The Arizona Department of Environmental Quality issued a warning for high particulate matter in Nogales on Tuesday and Wednesday.
ADEQ is forecasting high levels of fine (PM2.5) and coarse (PM10) particulate matter to rise at 5 p.m. and peak at 11 p.m. Tuesday. The particulate levels will remain high until about 10 a.m. Wednesday.
ADEQ attributed the forecasted increase to holiday celebrations and recommended people limit using fireworks, use gas or electric for cooking and if burning wood use dry wood only. Burning wet wood will release more particulate matter than dry wood.
Fine particulate matter is made up of small particles found in wood smoke, power plants and vehicle emissions. The coarse particulate matter often comes in the form of dust from dirt roads, open desert, farms and crushing operations.
"Weather plays a role," said Erin Jordan, public information officer for ADEQ. "Light winds mean smoke from fireworks and fireplaces often used during holiday gatherings can accumulate over the area."
ADEQ recommends those sensitive to pollution, children and older adults with respiratory problems limit outdoor activity while the particulate matter remains high.
Particulate matter is a microscopic solid and liquid droplet suspended in the air and can be made up of different substances.
The warning covers just south of Rio Rico to Nogales.