黃麴黴菌毒素(Aflatoxin)最常見於因濕熱而發霉的花生,花生粉,花生醬,玉米和堅果類之中。 這是一種比砒霜還毒的物質，只要吃下去廿分之一克(50 mg)就可以致命。 此外,長期食用被黃麴黴菌嚴重汙染的食物，會有罹患肝癌的可能。所以我每一次看到媒體報導市面上賣的食品有黃麴毒素超標的情況時，心裡都有一點害怕。不過經過上網做了研究分析以後， 我得到的結論是：「我們吃東西要小心，不過不要盲目地擔心」。

因為黃麴黴菌的毒性強烈,各國衛生單位都小心把關。以美國為例,就從來沒有疫情發生過。多年來，臺灣各衛生局查到被黃麴菌汚染的食品，其毒素超標通常只有兩倍到10倍 。 所以買到黃麴超標100倍(1,500ppb)以上的食品機會很小,我們不必擔心。

根據我的推算，就算超標100倍，我們也要每天吃一整包300公克帶殼花生，持續地吃半年以上，致癌可能性才會比較高。 或者是一次吃60台斤以上，才可能會中毒死亡。

參考資料:

Increased incidence of aflatoxin B1-induced liver tumors in hepatitis virus C transgenic mice

6,000 Tumors (adenomas or carcinomas) and preneoplastic lesions (hyperplasia or foci) were observed in 22.5% ( ~one in four) of AFB1-treated wild-type mice. The treatment was a single dose of AFB1 6 μg/g body weight (6,000 μg/kg bw). My note: if we linearly extrapolate the 1-in-4 ratio, this is equal to 24,000 μg/kg bw. However, we will use a more conservative figure, e.g. 6,000 μg/kg bw. For an adult 50 kg in body weight, it becomes 300,000 μg.

根據用白老鼠做實驗的結果保守推算, 一個50公斤重的成人，因黃麴黴菌致癌的劑量約為 300,000微克(ppb), 一微克等於十億分之一克。

AFLATOXINS : Occurrence and Health Risks

There are four major aflatoxins: B1, B2, G1, G2 plus two additional metabolic products, M1 and M2, that are of significance as direct contaminants of foods and feeds.

The induction of cancer by aflatoxins has been extensively studied. Aflatoxin B1, aflatoxin M1, and aflatoxin G1 have been shown to cause various types of cancer in different animal species. However, only aflatoxin B1 (AFB1) is considered by the International Agency for Research on Cancer (IARC) as having produced sufficient evidence of carcinogenicity in experimental animals to be identified as a carcinogen.

黃麴黴菌毒素一共分為6種(B1,B2,G1,G2,M1,M2)，其中M1,M2是新陳代謝的產物，這六種之中只有B1被國際癌症研究所認定可以致癌。

Aflatoxin rules and regulations

US food safety regulations include a limit of 20 μg/kg for total aflatoxins (B1, B2, G1 and G2) in all foods , except milk, and a limit of 0.5 μg/kg for M1 in milk. Higher limits apply in animal feeds.  My note: approx.  10 μg/kg of B1 in food.

LD50 lethal dosage is 0.5 to 10 mg/kg bw. However, we will use a more conservative figure, e.g. 1 mg/kg bw. For an adult 50 kg in body weight, it becomes 50,000 μg.

對於黃麴黴菌毒素，美國食品安全的規定，是每公斤的食物 所含有的毒素必須小於20微克 台灣則是15微克。

黃麴黴菌毒素的致死劑量是50,000微克。

Conclusion:

If you take in 300 grams/day of contaminated food 100 times above unsafe AFB1 level, you still need to eat it for 6 months in order to get cancer.

As an adult 50 kg in body weight, if the food you eat is 1,000 times above the unsafe AFB1 level, you will probably need to eat 60kg of it to die.

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161148/

http://poisonousplants.ansci.cornell.edu/toxicagents/aflatoxin/aflatoxin.html

http://www.foodsafetywatch.org/factsheets/aflatoxins/

http://www.chinatimes.com/newspapers/20140411000777-260113

http://www.chinatimes.com/newspapers/20151112000410-260114