The Cloud in Cancer's Silver Lining: New Study Fuels Worry That Environmental Toxins Are Boosting Cancer Rates

[Guest guest]

http://www.prospect.org/webfeatures/2001/06/kratz-v-06-15.html

June 15, 2001

The Cloud in Cancer's Silver Lining:

A New Study Fuels Worry That Environmental Toxins Are Boosting Cancer Rates

Vikki Kratz

The headlines were reassuring. Last week, the news media reported on a

National Cancer Institute (NCI) study that showed cancer rates in the United

States are declining. Prostate, lung and colon cancer had all experienced a

drop in both incidence and mortality rates, and overall deaths from cancer

were declining at a rate of about 1 percent a year. Not bad. But it's not

the whole story, either.

While the news reports touted dramatically falling prostate cancer death

rates, they ignored alarming increases in incidences of certain other types

of cancer. The NCI study showed that non-Hodgkin's lymphoma, acute myeloid

leukemia, and soft tissue sarcomas (tumors in fat, muscle, nerves and

joints) are all on the rise. What do all these cancers have in common?

Scientists have long suspected they're caused, at least in part, by

environmental toxins.

Of course, many factors go into determining whether or not you're going to

get cancer. Genetics, diet, bad habits -- they contribute to your overall

cancer risk. One of the biggest reasons most cancers are on a downward

spiral is because people are smoking less. Death rates are dropping because

doctors are able to screen for certain cancers earlier, and new drug

innovations -- like Novartis' Gleevec drug, which " targets " leukemia cancer

cells -- are fast tracking through the Food and Drug Administration. It's

supposed to be a new era for the war on cancer.

But if that's true, why are some cancers still on the rise? Leukemia

increased at a rate of 1.8 percent per year for all men. Soft tissue

sarcomas went up 3.3 percent a year for white women. Non-Hodgkin's lymphoma

increased among black women at a rate of about 3 percent a year and at a

rate of 4.1 percent for black men. The cancer also increased at a rate of

1.3 percent for white women. The rise in lymphoma has stumped the scientists

at NCI, who write " recent increases in incidence and mortality rates among

women cannot be explained. " (One reason they might be unable to explain the

increases in women is because many medical studies are done only on male

patients.)

" We're not seeing a huge epidemic of cancers related to a huge increase in

chemicals [in the environment], " says Dr. Balbus of the

Washington University School of Public Health in Washington, D.C. " But there

are certain trends that we don't have a good explanation for and that makes

us think of environmental causes. "

Non-Hodgkin's lymphoma has been linked in numerous studies to agricultural

pesticides. Doctors speak of a " lymphoma belt " across the Midwest, with Iowa

and rural Minnesota having the highest concentrations of lymphoma in the

country, particularly among farmers. One sign that an environmental toxin

might cause a cancer is if it begins showing up in younger populations,

Balbus says. According to the NCI study, incidences of non-Hodgkin's

lymphoma increased among black women " primarily among those younger than 65

years old. "

Pesticides are not just an occupational hazard, however. Chemical run-off

from the fields pollute rivers and streams. One study even showed that wind

could carry pesticides for up to 50 miles. And, of course, pesticide

residues can remain on the foods farmers harvest, where they are especially

dangerous to children. The EPA sets allowable pesticide tolerances on foods,

but those standards were created for adults, not kids. In 1996, Congress

passed a law that required the EPA to reassess the pesticide tolerances

specifically for children. But the agency has lacked the funding to

implement the law, resulting in lawsuits from the environmental community,

which is trying to get the government to enforce its own policy. The EPA's

problems may only get worse: Bush wants to cut the agency's budget by $500

million in 2002. Meanwhile, children's cancer rates are increasing just as

dramatically as the rates of some cancers in the general population.

Leukemia and brain tumors are the two most common forms of childhood cancer.

From 1973-1996, acute lymphocytic leukemia increased 17 percent. Brain

cancer jumped 26 percent. The causes of both cancers are still unclear, but

mounting evidence points to exposures to pesticides and industrial

pollutants as likely culprits. A recent report by the Institute of Medicine

noted a connection between Agent Orange exposure and rates of non-Hodgkin's

lymphoma and soft tissue sarcomas in Vietnam veterans. The report also

documented the link between Vietnam veterans exposed to the herbicide Agent

Orange and leukemia rates in their children.

The primary toxic ingredient in Agent Orange is a chemical called dioxin. It

used to be manufactured in the U.S. as an herbicide, but now it mostly shows

up as the by-product of industrial waste -- whenever plastic or vinyl is

burned, or whenever a paper mill decides to bleach paper with chlorine. The

U.S. has strictly regulated dioxin, reducing emissions of the chemical by as

much as 80 percent since the 1980s. Even so, scientists have discovered that

dioxin is a persistent chemical. It hangs around in the atmosphere, gets

into the water and the soil, and eventually makes its way into animal fat

and dairy products. It's especially persistent in the fatty tissues of

humans.

Today, the Bush Administration is sitting on a report by the Environmental

Protection Agency that finally declares dioxin to be a known human

carcinogen. The EPA spent 10 years examining the health effects of dioxin

and concluded that the health risks from the chemical were higher than

anticipated. People who consume even trace amounts of dioxin in fatty foods

and dairy products face a cancer risk as high as 1 in 1,000. Still, the Bush

administration has decided not to release the study in final form until the

Agriculture Department, the Food and Drug Administration, and even the

Justice Department have reviewed it.

Once the study is released, there will almost certainly be further

regulation of dioxin, which is why industry groups like the Chlorine

Chemistry Council and the American Chemical Council oppose it. The groups

complain that the study relies on outdated data and therefore exaggerates

dioxin's health risk. Food producers, including the American Meat Institute,

are concerned that the EPA's report will cut into meat and dairy sales. Last

year, the food producers accused the EPA of potentially creating " a health

scare that doesn't exist. "

By delaying the EPA's dioxin report and reducing funding for the agency,

President Bush proves his lack of commitment to public health. This year, as

the media reports only the good news from the NCI study, another 1 million

people will be diagnosed with cancer. We may not know the full impact of

environmental toxins on cancer rates, but President Bush should release the

information he does have -- and act quickly to start the research on

remaining questions.