What health concerns - the tiny mercury droplets on your floor if you should happen to break one? Sweep, don't vacuum, and put the shards, etc. in a sealable plastic bag, wipe down the spot with a damp paper towel to catch any remaining shards and put the towel in the bag as well - much as you might do with any broken light bulb.

Mercury is found naturally in the environment. Utility power plants (mainly coal-fired) are the biggest man-made source since the mercury that naturally exists in coal is released into the air when coal is burned to make electricity. Coal-fired power generation accounts for about 40% of the mercury emissions in the U.S

CFLs prevent some mercury emissions from getting into the environment because they help to reduce emissions from coal-fired power plants. A coal-fired power plant will emit 13.6 milligrams of mercury to produce the amount of electricity required to light an incandescent light bulb, compared to 3.3 milligrams for using a CFL.

As for cell towers...
Since there is electrical activity inside the human body, the question usually comes up as to whether radio waves emitted by cellular phone towers can influence cell function, and in particular whether they can cause cancer. There doesn't seem to be a large body of evidence suporting this. The same arguments were made sometime back regarding high voltage overhead power line towers.

Sometimes I think it's much ado about nothing. Like everything else considered frightening or dangerous today, I somehow survived my childhood playing with tinker toys, Lincoln Logs, toys with small parts, chewing on the fur and button eyes of my Teddy bear without having them taken away for my own good; getting heads caught between balusters without stairways getting banned. Well, you get my drift.

I don't minimize anyone's fear. Sometimes it would make more sense, though, if there was some real science to back up the fear.