Wagga Wagga has had the worst pollution in NSW at this time in previous years because it's when many farmers burn the remaining stubble before planting a new crop.
Often it seems like the farmers send smoke signals to one another because, once one farmer burns, you'll see a heap of them burning and creating hazy sunsets over the weeks in the lead-up to the autumnal rains - although they aren't what they used to be.
I understand their reason to burn is to do with reducing the likelihood of disease but the outcome is an increased chance of respiratory diseases for all people living in the area.
After seeing the columns of smoke in the distance for many years I was lucky enough to see the process up close the other day. It was interesting to see heaps of birds hunting as the mice fled the fire. It was also interesting to see the farmers driving laps around the flames, like some sort of bizarre ritual to mark the sowing of the paddocks.
Hobocop - From b3ta user XLVII