Estimation of radon exposures to workers at the Fernald Feed Materials Production Center 1952-1988.

The Feed Materials Production Center (FMPC) at Fernald, Ohio produced uranium metal products for use in Department of Energy defense programs. Radium-contaminated waste material was stored on-site in two K-65 silos on the west side of the facility and provided a source of 222Ra. The initial objective of this study was to estimate radon exposures to employees at FMPC working from 1952 to 1988. A modified Gaussian plume model was used to estimate exposures to workers. In an effort to validate these model-based estimates, we used 138 CR-39 film assays from window glass sampled in buildings throughout the site. Results from the CR-39 assays indicated a second substantial source of radon, the smaller Q-11 silos located in the production area. A response-surface regression analysis using a cubic spline model was fit to the CR-39 data to estimate 210Po surface activity levels at geographic coordinates throughout the facility. Knowledge of the age of the glass, the amount of contaminated waste in the Q-11 silos, and 210Po decay rates were used to estimate annual exposures to radon decay products (WLM: working level months). Estimated WLM levels associated with the Q-11 source term indicated that employees working in the vicinity during the period when they were filled with radium-contaminated waste (1952-1958) received substantially higher radon exposures than those from the K-65 source during this period. Results of the two models, corresponding to the K-65 and Q-11 sources, were combined to estimate WLM levels by year for each of the 7143 Fernald workers during the period 1952-1988. Estimated cumulative exposures to individual workers ranged from <0.5 to 751 WLM. Estimated radon exposures from this newly discovered source have important implications for future epidemiologic studies of lung cancer in workers at the Fernald facility.

Health effects in community residents near a uranium plant at Fernald, Ohio, USA.

OBJECTIVES: Health outcomes in persons who lived in the area surrounding a U.S. Department of Energy (DOE) uranium processing plant near Fernald, Ohio were evaluated using data of Fernald Medical Monitoring Program (FMMP) participants. METHODS: Residential history information was used to identify participants who lived in close proximity to the plant (less than 2 miles), in the direction of groundwater runoff (south of the plant), or used a well or cistern as a drinking water source. Standardized prevalence ratios (SPRs) for certain disease endpoints were calculated using the U.S. National Health Interview Survey(NHIS) and the National Health and Nutrition Examination Survey (NHANES) data files for comparison rates. RESULTS: Findings suggest that prior living within the Fernald exposure domain is related to increased prevalence of urinary system disease. Statistically significant elevations of bladder disease (standardized prevalence ratio or SPR = 1.32) and kidney disease (SPR = 2.15), including sub-categories, kidney stones (SPR = 3.98) and chronic nephritis (SPR = 2.03) were noted, as well as increased rates for hematuria and urethral stricture. In regression analyses with adjustment forage and sex, serum creatinine levels were increased in those who had lived close to the plant. Increased white blood cell count and hemoglobin levels, and decreased mean corpuscular volume were also found in those living less than 2 miles from the plant. Those who used a well or cistern for drinking water were found to have increased urinary microalbumin, red blood cell count and hematocrit. CONCLUSIONS: These preliminary findings will provide the basis for future hypothesis testing incorporating important determinants of exposure not included in this study, such as duration and calendar year of exposure, location relevant to prevailing wind direction, and age at exposure.