Audio problem: The CD playing in Lex's car is heard at exactly the same volume and quality from outside the car when Lex has his windows up and when he rolls one down. (00:10:20)
Continuity mistake: The lime slices on the side of Lex's and Amanda's drinks, in Club Zero, change position between shots.
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