THE FOLLOWING ARTICLE APPEARED IN THE

MAY 1999 ISSUE

THE POISON SLEUTHS

DEATH BY AFLATOXINS

-Dr. Anil Aggrawal

"Good morning doctor. Oh, my God, what are you doing today? You have the dead body of a young man today. What has happened to him? Please tell me."

"Good morning Tarun. The name of this young man is Suman Dubey. He is 25 years old and unmarried. He died this morning in his rented house. He was living alone in this house. He was basically a farmer, but had recently shifted from his village to live in a suburb of Delhi. He was doing some odd jobs for carrying out his livelihood. But he was also getting assistance from his family in his village. I mean, he used to get most of his food supplies from his village."

"That's alright doctor. But how exactly did he die?"

"Tarun, I am coming to that. For quite some time he was complaining of some vague symptoms. For instance, he was having pain in the abdomen and loss of appetite. He also noted some loss in weight, and a vague swelling of the abdomen. Since he was from a rural background, he did not believe in modern medicine. He was a staunch believer in traditional medicine only. He kept on ignoring his symptoms for quite some time. Last week he visited his village, where he consulted a local doctor. The doctor, after examination told him, that he was getting slow poisoning from some source. He believed that some of his foe was administering poison to him."

"Oh, really? And who was he?"

"We don't know yet. But the moment Dubey was told about it, he believed it. In fact, he told his family that his milkman wanted to poison him, and was probably poisoning him by giving him a daily supply of poisoned milk. He was daily taking one liter of milk from a milkman called Ramnath."

"But why would Ramnath want to kill him?"

"That is exactly the question, Dubey's parents asked him. We know this, because we have now interrogated Dubey's parents. Suman Dubey was unmarried as I have already told you. One day, Ramnath came to Dubey's house to deliver the milk along with his young and nubile sister Sita. Immediately Dubey fell in love with her. Once or twice, when she came alone to deliver the milk to Dubey, he even made attempts to make passes at her. Sita immediately complained about this matter to her brother, who came to his house to resolve the matter. There was a big fight between the two. The whole neighborhood knew about it. After this Ramnath stopped delivering milk to Dubey. This was quite expected. But then quite unexpectedly Ramnath again started delivering milk to Dubey. Dubey was initially quite surprised, but he agreed because in this way, at least he could be in touch with Sita."

"Oh, I see"

"But when the village doctor told Dubey that someone was trying to poison him, he immediately realized why Ramnath had started delivering the milk to him again. Probably Ramnath wanted to get even with him by killing him. He thought that the best way would be to kill Dubey was by giving him small quantities of poison through the daily supply of milk. So he resumed the milk supply to him."

"Oh, it indeed appears to me that Ramnath killed him through slow poisoning. Is slow poisoning possible doctor?"

"Oh yes. Arsenic is notorious for this. One could give this poison in very small amounts over a long period of time, and the victim would die of slow poisoning. There are several other poisons which could be used for slow poisoning. Dubey's parents have lodged a strong complaint against Ramnath, and the police has apprehended him. He however is asserting that he is innocent and that the police should release him immediately."

"What is your opinion in this case doctor?"

"Tarun, I am a scientist, and I believe in hard facts. I have done an autopsy on this man, and have come forward with some amazing findings..."

"Like what?"

"The thing that caught my attention immediately was that his liver was enlarged. I took some liver cells from there and looked them under the microscope. I was surprised to find that Suman Dubey was suffering from a form of liver cancer, known as hepatoma. This finding set me thinking and I did certain other tests. I measured his blood glucose, and I found that it was much less than what it should have been. In technical terms, he was suffering from hypoglycemia, which in plain and simple words means "low sugar in the blood". I also found a chemical known as alpha fetoprotein in his plasma..."

"Doctor, these symptoms don't appear like that of a poison to me. It rather appears to me that he died of liver cancer. Where is the criminality involved?"

"Tarun, he indeed died of liver cancer. But the problem with me is that a serious allegation has been made by Dubey's parents against Ramnath."

"That's right. And now you can tell the police that Ramnath is not guilty. And you can tell them that he died of liver cancer."

