Air quality advisories for the Bulkley Valley and Lakes District are likely to continue until there’s a change in the weather.
The environment ministry and Northern Health have continued the advisory for Houston, Burns Lake, Smithers and Telkwa because of high concentrations of coarse and fine particulates.
A road dust advisory has also been issued for Terrace.
Air Quality Meteorologist Barry Watson says road dust left over from winter sanding gets the blame for the coarse particulates (PM10) while wood smoke is behind the fine particulates (PM25).
Watson says coarse particulate readings tend to spike during high vehicle traffic hours like before and after work.
Burns Lake had the highest 24-hour concentrations of PM10 at 124.5, followed by Terrace at 78, Smithers at 65.3, and Houston 54.7. The provincial air quality objective is 50 micrograms per cubic metre over 24 hours.
Watson expects that the Terrace air quality should improve with wind and precipitation in the forecast.
Officials are advising residents to avoid strenuous outdoor activities and to stay indoors to reduce exposure.
Exposure is a particular concern for infants, the elderly, and those with chronic, underlying health conditions like heart and lung disease.