Fibrous glass, otherwise known as fiberglass or man-made vitreous fibers, have been in use for decades now- it is important to keep in mind that this is a diverse group of materials and the health effects vary within the group. There are now are multiple studies of workers examining the potential health effects with long-term exposure. Initial concerns centered on adverse effects on the respiratory system. Fortunately, the findings have been, for the most part, reassuring. Although there are a limited numbers of cases of benign respiratory diseases such pulmonary fibrosis, lung cancer risk is not elevated in studies that do not have concurrent asbestos or silica exposure.
Fibrous glass has also been associated with other effects such as dermatologic, and as you noted, renal- including limited evidence of increased risk of renal cancer; however this has not been confirmed. There is no evidence in these studies of workers exposed to fibrous glass, of adverse hepatic effects.
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