All that fog we've been experiencing isn't just water droplets. The Ministry of Environment and Island Health issued an air quality advisory Monday for the area within 15 kilometres of Duncan City Hall.
"High concentrations of particulates are expected to persist for the next three days," the advisory read, urging people with chronic medical conditions not to do strenuous exercise and stay indoors and in air conditioned spaces to reduce their exposure.
Exposure is particularly a concern for infants, the elderly and people who have diabetes, lung or heart disease.
The advisory also states there is a burning ban in effect for the area for the next three days.
An increase in air quality problems this fall and winter can be traced to the unusual weather we've been experiencing said Earle Plain, air quality meteorologist with the Ministry of Environment.
We've had few storms and little rain to clear the air, he said, while also experiencing high
pressure ridges and temperature inversions, like what's been hovering over the Valley for the past four to five days, that have trapped air close to the ground.
"That leads to stagnation," Plain said. "Inversions aren't good for air quality. Basically what an inversion does is it creates a lid over an area."
The choice of heating system people are making for their homes is also having an effect.
"We don't know for sure, but anecdotally I would say that, more and more people are turning to wood heat faced with the cost of natural gas, electrical sources of heat. It's a cheap alternative. And it can be a clean alternative if people use it properly."
Cumulatively, the number of people burning wood, particularly if they have old stoves or they are burning improperly, creates an issue.
"It makes a big difference," Plain said. "All those small sources of emissions add up and create a problem."
He said cleaner air is likely on the way, however, as some rain predicted for Wednesday should "cleanse the Valley."