ABSTRACT
The Hanford Environmental Dose Reconstruction Project estimated the radiation dose to individuals from historical emissions of radioactive materials from the Hanford Site in Washington State. Project validation studies using predicted activity concentrations of 131I on sagebrush (Artemisia tridentata) showed a systematic underestimation against historical data during cold weather months, indicating a need for sagebrush model improvement. A deposition model for semi-volatile organic materials presented by Komp and McLachlen (Environ. Sci. Tech. 31 (1997) 886-890) is adapted here for gaseous iodine onto sagebrush. The deposition model includes a temperature-dependent term based on an integrated van't Hoff equation. Calibration data for the model are obtained from a release of 131I in 1963. Modeling results for releases in 1946 show a good match between historical data and predicted results using the new model. The new model shows improvement over interception-fraction type models, but requires plant-type-specific calibration data.
Subject(s)
Air Pollution, Radioactive/analysis , Artemisia , Iodine Radioisotopes/pharmacokinetics , Models, Theoretical , Plants, Medicinal , Environmental Exposure , Environmental Monitoring , Humans , Public Health , Seasons , TemperatureABSTRACT
A case-control analysis of breast cancer deaths among PVC fabricators is presented. This study is an extension of a cross-sectional mortality study of deaths occurring among 17 PVC fabricators during the years 1964 to 1973. Relative risk estimates were derived and tested using the Mantel-Haenszel procedure. Although no statistically significant relative risks were found, a least significant relative risk analysis indicated that the underlying relative risk would have to be on the order of three to one in order to be detected. There does seem to be reasonable assurance that very large increases in risk for breast cancer do not exist among these PVC fabricators.
Subject(s)
Breast Neoplasms/chemically induced , Occupational Diseases/chemically induced , Polyvinyl Chloride/adverse effects , Polyvinyls/adverse effects , Breast Neoplasms/mortality , Female , Humans , RiskABSTRACT
A cross-sectional mortality study of 4,341 deaths occurring among current and former employees of 17 PVC fabricators during 1964-1973 is presented. The objectives are: (1) to identify any angiosarcoma deaths among the employees of these fabricators, and (2) to examine the distribution of deaths by cause. No angiosarcoma deaths were found among the study group. Sex-race-cause-specific Proportionate mortality Ratios (PMR's) were computed, using the corresponding U.S. mortality as the standard. Among white employees, there appears to be an excess in total cancer mortality, particularly that of the digestive system. Observed deaths were found to exceed the expected in cancers of the breast and urinary organs among white females. Deficit mortality was observed in cirrhosis of liver among both male and female white employees.
