Smoke exposure

Our local VFW was burning flags in a barrel and black smoke was billowing high up into the air. We were about a quarter of a mile away for 1-2 hours playing on a playground, but now I’m concerned because we could actually smell it a bit as we were waking back to our car and I wonder if we breathed those toxins in the whole time. I’m mostly concerned for my toddler. Does anyone know if this is a major health concern?

Has anyone else’s kids ever been exposed to smoke of any sort?