The role of fiber durability/biopersistence of silica-based synthetic vitreous fibers and their influence on toxicology.
This work summarizes what is known about the role of fiber durability/biopersistence of silica-based synthetic vitreous fibers (SVFs) and their influence on toxicology. The article describes the key processes leading from exposure to biological effect, including exposure, pulmonary deposition, clearance by various mechanisms, accumulation in the lung, and finally possible biological effects. The dose-dimension-durability paradigm is used to explain the key determinants of SVF toxicology. In particular, the key role played by the durability/biopersistence of long (>20microm) fibers is highlighted. Relevant literature on the prediction of in-vitro dissolution rates from chemical composition is summarized. Data from in-vitro and in-vivo durability/biopersistence tests show that these measures are highly correlated for long fibers. Both durability and biopersistence are correlated with the outcome of chronic inhalation bioassays. A schematic approach is presented for the design and testing of new SVFs with lower biopersistence.
Maxim
L Daniel
LD
Everest Consulting Associates, Cranbury, NJ, USA. postsf@aol.com
Hadley
John G
JG
Potter
Russell M
RM
Niebo
Ron
R
D000818:Animals; D019570:Inhalation Exposure / Q000009:adverse effects*; D008168:Lung / Q000473:pathology*; D008657:Metabolic Clearance Rate; D019016:Mineral Fibers / Q000633:toxicity*; D017640:Silicates / Q000737:chemistry / Q000633:toxicity*; D013997:Time Factors; D018675:Toxicity Tests / Q000379:methods*
D019016:Mineral Fibers; D017640:Silicates