Molds are microscopic fungi that live on plant or animal matter. Mold grows from tiny spores that float around in the air. When some of these spores fall onto a piece of damp food, they grow into mold.

Food mold feeds itself by producing chemicals that make the food break down and start to rot. As the bread rots, the mold grows, often within 24 to 48 hours. No one knows how many species of fungi exist, but estimates range from tens of thousands to perhaps 300,000 or more. Most are thread like organisms that can produce poisonous mycotoxin spores that are known carcinogens. These spores can be transported by air, water, or insects.

The Food and Agriculture Organization (FAO) of the United Nations estimates that 25% of the world’s food crops are affected by mycotoxins, of which the most notorious are aflatoxin. These toxins are a family of mycotoxins produced by certain fungi that are found on agricultural crops such as corn, produce, dairy, meat, & nuts.

It is important to take precautions with food. If you think it contains mold, do not sniff the item. This can cause respiratory trouble. If food is covered with mold, discard it. Put it into a small paper bag or wrap it in plastic and dispose in a covered trash can that children and animals can not get into.

Clean the refrigerator or pantry at the spot where the food was stored. Check nearby items the moldy food might have touched. Mold spreads quickly and it can cause a myriad of health issues.

More Info: en.wikipedia.org