What were the long term problems Egyptians had to deal with after the Plagues of Egypt?

[Mr Khan]

A volcanic explosion is what is supposed to have served as the historical basis for the Exodus story, the same volcano that wiped out the Minoan civilization. Seismic activity releasing gas into the Nile would have started the process, otherwise playing out as you described it in the OP. Interestingly, even the "firstborn" thing would have worked because of where different Egyptian household members would sleep (firstborn lowest to the ground, and if you have toxic natural gas flowing around in places...)