Kyle Shanahan: Air Quality from Bay Area Wildfires Could Impact 49ers' Opener

The NFL's season-opening slate on Sunday may already be in danger as wildfires continue to burn across the west coast. 

Officials from the league and San Francisco 49ers are monitoring the air quality around the Bay Area as the Niners prepare to host the Arizona Cardinals this weekend. On Friday, the air quality index rated at 194. The threshold for canceling practices or postponing games is 200. 

"If it gets to 200 that would be a huge deal," San Francisco coach Kyle Shanahan told reporters. "I know when it's above 150 that does affect a certain group of people that happen to be higher risk, pre-existing conditions, if it got above 150 you could lose a few players, but 200 is the mark where you can't go out there."

Per NBC Sports Bay Area's Matt Maiocco, the decision to postpone or move a game generally takes place the day before a scheduled game and relies on air quality ratings near the stadium. 

The Bay Area was covered in smoke and maintained an eerie orange glow over the past few days with intense fires raging across northern California. As of Friday, the Niners had no changes to their practice schedule heading into Sunday, but it wasn't exactly the most normal of training sessions. 

"We just got back in from walk-through and it's orange out here, too," Shanahan told ESPN's Nick Wagoner Thursday. "I feel like I'm in The Book of Eli—it's like an apocalyptic state out there."

Despite the unusual hue outside, the air quality on Thursday rated at 83 during practice. Friday's reading was much worse. 

Wagoner notes the NFL is seeking "definitive evidence" of an air quality rating above 200 for "a significant period of time" before making a determination on Sunday's kickoff. 

The Athletic's Matt Barrows reports a the Cardinals and Niners could swap home games and play Week 1 in Arizona as a contingency.

The Los Angeles Rams and NFL are also communicating about the air quality in southern California ahead of their Week 1 matchup against the Dallas Cowboys, but the game is expected to be played as scheduled.