This won't be a good Earth Day for environmental alarm bell industry. During the past year, more health scares over the environment failed to live up to their billing. Experts in the federal government now don't even rate environmental protection efforts as being all that important in this century's improvement in public health. As the environment looks to figure prominently in the year 2000 elections, now is the time for candidates to consider what can be learned from almost 40 years of environmental hysteria.
In 1975, Dr. Renate Kimbrough, then of the Centers for Disease Control and Prevention, reported polychlorinated biphenyls (PCBs) caused liver cancer in laboratory animals. PCBs were widely used in electrical equipment. Because PCBs don't degrade easily, they persist literally everywhere in the air, water and soil, and in humans and animals.
Although we now know such laboratory tests do not necessarily predict human risk, in the absence of other information, the result was worrying. A year later, Congress banned the manufacture and use of PCBs. Over the next two decades, many small studies of humans exposed to PCBs did not detect any cancer-causing effect of PCBs. But like the PCBs themselves, fear persisted.
In March, Dr. Kimbrough published the results of the largest-ever study of workers exposed to high-levels of PCBs. The exposures occurred between 1946 and 1977, so enough time passed for cancers to develop if PCBs caused them. No increase in cancer mortality was reported despite the high exposures. So at the very least, initial concerns over PCBs were exaggerated.
PCBs join a long list of environmental health scares of the last 25 years that have not lived up to their hype.
The Environmental Protection Agency labeled dioxin as the most potent carcinogen known to man. But a recent study reports no increase in cancer among U.S. Air Force personnel with the highest levels of dioxin exposure from handling Agent Orange in Vietnam. Recent studies have also failed to find an increase in cancer among hundreds of people heavily exposed to dioxin from a 1976 explosion at an industrial facility in Seveso, Italy.
A 1979 study reported living near electric power lines was associated with increased cancer in children. It set off a frenzy of alarm -- and research. The alarm is only now subsiding. A 1996 report from the National Academy of Sciences concluded there was no evidence that electric and magnetic fields from power lines and electrical appliances cause cancer. A related scare about cellular phones, launched in January 1993 on "Larry King Live," also subsided without evidence of harm.
Very high-level radiation can cause cancer. The public, though, has even been alarmed over low-level exposures. Researchers from the Johns Hopkins University carried out the largest-ever study of nuclear shipyard workers for the Department of Energy. In 1991, they reported no increased cancer among those highly exposed workers. There is no reason to think that far-lower "environmental" levels of radiation pose any risk.
Activist groups have been terrifying the public about exposures to pesticides, most notably DDT, for years, but the epidemic of cancer predicted by Rachel Carson in her 1962 book "Silent Spring" has not come to pass. Even Dr. Philip Landrigan of Mt. Sinai University and a leader of the anti-pesticide movement admits that there is no documented case of cancer resulting from the legal application of pesticides.
Despite the impressions left by movies like "A Civil Action," no cancer epidemic has accompanied society's ever-increasing use of manmade chemicals. According to federal agencies and the American Cancer Society, cancer incidence (new cases) and mortality have been falling since about 1990.
A particularly favorite topic of fear is kids and cancer. Since the scare about apple growth regulator Alar 10 years ago, we are constantly told cancer in kids is rising along with chemical use. Thankfully, it's not true.
The Journal of the National Cancer Institute reported the much-publicized increase in brain cancer in children during 1973-1994 was a result of better detection and reporting, not an increase in cancer. Similarly, the journal Cancer reported the incidence of childhood cancers has remained relatively stable since the 1960s or has risen only where there are adequate cancer registration systems. The journal "Pediatrics" reports the best news of all: Children's cancer mortality is down almost 40 percent since 1979.
Where does this leave us with respect to environmental scares? The environment has been such a bust in term of health impact that when the Centers for Disease Control recently rated the top ten public health measures of the century, environmental protection was left off the list. The CDC even rated fluoridation of drinking water to prevent tooth loss, but not environmental protection.
As part of their health scare arsenal, alarmists like to advocate the "precautionary principle" -- we should avoid risk because we're "better safe than sorry." But while the precautionary principle is appropriate in some circumstances -- car seat belts, for one, where they reduce an actuarial likelihood of injury -- it is inappropriate with the hypothetical nature of many environmental risks.
No one likes air and water pollution. But some is an inevitable consequence of human activities. By all measures, pollution is decreasing, and we should continue reasonable efforts to minimize it. But with 30 years of close examination into the impact of pollution on health, we should take rational steps toward pollution control, rather than acting hastily out of health-scare hysteria.
This simple message will be more effective than tying to "out green" Al Gore -- if his candidacy doesn't implode, that is.
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