In the slums of Sector 5, Aerith gives Cloud a tour of her hometown. They eventually meet a sickly man in a one-room home. This man is incoherent, able only to groan. Even worst, the room connects to a drainage pipe.
Aerith utters her famous lines:
Aeris: “This guy are sick. He passed out nearby and someone must have helped him here.”
Obviously, this is a translation error. The phrase is unintentionally hilariously for its awkwardness, contrasted against a serious scene.
However, due to Aerith’s upbringing, it makes sense for her to make such a grammatical mistake when speaking. She lives in the slums, and probably doesn’t have an education. Elmyra never mentions she’s taught her; Aerith was so intuitive and wise, she perhaps felt no need.
Yet, while Aerith grows up relatively privileged, the rest of Sector 5 suffers extreme poverty and harsher living conditions. As evident from the sick man, we find out he’s a clone of Sephiroth. The man has corrupted cells, which warps his brain. However, it doesn’t explain why he’s constantly sick.
Consider he’s in a pipe. A sign in front of the man’s pipe reads “Safety First”. This sign would only exist if it had been a drainage. However, it’s more likely to be a Mako pipe. The man inside must have been exposed to high levels of Mako, and became contaminated as a result.
The Mako contamination didn’t only affect the Pipe Man. The very unlucky woman in the bar’s bathroom needs:
He’s acquired food poisoning, it seems, and must have a severe case of diarrhea. Yet the bar resides in Wall market, Sector 5, with the giant pipe in the open. It’s no stretch to say that the fumes reach the restaurants in Wall Market. Some people, like the woman in the bathroom, don’t build a resistance to the area.
Perhaps this gives a little bit of an insight as to why Shinra’s exploitation of Mako is horrible. The damaging effects are pervasive.