Okay, this is from a few years ago, but aflatoxins are still obviously a fairly major concern with peanuts today:http://www.fda.gov/ICECI/ComplianceManuals/CompliancePolicyGuidanceManual/ucm074598.htm
I tend to mainly pull info from the more reputable/science based sites (although there's plenty of info about peanuts and their relationship to candida, cancer, food allergies etc if you wanted to do some research into it). Mercola's info is pretty credible IMO ~ this is straight from their site:PeanutsPeanuts contain beneficial protein, but many people are allergic to them and find them hard to digest.
They also contain aflatoxin, a carcinogenic, which may explain why peanut farmers have been found
to have disproportionately high rates of cancer.
Peanuts are high in fungus and, often, pesticides.
They do not contain any omega-3, which can contribute to distorting your omega-6:omega-3 ratio.
The peanut is actually a legume, not a nut (which is why they are often roasted).
Peanuts contain about the same amount of protein as soy and are low in starchy carbohydrates.Peanut ButterWhen buying peanut butter, only buy organic varieties.
Non-organic peanut butters are high in pesticides and fungus and contain aflatoxin, a potent carcinogenic mold.
To increase the protein in peanut butter (peanuts have about the same amount of protein as soy), Brewer’s yeast can be mixed in. This is especially useful for vegetariansSourced from: http://www.mercola.com/nutritionplan/foodalert.htm