threshold dose

A. We know the threshold dose - the level above which harm can be done - for most of these substances from animal studies.

Then you can do quality animal studies to determine the threshold dose for toxic or embryonic effects.

For most beneficial or recreational drugs, the desired effects are found at doses slightly greater than the threshold dose.

Although the threshold dose to cause toxicity is unknown in humans, lower doses are almost certainly less risky.

He said this would be a threshold dose based on the dosages of other ergot alkaloids.

Biological toxicity can be difficult to measure because the "threshold dose" may be a single organism.

It is because the 2D pattern (ideally rectangular) is defined by the number of photons in a limited area exposed above or below a certain threshold dose.

Experimental and epidemiological data do not support the proposition, however, that there is a threshold dose of radiation below which there is no increased risk of cancer.

Biologically based models using dose are preferred over the use of log(dose) because the latter can visually imply a threshold dose when in fact there is none.

They may indicate a threshold effect - there is only so much good that chemotherapy can do, and once you reach that threshold dose giving more will not make any difference.

It is commonly reported that there is a threshold dose, below which the plant likely won't produce any effects in the user, so a high dose is sometimes required.

Ott reported "visionary effects" of intranasal bufotenine and that the "visionary threshold dose" by this route was 40 mg, with smaller doses eliciting perceptibly psychoactive effects.

Other conditions such as radiation burns, acute radiation syndrome, chronic radiation syndrome, and radiation-induced thyroiditis are deterministic, meaning they reliably occur above a threshold dose, and their severity increases with dose.

The newest data base for 1950-1985 reported by the Radiation Effects Research Foundation, formerly the Atomic Bomb Casualty Commission, demonstrates powerfully against any "tolerance" or safe "threshold dose" of ionizing radiation.

Standards for exposure to benzene are expected by the UK government to be set in 1993: a level of 3 ppb is under consideration, although according to the World Health Organization there is "no known safe threshold dose".

Yoshihisa Matsumoto, a radiation biologist at the Tokyo Institute of Technology, cites laboratory experiments on animals to suggest there must be a threshold dose below which DNA repair mechanisms can completely repair any radiation damage.

While this linear approach remains the default, with sufficient mechanistic evidence suggesting a non-linear dose-response, EPA allows for the derivation of a threshold dose (a.k.a. reference dose) below which it is assumed that there is no risk for cancer.

Not only does the epidemiologic evidence show that there is no threshold dose below which ionizing radiation is harmless, but also undisputed evidence from humans shows that exposure at the lowest and slowest conceivable dose induces permanent, unrepaired genetic mutations.

April 19, 1943, Hofmann performed a self-experiment to determine the true effects of LSD, intentionally ingesting 0.25 milligrams (250 micrograms) of the substance, an amount he predicted to be a threshold dose (an actual threshold dose is 20 micrograms).