With due respect, I think your dad has overlooked the fact that many of those locals have built up immunities to things that you and I could never fathom.

There is a port (the name of which, escapes me) on the river near Wuxi that is licensed to handle really toxic chemicals and other bad things. In fact, you actually get a passport stamp when you go there (and another one when you leave),... perhaps because the government wants nothing to do with it.

My colleagues and I checked out a project in this special place several years ago and all became violently ill shortly after our lunch, but our hosts didn't miss a beat. That having been said, I should mention that they didn't hoard the "sea food" dishes in the same manner that is typical during such functions; if we had seen the river prior to meal, we would stuck with the rice and hit a McDonalds on the way back to SH.