Week of 06/24/2007

Dear EarthTalk: Are mothballs safe to use? If not, are there any environmentally friendly alternatives?

—Anna Wiener, Dearborn, Michigan

Even though they are not as popular as they once were, mothballs are still used by many people to keep stored clothes, furniture and carpets free of hungry pests like moths. But the very ingredients that make mothballs so effective as household pesticides—namely naphthalene or paradichlorobenzene (PDB)—also make them dangerous to any person or animal who breathes the fumes or ingests them directly. Such chemicals are often listed as primary offenders when household air is tested for indoor air pollution.

Exposure to naphthalene or PDB can induce relatively minor human health problems such as nausea, vomiting, headache, coughing, burning eyes and shortness of breath. The World Health Organization’s International Agency for Research on Cancer considers both naphthalene and PDB to be hazardous carcinogens as well. These chemicals, which are also found in some dry cleaning agents as well as household air fresheners and solid toilet-bowl deodorizers, have been found to nearly double the risk of non-Hodgkin’s lymphoma—a cancer of the blood—for those who come into frequent contact with them.

So what’s a conscientious homemaker to do? For starters, removing all mothballs and their flakes from the home is a good first step. Experts suggest donning gloves and even perhaps a mask before manually removing intact mothballs. Affected clothing can be machine-washed and dried several times, preferably on high heat settings. If the smell of mothballs continues to linger, any such clothes can be ironed—also with high heat settings, which tend to break down the active chemicals quicker. Sunlight also breaks down naphthalene and PDB, so leaving any affected items outside on hot sunny days may also help.

Carpets and upholstery co-mingled with mothballs should be vacuumed thoroughly, with vacuum cleaner bags containing mothball traces emptied immediately outdoors. If the mothball smell lingers after vacuuming, a professional cleaning might do the trick, although such services can introduce other harmful chemicals, such as the carcinogen perchloroethylene, into the household as well. (ChemDry and Zoots both offer in-home carpet and upholstery cleaning services that do not rely on harmful chemicals.) After any kind of mothball removal effort, the cleaned house or closet should be aired out, ideally with one or more fans blowing as much fresh outdoor air through as possible.

As to alternatives for keeping moths and other critters away from clothes and other valuable fabrics, Care2.com’s green home guru and author Annie Berthold-Bond suggests using home-made sachet pillows filled with a dried herb mixture combining two parts each of rosemary and mint, one part each of thyme and ginseng, and eight parts whole cloves. The herbs can be mixed and combined in the center of a bandana or handkerchief that is then tied with a ribbon and placed among the stored items. Also, Richards Housewares makes "Moth-Away Herbal Moth Repellant," a pre-packaged product that makes use of a similar formula. It’s available from planetnatural.com and other online environmental product websites.

CONTACTS: U.S. Environmental Protection Agency (EPA) Napthalene page; PlanetNatural Moth-Away page

Dear EarthTalk: Why do some people complain about fluoride in drinking water and toothpaste? I thought it was beneficial for dental health?

—Becky Johnston, Shoreline, WA

Communities began adding fluoride to water supplies in the early 1940s after decades of studies into why some Colorado residents were exhibiting a discoloration or "mottling" of the teeth but at the same time very low rates of actual decay. The culprit turned out to be high concentrations of a naturally-occurring fluoride that was running off into the water from Pike’s Peak after rainfalls. Research later concluded that adding small, controlled amounts of fluoride into public water supplies would act as a form of community-wide cavity prevention without causing the undesirable mottling known at the time as "Colorado stain."

Today, supporters of fluoridation cite research from the U.S. Centers for Disease Control showing that the very inexpensive fluoridation of drinking water has since correlated to significant reductions in incidences of tooth decay (15-40 percent) in communities across the country. But skeptics worry we may be getting too much of a good thing. While small amounts of fluoride will prevent tooth decay, excessive amounts can lead not only to irreversible tooth discoloration (today called "fluorosis") but also to other health issues, including an increased risk of bone breakage and osteoporosis.

The problem, says Fluoride Action Network (FAN), which is opposed to fluoridation, is that the very water supplies that are treated for dental purposes are also used in the making of many common food products—from baby formula and cereal to juices, sodas, wines, beers and even fresh produce. And with most toothpastes also adding fluoride, many people are ingesting far more fluoride than they should.

The main concern for most people is the discoloration of children’s second teeth once the baby teeth are gone. Besides being embarrassing, there is no cure. And some doctors worry that excessive fluoride may actually be promoting tooth decay rather than preventing it—and harming kids in other ways, particularly as they get older. FAN cites studies showing how low-to-moderate doses of fluoride can lead to eczema, reduced thyroid activity, hyperactivity, IQ deficits, premature puberty and even bone cancer.

On the other side of the debate, concerns have risen that our increased reliance on non-fluoridated bottled water instead of tap water may be leading to increases in tooth decay (some bottled waters have added fluoride). However, speaking in a May 2002 UPI Science News article, John W. Stamm, dean of the School of Dentistry at the University of North Carolina at Chapel Hill and a spokesperson for the American Dental Association, said, "It’s very important to realize that there are many sources for body fluids
The fact that one may be consuming variable amounts of bottled water seems to me to be insufficient reason to be concerned about a fluoride deficient diet."

Avoiding fluoride is difficult for those whose local water is fluoridated. And the only filters that can strain fluoride out of water are expensive ones that employ reverse osmosis, activated alumina or distillation. Switching to unfluoridated toothpaste—many varieties are available from natural health retailers—is one way to cut down on fluoride intake, especially for those who swallow toothpaste when they are brushing.

CONTACTS: Centers for Disease Control; Fluoride Action Network