Threshold theory

M = total mortality rate from lung cancer Mr = lung cancer mortality rate due to radon Mn = lung cancer mortality rate due to non-radon causes including smoking and all other factors, known or unknown r = average radon level in a county Then, from the linear-no threshold theory,... 

Eq.(l) is not valid, which means that the linear-no threshold theory fails, grossly over-predicting the cancer risk at low doses. 

My research eventually convinced me (and a great many others) that radon in homes is very much less harmful than the widely publicized estimates that were based on extrapolating from the number of excess cancers seen in uranium miners who had very high radon exposures. Those estimates were (and are) based on the assumption that the cancer risk from radiation is proportional to the dose, the so-called linear-no threshold theory (LNT). 

The classical threshold theory assumes the existence of a momentary absolute... 

Radon Cohen, B.L., Test of the linear-no-threshold theory of radiation carcinogenesis for inhaled radon decay products. Health Physics, 68,157-174 (1990). 

Space-filling networks of particles normally display a frequency-independent modulus. Near the percolation threshold, theory predicts a relation (de Gennes, 1976 Feng and Sen, 1984)... 

NA MacMillan, DC Creelman. Response bias Characteristics of detection-theory, threshold-theory, and nonparametric indexes. Psychol Bull 107 401-413, 1990. 

This section summarizes the quantum mechanical threshold theories of Brodskii and Gurevich for photoelectronic emission from metal electrodes into vacuum and into electrolyte solutions. 

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