"Tarun, you may be surprised to know that hepatoma can be induced by a poison, especially if low quantities of it are administered to someone over a long period of time"

"Really? That is most preposterous. I wouldn't believe it, if it were not coming from your mouth. Well, anyway what is that poison?"

"Tarun that is a very rare poison. It is called Aflatoxin"

"Aflatoxin? Never heard of that."

"Really. In fact, it is one of the most talked about poisons today. Some people believe that this poison is being used by certain nations in biological warfare."

"Come on doctor. It looks like we are again on to some interesting tales about poisons. Tell me about aflatoxins from the beginning"

"Tarun, our story of Aflatoxin starts at the most unusual place- the church..."

"The church? Come on doctor. How can the story of a poison start from such a holy place as a church?"

"In churches, a device if often used for sprinkling holy water. It is swollen at one end, and this swollen end has several tiny holes in it, through which holy water can be sprinkled. This little device is called aspergillum, after the Latin word for sprinkling, which is aspergo."

"I still can't make any head or tail of how this will lead us to such a deadly poison as Aflatoxin."

"It so happens that there is a particular species of fungus, which under the microscope looks exactly like the aspergillum. Its strands have a tiny end and a swollen end. To many mycologists - scientists who study fungi - this appeared rather like the aspergillum used in churches, so they named it Aspergillus. Since this fungus was yellow in color, and the Latin word for yellow is flavus, they preferred to call this fungus Aspergillus flavus, which became its botanical name. In 1960, an epidemic of serious liver disease was traced to the eating of moldy peanuts. Incidentally it was nothing but Aspergillus flavus, which had affected the peanuts. It was later realized that this fungus released a poison which actually caused the serious liver disease. The toxicologists were looking for a name for this newly discovered poison, and they resorted to the botanical name of the fungus from which the poison was coming. They took the first letter from the name of the genus (i.e. "A") and the first three letters from the name of the species (i.e. "fla"). Together the four letters form the word "Afla". Since toxin is another name for poisons, they added this world to "Afla", and the name of the new poison became Aflatoxin."

"Oh, that is most interesting. Doctor, you are incredible. You make things so interesting."

"Tarun, Aflatoxins are powerful, tasteless, odorless and colorless mycotoxins that are chemical metabolites produced not only by Aspergillus flavus, but by certain other species of Aspergillus as well such as Aspergillus parasiticus. It is also produced by certain other fungi such as Penicillum and Rhizopus. These are all soil based fungi. Several varieties of aflatoxins are known, but the most dangerous is Aflatoxin B1, with Aflatoxin G1, coming a close second. In fact, Aflatoxin B1 is thought to be the most potent liver cancer producing chemical. Aflatoxins are mutagenic (i.e. they cause mutations), carcinogenic (i.e. they produce cancers), teratogenic (i.e. they cause deformities in the fetus, if pregnant mothers take them), and acutely toxic to most animals and humans. They can cause animals, including humans, to lose their appetites, decrease their feed efficiency and/or cause death. Aflatoxins inhibit the body's immune system and reduce the effects of vaccines. In the U.S., the aflatoxins are the only mycotoxins that are specifically regulated by the Food and Drug Administration or FDA."

"Oh, I see"

"Human exposure to aflatoxins may occur accidentally by the consumption of foods that have been contaminated by Aspergillus during growth, harvest or storage. Nearly all agricultural products are potentially subject to contamination with aflatoxins. Common sources include grains (e.g., corn, rice, sorghum), peanuts, oilseeds (e.g., cottonseed oil, copra), legumes (soybeans, other beans), and tree nuts (e.g., almonds, pecans, walnuts). The use of Aflatoxin-contaminated feed for domestic animals may result in secondary exposure to humans by the consumption of products such as meat, milk and cheese, and eggs that contain residues of the aflatoxins or their toxic metabolites. The FDA has established enforcement levels of 0.5 part per billion (ppb) in milk and 20 parts per billion for other food products. This means that in the United States, concentrations of up to 20 ppb are permitted in human foods and only upto 0.5 ppb in the milk. Levels of up to 200 ppb are permitted in animal feeds, although there is now a serious concern for secondary exposure to aflatoxins from the use of animal products. As I told you, Aflatoxin B1 is a potent hepatocarcinogen in experimental animals, but tumors may also occur in the colon and kidneys. In rats, tumors develop after the administration of 0.2 micrograms per day or a single dose of 0.5 mg of Aflatoxin B1; the tumor incidence is 50 per cent at 26 months after the latter treatment. There are marked differences in the susceptibility of various species to carcinogenesis by Aflatoxin B1; rats are much more susceptible than mice."

