Dental Dilemma

Studies link dental x-rays to brain tumours, thyroid cancer, and low birth weight
Growth in dental use of CT machines raises radiation exposures dramatically

by Alex Roslin
The Georgia Straight
August 14, 2013

CAROLE-ANNE STANWAY HAD lived with blinding headaches for 17 years before she decided enough was enough.
The grandmother of five in Kelowna finally asked her doctor for an MRI to see what was wrong. He refused to give her a referral, saying the headaches were just from tension. He had put her on Tylenol 3 and antidepressants, but those hadn’t helped.
Stanway got an MRI done privately anyway, at a cost of $2,700. The result: she had three meningiomas, a type of brain tumour.
The good news was the tumours weren’t cancerous. The bad news was the specialist didn’t want to remove them unless they became cancerous because of the risk of brain damage.
Stanway put up with the headaches for five more years until, in 2002, they and other health problems forced her to stop working as an assistant in a medical office. She’s been on disability leave ever since.

Buffet of Pain Drugs
She has been prescribed a buffet of pain drugs, which, along with noninsured medical procedures and travel to see specialists, have drained her savings. The drugs reduced the pain for a while, but her body quickly got used to them. Then they didn’t help anymore.
She stopped taking the pain meds five years ago after they started to cause her kidney problems. Some of the drugs also gave her severe nausea. But she’s still on the antidepressants. “Chronic pain is difficult to deal with otherwise,” she said in a phone interview from her apartment.
A few months ago, her eyes started moving uncontrollably while she was reading, likely a side effect of meningioma, which can cause optic problems.
Stanway said doctors don’t know what caused her meningiomas, but she thinks dental X-rays are a possible culprit. “I had a lot of dental work done when I was younger. As children, we received a lot of radiation.”

Brain Tumour Risk Higher
In a study in the journal Cancer last year, 1,433 people with men­ingioma were found to be two times more likely to have had a “bitewing” dental X-ray as those without the illness. Those who reported having a panorex scanning dental X-ray (which gives a two-dimensional panoramic view of the mouth) before age 10 were 4.9 times more likely to have meningioma.
Meningioma is the most common form of primary brain tumour (tumours that start in the brain). Women get it more than twice as often as men.
Other studies have linked dental X-rays to thyroid cancer, breast cancer (in women who hadn’t worn a shielded apron), saliva-gland tumours, and glioma (a cancerous type of brain and spinal tumour).
Pregnant women who got a dental X-ray were three times more likely to deliver a low-birth-weight baby (weighing less than 2.5 kilograms), according to a 2004 study in the Journal of the American Medical Association.
Dental X-rays are the most common way Americans are exposed to human-made radiation, the 2012 Cancer study said.
Yet despite growing awareness about the risks of X-rays, radiation in many dental offices is actually rising. That’s thanks to the explosive growth of 3-D cone-beam CT (computed tomography) machines, which give off up to 60 times the radiation of a conventional dental X-ray.

[Read the entire story here.]

Nanoparticles: A Tiny Question of Safety

Revolution Without Regulation

How do you get the ketchup to slide easily out of the bottle? Nanoparticles. They're the miracle technology we're using in everything from sunscreen to paint. But how much do we really know about nanotechnology and its potential impact on our health?

August 11, 2012


If you have Robert Schiestl over to your house, don’t be surprised to see him peeking at ingredient labels on things in your kitchen or bathroom.

He can’t help it. Schiestl, a leading U.S. cancer expert, instinctively reads the label before he buys or uses a host of products — any food that’s partly white, toothpaste, sunscreen, shampoo, over-the-counter medicine.

He’s trying to avoid nanoparticles, which a growing pile of studies say may cause cancer, damage to organs and skin, Crohn’s disease and environmental pollution.

Labels in Canada and the U.S. don’t have to say whether a product contains nanoparticles — so to be completely sure, Schiestl avoids all products with two ingredients that are increasingly used in nano-form: titanium dioxide and zinc oxide.

The tiny particles causing the concern are as little as 10,000 times the width of a human hair and are measured in nanometres, or billionths of a metre.

They’re part of a revolutionary technology that’s been touted as “the most powerful tool the human species has ever used” — giving us the ability to build anything we can conceive molecule by molecule, and potentially leading to healthier lives and cleaner energy.

Governments, eager to get on the nanotechnology bandwagon, have shovelled huge public subsidies into nanotech in the past decade, fuelling its growth into a $250-billion-per-year global industry that is expected to grow to $3 trillion by 2015.

The subsidies have helped promote the use of nanoparticles in thousands of goods — everything from food colouring to scratch-resistant coating on eyeglasses and anti-bacterial agent in clothes.

Nanotech has even answered the age-old problem of getting ketchup out of the bottle. In 2007, German scientists developed a super-slippery nano-coating for bottles that lets ketchup slide out more easily.

Yet, more than a decade after nanoparticles started being widely used in consumer products, they are still subject to virtually no regulation in Canada, and little is known about their health impacts....