An air quality advisory for Williams Lake has been issued due to high levels of fine particulate matter.

The Ministry of Environment issued the advisory today since the air quality over the past 24 hours has deteriorated to the "poor" category in the city, following Air Quality Index measurements at the Columneetza Secondary School site and the library in Williams Lake.

The current weather system is transporting smoke from forest fires into the city, and the stagnant conditions are trapping the smoke, along with air pollutant from all sources in the valley bottom.

Although forest fire smoke is the main source of fine particulate driving the poor air quality, additional local sources include emissions from industry, road dust, and vehicle emissions.

The air quality advisory is expected to be in effect until the current weather patterns change.

The ministry is reminding the public that the Ministry of Forests and Range has placed a prohibition on all backyard burning, industrial pile burning, and camp fires (categories one, two, and three) within the Cariboo Fire Region.

Residents are asked to also avoid or reduce activities that could contribute to the high particulate levels, including operation of gas-powered lawn and garden equipment, discretionary vehicle trips, and unnecessary idling, and, if trips are necessary, to reduce speed.

Adverse health effects increase as air quality deteriorates, especially for children, the elderly, and those with existing health problems, such as heart disease, chronic obstructive lung disease, and asthma, the Ministry of Environment says.

Sensitive people can seek additional advice on how to best protect themselves during poorer air quality days by contacting the local public health officer or visiting Interior Health's website at www.interiorhealth.ca/index.aspx.