Roger Pielke of CSU, friend of CPR and Bonanza Creek, writes in Weatherwise [28:156-160; 1975] of an ice fall from a clear sky in Fort Pierce, Florida on 13 December 1973 a little before 1900 EST.
At the time, Roger was arising graduate student working under Joanna Simpson's direction. The ice in question fell through the roof of the Cappar family and broke a coffee cup and a wristwatch. It was the Cappar's good fortune that there was no hand near the cup or in wristwatch! But Mr. and Mrs. Cappar were littered with ice and roofing debris.
Well, Pielke's ice sample was subjected to chemical analyses and it had in it NO2, NO3, NH4, O-PH4, 63 ppm Na, pH 7.17 silver, selenium, gallium, germanium and mercury. As this stuff is part of the human enterprise and no other organism I know of, humans must be engaged in advection of stuff to distant ecosystems.
A check of airport traffic revealed several possible solid-H20 bombers headed for Miami International around the time of the icefall. Before the days of $600 toilet seats, chunky stuff from planes was not all that uncommon. An earlier icefall in the Brits district (Transvaal in South Africa) also fell from clear sky. It had the internal structure of ice and contained traces of tea, coffee and detergent. It was concluded that it came from a passenger aircraft on its way to Jan Smits Airport. The heater on the galley sink malfunctioned and the ice built up on the "garborator" and well, just fell off as a chunk rather than in the more liquid or vaporous states that one finds from time to time. You can just hear the whoosh of the sink drain as it opened to the thin air outside the plane and you can imagine the sub-sonic, quasi-parabolic trajectory of the solids heading for surface ecosystems.