The use of those spiral, energy efficient bulbs known as compact fluorescent lights has grown in recent years. But as their use has increased, so too have concerns clicked on over their risk of causing mercury poisoning when they shatter. Now comes two new studies adding to that alarm.  The first is by the state of Maine, which found that immediately after a fluorescent bulb is broken levels of mercury vapor often exceed federal guidelines by 100 times.  The second by the Mercury Policy Project found the use of compact fluorescents releases some two to four tons of mercury into the environment each year.  Despite these risks, however, researchers still maintain compact fluorescents, if used properly, are still a bright idea for lighting one’s home.