Mounting evidence suggests that exposures to chemical contaminants within our shared environment are playing a more significant role than previously appreciated in the burden of human cancer.
Vows of marriage. Oaths of citizenship. A jury's verdict. Words with the power to change our identities are usually spoken in public places. But a cancer diagnosis is almost always delivered within a private conversation that takes place, unwitnessed, behind the closed door of a doctor's office, on the phone, or, most unceremoniously of all, in a hospital room -- where, on the other side of the curtain, a television blares, a roommate is served lunch, and a cleaning staff mops the floor.
At age 20, while lying on a hospital bed in my own hometown, I was diagnosed with bladder cancer. Before my physician shared the bad news, he asked my visitors -- who were missing the first day of college classes to be with me -- to step out.
Then he pulled the curtain.
A few minutes later, he told my friends in the hallway, not unkindly, that they could come back in. And they did -- although they left soon after, tiptoeing out of the room, as though the hushed behaviour we used in the library was what was required now that I had cancer.
From my fourth-floor window, I watched as they crossed the parking lot and drove away. A construction crew arrived. Women carried flowers into a church. Mallard drakes splashed in the park lagoon. A high school team ran wind sprints across an athletic field. My high school. My church. The lagoon where, as a child, I had caught a fish. How strange. The familiar world, full of jackhammers, ducks, and Bible study, was rolling its regular programming, as if nothing extraordinary had just happened. As if I had not just been culled from my own life. Or so it felt to me then.
Perhaps because the rituals of being a cancer patient are so far removed from public life, we sometimes presume its causes are likewise located in an interior, intimate place. We blame our private behaviours or our genes themselves, which we've inherited, like so many place settings of China, from our personal ancestors.
And some of the roots of cancer are indeed found there. But cancer has a public dimension, too. Our genes reside within cells, and cells reside within living bodies that, in turn, reside within particular public environments. And, as we breathe, bathe, eat, and walk the dog, our environment -- with its carbon cycles and rivers, pollination systems and aquifers, industries and farms, geologies and jet streams -- comes to reside inside us.
Mounting evidence suggests that exposures to chemical contaminants within our shared environment are playing a more significant role than previously appreciated in the burden of human cancer. Some of these chemicals can damage our genes directly -- or silence their expression. Some interfere with the network of hormonal signals that serve as the body's communications system. Some change developmental pathways in early life in ways that make us more vulnerable to cancer in later life. All together, the new science is mounting a challenge to the way we regulate toxic substances. These regulations rarely consider the cumulative impact of multiple exposures to multiple chemicals over a lifetime.
Yet the public story of cancer is a hopeful one. First, it shows us where we can begin a meaningful program of cancer prevention. It's true that cancer rates among U.S. children have risen sharply and that cancer is now the leading killer of middle-aged adults. But it's also true that lung cancer rates are falling.
This happy outcome is the result of our collective efforts to denormalize tobacco -- to shun its use within public places, tax it steeply, restrict its advertising, and promote smoking cessation efforts. Ever-rising cancer rates are not the inevitable price of modern life.
The story of tobacco shows us that when an exposure to a chemical carcinogen is eliminated, lives are saved. It is a story that can happen again. A 2008 statement, signed by many cancer researchers and submitted to the US President's Cancer Panel, put it like this: the most direct way to prevent cancer is to stop putting cancer-causing agents into our indoor and outdoor environments in the first place.
Second, as it turns out, the cynical joke that "everything causes cancer" is not true. Most of the chemicals implicated as carcinogens are derived from the same two sources as those responsible for climate change: coal and petroleum. Finding substitutes for these two substances is already a priority for many governments. In this, an investment in green energy is thus also an investment in cancer prevention.
Of course, sending people off to redesign the petrochemical economy is a different assignment than encouraging them to quit smoking. It's a task so overwhelming that it requires all of us, with all of our various passions and talents, to act in concert.
Happily, this allows any one of us to seize on a single piece of the problem and work as hard as we can on that piece. People who love food can support local, organic farmers. People who love fashion can go after toxic chemicals used by dry-cleaning and cosmetics industries. People who love sports can insist on pesticide-free playing fields and golf courses. And so on.
Think of it this way: we are all musicians in a great human orchestra, and it is now time to play the Save the World Symphony. You're not required to play a solo, but you are required to know what your instrument is and play it as well as you can.
Thirty years ago, during our private conversation behind a gray, hospital curtain, while my friends waited in the hallway, my diagnosing physician assured me that, whatever the future held, he would take care of me. And he did. "Sandra, let's grow old together," he would often laugh.
Growing old has been my life's work as a cancer survivor.
But within that same conversation, my doctor also asked me some pointed questions about my possible past exposures to toxic chemicals. His questions that day let me know that bladder cancer is, by and large, an environmental disease. Understanding the public story of cancer became my life's work as a biologist. It's the starting point for my book, Living Downstream, and this film that has brought it to life.
Sandra Steingraber is the author of Living Downstream, recently published in second edition by Da Capo Press to coincide with the release of the Canadian documentary film adaptation. Produced by The People's Picture Company, the film is currently screening in select North American cities and will be available on Home Video DVD this fall. www.livingdownstream.com
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