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Officials are urging more than 200,000 residents across parts of Arizona and California to take precautions as dangerously high levels of air pollution sweep through the region.
On Friday, the Environmental Protection Agency (EPA) issued a warning about a significant spike in fine particulate matter, known as PM2.5, extending over an 80-mile area along the Arizona-California border. The city of Yuma, Arizona, faces the most severe conditions, with an air quality alert in effect until 9 p.m.
Health authorities are advising people to stay indoors, keep windows and doors shut, wear face masks if they must go outside, and use air purifiers when available.
What is PM2.5?
PM2.5 refers to tiny airborne particles less than 2.5 micrometers in diameter. These fine particles primarily originate from burning fossil fuels, vehicle emissions, industrial activities, and natural sources like dust storms. Due to their small size, PM2.5 particles can penetrate deep into the lungs and bloodstream, posing serious health risks over time.
Exposure to PM2.5 has been linked to heart disease, lung cancer, chronic respiratory conditions, strokes, diabetes, cognitive decline, and complications during pregnancy.
Affected Areas
The polluted zone stretches roughly 90 miles from the U.S.-Mexico border northward to Blythe, California. Yuma, with nearly 100,000 residents, is identified as the most impacted city. Including the broader metropolitan area, about 210,000 people live within the affected region.
In addition to PM2.5, the region is experiencing elevated levels of PM10-larger particles under 10 micrometers-which can also harm respiratory health. Dust storms along the border have contributed significantly to the poor air quality.
By mid-afternoon Friday, Yuma’s Air Quality Index (AQI) skyrocketed to 400, categorized as “hazardous,” the EPA’s highest risk level.
Understanding Air Quality Measurements
The AQI ranges from 0 to 500, with lower numbers indicating better air quality:
- 0-50: Good (minimal health risk)
- 51-100: Moderate (possible effects for sensitive groups)
- 101-150: Unhealthy for sensitive groups
- 151-200: Unhealthy for everyone, outdoor activity discouraged
With the AQI in Yuma reaching extreme levels, residents are strongly encouraged to limit outdoor exposure and take necessary health precautions until conditions improve.