The Elisabeth d'Ornano Association for ADHD

Children whose mothers smoked during pregnancy or who were exposed to lead have more than double the risk of having attention-deficit hyperactivity disorder (ADHD) as other children, new research shows.

And with exposure to cigarettes and lead, the chances of having ADHD soared. Children whose mothers smoked during pregnancy and whose blood showed signs of lead exposure had eight times the risk of having ADHD.

"When you have both exposures, there is a synergistic effect," said study author Dr. Tanya Froehlich, a developmental and behavioral pediatric specialist and an assistant professor of pediatrics at Cincinnati Children's Hospital Medical Center.

Froehlich and her colleagues used data on 2,588 children aged 8 to 15 from around the nation who took part in the 2001-2004 National Health and Nutrition Examination Survey. Tobacco exposure was assessed by asking mothers if they smoked during pregnancy, while lead concentrations were measured by a blood test.

About 8.7 percent of children met the criteria for ADHD, which is marked by inattentiveness, difficulty focusing, impulsivity and hyperactivity, according to the study. The ADHD group included 16.8 percent of children whose mothers smoked during pregnancy, compared to 6.6 percent of children whose mothers did not smoke.

Lead exposure was divided into three groups: low, medium and high. About 5.2 percent of children who had the lowest lead blood levels had ADHD. About 9.1 percent of children in the middle range had ADHD, while 13.6 percent of children in the highest third had ADHD, the researchers found.

Previous research has shown lead is toxic to children's brains and is associated with lower IQs and hyperactivity in children.

Lead can be found in:

• Paint older than 1978. Toys and furniture painted before 1976.

• Lead pellets, fishing weights, drape weights.

• Water pipes. Lead can be found in drinking water in houses in which pipes have been welded with lead. Although new construction codes require lead free welding, this element can still be found in some modern faucets.

• Contaminated soil by decades of emissions from cars or peeling paint from houses. This is why lead is more commonly found near highways and houses.

• Hobbies that require welding, glass, jewelry, ceramics varnish, miniature lead figures. (always check the labels).

• Painting and art supplies for children (always check the labels)

• Pewter jars and dishes.

• Batteries.

Children receive lead in their bodies when they take objects with lead to their mouth, especially if they swallow it. They can also receive lead when touching a lead object with dust or that is peeling y then take their fingers to their mouth or eat. Children can also inhale small amounts of lead.

Exposure to lead can be reduced by:

• if you suspect that the house`s painting has lead, try to paint it over with more modern paint.

• Keep the house dust free.

• Try that everyone washes hands before meals.

• Discard old toys in case you are not sure if paint has lead.

• Let the water run for a moment before drinking it or cooking with it.

• If water has been tested and it has lead, consider the possibility of installing a filter or use bottled water for drinking and cooking.

• Avoid can food from countries that don`t forbid lead welding.

• If imported wines have a tinfoil with lead, before consuming, clean the edge and neck of the bottle with lemon juice, vinegar or wine.

• No dot store wines, liquor or dressings with vinegar in lead crystal bottles for long periods of time, as lead can filter to liquid.