Mercury – a potent, developmental neurotoxin that can damage the brain, liver, kidneys and central nervous system. Infants and young children are particularly vulnerable to mercury’s toxic effects. Even at low levels, mercury is capable of causing a number of health problems including impaired motor functioning, cognitive ability and emotional problems. Higher or prolonged exposure can result in much more serious health problems. This is ordinarily not a problem, but if the bulb breaks clean up is a hassle. Mercury is a dangerous heavy metal, and proper cleanup and disposal of CFL bulbs is critical. Disposal of Mercury containing light products is a huge environmental challenge.