What I find frustrating and remarkable is that there appears to be no objective measure of the low level ash particulates that are a threat to VFR aircraft. If you have asthma for example, the pollen count provides a measure of threat that sufferers can consider and potentially avoid.
It is ridiculous that it is considered that there is no risk to anything at ground level in the UK yet as soon as you get a few 100 ft up the world is apparently quite different.
I'm not flying not because of any real safety concerns but because I don't want to risk accelerating insidious erosion etc damage to my turbine engines. What is really required though is an objective numerical value that can be measured across affected areas and engine/airframe manufacturers then recommend what they think is an acceptable level of contaminants for flying to take place.
Surely it can't be hard to measure, given the huge impact on peoples lives? It seems just all to subjective at the moment.