Answer: Mold

Fungi are industrious little organisms and it’s little surprise that you can find them nearly everywhere on Earth. Sometimes they’re quite useful. We purposely cultivate some of them to eat, we use some of them to grow the cultures that make cheese and other foods delicious, and the discovery of Penicillin, a fungal/mold derivative, is considered one of the most important scientific discoveries of the modern age.

But not all fungi are useful little friends, some of them produce mycotoxins that can do everything from giving us gastric distress to outright killing us. While most people think of black molds and other indoor molds when they think of mold-related health issues, indoor molds are responsible for a low number of illnesses. The primary vehicle by which mycotoxins harm humans is via crop-based transmission. Crops not treated with fungicides or harvested too early can harbor very harmful molds; in 2004, for example, 125 people died in Kenya after consuming improperly grown/stored corn.