I managed to get particles working! This was too add some life to the level, I also managed to figure out how to make haze using a refraction shader and a normal map. This meant the fire and smoke will also show some heat haze that adds more realism.
I was quite dissapointed because I had to cut back on the vegetation and didn't manage to get the foliage on the buildings but I did make some grass and tree's, using the vegetation tab I dotted them around the level and gave them a bending figure so they would sway, the results were quite promising. The grass blades were modeled using polys and not using alpha's.