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Sizing up radon’s risk

The Yukon government wants you to check the radon levels in your home and is even offering some limited assistance in determining whether or not you have too much of it.

The Yukon government wants you to check the radon levels in your home and is even offering some limited assistance in determining whether or not you have too much of it.

Radon is radioactive gas. It has no smell and you can’t see it. It is formed by the decay of radioactive rocks in the ground and seeps into our basements and crawl spaces.

There is radon gas in your home right now. In fact there is radon gas everywhere. But like most other things the dose makes the poison. The problem is that many of our homes here in the territory have too much of it. In fact, according to officials here in the Yukon 30 per cent of tested homes exceed guidelines set by Health Canada for radon concentrations of 200 Bq/m3.

Why is that a problem? Because radon causes lung cancer, and unfortunately most people who get lung cancer will die from it. So it is certainly something we want to avoid.

Thankfully there are ways to remediate radon that range from the very basic (like plugging cracks in your foundation) to the more complicated (installing ventilation systems that remove the gas from your home).

This push to remediate radon recently got me wondering about how dangerous radon actually is. After all, not all cancer risks were created equal, and before we dole out money for radon mitigation it is good to have a clear idea how bad this stuff is.

Readers will recall that several weeks ago news media across the country carried ominous headlines about the purported dangers of processed and red meat. The headlines followed the International Agency for Research on Cancer decision to re-categorize these two food item favourites. The IARC recently determined that processed meat “definitely” causes cancer and red meat “probably” causes cancer.

Some media outlets ramped up the sensationalism by reporting that the cancer agency had put processed meat in the “same category” as smoking and asbestos – a pretty frightening statement for those who are unfamiliar with the IARC’s categorization system but are well acquainted with their own love of cold cuts.

The IARC maintains a list various “agents” and categorizes them based on the state of the evidence regarding their cancer causing effect. Group 1 agents are those which have been conclusively linked to cancer. Group 2A agents are “probably” carcinogenic, while Group 2B agents are “possibly” carcinogenic.

Processed meat is now a Group 1 agent which does (technically) put it in the same category as radon and as I’ve already noted, cigarette smoke.

But how much does each increase your risk?

The thing is that the IARC’s categorization system wasn’t intended to tell us how much we are increasing our risk if we choose to munch on some processed meats while lighting up a cigarette in our radon inundated basement. It just tells us that we are definitely increasing our risk.

Studying whether something causes cancer is inherently difficult due to the sheer number of cancer causing agents we are exposed to in our daily lives. Quantifying the degree to which something causes cancer is many orders of magnitude more difficult.

It turns out that you can probably keep eating some processed foods in moderation. Eating two slices of bacon a day will increase your risk of developing colorectal cancer by about 18 per cent – not a number to ignore, but one that must be placed in context with the myriad other risk-taking behaviours we all engage in.

Contrast that with smoking – a well known carcinogen – which, according to Health Canada, increases your risk of dying from lung cancer by 2,500 per cent. You can see now why I say it was alarmist and misleading to say that smoking and processed meat are in the “same category.”

So where does radon fit in? Unfortunately, while the simple answer is “something in the middle,” quantifying the risk has been challenging for experts. While we can self-report our smoking and eating habits, telling researchers how much radon we’ve been exposed to in the various residences and workplaces we’ve spent time in during our lifetime isn’t really possible.

Radon is often touted as the second leading cause of lung cancer but it is a distant second to smoking. According to Health Canada smoking is linked to 90 per cent of all lung cancers while radon is linked to 16 per cent. These numbers add up to more than 100 per cent because it turns out radon takes things from bad to worse for smokers as the gas tag-teams with cigarette smoke to cause lung cancer.

In a study published in 2005 in the British Medical Journal researchers estimated that exposure to a lifetime of high levels of radon – 400 Bq/m3 – increases your cancer risk by a bit more than 50 per cent.

That is bad news for smokers. Why? Because increasing a big number by 50 per cent is worse than increasing a small one. According to the study exposure to such levels increased the risk of developing lung cancer increases from 10 per cent to 16 per cent. With non-smokers that risk increases by a similar amount – from 0.4 per cent to 0.7 per cent – but the risk remains much smaller.

The U.S. Centers for Disease Control uses more ominous numbers which suggest that the odds of developing lung cancer double as dosage doubles, but the theme remains – that is very bad news for smokers.

So what is the take away? If you want to avoid lung cancer your best bet is to quit smoking. That isn’t exactly surprising news.

But if you’re not convinced that you have the willpower to pull it off you should definitely take the Yukon government up on its offer of a free radon testing kit, because unfortunately that invisible gas could be making matters much worse.

Kyle Carruthers is a born-and-raised Yukoner who lives and practises law in Whitehorse.