Updated mortality analysis of the Mallinckrodt uranium processing workers, 1942-2012.

PURPOSE: Mallinckrodt Chemical Works (MCW) was the earliest uranium processing facility in the United States, and in 1942 produced the uranium oxide used for the first sustained and controlled nuclear fission chain-reaction at the University of Chicago. A second follow-up through 2012 was conducted of 2514 White male workers employed 1942-1966 at the MCW for dose-response analyses for selected causes of death. MATERIALS AND METHODS: Organ/tissue-specific dose reconstruction included both external (12,686 MCW film badge records, 210 other facility film badge records, and 31,297 occupational chest x-rays) and internal sources of uranium and radium (39,451 urine bioassays, 2341 breath radon measurements, and 6846 ambient radon measurements). Dust measurements from pitchblende facilitated quantitative risk estimates for non-radiogenic effects on the lung and kidney. Vital status was determined from multiple sources including the National Death Index and the Social Security Administration. Cox regression models were used for dose response analyses. RESULTS: Vital status was determined for 99% of the workers, of whom 75% had died. The mean lung dose from all sources of external and internal radiation combined was 69.9 mGy (maximum 885 mGy; percent workers >100 mGy, 10%) and there was no evidence for a dose response for lung cancer (Hazard Ratio (HR) of 0.95 (95% CI = 0.81-1.12) at 100 mGy). A significant association with radiation was found for kidney cancer (HR of 1.73 (95% CI = 1.04-2.79) at 100 mGy) and suggested for nonmalignant kidney diseases (HR of 1.30 (95% CI = 0.96-1.76) at 100 mGy). A non-radiation etiology could not be discounted, however, because of the possible renal toxicities of uranium, a heavy metal, and silica, a component of pitchblende dust. Non-significant HRs at 100 mGy for other sites of a priori interest were 0.36 (0.06-2.03) for leukemia other than CLL, 0.68 (0.17-2.77) for liver cancer, and 1.23 (0.79-1.90) for non-Hodgkin lymphoma. The HR at 100 mGy was 1.09 (0.99-1.20) for ischemic heart disease. An association was seen between dust and combined malignant and non-malignant lung disease, HR at 10 mgm-3year-1 of 1.01 (1.00-1.02). CONCLUSIONS: A positive radiation dose response was observed for malignant and non-malignant kidney disease, and a negative dose response for malignant and non-malignant lung disease. Cumulative measures of dust were significantly associated with malignant and non-malignant lung disease and suggested for malignant and non-malignant kidney disease. Small numbers preclude definitive interpretations which will await the combination with similar studies of early uranium processing workers.

Trade associations and labor organizations as intermediaries for disseminating workplace safety and health information.

BACKGROUND: There has not been a systematic study of the nature and extent to which business and professional trade associations and labor organizations obtain and communicate workplace safety and health information to their members. These organizations can serve as important intermediaries and play a central role in transferring this information to their members. METHODS: A sample of 2294 business and professional trade associations and labor organizations in eight industrial sectors identified by the National Occupational Research Agenda was surveyed via telephone. RESULTS: A small percent of these organizations (40.9% of labor organizations, 15.6% of business associations, and 9.6% of professional associations) were shown to distribute workplace safety and health information to their members. Large differences were also observed between industrial sectors with construction having the highest total percent of organizations disseminating workplace safety and health information. CONCLUSION: There appears to be significant potential to utilize trade and labor organizations as intermediaries for transferring workplace safety and health information to their members. Government agencies have a unique opportunity to partner with these organizations and to utilize their existing communication channels to address high risk workplace safety and health concerns.

Illness absences among beryllium sensitized workers.

OBJECTIVES: This study examined absence rates among US Department of Energy workers who had beryllium sensitization (BeS) or were diagnosed with chronic beryllium disease (CBD) compared with those of other workers. METHODS: We used the lymphocyte proliferation test to determine beryllium sensitivity. In addition, we applied multivariable logistic regression to compare absences from 2002 to 2011 between workers with BeS or CBD to those without, and survival analysis to compare time to first absence by beryllium sensitization status. Finally, we examined beryllium status by occupational group. Results. Fewer than 3% of the 19,305 workers were BeS, and workers with BeS or CBD had more total absences (odds ratio [OR] = 1.31; 95% confidence interval [CI] = 1.18, 1.46) and respiratory absences (OR = 1.51; 95% CI = 1.24, 1.84) than did other workers. Time to first absence for all causes and for respiratory conditions occurred earlier for workers with BeS or CBD than for other workers. Line operators and crafts personnel were at increased risk for BeS or CBD. Conclusions. Although not considered "diseased," workers with BeS have higher absenteeism compared with nonsensitized workers.

Occupational exposure and mortality among workers at three titanium dioxide plants.

BACKGROUND: A cohort of 3,607 workers employed in three DuPont titanium dioxide production facilities was followed from 1935 through 2006. METHODS: Combined and plant-specific cohort mortality was compared with the overall US population and other DuPont employees. The relationships between selected causes of death and annual cumulative exposures to titanium dioxide and chloride were investigated using Poisson regression methods to examine trends with increasing exposure. RESULTS: Among the 833 deaths, no causes of deaths were statistically significantly elevated either overall or plant-specific when compared to the US population. Compared to DuPont workers, statistically significantly elevated SMRs for all causes, all cancers, and lung cancers were found driven by the workers at the oldest plant. Comparing increasing exposure groups to the lowest group, disease risk did not increase with exposure. CONCLUSIONS: There was no indication of a positive association between occupational exposure and death from all causes, all cancers, lung cancers, non-malignant respiratory disease, or all heart disease.

Mortality among titanium dioxide workers at three DuPont plants.

OBJECTIVE: To evaluate the mortality among workers employed at three titanium dioxide plants in the United States. METHODS: We expanded and updated a cohort employed at titanium dioxide plants. Cause-specific standardized mortality ratios (SMRs) were calculated combined and stratified by plant for workers employed at least 6 months between 1935 and 2005. RESULTS: No indications of excess mortality from any cause were found. All causes SMR increased with length of plant operation as did most cause-specific SMRs. With lung, the target organ of interest, no increases in malignant or nonmalignant respiratory disease were observed. CONCLUSIONS: The mortality rates are comparable with the general US population. Increasing SMRs with length of plant operation is indicative of waning healthy worker effect with time since first employment. The results are comparable with other titanium dioxide cohort studies.