Tracking Nuclear Radiation StLouis Missouri

 Conclusions This paper reports radionuclide analyses of the 287 surface soil, dust and sediment samples, collected to test whether significant, off-site dispersal of radionuclides has occurred from the West Lake Landfill site in Bridgeton, MO.

A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable. Wiki

Levels of 210Pb in key samples were well above background activities, and were significantly out of secular equilibrium with other members of the uranium decay chain. This is strong evidence that the 210Pb originated by decay of short-lived, fugitive radon gas that escaped the landfill.

The use of the unsupported 210Pb marker was an important element of our analysis, allowing the identification of waste-impacted areas. 210Pb activities were highest in areas known to be contaminated with wastes from the Mallinckrodt uranium processing wastes. 

Radon soil headspace test and in-situ pore-volume radon activities for soil samples were widely variable, with too few samples available to directly relate these activities to the presence of uranium or uranium processing wastes in soils and sediments.

Some individual samples had very high ratios of radon in headspace to soil masses. Given the importance of radon releases from soils to air as a vector for public exposure to radioactivity, increasing the density and frequency of radon measurements around the West Lake Landfill should be an important priority. 

If the West Lake Landfill fire were to intrude upon areas with buried uraniumprocessing wastes, radon emissions may increase further. 

Isotopes of uranium and thorium reach high levels in sediments around Coldwater Creek. More disturbingly, indoor dusts in homes adjacent to Coldwater Creek have potentially higher levels of uranium and thorium than those found in sediments at known disposal sites. 

After reviewing the 287 environmental sample results, the most effective method for tracking uranium-processing wastes was to monitor unsupported 210Pb, as well as uranium and thorium in sediments and house dusts.

abstract 

Analysis of 287 soil, sediment and house dust samples collected in a 200 km2 -zone in northern St. Louis County, Missouri, establish that offsite migration of radiological contaminants from Manhattan Projectera uranium processing wastes has occurred in this populated area. 

Specifically, 48% of samples (111 of a subset of 229 soils and sediments tested) had 210Pb concentrations above the risk-based soil cleanup limits for residential farming established by the US Department of Energy at the Fernald, OH, uranium plant, which handled and stored the same concentrated Manhattan Project-era wastes; the geographical distribution of the exceedances are consistent with water and radon gas releases from a landfill and related sites used to store and dispose of legacy uranium wastes; and offsite soil and house dust samples proximal to the landfill showed distinctive secular disequilibrium among uranium and its progeny indicative of uranium ore processing wastes. 

The secular disequilibrium of uranium progeny in the environment provides an important method for distinguishing natural uranium from industrial uranium wastes. In this study, the detection of unsupported 210Pb beyond expected atmospheric deposition rates is examined as a possible indicator of excessive radon emissions from buried uranium and radium containing wastes.

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