The Human Experiment
In June 2010, a dermatologist cut a weird growth from my left wrist. The growth was wart-sized, grape-purple and stippled black. It was sensitive to the touch and bled when scratched.
Two weeks later, the doctor told me the tumor was malignant—melanoma, the deadliest form of skin cancer.
The doctor also told me this:
“You’re part of an experimental generation.”
She meant that in the past 30 years, she’d seen an alarming rise in skin cancer, and not just among older people. (I was 45.) Despite the advent of sunscreen and the fact that people don’t go outside as much as they used to, she’d even been seeing more moles—possible precursors to melanoma—on children.
One or more risk factors for melanoma, she reasoned, must have changed. My doctor’s guess: the human-caused depletion of atmospheric ozone, which allows more ultraviolet light—a leading melanoma risk factor—to reach our skins.
But other variables have also changed in recent decades, including the chemicals we’re exposed to through air, water and food. How much might such exposures be increasing the risk for melanoma and other forms of cancer?
Mostly, the answer is: We really don’t know.
And that’s the experiment, in which we’ve become the test subjects—without our knowledge or consent.
Less Death, More Cancer
My doctor’s language, inevitably, recalled Rachel Carson’s Silent Spring. Writing in the years when America first went whole-hog for synthetic chemicals, Carson warned that we were subjecting humanity and nature to a vast, uncontrolled experiment.
In 1964, Carson herself died of cancer. And in a decade that saw rising cancer rates and death tolls, fear of the malady metastasized. On December 23, 1971, President Richard Nixon signed the National Cancer Act, pledging to make the “conquest of cancer a national crusade.”
This epic initiative, inevitably dubbed the “war on cancer,” is now 40 years old. Most still gauge progress by how long we keep cancer patients alive, or by whether we’re approaching the “cancer cure” that Nixon sought. And there’s still disappointment that cancer remains uncured, countered with hopeful tidings of new gene-based therapies.
But here’s a fact you probably won’t hear much: You’re actually more likely to get cancer than when the war on cancer began.
In announcing his “conquest,” Nixon noted that cancer struck one in four Americans. Four decades later—and after hundreds of billions of dollars in research, radiation and chemotherapy—the figure has risen to about two in five. Nearly half of all men, and more than a third of all women, will get cancer. That’s about 1.6 million new diagnoses each year.
And for most major types of cancer, according to National Cancer Institute statistics, incidence remains higher than it was in the early ’70s. While record keeping in the early 1900s was less authoritative, cancer registries suggest incidence also rose steeply for most of the past century; by one estimate, it rose 85 percent between 1950 and 2001 alone.
Meanwhile, between 2003 and 2007, the incidence of liver cancer rose for men, along with thyroid cancer among women. Melanoma climbed for both genders; so did non-Hodgkin lymphoma, leukemia and cancers of the kidney and pancreas.
The news isn’t all bad: Incidence of two major types of cancer, colorectal and cervical, have dropped steeply in recent decades, largely because of improved screening. And cancer now kills less surely. Death rates for the most common forms—lung, breast, colorectal, prostate—have fallen in the past 20 years.
Even so, 570,000 Americans die of cancer annually—and the overall cancer death rate is only about 6 percent lower than it was in 1950. Our boat is still leaking; we’re just bailing faster.
This trend of “less death” and “more cancer” is starkest among children. Forty years ago, a child with cancer faced a virtual death sentence. (I had a sister who died of neuroblastoma in 1972 at age 5.) Today, most child cancer victims survive, and death rates keep dropping. But incidence keeps rising—by about 0.6 percent annually over the past 20 years, mostly driven by leukemia. An estimated 7 million American kids under age 10 are now living with cancer.
Nor is there any easy explanation for dramatic rises in cancers that strike primarily young adults, like testicular cancer. While cancer incidence is dropping in people over age 65, probably because of smoking’s long decline, it’s rising in people under 50 … despite smoking’s long decline.
