If the air is like it was here after Bárðarbunga, the amount it affects you is relative to how physically active you are. Also, the weather conditions have a huge effect on it. The biggest one, obviously, being which direction the wind is blowing and how hard. With the pollution maps we had, the plume was like a narrow cone emitted from the fissure, aimed at whatever direction the winds were on that day.
Are you getting a "blue haze"? That was the key characteristic here. When you're looking at distant mountains it often made them look like they were floating in the air. The period of time in Iceland's history after Laki went off were known as "Móðuharðindin", or "The Mist Hardships"; 20% of the population and 75% of the livestock died, and Denmark considered evacuating the whole island.