The apparatus developed can efficiently (952) collect organic or inorganic, participate or gaseous radioiodine in the usual concentration range including that below stable atmospheric iodine, and under severe ambient conditions. Response to noble fission gases was reduced to <10~* of an equal iodine airborne activity by heating the collector to approximately 120° C in clean purging air flowing at .14 m^/min for 11 min. Reliable sample size, ± SZ, was achieved by using a sample air flow regulator. Thyroid dose commitment was mathematically and graphically related to the iodine isotope distribution expected in the environment and to the response of the Civil Defense CDV-700 instrument used to evaluate the sample. Sensitivity of the method allows dose assessment of 1-2 rads to a child's thyroid.
Until 2006, continuous radon monitoring devices, CR, could either be calibrated by reference to known quantities or by internal adjustments and or alignments. In 2007, a policy was advanced by the National Radon Safety Board and the National Environmental Health Association mandating internal adjustment and or alignment. Further, calibrations could only be performed by radon chamber persons authorized by the specific device manufacturer, which was a process that was impossible for many chamber operators to achieve. The paper serves to examine the technical validity for routine internal adjustments to Honeywell and Sun Nuclear (Sun Nuclear Corporation, 425A Pineda Court, Melbourne, FL 32940-7508) devices in contrast to the clear market controlling advantages of the policy. The purpose for making radon measurements is to assess risk. Comparing the uncertainties associated with risk to counting uncertainties of Honeywell and Sun Nuclear CR devices, less than 1% of model 1027 devices would have a calibration error exceeding 25%, and those devices, at this Radon Measurement Proficiency limit, would produce results that were more precise and accurate than the radon risk uncertainty. This was true for CR devices that have not been internally adjusted nor corrected in any way. It was concluded that internal adjustment or alignment better supported business principles than science.
The U.S. EPA identified South Central Pennsylvania as a region having elevated radon levels. The thnist of this paper is to examine in some detail the TCS Industries, Inc., data base for eight Central Pennsylvania counties having a combined population of about 1.7 million people, which is 14% of the state population. TCS has been making and analyzing radon measurements since 1986. During the period 1986 to 1999 more than 125,000 measurements were recorded in the TCS data base. The data consisted of analyzed results from four subsets. Results were from mail order charcoal canisters, bulk orders from RMP certified companies for their placement, wholesales to retail vendors, and also direct home placement of canisters, track detectors, and continuous radon monitors. The data base for the eight South Central Pennsylvania counties for tile 13-y period consists of more than 27,000 screening measurements from non-duplicated addresses. The results were assembled into three studies. The locations of tile measurements were converted into individual latitude and longitude values. The data were divided into four blocks of concentrations from 740 Bq m(-3) to over 4,440 Bq m(-3). The data were plotted on computer generated maps for South Central Pennsylvania. The plots indicated both hot spots and regions of relatively uniform chronic levels of 740 to 1,480 Bq m(-3). An average value of the basement to first floor concentrations ratio was constructed from measurements made by TCS for real estate purposes. The ratio represents 1,608 sets of simultaneous measurements of basements and first floor radon values above 37 Bq m(-3). The measurements were made by trained personnel performed under tile EPA protocol for closed house conditions. The ratio was 2.3 at 1 standard deviation of 0.05 of the mean. A third study assembled all of the data into first floor radon concentrations and separately for addresses with only basement values. The average concentration data within each of the eight counties were converted into the probability of fatal lung cancers and compared with occupational risk of fatal cancers for nuclear power plant workers. This study illustrates the importance of a continuing strong measurement program in South Central Pennsylvania.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.