
Lead was used in many paints for hundreds of years. It was considered a superior way to protect your home or building from the elements - with a "metal" coating.
Unfortunately, lead is a neurotoxin - something that damages the nervous system. It has affected children and adults for generations. It is also what is called a "legacy toxin" - a toxin that can affect your progeny as well.
So does your home have lead paint? Lead based paints were outlawed in 1978, but were still allowed to be sold/used for a certain period of time even after that. A good rule of thumb - if the home was built in 1978 or earlier, treat all the paint as if it has lead in it.