Americans are being urged to stay indoors as toxic air pollution sweeps across parts of the West.
Emergency air quality advisories have been issued in Arizona and Colorado as blowing dust and wildfire smoke combine to create hazardous breathing conditions through Saturday.
Authorities are advising residents to limit time outdoors, avoid strenuous physical activity and keep windows closed where possible until conditions improve.
The advisories remain in effect through Friday evening in parts of Arizona and until Saturday morning in portions of Colorado, with officials urging residents to monitor local forecasts.
The warnings are especially urgent for older adults, young children and anyone with asthma, heart disease or other respiratory conditions, who face the greatest risk of serious health effects.
The Arizona Department of Environmental Quality warned that coarse particulate matter, known as PM-10, could reach concentrations that pose a health risk as dust is swept into the atmosphere. PM-10 particles, which can penetrate the lungs, can aggravate heart and lung disease, particularly among vulnerable groups.
Meanwhile, in Colorado, multiple counties are under Air Quality Health Advisories because of wildfire smoke drifting from active fires burning in Colorado and neighboring Utah.
Wildfire smoke is a hazardous mixture of gases, toxic organic compounds, and particulate matter, particularly PM2.5, that can penetrate deep into the lungs and enter the bloodstream, causing severe cardiovascular and respiratory issues.
The Arizona Department of Environmental Quality (pictured) warned that coarse particulate matter, known as PM-10, could reach concentrations that pose a health risk as dust is swept into the atmosphere
Officials say the pollution is being driven by strong, gusty winds whipping up thick clouds of dust in Arizona, while wildfire smoke continues to blanket large areas of Colorado.
In some locations, visibility could deteriorate as smoke and dust linger in the air, with authorities warning that conditions may become unhealthy even for otherwise healthy people.
Anyone who begins experiencing coughing, shortness of breath, chest discomfort or worsening respiratory symptoms is encouraged to move indoors immediately and reduce exposure until air quality improves.
Arizona officials have issued PM-10 High Pollution Advisories covering the Phoenix metropolitan area, Pinal County and Yuma, where powerful winds are expected to generate widespread blowing dust.
The advisory for Maricopa County, home to the Phoenix metro area, remains in effect through Friday, while separate advisories cover Pinal County through Saturday and the Yuma area through Friday evening.
Officials are urging residents to consolidate travel where possible, slow down or avoid driving on dirt roads, stabilize loose soils around homes and businesses, reduce or eliminate fireplace use, and avoid operating gas-powered lawn equipment that could worsen air pollution.
The advisories include Montrose, Ouray, San Miguel, Dolores, San Juan and Hinsdale counties, where moderate to heavy smoke is expected to persist through at least Saturday morning.
A separate advisory has also been issued for Pueblo and Custer counties, where smoke from the Aspen Acres wildfire is forecast to continue affecting air quality.
Meanwhile, in Colorado (pictured), multiple counties are under Air Quality Health Advisories because of wildfire smoke drifting from active fires burning in Colorado and neighboring Utah
Colorado health officials warned that if smoke becomes thick in neighborhoods, residents should remain indoors whenever possible, particularly those with heart disease, respiratory illnesses, older adults and young children.
Authorities also advised people to limit outdoor activity when moderate or heavy smoke is present and to consider temporarily relocating if smoke infiltrates homes and begins causing illness.
One key indicator of dangerous conditions is visibility. Officials said that if visibility drops below five miles because of smoke, pollution levels have likely reached unhealthy concentrations.
The combination of airborne dust and wildfire smoke can significantly reduce air quality by increasing concentrations of tiny particles that irritate the lungs and airways.
Even healthy people may experience eye irritation, coughing, throat discomfort or shortness of breath during periods of poor air quality, while those with existing medical conditions face an elevated risk of more severe complications.
Residents across the affected areas are being urged to continue monitoring official forecasts as conditions can change rapidly depending on wind direction and wildfire activity.
Health officials say the simplest way to reduce exposure is to remain indoors with windows and doors closed as much as possible until the advisories expire.
