The trouble with tampons.

Tampons have been around since the 1930s, and women have largely taken their safety for granted. But over the past three decades there has been a staggering increase in illnesses that were once thought of as rare, including endometriosis, fibroids (growths in the uterus), pelvic inflammatory disease, PCOS (polycystic ovarian syndrome), and cancer, causing some to take another look at those ubiquitous products.

In the late 1970s and early 1980s, there was an outbreak of Toxic Shock Syndrome (TSS), caused by Staphylococcus aureus, a bacterium whose toxins are amplified by several synthetic fibers that were being used in tampons to increase absorbency. More than 50 women died and more than a thousand suffered.

The worst offenders were Procter and Gamble's ultra-absorbent Rely tampons. According to the book Soap Opera: The Inside Story of Procter and Gamble, the company dismissed consumer complaints about the tampons for years. A 1975 company memo disclosed that Rely tampons contained known cancer-causing agents and that the product altered the natural organisms found in the vagina. Rely tampons were taken off the shelves in 1980, but many women claim they left a legacy of hysterectomies and loss of fertility.

After this crisis, carboxymethylcellulose, polyacrylate rayon (a derivative of wood pulp) and polyester were outlawed for tampons, but viscous rayon can still be used, which concerns some observers. "Viscous rayon can still amplify toxins to some extent, and the lowest risk [for TSS] would be had by using all cotton," says Dr. Philip Tierno of the New York University Medical Center. Today most tampons are made with rayon, conventional cotton, and undisclosed chemical fragrances. The Food and Drug Administration (FDA) insists such tampons are safe.

The TSS specter has not disappeared. As the National Women's Health Network points out, the Centers for Disease Control and Prevention track the syndrome only through voluntary reporting, so it is difficult to know the true threat. Three years ago, a 13-year-old London girl died after using tampons for the first time.

Further, according to Women's Health International, several American tampon brands have been rejected in Japan, where government regulation of the industry is stricter. The stated reason? High bacterial levels.

Some college courses on women's health conduct a simple class demonstration: Place a new tampon in a glass of water. After it absorbs water, remove it, and watch all the remaining fibers floating in the water. These fibers remain inside a woman's uterus.

In the U.S., more than one billion tons of pesticides and herbicides are sprayed on cotton crops every year; and residues may taint tampons. Many of these pesticides can damage the nervous system, lead to cancer or function as hormone disruptors.

Although the effects of hormone disruptors on women's health are poorly understood, it is known that estrogen itself can cause problems at certain levels. Dr. Susan Lark, author of Fibroid Tumors and Endometriosis, notes that women "are at higher risk of developing fibroids or endometriosis ... if they have high levels of estrogen ... or use estrogen-contaminating medication [such as Hormone Replacement Therapy]." A 1996 report in the journal Science concluded that when estrogen-like chemicals are combined, they often become more damaging. Jan Stout of Physicians for Social Responsibility argues, "We're creating a threat to an entire generation."

Much of the cotton crop in the U.S. is now also genetically engineered, a fact that has some health advocates worried over long-term effects. The London-based Institute for Science in Society has warned that genetically engineered cotton in tampons and bandages could give rise to antibiotic-resistant bacteria.

Further, what is the risk to women's health posed by highly toxic dioxin, a by-product of the chlorine bleaching process historically used to make tampon fibers white? According to the Village Voice, in 1992 a Congressional subcommittee uncovered an exchange of memos in which FDA scientists reported discovering trace levels of dioxin in some tampons. "Citing studies that indicated dioxin was unsafe at any level ... subcommittee chair Ted Weiss accused the FDA of ignoring its own scientists' warnings," wrote the Voice.

In the mid-1990s, tampon manufacturers switched to "elemental chlorine-free bleaching," reducing the production of dioxin. However, the FDA acknowledges that the alternative process can still "theoretically generate dioxins at extremely low levels." The agency says even average background levels of dioxin may lead to developmental and immune problems and birth defects.

Since a typical woman uses more than 11,500 tampons in her lifetime, even small traces of dioxin may add up. Yet the FDA has not called for testing of potential dioxin levels in tampons, and does not require package warnings. Alternatives to conventional tampons include organic cotton products such as GladRags (800-799-4523, www.gladrags.com), Organic Essentials (806-428-3486, www.organicessentials.com) and Natracare (303-617-3476, www.natracare.com), sea sponges (SeaPearls, 800-219-9765, www.jadeandpearl.com) and The Keeper (800-799-4523, www.keeper-menstrual-cup.com), a menstrual product made from all-natural rubber.

Ilya Sandra Perlingieri is the author of the 2003 book The Uterine Crisis.

MELISSA KNOPPER is a Colorado-based journalist specializing in health and science reporting.