"Oh, that is interesting."

"Tarun, very high levels of aflatoxins occur in foods in certain regions of Africa and Asia, and people in these regions suffer a high incidence of liver cancer. Within Swaziland, Kenya, Uganda, and Thailand, where epidemiological studies have been conducted, in certain areas the climatic conditions (i.e., high temperatures and high humidity) are favorable for fungal growth; the food supply from these regions shows a relatively high Aflatoxin contamination, and the average Aflatoxin consumption exceeds 10 micrograms per kg of body weight per day. In other areas of the same countries where lower temperatures and lower humidity prevail, the food supply shows a relatively lower Aflatoxin contamination and the average human Aflatoxin consumption is less. In these areas, the incidence of liver cancer is also less. This is a fairly good evidence that aflatoxins are connected with liver cancers. Within each country, there is a direct relationship between the incidence of liver tumors (cases/100,000 people/year) and the average daily dietary intake of aflatoxins in contaminated agricultural products."

"That is interesting. You were saying that aflatoxins are also used by certain nations for biological warfare"

"Tarun, first of all you must know, what biological warfare is. It is the use of living organisms or their products by a nation for killing the people of its enemy nation. The earliest instance of biological warfare is provided by ancient Mayans, who used to throw deadly snakes in their enemy camps. Now the biological warfare is much more advanced and complicated. People are thinking of using aerosols of deadly bacteria and viruses to decimate their enemies. These aerosols can be released in the enemy territories in the same way that traditional bombs are dropped. On 17.10.96, Alan George of the London Observer reported some interesting facts about Iraq's weaponizing of Aflatoxin. According to him, in May 1988 Iraq began studies on Aflatoxin at its Al Salman facility where the toxin was produced by the growth of the fungus Aspergillus in 5.3-quart flasks. In 1989 Iraq moved its Aflatoxin production to a facility at Fudaliyah. In November, 1989, trials using Aflatoxin warheads (in 122 mm artillery rockets and R400 aerial bombs) were conducted. In 1990 between spring and December 1990, it produced 481 gallons of Aflatoxin in solution. Between May 1990 and August 1990, trials using Aflatoxin warheads were continued. In December 1990 large scale "weaponization" of biological agents started. In 1991 Iraq's Gulf War arsenal included sixteen R400 Aflatoxin bombs and two Aflatoxin warheads for enhanced Scud missiles. In total Iraq produced 572 gallons of concentrated Aflatoxin, of which 410.8 gallons were put into munitions. There is however no evidence that these Aflatoxin weapons were ever used. But under these circumstances, United Nations has continued its sanctions over Iraq."

"That is most interesting. Coming to our original case, do you think, Ramnath was intelligent enough to mix aflatoxins in the milk, to cause liver cancer in Suman Dubey so he may die?"

"I don't think so. Although there is a distinct possibility of someone doing so, if he were intelligent enough. Ramnath is an illiterate person, and I don't think, he even knows about aflatoxins. I think the rice that he was getting from his village was moldy, and he got his poisoning from that. In fact, I have examined the rice stores in Dubey's house and they are indeed moldy. I examined some of the rice grains under the microscope and I could indeed find Aspergillus in it. So that solves our case. Come, let us tell the police that Ramnath is innocent and that they should release him."

"Very clever indeed. This was a most interesting discussion doctor. Without your masterly deduction, police could have unnecessarily went on harassing Ramnath. Suman Dubey's relatives and other people might have thought, it was a case of killing by Ramnath. Tell me what are you going to tell me the next time?"

"Tarun, next time, I would tell you about a very interesting poison, nitric acid. "