 In recent years, mold has been blamed for all sorts of vague subjective symptoms, but we have little scientific evidence that mold has anything to do with them. However, this concept of toxic mold syndrome has permeated the public consciousness, perpetuated by disreputable predatory practices by those making money testing homes for mold spores or testing people's urine or blood. But all these tests are said to just further propagate misinformation and inflict unnecessary and often exorbitant costs on patients desperate for a diagnosis. The continued belief in this myth is perpetuated by those charlatans who believe that measles vaccines cause autism, that homeopathy works, and that fluoride in the water should be removed. Mold toxin contamination of food, however, has emerged as a legitimate issue of serious concern, perhaps even more important than other contaminants might make their way into the food supply. Hundreds of different types have been identified, but only one has been classified as a known human carcinogen, and that's aflatoxin. The ochrotoxin I've talked about before is a possible human carcinogen, but we know aflatoxin causes cancer in human beings. In fact, aflatoxins are amongst the most powerful carcinogens we know about. For example, it's been estimated that about a fifth of all liver cancer cases may be attributable to aflatoxins, and since liver cancer is the third leading cause of cancer deaths worldwide and kills so rapidly after diagnosis, the contribution of aflatoxins to this deadly cancer is quite significant. And once it makes it into food, there's almost nothing you can do to remove it. Cooking, for example, doesn't help, so once it makes it into crops, or the meat, dairy, and eggs from animals consuming those crops, it's too late. So we have to prevent contamination in the first place, and that's what we've been doing for decades in this country. Because of government regulations, companies are almost always sampling for aflatoxin, resulting in nearly a billion dollars in losses every year, which may get worse if climate change worsens aflatoxin contamination in the Midwest Corn Belt. So on a consumer level, it's really more of a public health problem in the less industrialized world, such as African countries where conditions are ripe and farmers can't afford to throw away a billion dollars worth of crops. Indeed, aflatoxin remains a public health threat in Africa, world China, Southeast Asia, affecting more than half of humanity, which explains why the prevalence of liver cancer in those areas may be 30 times higher, but it is not a major problem in the US or Europe. For example, only about 1% of Americans have detectable levels of aflatoxins in their bloodstream. Why even 1% though? Well, the FDA works to ensure that the levels of exposure to these toxins are not kept as low as possible, but instead as low as practical. For example, in California, there's been an increase in unacceptable aflatoxin levels in pistachios, almonds, and figs. Unacceptable in Europe, that is, so it affects our ability to export, but not necessarily unacceptable for US consumers as we allow twice as much aflatoxin contamination. Figs are unique since they're allowed to dry on the tree. This makes them particularly susceptible to aflatoxin production. It would be interesting to know about the fig consuming habits of the 1% of Americans who turned up positive for the toxin. If figs were to blame, I'd encourage people to diversify their dried fruit consumption, but nuts are so good for us that we'd really want to keep them in our diets. The cardiovascular health benefits outweigh the carcinogenic effects, preventing thousands of strokes and heart attacks for every one case of liver cancer. Thus, the population health benefits provided by increased nut consumption clearly outweigh the risks associated with the increased aflatoxin exposure. So we're left with aflatoxin being mostly a problem in the developing world, and because of that it remains a largely and rather shamefully ignored global health issue where attention has been paid. It's been largely driven by the need to meet stringent import regulations in the richer nations of the world, rather than protect the billions of people exposed on a daily basis.