Our chemical romance
Cancer itself is complicated. It’s really more than 100 diseases, affecting numerous parts of the body and presenting a wide range of medical challenges. But broadly, cancer happens when cells in our body grow out of control.
Human bodies make cancer cells constantly, and as far as we know, they always have. (Clinical descriptions of cancer seemingly date to ancient Egypt.) Usually, our bodies kill them off. When such cells do thrive, the causes of the disease are sometimes readily identifiable: Lung cancer is largely attributable to smoking; a small number of cancers are caused by viruses (with liver cancer, for instance, linked to Hepatitis B and C). Diet and sedentary lifestyles have been implicated in some cancer. Genetics play a role, though likely much less than most people think.
Meanwhile, ever since surgeon Percival Pott observed in 18th-century London that chimney sweeps were prone to cancers of the scrotum, we’ve also known that many environmental pollutants are carcinogens. Asbestos (still used in automobile brake pads) is one. So is benzene, a common pollutant in automobile and factory exhaust. Likewise, formaldehyde, found in consumer products including some wooden furniture and recently designated a “known human carcinogen.”
Industrial workers still often bear the brunt of the most severe exposures. The threat is also elevated for inhabitants of areas like Louisiana’s “Cancer Alley,” a stretch of the Mississippi River known for massive toxic releases from the petrochemical industry, and for exceptionally high cancer rates among its mostly poor, mostly black residents.
Yet the increase in cancer rates isn’t confined to specific regions or occupations. Increasingly, researchers are interrogating the environment as a cause of cancer—and suggesting that cleaning up the environment may help prevent it.
After all, the past century’s rise in cancer has been paralleled by the rise in synthetic chemicals and other pollutants in everyday life. In the years following World War II, plastics took over for wood, metal and glass. And from 1950 through 1975, pesticide production—Rachel Carson’s key concern in Silent Spring—grew sevenfold, to 1.4 billion pounds a year.
In 2008, according to a U.S. Environmental Protection Agency inventory, there were some 84,000 synthetic chemicals on the market. (There are surely more today.) Most are made from coal, oil or natural gas. But only a handful of these substances have ever been tested for health effects. We’re in contact with many of them on a daily basis. They’re in diesel soot and they’re in shampoo. They reach us through the packaging that contains our food, the pesticides on apples and the flame-retardant fabric woven into children’s car seats.
Some of these chemicals accumulate in our bodies. Others are shed into the environment, where they may persist for decades.
A growing array of studies, for example, link cancers, including breast, prostate, leukemia and multiple myeloma, to pesticide exposure. I was personally intrigued that a 2007 study from Italy tied melanoma to household pesticide use.
Perhaps the most surprising survey was “Reducing Environmental Cancer Risk: What We Can Do Now.” The April 2010 report was issued by the President’s Cancer Panel, chaired by two appointees of President George W. Bush. The widely publicized report cited “a growing body of evidence linking environmental exposures to cancer.”
Tiny exposures, mysterious effects
The scope of the synthetic-chemical problem is huge. The 1976 Toxic Substances Control Act requires the testing of potentially toxic substances. But while there are tens of thousands of synthetic chemicals in circulation, the vast majority haven’t been fully tested for health risks, and only a handful have been banned. There’s not even a complete ban on known carcinogens like asbestos. Yet it’s not up to industry to prove its chemicals are safe—it’s effectively up to everyone else to prove that they’re dangerous. And with everyone exposed to hundreds of chemicals daily, that’s a much tougher proposition.
Indeed, the more researchers learn, the thornier their questions become.
One problem is that big doses of a chemical aren’t always necessary to create big problems. Even tiny exposures can have huge effects, depending on when the exposure happens.
Take breast cancer. A 2011 University of Buffalo study found that women’s DNA can be altered by exposure to air pollution when they are young and when they give birth to their first children. That alteration increases the mother’s risk of premenopausal breast cancer. And while the pesticide DDT doesn’t appear to be a factor in breast cancer among adult women, a 2007 study found increased risk of breast cancer in women who were under age 14 when DDT usage peaked.
