A widely accepted viewpoint is to consider candidates for cosmological dark
matter as neutral and weakly interacting particles, as well as to consider only
light elements in the pregalactic chemical composition. It is shown that stable
charged leptons and quarks can exist and, hidden in elusive atoms, play the
role of dark matter. The inevitable consequence of realistic scenarios with
such composite atom-like dark matter is existence of significant or even
dominant fraction of "atoms", binding heavy -2 charged particles and He-4
nuclei. Being alpha-particles with shielded electric charge, such atoms
catalyse a new path of nuclear transformations in the period of Big Bang
Nucleosynthesis, which result in primordial heavy elements. The arguments are
given, why such scenario escapes immediate contradiction with observations and
challenges search for heavy stable charged particles in cosmic rays and at
accelerators.Comment: Prepared for Proceedings of Blois2007 Conferenc
