Such as the construction of roads and aqueducts, and of sewers that could wash the filth of the city into the Tiber.
Being a capitalist country is known to be one of the major cultural patterns the United States adopts that would then result in a high level of solid waste. Industrialisation inevitably could cause to more wastes. What's worst, sometimes these wastes are not properly disposed or even treated.
Northern Europe because it was probably cold and had animals that are egstinct now but we're alive then. I think colder areas have more dangerous creatures.
This is an interesting question. It's possible that Japan would have become an imperialistic power because before the starting of the World War Two, Japan already had started showing the same behavior towards other weaker countries as did other nations who were imperialistic.