A rapidly growing fungus that produces a yellow-green colony within ten days, when incubated at 25oC (77oF). It is very common worldwide especially in the subtropical and tropical regions. It can be isolated from soil, mangrove swamp, sewage sludge, foodstuffs including ground black pepper, bird feathers, gastrointestinal tract of man and animals, wood pulp, insects, cotton fabric, leather, and frescoes of a monastery. It produces aflatoxins which are very toxic to man, animals, fish, insects, and birds. Production of aflatoxins is dependent upon the substrate present and the growth conditions (temperature, relative humidity, etc.). Aflatoxins are toxic to the liver. They are teratogenic, mutagenic, and a known animal and suspected human carcinogen. Exposure to the aflatoxins occurs primarily when contaminated food is ingested. Occasionally it produces pulmonary infections when inhaled, eye (corneal) infections, ear infections, nasal and sinus infections, and may cause allergic disease.