Linear non-threshold (LNT) fails numerous toxicological stress tests: Implications for continued policy use.

The linear non-threshold (LNT) dose-response model has long been employed by regulatory agencies to assess cancer risks from exposures to chemical carcinogens and ionizing radiation. Herein a series of fundamental historical, physical, chemical, and biologically based toxicological "stress tests" were "administered" to the LNT model, showing important limitations for its use in low dose extrapolation for all endpoints but with particular focus on cancer risk assessment where it is commonly applied. These limitations reveal that its capacity to make low-dose cancer-risk predictions is seriously flawed, precluding its use as a reliable model to estimate low dose cancer risks.