That much silica wont hurt you anyways. Silicosis is the condition caused by inhaling excessive amounts of silica, not Mesothelioma and thats (Silicosis) mostly just a concern for sandblasters that go through thousands of tons in a lifetime. You will inhale more silica during a day at the beach than you would with a joint of silica dusted weed.
Mesothelioma is a condition caused from Asbestos exposure ONLY. Fiberglass could be an issue because of the polymers it is sometimes extruded with. Either way smoke through a filter or bong, if you are worried about it.