While lead poisoning was a problem in ancient Rome, it is not believed to have been a major factor in the fall of the Roman Empire. The decline and eventual collapse of the empire were caused by a combination of internal and external factors, including political instability, economic decline, military overextension, and invasions by barbarian tribes. While lead poisoning may have contributed to the overall health problems that affected Roman citizens, it was not the primary factor responsible for the empire's downfall.