Risky business: Do cell phones, fish, plastic containers and aluminum really pose dangers?

Posted on Oct 12, 2008 in Health Optimization

By Mary Powers

Do consumers out there, particularly parents, trying their best to avoid unnecessary risks, physicians and public health officials feel your pain.

Do the benefits of a high-fish diet outweigh the risks that the fish might contain toxic levels of mercury?

Is the cell phone a tween-daughter begged for now increasing her odds for a brain tumor later in life?

Did the expectant parents inadvertently raise lead levels in their home and neighborhood as they were turning the spare bedroom in their Midtown bungalow into a nursery?

“It is very confusing,” said Dr. Bryan Williams, deputy director of the pesticide laboratory at the National Center for Environmental Health, which is part of the federal Centers for Disease Control and Prevention.

“There is constantly conflicting information out there. Most of the research related to environmental toxins doesn’t take place in pristine laboratories, but the real world. There are a lot of ambiguities surrounding these studies.”

Williams counseled common sense and a little skepticism in assessing claims. He is an environmental epidemiologist and toxicologist who until recently was on the University of Tennessee Health Science Center faculty. He also recommended focusing on reducing one’s risk to known killers, including tobacco and motor vehicle and other accidents.

In his own life, Williams avoids pesticides and lawn chemicals.

“That is a personal choice. I wouldn’t be greatly increasing my family’s risk by using them,” he added.

There is some good news.

Because the Mid-South pulls its water from an underground aquifer, water flowing from local taps today has been sequestered underground for about 2,000 years.

Also, vaccines are safer. It has been more than a decade since federal officials approved a new whooping cough vaccine that causes less fever and other side effects. All routine childhood vaccines are now produced without thimerosal, a once-common mercury-based preservative. And several high-powered scientific panels have cleared vaccines from claims they were the driving force behind the nation’s soaring autism rate.

As for Teflon, love it or fear it, the clock is ticking.

Discovered by chance in the 1930s, Teflon’s main ingredient now turns up in everything from cookware to clothing. That ingredient, the chemical perfluorooctanoic acid also known as C8, has been linked to cancer and other problems in laboratory animals. A federal scientific advisory panel has classified it as a “likely” cancer-causing agent. Producers have agreed to a government plan to slash use by 95 percent by 2010 and try to end it completely by 2015.

But plenty of questions about other health risks remain. Here’s the latest on a couple of them.

Cell phones

Do cell phones increase the risk of brain tumors?

Cell phones rely on a type of electromagnetic energy widely known as radiofrequency energy. At high enough levels, think microwave ovens, the energy generates enough heat to pop popcorn or cook pork chops.

While cell-phone users needn’t worry about scorched ear lobes, some scientists warn long-term exposure might leave them at increased risk for certain brain tumors. The risk, they fear, is greatest for young people whose brains are still developing and who will likely be using the cell phones longer than their land-line parents.

In Memphis, Dr. Allen Sills gets lots of questions about cell-phone safety. Sills is director of Methodist Healthcare’s Neuroscience Institute and a University of Tennessee Health Science Center associate professor of neurosurgery.

“Overall to date, there is no conclusive evidence that there is a causative link between cell phones and brain tumors,” said Sills, speaking with a cell phone pressed to his ear. “There is some conflicting data, but you need a large number of patients and a long time interval to see what the effects may be.”

But Sills said preliminary data supports taking a cautious approach to cell-phone use by children.

At a recent congressional hearing focused on cell-phone safety, the director of the University of Pittsburgh Cancer Institute used a model to illustrate why. Dr. Ronald Herberman showed legislators that cell-phone radiation penetrated farther into the brain of a child than an adult brain.

Herberman was among those calling for stepped-up research and oversight.

This summer, Herberman made headlines when he issued a memo to the institute’s faculty and staff urging them to reduce cell-phone use or to use a headset. He recommended children use cell phones only in emergencies. He cited unpublished advice as the basis of his warning.

His warning is at odds with the repeated assurances from government and private agencies, including the American Cancer Society, that no evidence links cell phones with an increased risk of brain tumors.

But Herberman’s concerns aren’t unique. Back in 1998, two University of Washington scientists reported cell-phone radiation was strong enough to damage DNA in rats. More recent studies from Europe and Israel linked the phones with an increased risk of certain malignant and benign tumors.

In June, more than 20 investigators signed a French document urging caution regarding cell-phone use until the possible risks, including cancer risks, are better understood.

Sills warned definite answers aren’t likely soon. “Brain tumors come in many shapes and sizes. In most cases, there isn’t a single cause,” he explained.

Aluminum

Does aluminum pose a health risk?

