An Environmental Protection Agency report showed Longford had 30 counts of PM2.5, or fine particles, above the Australian national air quality standards.

The agency said a combination of cold, calm weather mixed with people using wood heaters often resulted in a built-up of smoke in residential areas.

Monitoring at Longford has continued since 2012, and showed that last year it had 17 more days of heightened air pollution than the agency's monitoring station at Launceston's Ti Tree Bend.

Although wood smoke is a main contributor of PM2.5 levels, the EPA said build-up could also be affected by complex chemicals, such as tar and other related compounds.

"However, other sources of particles are airborne dust, aerosols from sea salt, vehicle emissions and industrial processes," a spokeswoman said.

She said a collaborative program to monitor air quality and earmark smoky chimneys was being run and would include householder education.

The program is jointly run by EPA, Launceston City Council, Northern Midlands Council, Department of Health and Human Services and the Menzies Research Institute at the University of Tasmania.

Residents with wood heaters are reminded to use dry, well-seasoned wood, to burn wood on high for 20minutes after adding to the firebox and to prevent smouldering.