To make matters worse, aflatoxins react strongly to the hepatitis B virus (HBV), the most common cause of liver cancer in the world. In countries where HBV is endemic, such as in China and some African nations, ingesting the mold intensifies and speeds liver failure by acting as an immunosuppressant. Consequently, there are over 750,000 new reported cases of primary liver cancer reported yearly worldwide, making it the sixth most common cancer for humankind, according to 2008 statistics from the World Cancer Research Fund International.
The cost in human life is likely due, in part, to international trade issues. Because aspergillus standards in developed countries are so high, African nations export much of their pure commodities overseas, leaving the tainted crops at home for consumption by locals. Natural disasters that increase foreign demand for African products—like floods and droughts in industrialized countries—only compound the issue.
Researchers at the University of Pittsburgh (Pitt) estimate more than five billion people worldwide are at risk for chronic exposure through contaminated foods, according to a March 2012 study published in PLoS One.
“Strict aflatoxin standards mean that many nations will export their best-quality foods and keep contaminated foods domestically, resulting in higher aflatoxin exposure in low- or middle-income nations where hepatitis prevalence is high,” wrote co-authors Felicia Wu and Hasan Guclu, both Pitt faculty members.
Whereas the U.S. is most often spared the cost in human health, the repercussions aren’t nil. Dairy cows and cattle, already stressed from living in close proximity to large numbers of animals, are at particularly high risk for succumbing to aflatoxicosis, though they can handle higher doses of toxin. Pets, too, are susceptible to the poison. In 2007 aflatoxins forced a nationwide pet food recall—but not before dozens of man’s best friends fell ill and died.
Researchers have not yet found an animal species immune to the aspergillus’s effects. The spores are so poisonous that even destroying the contaminated crops is an ordeal. Scientists worldwide keep careful tabs on aflatoxins in a large-scale effort to avoid outbreaks of aflatoxicosis, according to Stinson.
“Our understanding is that in some cases you can't even incinerate (contaminated food) safely because the aflatoxin can get airborne and be inhaled,” she says. “If there is a high level of aflatoxin…they're going to be in the position of having to store and destroy crops.”