Many kinds of adequate sanitation would not have resulted in filtering the water as appropriate to exclude the parasites.
Even the wealthiest still drank water that ultimately came from the watering hole, thousands of years ago. Without much scientific understanding there is little reason to believe effective intervention would have been hoarded by the rich.
Even the wealthiest still drank water that ultimately came from the watering hole, thousands of years ago. Without much scientific understanding there is little reason to believe effective intervention would have been hoarded by the rich.