Houston air quality was classified as unhealthy early Wednesday, according to Air Now, but has since been upgraded to moderate.
Residents with heart or lung conditions, the elderly and children have been advised to reduce exposure by avoiding strenuous outdoor activities and staying indoors. Particulate matter levels of 2.5 reported by Air Now were particularly high on Wednesday morning. This is a measure of particulate matter in the air.
“The problem with particulate matter is that it’s so small, it goes through a lot of the mechanisms your body needs to keep pollution out,” said Loren Hopkins, chief environmental science officer for the Houston Department of Health.
Larger particles are blocked by the body through mechanisms like nasal hair and mucus, she said. The fine dust particles can cross the body’s barriers and cause concern.
“The particulate matter can go all the way up to your lungs and then into your bloodstream,” Hopkins said.
Particulate matter can increase the risk of an asthma attack, heart attack and stroke.
Air quality is expected to improve throughout the day, according to Space City Weather. Air Now forecast good air quality for Thursday.
The air quality warning warns residents of the presence of particulate matter, but not of the composition of the particles. So depending on the particles themselves, the effects can go beyond those listed if the particles are made of something harmful, Hopkins said.
Wednesday morning’s unhealthy air quality was caused by controlled burns Tuesday in southwest Louisiana that produced smoke that was carried by the wind into Houston, Space City Weather reported. The smoke has stayed near the ground but will eventually clear.