The air in Prince George is getting cleaner and a new analysis by a team of University of Northern British Columbia researchers suggests the city’s industrial sector deserves much of the credit.

Environmental Science Professor Dr. Peter Jackson and a group of undergraduate and graduate students analyzed fine particulate matter (PM2.5 : particles less than 2.5 microns in diameter) air quality data in Prince George and discovered that the most dramatic improvements in air quality have come when the wind pushes the air from the heavy industrial zone into the city centre.

“When winds come from the east, which is carrying the air from the heavy industrial zone, the trend over the past 12 years is a pronounced decrease in the fine particulate matter in the air,” Jackson explains.

The students conducted the initial analysis as part of a laboratory course in the winter 2017 semester. They took 12 years’ worth of air quality data collected at the Plaza 400 site in downtown Prince George and analyzed it using a new statistical tool using the R open-source programming language. The program, called openair, allowed the students to extract trends that are not easily visible looking at a spreadsheet. 

“One of the challenges of looking at trends in air quality data is that there is a lot of noise in the signal,” Jackson says. “The values go up and down and all over the place. For instance, there are forest fires some years and not others. Trying to tease out a long-term trend in an otherwise noisy signal is tricky.”

Jackson and Environmental Science undergraduate students James Albino, Brayden Nilson and Jordan Pawluk, Geography undergraduate student Cody Birch and Natural Resources and Environmental Studies PhD student Taras Tereshchak published their findings as a peer-reviewed UNBC Natural Resources and Environmental Studies Institute Research Extension Note, Trends in Fine Particulate Matter (PM2.5) Concentrations in Prince George, British Columbia, Canada.

For the students, the course gave them an opportunity to tackle a real research question, close to home.

“I felt like we had a really good reason to be doing the research we were doing,” says Pawluk, a fifth-year student. “It was a really hands-on experience that will help in the future when we begin our careers.”

The students were able to work closely with a community partner, the Prince George Air Improvement Roundtable (PGAIR), and presented their findings to the organization’s board of directors.

“This course gave me the opportunity to not only to be a part of the community, but also look at the unique challenge and opportunities facing air quality in Prince George,” Tereshchak says.  “This methodology of analyzing the direction of where the main amount of the pollution was coming from was quite interesting. It was something I have not seen before and I’m going to definitely keep it in mind and use it in the future.”

Birch said the course was special because rather than producing a research paper for a professor, their findings turned into a published journal article with all the students listed as co-authors.

“It was a really unique experience being published as a student,” says Birch, a fourth-year student. “It was a little nerve-wracking knowing that your work is going to be published. At first I was not overly certain of myself and my skills, but with the support of everyone in the class it turned out very well.”

Nilson is in his fourth year and is completing a minor in atmospheric science. He was intrigued both by the nature of the project as well as working on the draft of the research paper.

“It’s great to be recognized in that way for the work that we did as part of the class,” he says. “Having a paper published as an undergraduate student will be an asset when I start looking for a job after graduation.”

Jackson and the students found that although the highest overall values of particulate matter still occur when the wind comes from the east, that wind direction had the largest relative and absolute decrease in particulate matter.

Among the findings are that fine particulate matter decreased overall by 29 per cent during the 12 years, but that was primarily driven by decreases of 35 per cent when the wind came from the east. The researchers found the decline in acute levels was also pronounced with wind from the east: a 30 per cent reduction in 98th percentile PM2.5 levels over the past 12 years. 

For years, industrial plants in Prince George have been investing in technology to reduce the amount of particulate matter released into the air, but measuring the effectiveness of their investments has been a challenge, according to Jackson.

“We know that industry, especially the pulp mills, have been spending hundreds of millions of dollars on upgrades that reduce the amount of particulate matter they release into the air,” Jackson says. “It has been frustrating not being able to detect that in the actual monitoring data, but this study suggests that what they are doing is working.”