FOR WHAT IT'S WORTH-- We use charcoal samplers to comply. For each iodination, we compare starting activity against activity released to environs. Over the past 40 iodinations, 36 have released between 0.01% and 0.15% of the starting activity. The remaining four released 0.9%, 0.25%, 1.7% and 2.8% Bill Fendt, U of Delaware