Path of the run took me into some serious pollution haze, which was odd for this time of year. Thought it would be local, but, in the event, it extended over a good bit of the run, and then I had to return through it. Checking the pollution monitors on return to the rooms, the levels were third-world levels, the sort of numbers that kept me in the rooms with a HEPA whirring away when I visited here in winter. Will increase the hydration in the coming days, etc.
That which does not kill us will quite likely try again tomorrow.