The findings contradict the LNT hypothesis as it relates to mutation and cancer induction, as a dose threshold
would be expected to overcome the protective barrier.
One view holds that arsenic has a dose threshold
below which exposures aren't harmful.
An important 2004 study by the National Academy of Sciences concluded that "there is no compelling evidence to suggest a dose threshold
below which the risk of tumor induction is zero.
However, the exposure of the workers directly at the facility was quite high in one dose and these workers were found to have an increase in cancers indicating a dose threshold
for increase cancers (Koshurnikova 2002).
Exceeding the dose threshold
of these random events only increases the probability of failure(s) occurring and not the certainty of failure.
The conclusions drawn by researchers were that visual function can be rescued and preserved in this animal model of disease utilizing ACT's GMP-manufactured human ES-derived RPE cells with a functional dose threshold
and that these cells may provide an effective donor cell source to rescue photoreceptors in conditions like AMD, where RPE function is compromised.
Deterministic effects are those radiobiological effects that increase in severity as the radiation dose increases and for which a dose threshold
11), and [delta] is the threshold parameter such that the dose threshold
for each individual chemical is given by [[delta].
The conclusions drawn by researchers were that visual function can be rescued and preserved in this animal model of disease utilizing GMP-compliant human ES-derived RPE cells with a functional dose threshold
and that these cells may provide an effective donor cell source to rescue photoreceptors in conditions like Age-related macular degeneration (AMD), where RPE function is compromised.
Linear dose-response relationships were identified at sufficiently low doses, with no evidence of a dose threshold
below which nanoparticle instillation ceased to cause inflammation.
Data modeling with the FSCR method provided maximum effect parameters (asymptotes) and dose threshold
parameters for each chemical and for the mixture.
In vivo studies support a dose threshold
for skin papilloma formation in response to TPA (2,3).