Some of this stuff is very time sensitive, ie only usable within a short period of time so any delay could render it unusable.
I've carried enough radioactives while on freighters, generally no problems at all if all the packing and shipping regulations are followed. Gets interesting if you have a spillage, need a physicist to certify the clean up.
Generally only very small quantities carried by air due to strict total limits, you will not see 44gal drums, and no shipment which requires monitoring can go by air.
Try a dangerous goods acceptance course if you are really interested, takes about three days and will bore you to tears.
