Because farming takes place outdoors and in dirt, such contamination is a fact of life. Over the centuries, the main culprit in mass food poisoning often has been contamination of unprocessed crops by fungal toxins – a risk that is exacerbated when insects attack food crops, opening wounds that allow fungi (molds) to get a foothold.
每一年都有无数的包装食品因为含有昆虫尸体、有毒霉菌，细菌和病毒等“全天然”成份而被暂停上市或者召回。这是因为种植业大多在尘土飞扬的露天环境中进行，自然也无法避免这类污染。几个世纪以来，大规模食物中毒事件的最大元凶往往是真菌毒素对未处理谷物的污染——当昆虫侵袭农作物并造成伤口，令真菌（霉菌）得以附着之时，这一风险也随之急剧扩大。