Trivia: The asylum to which Lex is taken at the end of the episode is called "Belle Reve," which is French for "beautiful dream." It is also the name of the family mansion that once belonged to Blanche and Stella DuBois in "A Streetcar Named Desire." The mansion was lost, but it was the one memory to which Blanche clinged throughout her descent into madness. Belle Reve is also home to many lesser powered super villains in the DC universe, including some of Superman's enemies.
Trivia: Michael McKean, who guest stars as Perry White, is married to Annette O'Toole, who plays Martha Kent.
Trivia: When at Molly's, Lex tells Clark she sent another email and asks if Clark recognized it, which belongs to Martha Kent. The email address is "CNH320@instamail.org." CNH 320 was the license plate number of the General Lee in "The Dukes of Hazzard" (which stars John Schneider who plays Johnathan Kent).
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