Not all clay litter contains silica, or is high dust..I just looked up the litter I use which is 99.9 dust free..can't really get much better than that. Scent free and contains no silica...yes it tracks but that's not a concern. so other than the environment thing I feel comfortable using my clay clumping litter.. id love to switch to a different type for environmental reasons but it's not financially feasible with as many cats as I have and I don't like pine pellets which would be the only other option