Not like there are not any heavy metals in soil or anything. ;-). I wont argue with you guys about this stuff as I am not educated in these matters well enough to be considered an authority.
Yeah, I suppose adding heavy metals would be an issue in an organic garden, but as far as I know plants do not suck up what they don't need in most cases. But on a lawn, adding organics with trace nutrients is a plus...
My lawn is not spectacular by anyone's definition, lets just say it is "diverse" and we can pick baskets of strawberries from it in June. However it does grow well, and I have no bare patches and it is good for bare feet. I attribute the diversity to the previous owners likely mowing the "dirt" when they built the house until it turned green. I just "seed and feed" rather than "weed and feed". If I weed-killed there wouldn't be a heck of a lot left.
The grass around the pond looks 100x better then the yard and it is only a few weeks old.
I don't have grub or pest problems, and I happen to like dandelions as they are a sure sign of warm soils and time to garden. I just don't like them in the garden. Best part it is cheap to deal with.
