For Pace and all the others who persist with this nonsense that they can 'see' this contaminant when they fly.
The only way you can 'see' it in the air is at night with a torch shone up into the sky. Try it. Over the last few days, just south of LGW, the sky was stuffed with flurries of small particles. There were slightly less last night. You are breathing them in by the million all day. They will lodge in your lungs and cannot be removed. Your engines will ingest them. Whether they are dangerous I know not, but do not be fooled by clear blue skies. Look at your car?