Veritas, If you are making an argument about water running over crushed water, dont you also have to consider ill effects of fertilizer and lawn treatments? I also don’t think its clear that if there is any truth to the rubber dust argument, that it would maintain the same potency over time, vs. repeated applications of fertilizers that will always be full potency.
As for petroleum products in general, what do you think the exposure is to grass, vs. a wii controller, cell phone case, car interior, toys, furniture, etc.