Warnings of poor air quality in Mecklenburg and Cabarrus until Wednesday night

The NC Department of Environmental Quality issued an air quality warning for Mecklenburg and Cabarrus counties until 8 p.m. Wednesday.

According to the ministry, air quality in both counties has been given an orange rating, meaning that air quality may be harmful to sensitive groups such as people with lung problems or asthma, as well as the elderly and children.

“If the air quality is poor for someone who has asthma, for example, it may be difficult for them to be outdoors,” says Steve Wilkinson, a meteorologist with the National Weather Service. “So they should limit prolonged physical activity outdoors.”

Wake and Franklin counties were also under Code Orange, and a poor air quality warning was issued Wednesday.

Both Mecklenburg and Cabarrus Counties are expected to score 108 on the Air Quality Index, which measures air quality in value groups. Between 0 and 50 is good, 51 and 100 is moderate, 101 and 150 is unhealthy for sensitive groups, 151 and 200 is unhealthy, 201 and 300 is very unhealthy, and anything above 301 is hazardous.

The rest of the state was under Code Yellow, or moderate air quality. Air quality in all four districts is expected to be downgraded to Code Yellow on Thursday, according to the AQI.

How air becomes bad

According to Wilkinson, poor air quality may be caused by particles or a microscopic mixture of particles from pollution that accumulate in ground-level ozone but are then not dispersed.

“It was reasonably comfortable for a while, but now it’s getting hotter. So basically you have a hot atmosphere that’s not moving much,” he said. “When there’s a strong wind that moves things around, it gets dispersed and spreads out. And when there’s very little wind, it just gathers up. That’s the main problem.”