I agree that iodized salt doesn't smell different to me. But 60 ppm is enough to smell though. Chlorine is a swimming pool is around 3 ppm and often smellable. Bromine, another halide, in that range is odorless.
The iodine in salt is nowhere near as volatile as chlorine. It's intentionally in a form that isn't very volatile. They are not comparable based strictly on concentration as you point out with bromine. I was saying that iodine in its form in salt is not perceptible at the concentrations listed.
Even if they were equivalently volatile and perceptible to the human sense of smell, the comparison doesn't work since those ppm measurements are in different mediums (water vs NaCl) and once salt is added to liquid it would be in much smaller concentrations than 3ppm unless you are making a sauce with > 5% salt (yuk).
To further separate those things, you are not actually smelling the chlorine at that concentration. That is the concentration in water. You are smelling at the concentration of chlorine to air where the chlorine have been volatalized and is sitting in a somewhat dense cloud on top of the water.
Edited for clarity
Edited by BadRabbit, 27 April 2012 - 06:43 AM.