Secondhand Smoke: Children Ages 4-17 with Blood Cotinine* Levels, Selected Years 1998-2008.

Children Ages 4-17. Any detectable cotinine: 1988-1994 87.4%; 1999-2000 64.2%; 2001-2002 52.6%; 2003-2004 61.1%; 2005-2006 48.9%; 2007-2008 50.0%. Blood cotinine more than 1.0 ng/mL: 1988-1994 23.7%; 1999-2000 16.9%; 2001-2002 16.1%; 2003-2004 17.1%; 2005-2006 11.6%; 2007-2008 15.3%.

Children Ages 4-11. Any detectable cotinine: 1988-1994 87.7%; 1999-2000 64.4%; 2001-2002 55.1%; 2003-2004 63.7%; 2005-2006 51.4%; 2007-2008 52.6%. Blood cotinine more than 1.0 ng/mL: 1988-1994 25.7%; 1999-2000 17.7%; 2001-2002 18.1%; 2003-2004 18.7%; 2005-2006 12.3%; 2007-2008 16.7%.

Children Ages 12-17. 1988-1994 87.0%; 1999-2000 63.9%; 2001-2002 49.6%; 2003-2004 57.9%; 2005-2006 46.0%; 2007-2008 47.0%. Blood cotinine more than 1.0 ng/mL: 1988-1994 21.1%; 1999-2000 16.0%; 2001-2002 13.6%; 2003-2004 15.0%; 2005-2006 10.8%; 2007-2008 13.7%.