Mercury can be toxic to humans in even slight amounts. For this reason, broken compact fluorescent lights should be disposed of properly. A fluorescent light bulb can contain around 5 mg of mercury. Larger bulbs or bulbs with higher wattages may contain even more mercury.
Several factors play a role in how severely a person will react to mercury exposure. Such factors include the form of mercury exposed to, the dose or amount exposed to, duration of exposure, a person's age and route of exposure (ingestion, inhalation, dermal contact).
Mercury takes a few chemical forms. Methylmercury can be found in some fish and shellfish. Elemental mercury is the type of mercury found in fluorescent lights.
Overexposure to methylmercury in fetuses and infants can affect memory, attention and motor skills. Symptoms of exposure to elemental mercury include tremors, insomnia, respiratory failure, changes in nerve response, muscle atrophy and death.
Mercury is a recyclable material so instead of disposing fluorescent bulbs into landfills, they should be recycled or taken to a facility capable of properly disposing of broken or used fluorescent bulbs.