There aren't good candidates for highly non-linear processes that can accumulate but take decades to hit some threshold. Biological systems are full of homeosta

There aren't good candidates for highly non-linear processes that can accumulate but take decades to hit some threshold. Biological systems are full of homeostatic mechanisms that prevent such slow accumulation and if and when they break they do so suddenly, so virtually all the other candidates don't fit the profile because you expect incidence to be distributed evenly as a function of age or occurring early (e.g. embryonic lethal).