Smoke particles can change DNA, cause cancer, says B.C. scientist of wildfire health risk

Later this week, residents in certain parts of central and northern B.C. affected by wildfire smoke can expect to breathe a little fresher air. However, a scientist warns that the poor air quality experienced in recent weeks can have long-term health consequences.

The most recent data from the B.C. government indicates that as of Monday morning, Prince George and Quesnel continued to record a high score of "10+" on the air quality health index (AQHI), indicating people living in these areas, and those in the surrounding regions continue to face significant health risks due to air pollution.

However, the province predicts that the air quality indices in both municipalities will improve to "5" on Monday evening after showers and thunderstorms forecast by Environment Canada. The index will then rise slightly to "6" on Tuesday, which means residents will still face moderate health risks due to the lingering poor air quality.

In northeastern B.C., Fort St.John, the closest city to the Donnie Creek wildfire that has already consumed over 580,000 hectares of land, scores between "4" and "5" on the index for Monday and Tuesday.

The AQHI, developed by Health Canada, is an online tool that assesses the severity of air pollution and its potential impacts on the general population and vulnerable groups such as seniors, infants, and individuals with heart or lung conditions in the short term. 

It incorporates real-time levels of three common pollutants found in Canadian air: fine particulate matter, ground-level ozone, and nitrogen dioxide.

According to Michael Mehta, an environmental studies professor at Thompson Rivers University in Kamloops, this summer might go down as the worst in B.C. history in terms of exposure to air pollution caused by wildfire smoke. 

Mehta says smoke-induced air pollution can lead to short-term health issues like minor irritations in the nose and throat and long-term health problems, including cancer.

"Air pollution exposures cumulative from the moment you're born or even before you're born. The particles of air pollution tend to build up in your body over time and create more and more of what we call genotoxic effects, more carcinogenic effects.

"They can change the DNA. They can create cancers and, of course, they can also lodge in the organ systems [and] in the brain in particular, leading potentially to a wide range of dementias," he told CBC's The Early Edition.

There are studies linking higher rates of cancer with exposure to wildfire smoke, including a 2022 study in the Lancet that looked at population data in Canada over 20 years. 

It found that long-term exposure to wildfire smoke can increase the risk of lung cancer and brain tumours, but the study's authors, led by Jill Korsiak of McGill University's department of epidemiology, biostatistics and occupational health, said further research is needed. 

While it takes time to see whether wildfire smoke can cause cancer, nine-year-old Carter Vigh in 100 Mile House died last Tuesday, a tragic incident that his parents attributed to a severe asthma attack made worse by wildfire smoke shrouding the community.

To combat the effects of wildfire smoke indoors, Mehta recommends using HEPA (high-efficiency particulate air) filtration equipment both at home and in the office, as it provides the best protection.

Peacock Creek fire evacuation order partially rescinded

With around 380 wildfires raging in B.C., the province currently has the highest number of blazes in Canada. 

The authorities have identified 23 "wildfires of note" that are highly visible, threatening, or potentially damaging, up from 20 on Saturday. Additionally, there are over 70 wildfire-related evacuation alerts or orders, mostly concentrated in several regions of B.C.'s central Interior.

On Monday morning, the Regional District of Bulkley-Nechako partially lifted the evacuation order in an area affected by the Peacock Creek wildfire south of Houston, B.C., while expanding the evacuation alert for the same area.

In its air quality advisory on Sunday, the British Columbia government emphasized that individuals with pre-existing health conditions, respiratory infections, seniors, children and pregnant people are more susceptible to the adverse effects of poor air quality.

The province recommends that the vulnerable population follow these guidelines:

• Reduce or cease physical activity if experiencing difficulty breathing.
• Stay cool and stay hydrated by drinking plenty of water.
• Always carry any necessary rescue medications with you.