Originally posted by eddie1960 in desert climates the sand becomes a big issue, but no need to really worry about fungus anymore
At elevation, fungus is not an issue. Whether I'm at 3500ft / 1050m in the central Sierra Nevada mountains, or at 5500ft / 1650m in Bisbee on the Arizona-Sonora border, or at 8500ft / 2550m in Zacatecas Mexico, or at 10500ft / 3150m in Breckenridge Colorado or Alaska Guatemala (*), fungus is not a problem.
In the deserts of my experience between British Columbia and Guatemala, dust and sand have not been issues -- as long as I avoid blowing sand. But sand and salt and moisture (and fungus) do become issues on windy seacoasts. I *do* want a WR lens for my next expedition up the Pacific coast from Cabo San Lucas (BC) to Cape Scott (the other BC).
Moisture and fungus are also annoying in tropical lowlands, although I had no such problems in Belize. But I mostly avoid tropical lowlands. Highlands are much nicer. Except during blizzards.
(*) 'Alaska' Guatemala is on the volcanic rim of the collapsed Atitlan caldera, the highest point on the Pan-American Highway between Alaska USA and Tierra del Fuego.