Smoke from U.S. wildfires affecting air quality in B.C.

Smoke and haze settle among the mountains, a familiar sight during B.C.’s wildfire season. (CTV News)

Wildfires south of the border are responsible for “much” of the smoke that has prompted an air quality warning in one region of B.C., according to officials.

The provincial wildfire service said an increase in local, lightning-caused fire starts was only partially responsible for poor air quality in parts of the southeast fire centre—including where parts of the Kootenays border the United States.

“As wildfire activity increases, so has smoke across many areas of the region. Much of this smoke is originating from fires south of the Canada-U.S. border and will have varying impacts over the coming days,” an update Saturday evening said.

An air quality warning is in effect for multiple regions in the province outside of the densely populated Lower Mainland, where there has been a surge in new fires over the weekend.

“Smoke is causing or expected to cause poor air quality and reduced visibility,” according to Environment and Climate Change Canada’s warning. “During a wildfire, smoke conditions can change quickly over short distances and can vary considerably hour-by-hour.”

The issue of smoke travelling across the border caused a political firestorm in recent days, in part prompted by a social media post from U.S. President Donald Trump.

“We are holding Canada responsible for the fact that they are not properly maintaining their Forests, and Brush therein, and the United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous, and totally unacceptable!” the president wrote Friday on Truth Social.

“This is Willful Negligence, and becoming a yearly occurrence, costing the United States Billions of Dollars, which cost of this pollution must of necessity be added to the TARIFFS Canada is currently paying.”

That post came as smoke was choking American cities, including Chicago, New York and Detroit.

Ontario Premier Doug Ford was asked Friday about the growing number of American criticisms of wildfire management. In response, he alluded to Canada’s contributions to fighting U.S. fires, including those that ripped through California last year.

“Maybe what you should do, rather than complain, is send support, send help, because we have done the exact same thing for our American friends, and that’s what you’re supposed to do,” he said.

Just days before Trump’s post, 56-year-old Canadian pilot Nicholas Dale was killed while fighting a forest fire in Colorado.

With file from CTV News’ Luca Caruso-Moro