Radon measurements and analysis for central Pennsylvania counties having elevated radon levels.

摘要

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.