Lead Paint?

Lead-based paints were banned for residential use in 1978. Homes built in the U.S. before 1978 are likely to have some lead-based paint.

https://www.cdc.gov/nceh/lead/prevention/sources/paint.htm#:~:text=Lead%2Dbased%20paints%20were%20banned,have%20some%20lead%2Dbased%20paint.?