In the first place, as we shall see, the necessary data are not available, even today. In the second place, the traditional toxicological assumptions did not hold up under scrutiny. For many poisons, there is no safe dose. And finally, impartial experts are almost never impartial. Someone is paying their hefty fee and that someone often gets the benefit of the doubt when it comes time to interpret whatever data is available.
Experts can be bought, it turns out.
There is no agreement on ways to test for genetic damage. Without agreement on test methods, people cannot agree on which data to include in a risk assessment. For these toxicants, any exposure may cause some damage. If genetic damage occurs in a germ cell, it may be inherited by successive generations. Any exposure to certain carcinogens may initiate a sequence that results in cancer.