Look up and read "Geophysical Characterization of the Chicxulub Impact Crater" (2013) as well as "The Cretaceous-Tertiary Mass Extinction, Chicxulub Impact, and Deccan Volcanism" (2012) as well as looking up "chondrite" which is what the Chicxulub Impactor was. Then tell me where you see evidence that the Chicxulub Impactor was in any way radioactive. It should also be noted per the second study that the Deccan Traps were erupting long before, during and long after the impactor struck and obviously would have had devastating effects on both flora and fauna. As for a decrease in dinosaurs before the impact you can read the following:
To add to the above a more recent article suggests that the impactor itself was, based on a more recent estimate of Iridium found in the K-Pg layer, significantly smaller at about 5.7 km/3.5 miles versus the original estimate of 6 miles.
Edited by cormac mac airt, 17 November 2013 - 04:35 AM.