Residents in Washington and parts of Beaufort County could experience unhealthy air quality today as air-quality officials expanded an advisory.

The advisory for air pollution indicates that residents from Cape Carteret to Morehead City, Havelock, New Bern, Washington, Plymouth and Columbia could experience unhealthy air quality, depending on wind directions.

A wildfire in the Croatan National Forest County has grown to more than 21,000 acres, generating heavy smoke that can contain high levels of particle pollution. The fire is centered between Havelock and New Bern, and satellite photos show a large plume of smoke drifting downwind. Winds are expected to blow toward the northeast on Wednesday.

The N.C. Division of Air Quality does not have a monitor close to the fire, but previous measurements have found unhealthful air-pollution levels in smoke directly downwind of wildfires. Some of the highest particle pollution levels that DAQ has ever measured were in smoke plumes from wildfires.

The primary pollutant of concern is fine particles, which are extremely small particles and liquid droplets in the air. Particles can be harmful to breathe and contribute to haze and other air-quality problems.

The air-pollution forecast for today estimates that fine particle levels could exceed the standard of 35 micrograms per cubic meter averaged over 24 hours. High particle levels can impair breathing and aggravate symptoms in people with respiratory problems, and irritate the lungs in healthy individuals. People with chronic lung ailments and children should reduce physical exertion and outdoor activity.

Forecasters have predicted Code Red or unhealthful air quality in portions of Craven, Jones and Pamlico counties. Also, residents could experience Code Orange conditions, or unhealthful for sensitive groups, in the following counties: Beaufort, Craven, Hyde, Jones, Martin, Pamlico, Pitt and Washington. Air-quality monitors as far west as Raleigh and as far north as Tarboro have shown increased particle pollution because of smoke from the fire, and smoky conditions may be encountered throughout the central and northern Coastal Plain.

The forecast means people who are sensitive to air pollution should avoid or reduce prolonged or heavy exertion outdoors. Sensitive groups include the elderly, children, people who work or exercise outdoors and those with heart conditions and respiratory ailments such as asthma, bronchitis and emphysema. Everyone else should reduce prolonged or heavy exertion.

Fine particles can penetrate deeply into the lungs and be absorbed into the bloodstream, causing or aggravating heart and lung diseases. People most susceptible to particle pollution include those with heart and respiratory conditions, the elderly and young children. Symptoms of exposure to high particle levels include irritation of the eyes, nose and throat; coughing; phlegm; chest pain or tightness; shortness of breath; and asthma attacks. In extreme cases, particle pollution can cause premature death.

The Division of Air Quality issues daily air forecasts for the Triangle, Charlotte, Asheville, Hickory, Fayetteville and Rocky Mount metropolitan areas. In the Triad, forecasts are issued by the Forsyth County Office of Environmental Assistance and Protection. For additional information, call 1-888-RU4NCAIR (1-888-784-6224) or visit the DAQ website at www.ncair.org or Forsyth County’s website at, http://www.co.forsyth.nc.us/eap/.