Whether cell phones and other electromagnetic-radiating technologies are hazardous to health remains a controversy Elizabeth Barris hopes is not left hanging in the air. 

Barris, a documentarian and director of the nonprofit foundation The People's Initiative, is petitioning Congress to mandate that all cell phone product packaging, infrastructures that carry Wi-Fi signals and other EMR-related product packaging carry warning labels.

The petition, entitled The Children's Wireless Protection Act, also requests that Wi-Fi in public schools be replaced with hard-wired Internet access.

"The bill is basically giving people fair warning," Barris said. "You know when you look at a cigarette package? That's what it's going to have on it."

Barris said she used to spend hundreds of minutes monthly talking on the cell phone but only uses the phone now for 30-second calls and emergencies due to pain sensations in her ear.

 A doctor's diagnosis determined Barris' ear was fine. However Barris disagrees because she said the discomfort lessened after she reduced cell phone usage.

"Cancers and tumors take years to develop," Barris said. "We're going to see a tsunami of brain tumors in the next 10 years, 15 years, 20 years, 30 years, from children, young adults and adults who use their cell phones on a regular basis." 

Barris has collected 200 signatures on the foundation's website.  But this is not the first time she lobbied for warning labels on wireless product packaging and facilities that carry the signals.

California recently rejected her petition, stating that the matter was federal jurisdiction. Barris also submitted a letter of request to Gov. Arnold Schwarzenegger, First Lady Maria Shriver and the Department of Health and Human Services.

There is currently no consensus among American experts that electromagnetic radiating products, such as cell phones, televisions, GPS systems and wireless computers, can directly cause health side effects.

"The concern is more theoretical than experimentally based or epidemiologically based," said Michael Rich, director of the Center on Media and Child Health and associate professor of pediatrics at Harvard Medical School. "We have no evidence that either indicates it is a problem or it is not a problem." 

Rich said whenever a cell is subjected to radiation of any kind there is a potential of changing the way it develops and repairs itself, but a lack of adequate testing models means it will take years or decades before the results are known.

"There have been animal models of various aspects of this that show you can certainly disrupt development and repair,” Rich said. 

"But it's a huge leap from that to saying cell phones could cause that level of radiation because the magnitude of radiation they exposed animals to was probably hundreds, if not 1,000-fold greater than a cell phone can generate... We're talking about radiation like putting an animal in a microwave."

Children are likely at the highest risk because the skull is thinner than it is in adult life and the brain is still actively building itself, Rich said. 

Gerald E. Loeb, a professor of biomedical engineering at the University of Southern California, said the risk of electromagnetic radiation causing health problems is probably going down even though the number of devices available is going up.

"One of the big motivations in engineering these devices estimates them much more efficient so they're actually radiating much less power than they used to. That's why your cell phones get lighter and lighter every year," Loeb said. "But -- if it was going to cause cancer, it would be causing cancer in the earlobe because almost no energy gets deep into the brain where people are worried about brain tumors.

"It's also the case that the frequencies they're operating at are going up. And once you get above a couple hundred megahertz, very little energy actually penetrates the body," Loeb added.

For example, digital television operates at a much higher frequency of transmission than analog television so there is almost no absorption of the energy beyond the surface of the skin.

Another reason why studies revealing negative effects may be limited is because industries do not always make their findings public.

Nitin Mehta, a recent biomedical engineering graduate at USC, interned at a medical device company. There he researched the usability and long-term health effects of a heart support device and its external components.

Due to a company nondisclosure agreement, Mehta could not provide the specific details of the system design. However, he found one of the components emitting EMR may cause patients to have headaches and dry eyes during long-term usage.

"I recommended more labeling claims to inform users of potential long-term hazardous effects of the technologies,” Mehta said.  "In the most crude forms humans use technology far more than they should be using it so ... it's the responsibility of the manufacturers themselves to make the user aware and put the label at such places that make the label constantly visible."

"What we do know is people typically read and pay attention to promotional material far more often than they pay attention to warnings with products," said Sari Shepphird, a clinical psychologist and author based in Los Angeles. "The biggest problem is getting people to read the warning labels first of all because most people don't pay attention to them."

Shepphird said studies on products such as cigarettes and medication have proved  educational campaigns are better.

"Changing a person's behavior is difficult and complex so it's not just that a person needs to know about harm or potential harm," Shepphird said. "They need to feel that they are personally susceptible to the harm and they have to clearly understand the action that needs to be taken to avoid the harm."

Eric Barr, a software developer, recently celebrated the birthday of his 2-year-old son Michael. Barr said he tries to keep the cell phone away from his son whenever possible.

"It's probably okay to put the [warning] labels on there," he said. "There are probably a lot of uneducated people who don't read as much as we do about the potential negative effects and could be helped by that...It's again, better safe than sorry."