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.

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[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?

BY ALEX ROSLIN
August 11, 2012

THE MONTREAL GAZETTE

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....

Nuclear Fishin'


[This story was nominated for a Canadian Association of Journalists award for investigative reporting and by the Western Magazine Awards for a prize in the environment category. -AR]

Japanese tests have revealed high radiation levels in some Pacific Ocean seafood, creating concern among doctors at B.C. universities

by Alex Roslin
The Georgia Straight
July 19, 2012

Are fish from the Pacific Ocean and Japanese coastal and inland waters safe to eat 16 months after the Fukushima nuclear disaster?
Governments and many scientists say they are. But the largest collection of data on radiation in Japanese fish tells a very different story.
In June, 56 percent of Japanese fish catches tested by the Japanese government were contaminated with cesium-137 and -134. (Both are human-made radioactive isotopes—produced through nuclear fission—of the element cesium.)
And 9.3 percent of the catches exceeded Japan’s official ceiling for cesium, which is 100 becquerels per kilogram (Bq/kg). (A becquerel is a unit of radioactivity equal to one nuclear disintegration per second.)
Radiation levels remain especially high in many species that Japan has exported to Canada in recent years, such as cod, sole, halibut, landlocked kokanee, carp, trout, and eel.
Of these species, cod, sole, and halibut, which are oceanic species, could also be fished by other nations that export their Pacific Ocean catch to Canada.
The revelations come from the Japanese Fisheries Agency’s radiation tests on almost 14,000 commercial fish catches in both international Pacific and Japanese waters since March 11, 2011, when an earthquake and tsunami triggered multiple meltdowns at the Fukushima Daiichi Nuclear Power Plant.
The wrecked plant spewed enormous amounts of radiation into the Pacific, where cesium levels near the Fukushima coast shot up to an astonishing 45 million times the pre-accident levels.
Japan’s Fisheries Agency data is easily the most comprehensive on Fukushima’s radioactive impacts on the Pacific Ocean, home to the world’s biggest fishery and a major food source for more than a billion people.
The numbers show that far from dissipating with time, as government officials and scientists in Canada and elsewhere claimed they would, levels of radiation from Fukushima have stayed stubbornly high in fish. In June 2012, the average contaminated fish catch had 65 becquerels of cesium per kilo. That’s much higher than the average of five Bq/kg found in the days after the accident back in March 2011, before cesium from Fukushima had spread widely through the region’s food chain.
In some species, radiation levels are actually higher this year than last.

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[Read the rest of this story here and the original version on the Georgia Straight's website here.]

After Fukushima, fish tales


by Alex Roslin
January 14, 2012
The Montreal Gazette

After the world’s worst nuclear accident in 25 years, authorities in Canada said people living here were safe and faced no health risks from the fallout from Fukushima.

They said most of the radiation from the crippled Japanese nuclear power plant would fall into the ocean, where it would be diluted and not pose any danger.

Dr. Dale Dewar wasn’t convinced. Dewar, a family physician in Wynyard, Sask., doesn’t eat a lot of seafood herself, but when her grandchildren come to visit, she carefully checks seafood labels.

She wants to make sure she isn’t serving them anything that might come from the western Pacific Ocean.

Dewar, the executive director of Physicians for Global Survival, a Canadian anti-nuclear group, says the Canadian government has downplayed the radiation risks from Fukushima and is doing little to monitor them.

“We suspect we’re going to see more cancers, decreased fetal viability, decreased fertility, increased metabolic defects – and we expect them to be generational,” she said.

And evidence has emerged that the impacts of the disaster on the Pacific Ocean are worse than expected.

Since a tsunami and earthquake destroyed the Fukushima Daiichi Nuclear Power Plant last March, radioactive cesium has consistently been found in 60 to 80 per cent of Japanese fishing catches each month tested by Japan’s Fisheries Agency.

In November, 65 per cent of the catches tested positive for cesium (a radioactive material created by nuclear reactors), according to a Gazette analysis of data on the fisheries agency’s website. Cesium is a long-lived radionuclide that persists in the environment and increases the risk of cancer, according to the United States Environmental Protection Agency, which says the most common form of radioactive cesium has a half-life of 30 years.

The Canadian Food Inspection Agency, which monitors food safety, says it is aware of the numbers but says the amounts of cesium detected are small.

“Approximately 60 per cent of fish have shown to have detectable levels of radionuclides,” it said in an emailed statement.

“The majority of exported fish to Canada are caught much farther from the coast of Japan, and the Japanese testing has shown that these fish have not been contaminated with high levels of radionuclides.”

But the Japanese data shows elevated levels of contamination in several seafood species that Japan has exported to Canada in recent years.

In November, 18 per cent of cod exceeded a new radiation ceiling for food to be implemented in Japan in April – along with 21 per cent of eel, 22 per cent of sole and 33 per cent of seaweed.

Overall, one in five of the 1,100 catches tested in November exceeded the new ceiling of 100 becquerels per kilogram. (Canada’s ceiling for radiation in food is much higher: 1,000 becquerels per kilo.)

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[Read the entire story here, and visit my investigative journalism blog here.]