Silica toxicity for macrophages in vitro: a new cytotoxicity test.

Soluble factors released from silica-damaged macrophages inhibit proliferation of various haematopoietic cells in long term cultures. The same holds true for damage induced by heat, non-physiological pH, freezing and thawing. This phenomenon is dose-dependent and correlates with the degree of macrophage viability. Thus, a base for measuring the amount of damage to the macrophage is established.