On Friday, more than 2,000 people will attend a conference on "Women's Health and the Environment" at the David L. Lawrence Convention Center Downtown. It is sponsored by Teresa Heinz Kerry, The Heinz Endowments and Magee-Womens Hospital of UPMC, and will present the latest scientific information on how environmental toxins affect women's health and what women can do to protect themselves.

The following article is adapted from a newly released book by Teresa Heinz Kerry and her husband, Sen. John F. Kerry of Massachusetts, titled "This Moment on Earth: Today's New Environmentalists and Their Vision for the Future." (Copyright (C) 2007 by Sen. John Kerry and Teresa Heinz Kerry and published by Public Affairs. All rights reserved.)

Teresa Heinz Kerry is chairman of The Heinz Endowments and The Heinz Family Philanthropies (www.heinz.org).

Long before Pittsburgh became my American home, I had a home in Africa. My family's residence in Mozambique was a remarkable place to grow up. On many weekends and holidays, my playground was the African savanna, with its starry skies and grassy arid wilderness, populated by eerily shaped trees.

The sense of connection with my natural surroundings that I learned from growing up in Africa, and from my parents' example, shaped my relationship to what we now call "the environment." The modern definition of the term, though, suggests the environment is external to ourselves, which is neither accurate nor meaningful. The environment is not just a passive backdrop to our lives; it is part of us, woven into every facet of our lives. The decisions we make every day affect the environment -- from the cars we drive, to the foods we eat, to the products we use -- and the environment we help to create, in turn, affects us.

As we re-define our understanding of the environment, we need to think more about the products we use on a daily basis. How many of them have ingredients that we cannot even pronounce, with chemical properties we do not understand? Many of us take our showers behind vinyl curtains and use shampoos and lotions with added fragrance and other modern chemicals. We may scrub down a cutting board with a disinfectant, vacuum the stain-proof carpet, put on clothes labeled "wrinkle-free" and do laundry with "ocean-scented" detergent. Perhaps we drink milk that originated at a factory farm, where the animals were pumped full of antibiotics and growth hormones, or we eat a peach that was grown under the influence of multiple pesticides.

The truth is that we are coming into contact with hundreds, if not thousands, of industrial chemicals every day, just in the products we use. When the Pittsburgh environmentalist-writer Rachel Carson first published "Silent Spring" in 1962, she wrote that there were approximately 500 new industrial chemicals "to which the bodies of men and animals are required somehow to adapt each year, chemicals totally outside the limits of biologic experience."

Since that time, the number of chemicals on the consumer market has multiplied dramatically. According to the Environmental Protection Agency, pesticide use has increased by about 50 percent over the past 36 years. There now are more than 80,000 chemicals in widespread use in commerce. This year, the United States will manufacture or import more than 1 million pounds each of about 3,000 of these chemicals.

Rachel Carson asked the right question: What impact do these chemicals have on the ecosystem, including our own bodies? Unfortunately, that is a question we still cannot answer.

Many consumers assume that because the government requires tough testing of medications before they enter the market, it is equally tough in examining all of the products we use on our bodies and in our homes. Sadly, that's not true.

Outside of drugs and pesticides, the chemicals used to make many of the products we use each day are never tested to determine if they are harmful to human health. The current law requires that new chemicals -- 1,700 of which enter the market each year -- be tested for toxicity only if, based on the profile of similar chemicals, there are scientific grounds for believing they could prove harmful. This is no more effective than closing the barn door after the horses have bolted.

To then ban or restrict the use of a chemical, the EPA must find that it poses an "unreasonable risk," but the definition of "unreasonable" is so limited that in the 30 years that the laws have been on the books, the EPA has banned or limited only five existing chemicals or groups of chemicals. Our laws do not even require manufacturers to label many of the chemicals that we encounter on a regular basis.

This is of particular concern because we know without doubt from testing people's blood, urine, serum, saliva, hair and body tissue that the chemicals we use are seeping inside of us. Every one of us -- women and men, young and old, whether we work in factories or offices -- carries nearly 200 different synthetic or toxic chemicals in our fatty tissues. Many of us carry far more.

Knowing that there are 80,000 industrial chemicals on the market today and that many of them can enter our bodies, we must ask if there is a connection between disease and the substances we use so indiscriminately.

Here are some unsettling facts: One woman in three will develop cancer over the course of her life. Some 5 to 10 percent of couples are infertile. Autoimmune diseases like lupus and multiple sclerosis, in which one's immune system attacks itself by mistake, are on the rise. Seventy-five percent of those who suffer from these diseases are women.

Since the 1960s, we've seen a particularly disturbing trend in the number of women diagnosed with breast cancer, especially young women. In the 1960s, one in 20 women nationally was diagnosed with breast cancer. By 1993, it was one in nine. Today, it is closer to one in seven. Some of this increase may be due to advances in detection, and a fraction is attributable to hormones prescribed to women, but the causes of most cases of breast cancer cannot be explained.

Of course, breast cancer is just one of the potential consequences of the toxic soup that surrounds us, and many pioneering Americans -- among them Terry Collins, who heads Carnegie Mellon University's Institute for Green Oxidation Chemistry, and Dr. Devra Davis, who leads the Center for Environmental Oncology at the University of Pittsburgh Cancer Institute -- are working to identify the link between our health and the way we steward our environment.

There is now a concerted effort to "green" the entire UPMC medical system, which increasingly understands that it must prevent illness and promote health alongside its efforts to detect and treat diseases.

The news that we are surrounded by an alphabet soup of toxic, unregulated chemicals may seem, at worst, alarming, and, at best, overwhelming. In response, Rachel Carson's words from "Silent Spring" are worth remembering:

"If, having endured much, we have at last asserted our 'right to know' and, if knowing, we have concluded that we are being asked to take senseless and frightening risks, then we should no longer accept the counsel of those who tell us that we must fill our world with poisonous chemicals; we should look about and see what other course is open to us."