[walrus01]

One can go down a pretty nasty toxic waste rabbit hole if you research all the attempts at chemical treatment for wood utility poles (for electrical grid and telecom, historically). Particularly a place like WA, OR, ID, BC having plenty of trees also has a mostly aerial electrical and telecom distribution last mile. And of course the companies that own and must maintain these poles have an interest in them lasting as long as possible...

My understanding right now is they've gone back to more traditional tar/creosote impregnated and coatings.

[Scoundreller]

Don't forget rail ties!

[hinkley]

I met someone whose ancestors lived in Missouri clearing the swamps. Those swamp trees made good railroad ties. And then creosote was introduced and the ties lasted ten times as long, so demand crashed over the next few years as the old ties were swapped out one last time.

As near as I can tell the economy never recovered. They grew cotton but that’s mostly overseas now too, and at any rate means arsenic accumulation.

Some people were trying to engineer a strain of rice that absorbs less arsenic. Apparently cotton and rice growing conditions overlap enough that this is a potential option.