Green Guide, Catherine Zandonella, M.P.H
Published September 30, 2005
We want our kids to go back to school with glowing smiles, healthy bodies and sound minds. New studies looking at fluoride, ozone and mercury suggest ways to protect our kids' health this fall.
How Safe Is Fluoride?
Fluoride helps protect your children's teeth, reducing decay in "baby" teeth by 60 percent and in permanent adult teeth by nearly 35 percent, according to the American Dental Association (ADA). But the key to good health is to make sure children are getting the proper amount.
Some kids get too much fluoride from combined sources such as sodas made in areas with fluoridated water and by swallowing fluoridated mouthwashes and toothpaste. Too much fluoride during childhood can cause a permanent brown mottling of the teeth known as fluorosis. And some studies of animals and humans have linked ingestion of fluoride in drinking water to an increased risk of a osteosarcoma, a bone cancer.
Cancer Controversy?
Dental-health professionals say that cancer fears are unfounded and that fluoride presents no health risk at the recommended level in drinking water, 0.7 to 1.2 parts per million (ppm). The studies linking fluoridated water to cancer failed to control for other cancer-related factors, such as increased industrialization, says Howard Pollick, B.D.S., M.P.H., a professor of dentistry at U.C. San Francisco.
Researchers at the Environmental Working Group argue that the cancer risk is real, and they've petitioned the government's National Toxicology Program to add fluoride to their list of carcinogens. The EWG also cites studies showing that fluoride accumulates in bone and damages human chromosomes. "It is the total package that they need to look at," says Richard Wiles, senior vice president of the EWG.
Pollick acknowledges that fluoride, like other minerals, migrates to the bone. He says, however, that numerous reviews have found insufficient evidence that fluoride causes chromosome damage at commonly encountered levels.
In an effort to settle the controversy, the National Academy of Sciences is reviewing the toxicity of fluoride in a report due out in 2006.
Meanwhile, dental-health experts say that while cancer is not a risk, fluorosis is a concern for children who ingest too much total fluoride. Parents should take simple steps to make sure their children are getting the proper amount.
What You Can Do
*Children should brush at least twice daily with a fluoridated toothpaste and floss once a day under parental supervision.
*For young kids who aren't yet capable of spitting out toothpaste, use a non-fluoridated toothpaste like Orajel Toddler Training Toothpaste.
*Have children see a dentist regularly.
*The ADA recommends avoiding the use of fluoridated mouth rinses for children under six years of age because they may swallow the rinse.
*Check fluoride levels in your water by calling your local water company or the Department of Public Health.
*If you don't have fluoridated water, Pollick recommends considering a fluoride supplement for children (available only by prescription).
*If your water's fluoride level is above 1.2 ppm, you can reduce it using a reverse-osmosis or water-distillation unit.
*Infants fed formula reconstituted with fluoridated water are not at risk of getting too much fluoride, say experts at the American Academy of Pediatric Dentistry.
Ozone and Exercise
Three new independent studies have strengthened the link between ozone and increased death rates. All three studies, published in the July Epidemiology, found that for every 10 parts per billion increase in average daily ozone, the total mortality rate went up by at least four-fifths of a percent. The rates are about twice as high in the northern hemisphere during the summer. "What is really striking is that all three studies were conducted differently but they all found basically the same thing," says David Bates, M.D., Professor Emeritus of Medicine at the University of British Columbia.
Most of these deaths were in older people with heart and respiratory conditions. In children, ozone can cause respiratory conditions and asthma attacks. Some 49 percent of the population lives in areas of elevated ozone levels. Produced by sunlight reacting with pollution from cars and industrial sources, ozone levels are highest between noon and 3 p.m., so children heading out to play during and after school encounter the highest ozone levels of the day.
What you can do
*Check daily air-quality levels at
www.epa.gov/airnow/where/
*Check your area's ozone "grade" at
www.lungaction.org/ reports/stateoftheair2005.html
*Children should limit prolonged or heavy exertion outdoors on days with unhealthy ozone levels.
*See asthma checklists in GG #92 and #56-#57.
Minding Mercury
We know mercury in fish is toxic, but giving up fish means missing out on omega-3 fatty acids that help foster brain development both before birth and during early childhood. Now a new study published this May online in Environmental Health Perspectives of 135 mothers and their babies in eastern Massachusetts has found that the benefits of eating fish outweigh the risks, as long as you choose fish that are low in mercury.
For each additional weekly serving of fish that the mothers ate, their babies' cognitive scores increased by an average of 4 points, or about 7 percent. However, for each increase of 1 ppm of mercury, the babies' scores dropped by 7.5 points, or 12.5 percent.
What you can do
*Consult The Green Guide's Fish Picks list of low-, moderate- and high-mercury fish at
www.thegreenguide.com/doc.mhtml?i=103&s=fish
*See also "Which Fish, Now?"
