well here are some fun facts
Date Hazardous Materials Used in Paint
1953 Paint industry standards reduced lead levels in paint to 1.0% (or 10,000 parts per million)
1962 Lead reduced to 0.5% (or 1,000 parts per million). Most buildings constructed before 1960 contain heavily leaded paint.
1972 The Lead Based Paint Poisoning Prevention Act established the level of 0.5% in house paints.
1972 Mercury compounds were banned by the Environmental Protection Agency from use in marine paint.
1978 The final 1977 Lead Based Paint Poisoning Prevention Act regulation set the maximum allowable level at 0.06% (or 600 parts per million) became effective and lead at 0.06 percent or more was banned from consumer paints. The Washington State Department of Health estimates 1.2 million homes in Washington have lead based paint. Refer to Banned Lead Products for more information.
1990 Mercury in interior latex paint was banned by the Environmental Protection Agency. Up until it was banned in interior paints in 1990, paint was the third largest manufacturing use of mercury. Most buildings constructed before 1990 or 1991 probably contain some mercury in their paint.
1992 Mercury in interior paint banned but most manufacturers had reduced the amounts of mercury in their products before these dates. Refer to Banned Mercury Products for more information.
1993 A Consumer Product Safety Commission study of consumer paint samples found that paints on the market meet the standard and are actually below the 0.06 percent level.
1996 Lead was not banned from gasoline used in transportation until December 1995. See Banned Lead Products for more information.
Excellent information about historic paint ingredients (including 20th century paints) and many other building topics is available on The Old House Web at www.oldhouseweb.net
. As an example refer to Painting Historic Interiors.
so you should worry about mercury poisoning more than lead.