As the most abundant metal on Earth, there is plenty of aluminum available to cause problems. Animal and laboratory studies show that at a high enough dose it is harmful to the brain and nervous system. But conclusive evidence linking aluminum — whether from sauce pans, dental fillings or antiperspirants — to human disease is rare.

Kidney dialysis is one exception.

Dialysis exposes patient blood to so much water — more than 26,000 gallons during a single treatment — that in the past the trace amounts of aluminum found in tap water built up to toxic levels, Dr. Brad Canada said. Canada is a kidney specialist with the UT Medical Group and an assistant professor at the UT Health Science Center.

It left dialysis patients at increased risk for a variety of problems, including the mental confusion and memory problems of dementia.

Canada said the realization prompted changes in dialysis treatment that have largely eliminated the risk.

Meanwhile, scientists and federal health officials said there is no conclusive evidence linking aluminum to other health problems, including Alzheimer’s disease or breast cancer. But questions remain.

The National Cancer Institute officials noted conflicting research results regarding possible links between aluminum in deodorants and antiperspirants and a woman’s breast cancer risk. The NCI Web site cited studies published in 2002 and 2006 that found no connection. A smaller 2003 study reached the opposite conclusion.

Links between Alzheimer’s and aluminum are also murky. Researchers cite the challenge of trying to sort out various risk factors, ranging from a person’s age and education to environmental factors and family history. The Alzheimer’s Association notes that research has failed to find a link between everyday exposure to aluminum through cookware and deodorants.

Fish and mercury

Is it safe to eat fish?

Fish provides diners with a tasty high-protein, low-fat menu item that is naturally packed with nutrients proven to reduce their heart disease risk. There are hints the same nutrients — two omega-3 fatty acids — might also reduce the risk of Alzheimer’s disease or boost the academic performance of youngsters.

Of course, some of those same fish pack worrisome levels of mercury.

“It is pretty confusing,” said Dr. Jennifer Morrow, a Memphis cardiologist. “I eat a tremendous amount of fish. But I personally try and limit sushi tuna to once a week.”

Mercury is found naturally in minerals like granite. It is a byproduct of forest fires and volcanic eruptions. But humanity is also releasing plenty more into the environment by burning fossil fuels and improperly discarding mercury-containing products like fluorescent light bulbs.

The metal accumulates in water and eventually the fish who call them home.

While nearly all fish contains trace amounts of mercury, health concerns focus on certain fish and certain diners.

Fetuses and young children, both of whom have rapidly developing nervous systems, are particularly sensitive to mercury. Problems range from mild to severe, including mental retardation and blindness.

That’s why federal health officials recommend children and women who are pregnant, trying to become pregnant or who are breast feeding avoid fish varieties with high mercury levels. It is a short list — shark, swordfish, king mackerel and tilefish.

Morrow urges her patients to follow the American Heart Association’s recommendation and eat omega-3-rich, fatty fish at least twice a week.

“Eating fish is the most efficient way of getting omega-3 fatty acids. It is more natural, less processed,” she said.

“But you do need to limit your intake of mercury-containing fish, which generally are large fish,” she said. Safer options include salmon, shrimp, canned light rather than albacore tuna, sardines, pollock, fish sticks and catfish. Just don’t fry the catfish.

BPA

Does this chemical harm developing brains and nervous systems?

The chemical is bisphenol-A or BPA. Around for more than a century, it has been a popular component of various consumer products for 50 years.

These days, more than 6million pounds of it are produced annually in the U.S. It is used to make everything from dental sealant and baby bottles to the lining of food and drink containers. Tiny amounts of the chemical sometimes leach into food and beverages, especially when the containers are heated.

So maybe it’s not surprising a 2007 study found 93 percent of Americans tested had traces of BPA in their urine.

A decade earlier, research in animals sparked concern about the chemical’s potential impact on human health. There is evidence BPA mimics the activity of the hormone estrogen. In animals, it has been tied to a possible increased risk of early puberty and certain cancers.

Concern grew earlier this year when the National Toxicology Program issued two draft reports expressing “some concern” about BPA and human health. Authors focused on the possible risk to the developing brains and nervous systems of infants and children.

Then in September, research published in the Journal of the American Medical Association identified a possible new threat. In that study, patients with the highest levels of BPA in their urine were more than twice as likely as those with the lowest level to be battling heart disease or diabetes.

For now, officials at the federal Food and Drug Administration, which has authority to regulate BPA, are defending its safety. But they have asked another scientific advisory panel to revisit the issue.

For consumers who don’t want to wait, options include switching to glass bottles or choosing plastic made without BPA. To do that, check the bottom of the bottle or container. The number 7 inside the triangular recycling symbol means BPA might be an ingredient.