So, when smoke previously damaged the lungs of fire fighters, it wasn't global warming. But I thought they had oxygen tanks to use to prevent whatever it used to be that damaged their lungs. From what I've seen, the LA area probably doesn't have enough oxygen tanks for all the people working the fires so maybe there is confusion and politicians say global warming when they should say unprepared. 
Well, they are air tanks, not oxygen. The last thing you would want is to be in a working fire with a tank of oxygen on your back.
Even the most fit firefighters can only get about 20 minutes out of one "30 minute" tank, because of the physical effort required fighting the fire (my personal best was 17 minutes). We used them in house and structural fires, and when confronting fires which produced combustion byproducts that made a truly unbreathable atmosphere (or leaking chemicals from a wrecked truck).
Imagine changing those out three times an hour...and trying to fight a wildfire, too.
It's no secret that some nasty stuff gets released in wildfire smoke, and that includes the combustion byproducts of literally anything that has been dumped out there in the weeds. It goes with the territory, and firefighters are aware of the risks when they take the job.