Market Farming

[Mike Steinberg <mstein AT mail.wclynx.com>]

I would like to hear fellow farmers opinioins about the use of 
vermiculite in a seeding mix. I have been using it, along with bat 
guano, cocoa pithe, and oyster  shells as my seeding mix. I am having 
concerns about the effects of vermiculite dust -does it remain in the 
soil after planting, and then could it become unhealthy to breathe 
because of its dust?