Lead is a human and environmental health concern because it is toxic to the body, even in small amounts. Once released into the environment it tends to linger and accumulate in the food chain. Lead is used in products such as electric cable sheathing, interior and exterior paints, and in lead pipes or lead solder used on copper plumbing pipes. Human exposure most often occurs through lead dust which is released when lead paint deteriorates or is disturbed during demolition or renovation. Exposure from drinking water that has been contaminated by lead pipes or through soil contaminated by exterior leaded paint or leaded gasoline is also possible. Lead can cause severe and lingering ill effects. At elevated levels in the body it can cause damage to the kidneys, liver, brain and nervous system. Once identified on work sites, lead becomes a health hazard to contractors and a potential future liability for property owners and architects responsible for the project. Because of the potential danger associated with lead dust caused by renovation and demolition activities in older buildings, lead clean-up or removal must be handled by certified professionals to ensure hazardous materials are abated and disposed of in a safe, responsible and cost effective manner.