One cause of cancer may be blowing in the wind

Scan page 17

The cancer death toll is now over 430,000 deaths per year. It is now the leading cause of death in the United States. Although hundreds of millions of dollars have been spent to develop cures for various cancers, success has been limited.

What is being done to prevent cancer? The answer is—very little. Experts seem to be divided on the role of pollution and other environmental factors in causing cancer, and manufacturers' associations and trade groups are quick to exploit such divisions.

Common sense tells us that living downwind from an oil refinery is hazardous to your health. But isn't that "unscientific?" We need hard evidence. Fortunately the real weight of evidence is overwhelming; it is our manipulated «What do we value perception that seems scanty.

This past July, a study was released that "turned up data that suggest a link between high rates of respiratory cancer and the locations of petrochemical plants in 133 counties in 27 states east of the Rocky Mountains" (New York Times July 22, 1985).

The study compared the incidence of respiratory cancers upwind versus downwind and near versus far from petrochemical plants. According to the study, "almost all counties with high incidence rates had plants nearby or were downwind of such plants."

For example, Chamber County, Texas, had a respiratory cancer rate of 106.2 cases per 100,000 population in the period studied. But remote from petrochemical plants and the winds from them, Presidio, Texas, had a rate of only 13.3 cases per 100,000 during the same time interval.

Methodological shortcomings

Did this new data initiate a move toward greater regulation of atmospheric pollution? No! The initial responses were largely confined to the methodological shortcomings of the study. Unfortunately, there is little interest or funding for the more rigorous epidemiological studies. After all, definitive data might make a strong case for regulation.

Current efforts have attempted to identify specific ingredients in petrochemical emissions that may be carcinogenic. This completely ignores the human reality. We are exposed to a mixture of chemicals, some of which may not be directly carcinogenic, but "promote" or activate others.

The Environmental Protection Agency (EPA) has used these distinctions to limit investigation and regulation. The EPA tried to separately consider "mutagens" that alter the chromasomes of cells, and "epigenetic substances, which are involved in cancer causation, but do not alter genetic material.

Public pressure forced the EPA to retreat from this false distinction, but foot-dragging is still the rule. Recently, the EPA announced the creation of an "intention to list" list. Under this designation, it can take four years before a final regulatory standard goes into effect.

Epidemiological methods

Epidemiological studies fall into two broad categories: "prospective or follow-up" studies and "retrospective or case-control" studies.

In a "prospective" study, a group of people of similar ages are followed by interview and questionnaire for a number of years. Careful records of occupation, lifestyle, health history and cause of death are maintained. From this information, mortality ratios for different categories can be calculated.

Because such studies take many years to complete, often a "retrospective" study is used. People with a given disease (the cases) are identified and matched with people who do not have the disease (the controls). Both groups are given the same interviews and questionnaires. Differences between the groups are then used to calculate risk factors for the different categories.

Unfortunately, both types of studies are very expensive. So we are hampered by the lack of controlled data as well. As B.J. Steigerwald of the EPA said, , "Major epidemiological studies don't seem to be in the cards." This is not surprising given the billions of dollars in profits that would be lost by major polluters if they were held accountable for the human misery they create.

Further evidence that points to environmental causes of cancer is detailed by Samuel Epstein, in "The Politics of Cancer."

Certain countries have low or background rates of incidence for certain cancers. Cancer of the mouth is very rare in the United States, but it is up to 35 times more common in countries where betel nut is regularly chewed.

In Japan, the incidence of colon and rectal cancer is low due to the large amount of fiber consumed, but stomach cancer is widespread, probably due to the extensive use of charcoal broiling. In the United States, the incidence rates are reversed. When Japanese immigrant families are studied in the United States, a change to the general American pattern appears quickly, often in a generation.

Enough data has been amassed to lead a sub-agency of the United Nations World Health Organization to estimate that 70 percent to 90 percent of all cancers are due to environmental causes! Cancer is the only major fatal disease in the industrialized world whose incidence is sharply rising, according to Epstein.

Rese arch has demonstrated that there is no safe level of exposure to carcinogens. No matter how low the level, measurable health effects occur if the exposure persists. Many carcinogens are concentrated in body tissues as well, raising the effective exposure levels.

In the face of hundreds of studies demonstrating an environmental link to cancer, industry groups practice denial and disinformation. The government agencies charged with protecting our health have lost sight of that responsibility. Regulation is slow and the process is often further delayed by legal action from giant corporations.

A dangerous and immoral trend is the growing reliance on cost-benefit analysis to determine which hazards should be regulated. This analysis measures in dollars the cost of eliminating a health risk versus the benefit to health.

Who determines the worth of human life? Cost-benefit analysis completely denies this worth and further reduces people to commodities. Commodities to be bought, sold, or replaced as needed by the corporations.

The question becomes one of value: What do we value more highly, human health and safety or corporate profit?

In spite of the gloomy statistics presented here, there is a real basis for optimism. If cancer is not an arbitrary killer that strikes randomly and without warning, we can control and limit it by reducing our exposure to carcinogens. The power rests with us to control the problem.

Author's note: I hope you have enjoyed the first two columns of "Hazardous to Your Health" as much as / have enjoyed researching and writing them.

I'm a research associate at the University of California, San Francisco. My knowledge in health promotion, epidemiology, environmental problems, and changing society is largely self-taught. Like everyone, I would like your feedback. Please write with questions or comments about past columns, suggestions for future ones, and your ideas on health. I'll respond to everything in some way.

----- pull-quotes -----

more -human health or corporate profit?"