Conditions of water pollution vary from year to year, but observe the general rule of thumb of avoiding a dip in the immediate vicinity of major industrialized port  Genoa, Naples, and Palermo.
You should avoid swimming near big industrial ports.
mnli hypothesis: You should avoid swimming near big industrial ports. premise: Conditions of water pollution vary from year to year, but observe the general rule of thumb of avoiding a dip in the immediate vicinity of major industrialized port  Genoa, Naples, and Palermo.