Sandy Travis walks down leafy President Street near her home in the Eastport section of Annapolis and points out neighbors' houses.
"That woman has cancer, that person has cancer, and that person has cancer. And there's a transformer right over there," she says, singling out a utility pole across the street.
Although scientists disagree on whether the electromagnetic fields generated by power lines can cause cancer, Travis says she wants a lot more answers before Baltimore Gas & Electric Co. expands the substation two blocks from her house and strings new power lines in her neighborhood.
"I take walks," explains Travis, a free-lance writer and mother of a 17-month-old girl, Katy. "And if they put a line overhead I don't know if I'm going to feel like walking."
BG&E officials say Travis and her neighbors have nothing to fear. And they warn that there could be blackouts this winter if the substation is not expanded to supply power to the rapidly growing Annapolis Neck area.
But BG&E's $3 million expansion of the Tyler Avenue substation has been snagged by the public concern growing nationwide over electromagnetic fields, or EMFs. The project has been held up a month while the Annapolis City Council listened to six hours of often technical testimony from BG&E witnesses and opponents in a pair of hearings this week and last month.
"There is insufficient data to lead you to the conclusion that these fields cause cancer," said Linda Erdreich, an epidemiologist from New York who testified Monday night for BG&E.
But, in a comment typical of neighbors opposing the project, Keith Oliver, a local environmentalist, told the aldermen: "You've heard there is insufficient evidence to conclude that EMF causes cancer, but I also believe there is insufficient evidence to conclude that EMF does not cause cancer."
For more than a decade, scientists have debated -- often heatedly -- whether electric and magnetic fields given off by electricity are harmful to humans. Some researchers have suggested they may be dangerous, but many others are skeptical, noting that the fields generated by neighborhood power lines, appliances and household wiring are often weaker than those produced naturally by earth's gravity.
A draft report issued last fall by the U.S. Environmental Protection Agency, which concludes that EMFs are a "possible, but not proven, cause of cancer in humans," has heightened the dispute. Some are urging the government to regulate magnetic field levels, while others have assailed the report as "crackpot science," as one critic put it.
HUGE POTENTIAL IMPACT
Proving that electromagnetic fields are harmful could have tremendous impact on society, since they are generated by virtually everything, from power lines and transformers to video display terminals and common household appliances such as hair dryers, toasters and televisions.
Electric utilities have a major interest in the issue, since power lines crisscross the country. BG&E, for instance, has 52,000 miles of overhead distribution and transmission lines in central Maryland and another 26,500 miles of underground wires and cables, according to spokesman John Metzger.
While differing on whether EMFs are a health risk, many scientists agree that they should be investigated more because of epidemiological studies linking them statistically to cancers, particularly childhood leukemia, brain tumors and even breast cancer in men.
One such study, conducted by Genevieve Matanoski of Johns Hopkins University, found that New York telephone line workers got cancer -- including two very rare cases of male breast cancer -- at twice the rate of other phone company employees.
A California study funded by the utility industry found recently that children who lived nearest to neighborhood power lines were 2 1/2 times as likely to have leukemia as were children who lived farther away. Frequent use of hair dryers and watching black-and-white televisions also were linked with increased leukemia risks in the preliminary results, released in February.
Utility officials counter that there are just as many studies finding no EMF-cancer links as there are those making positive connections. And they note that statistical associations do not mean EMFs actually cause cancer.
There are more than 100 studies under way to try to settle the dispute, but scientists on both sides say it could be three or four years at least before much more is known.
With public concern growing, some local and state officials already have begun to regulate EMF exposure. Seven states limit electric field strength at the edge of transmission line rights of way, while New York and Florida limit magnetic fields, which are more often associated with health effects, according to Editorial Research Reports. Officials in Alexandria, Va., concerned about EMF exposures ordered that overhead power lines on narrow residential streets there be buried underground, at a cost of $2 million.
NO HAZARD HERE?