Visible crew/equipment: Martha and Lionel are in the barn when everything starts to fall apart. The camera shot changes from them to a boat falling from the rafters. As it falls there is a visible production crewmember hiding next to the window, holding a hay bale. (00:28:15)
Visible crew/equipment: When Lex is driving out of the dam and the police arrive, Lex exits his car and two crew members heads are reflected in the glass window of his door. (02:35:30)
Answer: The kryptonite only creates mutations when it reacts with the environment and an individual. Remember, the FDA and several environmental groups did check out Smallville after the meteor shower, but found no danger in the rocks. Obviously they're not always emitting mutating rays, or all the flora and fauna of the surrounding area would be horribly mutated.
Phoenix