Mercury

• Mercury is a neurotoxin and can accumulate in the body, causing brain and nerve damage, especially to fetuses, young children and the elderly. Each CFL contains about 5 mg of mercury. If a bulb breaks, consumers must clean the mercury safely. A study by Maine's Bureau of Remediation and Waste Management found, however, that federal guidelines for chronic mercury vapor exposure were exceeded by up to 100 times, even after cleanup.
  
  

Clean up

• If a bulb breaks, consumers must keep people and pets clear, implement proper ventilation and avoid vacuuming. You must take old or damaged bulbs to an authorized recycling center. If that is not possible, you must seal the bulbs in at least two plastic bags before putting them in the regular trash. Even then, the bulbs can break and tear the bags, causing mercury vapor pollution as the trash is taken to a landfill. At the landfill, mercury can leach into the ground and contaminate the water supply.
  
  

Electromagnetic Fields

• A second possible health concern relating to CFLs is that they emit powerful electromagnetic fields (EMFs) close to the bulb. Studies by the French research entity CRIIREM, confirmed by the Flemish Institute for Technological Research, reveal a high level of EMF up to 3 feet away from the bulb. CRIIREM now has issued warnings not to use the bulbs as desk or reading light sources. In addition, EMFs can travel along electrical wiring in a house, exposing occupants to something called "dirty electricity" and increasing their risk of cancer.
  
  

UV Radiation

• A third potential problem of using CFLs is that they give off UV-B and some slight amounts of UV-C radiation. UV-B radiation is harmful to skin and eyes. UV-C radiation, not usually seen because it is completely absorbed on its way through the atmosphere, is more harmful than UV-B radiation. A report in the medical journal The Lancet stated that these types of radiation increase the risk for skin cancer and other problems for those with skin conditions and hypersensitivity to light. However, so-called "double-envelope" CFLs (those with an outer layer of glass instead of just the fluorescent tubes) prevent most or all of this radiation from escaping. Because single-envelope CFLs cost less, people might be more inclined to buy them instead of the safer, "double-envelope" ones.
  
  

Other Concerns

• Some research indicates that migraines can be triggered by CFLs because of flicker in aging bulbs. Additionally, toxic flame-retardant chemicals used in CFL electronic circuits can harm systems in the body. Some CFLs are coated with titanium dioxide, which is made up of nano-particles that have been implicated in tissue inflammation and cardiovascular abnormalities. Finally, the blue light given off by CFLs can inhibit melatonin production, leading to sleep disruption, cancer and other health problems.