Tower power.

Byline: SHERRI BURI McDONALD The Register-Guard

WHAT CONCERNS Martha Johnson most about the cell tower proposed near her home off River Road in Eugene isn't that it would ruin the view from her back deck or reduce the value of her property. Johnson, a nurse, says she worries most about the potential health effects from the radio waves that would beam down from the tower 24 hours a day.

The 80-foot to 130-foot towers, which are popping up around Lane County - and across the nation - emit radio frequency radiation to transmit cell phone conversations.

But Johnson and others living and working near these towers are uneasy about long-term exposure - the effects of which aren't known.

"I'm not against cell phones at all; I think it's a really great technology," Johnson insists. "But I think we've walked blindly into it, and our government hasn't done much to guide us or protect us."

Johnson is among a growing number of Lane County residents who are fighting tower sites in their neighborhoods and are urging local planners to reject requests to put towers near homes and schools. Disputes have erupted over Verizon Wireless' proposed tower next to a residential area off Franklin Boulevard in Eugene, and Sprint's proposed tower next to a University of Oregon housing complex on Villard Street.

The controversies prompt many questions. What health risks, if any, are associated with cell phone technology? Do federal rules on the towers and phones protect the public? What power, if any, should local governments and residents have in cell tower siting?

Those questions are at the heart of a long-standing global debate.

The vast majority of studies on the issue are funded by the wireless industry. Many countries, including the United States, have reviewed the scientific evidence and concluded that it doesn't show adverse health effects from cell phones or towers.

The evidence doesn't prove they're safe either. Some studies have raised questions about possible effects, such as DNA damage and cancer, that scientists say warrant further investigation.

But it will be years before researchers determine the long-term effects of decades of cell phone use.

Given the large body of conflicting research, people draw their own conclusions.

Wireless industry and U.S. government officials conclude that absent any evidence of harm, go ahead and use the phones, and don't worry about the towers because their emissions are infinitesimal.

Others, including the Stewart Group, a panel of independent experts commissioned by Britain that issued a report last year, recommend a more cautious route, especially for children. The group reported that children might be more vulnerable to any unrecognized health risks from mobile phones because their heads and nervous systems are still developing.

Most consumers seem to figure that cell phones must be safe because so many people use them.

At the University of Oregon, 19-year-old sophomore Ariel Ungerleider estimates that three-quarters of students on campus carry mobile phones. In a typical day, Ungerleider spends an hour or two on her cell phone - usually in a series of short conversations.

"I kind of worry about (health risks)," she said, "but with all the new products out, you assume they're getting better."

Sept. 11 spurs sales

The phones are more popular than ever following the Sept. 11 attacks on New York and the Pentagon. During the attacks, many people used cell phones to call family members. The phones relayed the final words of some passengers on United Airlines Flight 93, which crashed in Pennsylvania after passengers reportedly tried to tackle the hijackers.

Since Sept. 11, about 2 million people have bought cell phones, estimates Roger Entner, an analyst with the Yankee Group, a Boston technology research company.

Some would have bought the phones anyway, Entner said. But Sept. 11 was the deciding factor for many, he said.

Cellular towers, meanwhile, have become a fixture of the landscape - and cellular wavelength franchise fees have become a fixture for the federal government.

The government began auctioning the wavelengths in 1994, and has reaped more than $39 billion in fees, according to the Federal Communications Commission. The revenue goes to cover general government expenses.

Mobile phones are minitransceivers, which send and receive radio waves to fixed base stations - or cell towers. The base stations are linked to a central switching station that routes calls.

Cell phones usually operate at relatively low frequencies of 800 to 900 megahertz. They share a part of the electromagnetic spectrum with radio and television transmitters and microwaves.

The spectrum ranges from low-frequency radiation, such as electrical power, to high-frequency radiation, including X-rays and gamma rays. Radio frequency, which is used by wireless phones, lacks the power to cause the serious biological damage of X-rays and gamma rays. However, exposure to high levels of radio frequency energy can heat tissue, similar to how a microwave oven heats food.

To curb the heating effects, the FCC, which regulates radio frequency from cell phones and cell towers, has set exposure limits. Adopted in 1996, the standards are based on guidelines developed by private experts and on assessments by federal agencies.

The FCC standard for radio frequency transmissions from base stations is 580 microwatts per square centimeter for a base station operating at a frequency of 800 to 900 MHz.

The energy is most intense at the antenna and drops off rapidly the greater the distance from the antenna. FCC engineers say that to be exposed to the maximum energy, a person would have to be within a few feet of the antenna at the antenna's height.

Government and cellular industry experts say the limit is set so low that radio frequency from towers shouldn't harm people who live or work near them.

"I don't think any scientists who look at the evidence think there's a risk from these base stations," said Ed Mantiply, a physical scientist with the FCC.

The limit assumes continuous exposure and is set 50 times lower than the level at which heating effects from radio frequency radiation have been recorded, he said.

The actual radio frequency coming off a tower is usually a fraction of the maximum allowed.

"We almost never see more than 1 microwatt per square centimeter from a base station," Mantiply said.

Even taking into account co-location of antennas - when antennas for several different companies are placed on the same tower - emissions are still well within government guidelines, he said.

