Two monitors are in place to help Revelstoke residents make informed decision about exposure to smoky air.
The monitors were purchased by the community following the smoky summer of 2018, after the city was denied provincial funding to install an air quality monitoring station.
“I figured I wasn’t the only person who was interested in the information,” said concerned citizen Ian Houghton, who started the a crowdfunding campaign to buy the sensor. He also built the Revelstoke Air Quality website to make it easy to assess local air quality at a glance.
The two PurpleAir sensors located on private property use lasers to detect particle matter including dust, smoke and other organic and inorganic particles.
From this reading, an AQHI (Air Quality Health Index) Value is determined. AQHI is a value from 1 to 10+, designed to help people make informed decisions in different levels of air pollution. It advises when it’s safe to conduct physical activities outdoors, or when it’s best to avoid exposure to poor air.
An adjustment to the scale was proposed in B.C. in 2018 in response to the affects of wildfire pollutants.
The AQHI-Plus index puts greater weight on the PM2.5 particle size, caused by combustion of fossil fuels and wood. The tiny particle can travel deep inside lungs and get lodged, causing heart and lung disease as well as premature death. Due to size and time taken to settle out of the air, it is considered the worst public health problem from air pollution in the province, according to the Ministry of Environment.
Houghton’s website has the ability to show both the AQHI and the AQHI-Plus value. A noticeable difference in value between the amended and the original index exists. For example, on July 15 at 12 p.m., the AQHI Reading in town was shown as a moderate reading of six advising:
•General Population: No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.
•At Risk Population : Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms.
However the the AQHI-Plus showed a very high health risk reading of 13 recommending:
•General Population: Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.
•At Risk Population: Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion.
The BC Ministry of Environment considers PurpleAir sensors useful tools for “Citizen science,” but cautions against the reliability of the devices. The ministry says the location of the sensors can affect the reading, for example an air monitor too close to a large source of emission will provide a reading not representative of the overall air quality.
“Low cost sensors do have a limited ability to calibrate or to know when they are at the end of their life,” said Donna Haga, senior air quality meteorologist for the BC Department of Environment. “However they are useful in providing information on areas where there are no air-quality station available.”
Houghton mentioned the city reached out to him after the monitors where acquired and said they seemed happy having them in place but didn’t know if they planned to do anything with the data.
“I’m not a scientist nor an air quality expert, just a concerned parent who wanted to make more informed decisions about outdoor recreation for myself and my kids,” said Houghton.
Houghton hopes to further develop the website with new features such as graphing short term data but says he’s not sure when he will find the time.