Good (frequent/cheap) flight connections are more important than location itself. Flying e.g. from Tallinn to Athens takes about 5 hours (about 3 hours of actual flight time).
If you use the entities' preferences to decide what's ethical, then everything is (or can be), because you can just adjust their preferences accordingly.
Short search for "black pepper carcinogenicity" doesn't turn up anything except a few studies on rats and mice, and one of them shows no adverse effect. Do you have anything better?
This is the reason I have mixed feelings about making predictions of events that I can influence. I'm curious whether there is any research about this 'jinxing' - does predicting low chances of success at a task make people less likely to succeed? Or (maybe) the opposite?
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30462-1/fulltext