They won't receive their abilities immediately. Some traits of the elements may be present because they do have an affinity for them, it's what allows them to develop their powers anyway, but it won't be anything too supernatural. Nixie's colder-than-normal skin is kind of a perfect presentation of this. :3 The 'crystals' will really be what the scientists developed to store the energy that they had been using to try and trigger these abilities in soldiers during the Cold War. Calling them crystals is a bit of a misnomer, but it is what a bunch of middle-schoolers would come up with.

Does that help at all? :3