Inconclusiveness of scientific and medical tests

Certain phenomena may not lend themselves to conclusive results when tests are designed for them, whether because of the inadequacies of the test or because of the difficulty of detecting the phenomena. This uncertainty can then be misused to assert that there is no detectable evidence for the phenomena.

This is clearly evident in the determination of thresholds of toxicity of chemicals or radiation on humans, especially in the case of long-term effects of low exposure levels. Inappropriate tests can be used to deny the existence of hazards, at least in the short-term, without revealing the inadequacies of such tests in the case of long-term, low level exposure. Such tests are then used to justify legal thresholds which ultimately prove hazardous to health. The situation is complicated by the different degree to which people are affected by such tests. Some people have a higher tolerance to exposure than others.