{"thcode":2,"term":{"code":1180,"name":"toxic radionuclide contamination","parent":769,"scope":"Introduction into the environment of unstable isotopes of elements that undergo radioactive decay, emitting radiation that is harmful to organisms."},"uf":[],"bt":[{"code":769,"name":"contamination and pollution","parent":1174,"scope":"Introduction of harmful substances into the environment by human action or natural processes."},{"code":1174,"name":"topics","parent":1,"scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":320,"name":"ecotoxicology","parent":650,"scope":"Scientific study of causes, dispersal, and effects of contaminants on the environment."},{"code":345,"name":"environmental health (human)","parent":533,"scope":"Effects of the environment on human health."},{"code":1552,"name":"radon","parent":1427,"scope":"Noble gas element with symbol Rn and atomic number 86 <http:\/\/periodic.lanl.gov\/86.shtml>"}]}