I have commented on spray basting before and will every time the subject comes up. We all have a given amount of lung tissue, when that becomes scared, it no longer works to get oxygen into your blood. You can operate on decreasing amounts of lung tissue and not even know you are losing it. There are so many environmental hazards over which we do not have control, that not to eliminate as many as we can may not be a wise choice.
I have an autoimmune lung disease which robbed me of 60% of my lungs. I can still lead a fairly "normal " life with the 40% I have left, but I need to use supplemental oxygen most of the time.
I do not know the advantages or disadvantages of spray basting but I will not take the risk of finding out.
Ask yourself, how many times have we been told a product is safe only to find out after it is too late that the experts were wrong?
Happy quilting and may all you "lungers" have a good breathing day. :)