Special risks may apply to fetuses and children, who break down and purge chemical invaders more slowly than adults.
One example involves a chemical known as diethylstilbestrol, a synthetic estrogen widely prescribed to ease pregnancy discomforts from the 1940s through the ’60s. According to a new National Cancer Institute study, the women who took DES didn’t necessarily get sick. But their daughters did: Years later, they proved 40 times more prone to a rare form of vaginal cancer. They also had increased risk of breast cancer and reproductive problems.
Are there others out there? “Hormone mimics,” as ingredients of pesticides, plastics and personal-care products, are today a part of daily life—a part too little researched, say critics.
Because the chemicals of concern aren’t just mutagens—substances that damage the structure of genes. Researchers are also exploring the behavior of genes, or whether they are activated or deactivated. An “oncogene,” switched on, can lead to cancer; a cancer-fighting gene, meanwhile, can be shut off, allowing cancer to develop. Many hormone-mimics, researchers say, can throw that off-switch, leaving people vulnerable to cancer and other threats. And such hormone-mimics are found in everything from laundry soap and shampoo to weed killers and prescription drugs.
The right chemistry
Some researchers have gone so far as to suggest that nearly all cancers have an environmental component. Still, protecting us from this complex chemical soup would be daunting. As famed medical researcher John Bailar once wrote, “Cancer prevention on a large scale is likely to require substantial changes in our personal habits,” as well as “very expensive measures to clean up the environment and the workplace” and other changes, too.
Yet public-health campaigns work. Removing lead from gasoline, for instance, has meant less of it in children’s blood … and higher IQs and fewer developmental problems.
There is the promise of “green chemistry,” the movement to reduce unnecessary usage of petrochemicals and create nontoxic alternatives. But significant progress on that front will likely require government incentives, or mandates requiring industry to change its ways.
One hope is U.S. Sen. Frank Lautenberg’s Safe Chemicals Act. The bill would require chemical makers to prove their products are safe for humans and the environment before selling them, rather than pulling them from the market after they’ve been proved harmful. But Lautenberg (D-N.J.) has introduced the act seven years running, and gotten little traction, no doubt partly thanks to a chemical industry that spends $50 million annually lobbying in Washington.
Rather than continuing to spin our wheels, Devra Davis offers a novel solution.
Epidemiologist Davis—also author of such books as The Secret History of the War on Cancer—notes that the parties best able to judge the threat posed by these chemicals are the companies who make them. But she writes that corporations, fearing lawsuits and diminished profits, have either avoided doing the research or suppressed it. Meanwhile, people fall ill and die from lack of information.
So Davis, who now runs the Washington, D.C.-based Environmental Health Trust—proposes a “truth and reconciliation” commission on man-made toxins: “If we gave [industry] a free pass to come forward … [citizens] would then be informed,” she says. While this would mean granting amnesty for past chemical releases, instead, “We’d do medical monitoring and surveillance. We’d all be better off. …
“No matter how much money we spend on finding and treating cancer, no matter how good we get at treating it … if we don’t reduce the demand, we’ll never win.”
Wrong War, Wrong Race
Cancer patients, understandably, care less about why there’s cancer than how to treat theirs. And as cancer victims go, I’m lucky; I quickly learned that mine hadn’t spread. My only keepsakes so far are a couple of scars (including one for the lymphectomy).
I’m glad for that, and glad that there are ways to help people sicker than me. But I’m less interested in the war on cancer everyone will be talking about. It feels like the “war on terror” or the “war on drugs”: a hugely expensive effort to fix a problem whose causes we’re ignoring.
What I want to know is, why are we getting sick? Why has melanoma incidence tripled since the 1970s? Why is thyroid cancer rising even faster? Why are men younger than me increasingly getting tumors in their testes? Why are babies getting more cancer?
And in a country where you can’t swing a surgically excised lymph node without hitting someone’s Race for the Cure, why does no one ever hold a Race for the Cause?