May 14 (UPI) -- Mexico City's environmental officials issued an emergency alert Tuesday as nearly two dozen fires worsened poor air quality in the region.
The Environmental Commission of the Megalopolis urged residents to avoid outdoor activities, and infants, the elderly and those with respiratory illnesses to stay indoors entirely.
The city's IMECA air quality index increased from 144 to 158. The index includes five levels on a scale from zero to more than 200. Zero to 50 is "good," 51 to 100 is "regular," 101 to 150 is "bad," 151 to 200 is "very bad" and more than 200 is "extremely bad."
Firefighters are attempting to contain the wildfires, but to help reduce pollution in the city, officials asked residents to reduce emissions from vehicle use and notify authorities of any activities that could ignite more fires.
Smoke from fires in Oaxaca and Guerrero is covering parts of Mexico from the east to the west coasts. Smoke in the southern Gulf of Mexico could prove troublesome for the United States, the National Weather Service warned.
"Heads up Central U.S.: When the front draped across the northern Gulf of Mexico (the one keeping everyone cool) lifts north this week in response to a western U.S. trough, don't be surprised if it turns smokey," NWS meteorologist Patrick Marsh tweeted Sunday. "That's a lot of smoke in the Bay of Campeche poised to advect north."