I had already stopped buying talcum powder because of suspected links between talc and cancer. Now I read recently in The Ecologist that large scale mining for soapstone (the principal ingredient in talc) is causing large scale damage to nature reserves in Rajasthan, India. As a result of this damage, the already highly endangered Indian tiger is being pushed even closer to extinction. The quarrying not only destroys tiger habitats but also devastates the forest and watersheds vital for the well being of local people. Read more in this report from the Environmental Investigation Agency.
If you're looking for an alternative to talcum powder, Neals Yard Remedies sells a body powder made from corn starch, which is what I have bought recently. Or you could just do without, which is what I'm going to start doing in the future!