Many groups around the world have reviewed the research and found no sign that radio frequency from cell towers can cause a hazard, said Jo-Anne Basile, spokeswoman for the Cellular Telecommunications & Internet Association. Britain's Stewart report found that "the balance of evidence indicates that there is no general risk to the health of people living near base stations, on the basis that exposures are expected to be small fractions of guidelines."

The report added, however, that anxiety created by insensitive siting of base stations - near schools, for example - can endanger some peoples' well-being. The report, as well as the World Health Organization, urged care when siting base stations near schools.

Some, however, believe the limits should be more restrictive.

The FCC's standards are based on levels of radio frequency that caused heating in animals; they don't address possible biological effects, such as headaches, sleep disturbances, immune system changes and mental impairment, which can occur at exposures 1,000 times lower than the FCC limit, said Cindy Sage, a Santa Barbara-based consultant specializing in radio frequency issues.

Some lab studies of human volunteers exposed to radio frequency found changes in brain activity, reaction times and sleep patterns, according to a May 2001 report by the U.S. General Accounting Office. The effects are small and have no apparent health significance, according to WHO, but more study is needed, the report said.

"We need a new set of limits that address biological effects," Sage said. "If we did, the limits would be at 1, or 0.5, or 0.1 (microwatts per square centimeter)."

Salzburg, Austria, has adopted the lowest exposure limit in the world for base stations -.01 microwatts per square centimeter.

Salzburg and other towns with extremely low exposure levels are setting policies that have no foundation in science, industry spokeswoman Basile said.

Sage countered that inconclusive research shouldn't prevent communities from trying to protect the public from potential harm.

George Carlo, a scientist who directed a $28 million, five-year, industry-funded cell phone research program and later became one of the industry's chief critics, said he also has concerns about the towers.

Carlo, who is based in Washington, D.C., said he would speak up if a tower were proposed near his home or at a school his children attended.

There is no empirical scientific evidence linking base stations to health effects, but there's enough evidence to suggest a theoretical risk, he said.

"There are red flags (with base stations) ... they're just not as strong as with the cell phones," Carlo said.

Depending on their configuration and the direction of their signals, some base stations could pose a risk, he said, while others might not be a problem. "Until specific studies are conducted to assess whether or not the type of radiation from base stations causes health effects in humans, we're guessing (about their safety)," Carlo said.

Few studies have been done on base stations. So, opinions are based on research over the past decade on cell phones. People holding cell phones to their heads are exposed to much higher levels of radio frequency than people living near a tower. But the body of research on cell phones is complex and conflicting. Scientists disagree on whether cell phones pose a health risk, let alone the towers.

The FCC has a different standard for exposure to radio frequency energy from cell phones held to the head. The maximum limit, called the specific absorption rate, or SAR, is 1.6 watts per kilogram over one gram of tissue.

Manufacturers must do pre-market tests on phones to ensure they meet the guideline. The FCC reviews the results. The FCC Web site (http://www.fcc.gov/oet/rfsafety) enables consumers to check the SAR of their model.

Like the standard developed for base stations, the SAR was set to protect consumers from radio frequency energy's heating effects. The SAR in the United States is lower - that is, stricter - than in many other countries.

Based on the available research, cell phones operating at or below the SAR standard are safe, said Russell Owen, chief of the U.S. Food and Drug Administration's radiation biology branch.

Alarming studies

Carlo said some studies simulating radio frequency exposure from cell phones raise alarms. The studies show risk of genetic damage, tumors and leakage in the blood-brain barrier, which protects the brain from toxins, Carlo said.

Even if the risks are small, they're significant from a public-health standpoint because so many people use the phones, Carlo said.

"Children are a group at special risk because nobody has any idea of the impact of a lifetime of exposure in terms of these radio waves," Carlo added.

Evidence indicates that children absorb more radio frequency energy per kilogram of body weight from electromagnetic fields than do adults, according to the Stewart report in Britain. From the same cell phone, a 1-year-old could absorb about double and a 5-year-old about 60 percent more than an adult, the report said.

The Stewart Group discouraged the widespread use of mobile phones by children under 16 and recommended that the mobile phone industry not promote the use of cell phones by children.

U.S. agencies don't send as strong a message. The FDA, in its `Consumer Update on Wireless Phones,' says, "the scientific evidence does not show a danger to users of wireless phones, including children and teen-agers."

Leery consumers can spend less time on the phone, and use a headset to place more distance between the phone's antenna and the body, the agency said.

The FDA included the precautions only as a response to public concerns, the FDA's Owen said. "Many individuals have expressed a concern despite the fact that we do not find an existence of any hazards," he said. "These are simple ways to reduce exposures if people have concerns."

FOR MORE INFORMATION

Federal Communications Commission: www.fcc.gov/ marketsense for "Cell Phones & Your Health" and "Cell Phone Consumer Guide." www.fcc.gov/oet/rfsafety for data on radio frequency; [phone]

Food and Drug Administration: www.fda.gov/cdrh/phones; [phone]

Cellular Telecommunications & Internet Association: www.wow-com.com; [phone]

General Accounting Office: www.gao.gov; "Research and Regulatory Efforts on Mobile Phone Health Issues"

U.K. Stewart Group report: www.iegmp.org.uk

World Health Organization: www.who.int for fact sheets on electromagnetic fields.

"Cell Phones: Invisible Hazards in the Wireless Age," book by George Carlo and Martin Schram