Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

ADD & ADHD Health Center

Font Size

Kids Exposed to Mercury, Lead at Risk for ADHD

Mercury and Lead Linked to More Symptoms of ADHD continued...

In contrast, Inuit children with even low to moderate blood levels of lead -- closer to levels measured in some U.S. children -- were more than four times more likely to have problems with hyperactivity than kids with lower lead levels.

"The effects we are seeing are at very low levels of exposure. In [the] U.S. and Canada, for example, we estimate that 10% of children would be exposed to [these] blood lead levels," says Muckle. U.S. children can be exposed to lead when they eat tiny chips of lead-based paint, which can be found in homes built prior to 1978.

The study is published in Environmental Health Perspectives. It was paid for by government grants from the U.S. and Canada.

Mercury Exposure Before Birth

Other studies that have looked for a link between mercury exposure and ADHD have had mixed results. A study of children in the Faroe Islands, where marine mammals like whales are dietary staples, also found attention problems in school-aged children exposed to high levels of the heavy metal before birth.

But another study, of children in the Seychelles Islands, found no clear link between mercury exposure before birth and behavior problems.

"It's quite an interesting sort of finding, really. In the Seychelles they found that the more mercury exposure before birth, the higher the child's IQ. In the Faroe Islands, the more mercury, the worse off the kids were," says Justin Williams, MD, a psychiatrist at the University of Aberdeen in Scotland. Williams was not involved in the study.

Williams says the differences may come down to the source of the mercury. In the Seychelles, pregnant mothers were getting mercury through diets high in fish. Fish is also high in essential fatty acids that may protect developing brains. In the Faroe Islands, mothers got mercury by eating marine mammals, which lack the protective fatty acids found in fish.

"As always, you have to look at these studies and be very cautious, really. What we may find is that mercury is a marker for someone else. It's not necessarily a causal relationship," he says.

1 | 2

Today on WebMD

Post it notes
Symptoms and treatments.
Close up of eye
What's zapping your focus?
man driving car
How to manage your impulses.
contemplating woman
Learn to stop procrastinating.
concentration killers
Woman taking a vitamin or supplement
ADHD and Substance Abuse
Reduce Side Effects ADHD Medications

boy eating egg
smiling man
ADHD in Marriage and Romantic Relationships
Adult man lying awake in bed