The Chronicle Herald (Provincial)
Radon, arsenic avoidable risk factors
When we think of factors that increase our risk for cancer, a few easily pop up: a person's age, family history, and whether they smoke or not.
But exposure to some substances found in our environment can also play a big role.
“It turns out it's about 30 per cent of your cancer risk is encompassed in what you're exposed to. So, what do you drink in your water? What do you eat? And what do you breathe?” said Garaham Dellaire, professor and director of research in the department of pathology at Dalhousie University.
Dellaire is leading a multidisciplinary team of researchers to study two of the most abundant environmental causes of cancer, or carcinogens, in Canada — radioactive radon gas and metallic arsenic.
Both substances are found in large amounts across the country, including Nova Scotia, due to the geology of the area, said Dellaire.
The soil in Canada has large amounts of granite rocks which contain uranium. When uranium breaks down, it forms the odourless, colourless, radioactive gas,
called radon.
The gas is directly linked to 10 per cent of lung cancer cases in Canada. It also increases lung cancer risk for people who smoke.
Dellaire said radon may accumulate to dangerous levels in homes that don't have good circulation or in open basements. Radon can also dissolve in water. If your home is on well water, you can get exposed to the gas during a shower, for example.
While radon is found in high amounts closer to the ground, it can easily move through a building. This means that people living in higher levels will also get exposed.
When you breathe in radon, it releases particles that damage your cells. The gas can also further break down into polonium, which attaches to dust particles.
“Even if you've remediated for radon, you actually have to go around and vacuum and clean up that dust. For another three months, you still have radioactive dust all over your basement,” said Dellaire.
The dust particles can get caught in your lung tissue and if you're a smoker, your lungs won't be able to clear the dust quickly. This increases the time you're exposed to the dust and consequently your susceptibility to cancer.
LOOKING FOR ARSENIC IN TOENAILS
The other substance, arsenic, is present in the soil and can also leach into municipal and well water. Up to 70 per cent of well water in Nova Scotia is contaminated with arsenic.
Researchers at Dalhousie University have been investigating arsenic exposure by collecting toenail clippings from research participants through the Atlantic PATH research project. Toenails were used because they grow slowly and are not usually exposed to chemicals such as nail polish. The study found a significant relationship between high concentrations of arsenic in well water and that in the clippings.
Preliminary results of another study found up to 115,000 Atlantic Canadians are drinking water that puts them at risk of cancer and kidney, bladder, and prostate cancer because of the levels of arsenic in their water, said Dellaire.
There are a few things people can do to mitigate the effects of these dangerous carcinogens, Dellaire added.
GET IT TESTED
For radon, people renting a basement apartment should request the apartment be tested before moving in. If you're buying a new home, it should also be a condition to get the home tested for radon levels.
Dellaire recommended visiting evictradon.org as a good resource for information on the radioactive gas.
There's no dedicated website for information on arsenic and education about the substance is lacking compared to radon, he said. People can find out if they're being exposed by getting their water tested for arsenic if they're on well water.
People can also bring up any concerns they have about past exposures to their family doctor.
“One of the things you could do through your doctor is request that your toenails be tested for arsenic,” said Dellaire.
“We're trying to make this a lot easier for people who are accessing health care through Nova Scotia Health Authority.”
He said he hoped the research project he's embarking on with the team at the Canadian Environmental Exposures in Cancer Network will help launch a campaign to educate the public about the two carcinogens.
The project, which received $2 million in funding from the Canada Foundation for Innovation, also aims at driving policy change to reduce the maximum acceptable levels of radon and arsenic in Canada.
Part of the funding will be used to build a metal-free lab at the University of Calgary where Dellaire's colleague Aaron Goodarzi is based. The lab will allow the team to measure long-term exposure to radon.
More information about the project is available at www.ce2c.ca