controls matched to each case on gender, race and age at risk). Our study showed a weak association between internal uranium dose estimated from urinalysis results and multiple myeloma risk: OR = 1.04 (95% CI 1.00-1.09) at 10 microGy with the inclusion of other risk factors. The parameter estimates and the corresponding odds ratios were very similar when internal doses were imputed for subjects without urine samples. Further studies that include updating this cohort and combining with workers from other gaseous diffusion plants are needed to investigate the relationship between multiple myeloma risk and radiation or other chemical exposures.

Epidemiology of Leukemia and Multiple Myeloma in Golestan, Iran

“…Age and race are considered as risk factors for multiple myeloma. Exposure to radiation and occupational exposures to high levels of benzene or formaldehyde are considered as risk factors for both multiple myeloma and leukemia (Romanenko et al, 2008;Yiin et al, 2009;Rhomberg et al, 2011).…”

Uranium carcinogenicity in humans might depend on the physical and chemical nature of uranium and its isotopic composition: results from pilot epidemiological study of French nuclear workers

“…Similar results were reported among Sellafield workers [31], where a statistically significant trend with external radiation exposure among plutonium workers was observed in comparison with non-radiation exposed workers. Several studies on uranium workers reported an increase in mortality due to lymphatic or hematopoietic malignancies [36][37][38][39][40][41][42][43][44][45][46] but only a few of them investigated the relationship with uranium internal exposure [38,[45][46][47][48]. Ritz et al [46] observed a positive association (trend) between internal radiation dose and risk of mortality from lymphatic and hematopoietic malignancies in the Rocketdyne plant worker cohort.…”

“…Their doseresponse analyses showed that the second (21-50 lg y) and third (51-125 lg y) quartiles of internal uranium exposure were significantly elevated for NHL (RR = 9.95 (95% CI: 1.22-81.26) and RR = 8.85 (95% CI: 1.11-70.88), respectively) while the fourth quartile ([125 lg y) was non-significantly elevated (RR = 5.74 95% CI: 0.72-45.48) [47]. Lastly, a nested case-control study of multiple myeloma (MM) conducted among workers at the Oak Ridge gaseous diffusion plant [48] found that the risk of MM increases with increasing internal uranium dose to red bone marrow. The risk was 1.04 (95% CI: 1.00-1.09) at 10 lGy after accounting for age, race, sex, and occupational chemicals, such as mercury, nickel, and TCE [48].…”

DoReMi workshop on multidisciplinary approaches to evaluating cancer risks associated with low-dose internal contamination

“…Nevertheless, most studies conducted up to now were limited in their capacity to demonstrate an associated risk, mainly due to their reduced statistical power or to the poor quality of their dosimetric data (Guseva Canu et al, 2008a). However, new studies have been recently launched in the US based on updated cohorts with comprehensive exposure assessment and internal dose estimation and have already provided informative results with respect to the lymphatic and haematopoietic tissue malignancies (Yiin et al, 2009;Chan et al, 2010;Boice et al, 2011). In Europe, a similar study was conducted in France, in the framework of a pilot investigation; though internal doses have been only partially assessed.…”