ICRP in its new review (2007), considered possible challenges to its linear non-threshold model but concluded that for the purposes of radiological protection, it is scientifically reasonable to assume that the incidence of cancer or hereditary disorders will rise in direct proportion to an increase in the equivalent dose in the relevant organs and tissues, below about 100 mSv. ICRP also considered issues such as cellular adaptive responses, genomic instability and bystander signaling but notes that ‘since the estimation of nominal cancer risk coefficients is based upon direct human epidemiological data, any contribution from these biological mechanisms would be included in that estimate’ (Wrixon, 2008).