Trivia: Martha makes a remark suggesting she thinks Bridgette Crosby and Dr Swan are together to which Bridgette comments "In another lifetime." Bridgette is played by Margot Kidder, who played the original Lois Lane, Prof Swan was played by the late Christopher Reeve. A nice touch I think.
Trivia: When Dawn is looking through the yearbook, some of the names seen are people who worked on "Smallville." Mairzee Almas was one of the directors who would go on to direct Kreuk (Lana) in "Beauty and the Beast" and a few other DC shows. Assistant editor Anthony Ashley, assistant directors Jen Carpenter and Rob Duncan, costume designer Caroline Cranstoun, and location manager Michael Hauka. Many would also go on to work on other DC shows.
Trivia: The Daily Planet article about Lionel Luther being found guilty was reported by Perry White. When Perry was seen in season 3, he was a disgraced reporter, after Lionel got him fired, who worked as a tabloid reporter. He vowed to get sober and get his career on track at the end of the episode "Perry." He isn't physically seen again until the end of season 9.
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