THE FOLLOWING ARTICLE APPEARED IN THE

APRIL 1998 ISSUE

THE POISON SLEUTHS

DEATH BY IODINE

-Dr. Anil Aggrawal

"Good morning doctor. Oh, my God, what are you doing today? You have the dead body of an old man. He has some brownish-yellow stains too around his mouth. What happened to him? Please tell me."

"Good morning Tarun. The name of this 57 year old man is Ramlal. He was living alone in this house. He had no children, and his wife expired some time back. From all the accounts of neighbors, it appears he was having some depression. There were other reasons for depression too. He was a gambler and had taken a lot of money as loan from his friends. Some of them were pressing him to return his amount, and some were even threatening him with dire consequences, if he did not return the amount soon. The main among these was a person known as Mahto. He was seen entering Ramlal's house yesterday evening. Nobody knows what happened after that. Today morning when the maid came to Ramlal's house and knocked at his door, nobody opened the door. She got suspicious and called the neighbors. The neighbors broke the door open and found Ramlal dead."

"Oh, I see. So definitely Mahto must have killed Ramlal."

"Don't jump to conclusions Tarun. How do you know he didn't die a natural death?"

"Well.....I thought that was the most natural conclusion to make. But come to think of it, Ramlal could well have died a natural death too."

"But surely he didn't die a natural death. The reason is that a bottle was found in the room containing some dark liquid. The bottle was marked "poison" and it was half empty. As you can see Ramlal's face, the angles of his mouth are stained. It does appear he had taken this liquid."

"Oh, yes, now I see. The area around his mouth is stained brownish yellow. So do you think Mahto gave him this poison?"

"Well, this is what police is thinking. They have come to a startling conclusion. According to them, Mahto went to Ramlal's house to ask for money, but when Ramlal couldn't give him the money, Mahto wanted to get even with him, and gave him this poison. They have called Mahto, but he is denying this allegation completely. He says, that he did go to Ramlal's house and demanded his money, but when Ramlal expressed his inability to pay up, he left after giving him another warning."

"It is quite possible that the police would torture Mahto to arrive at the truth."

"Well, the possibility can not be ruled out. But I have examined Ramlal's dead body, and it appears to me Mahto is indeed innocent."

"Oh, my God. How can you say about Mahto's innocence by just looking at Ramlal's dead body?"

"Tarun. I have examined the contents of the empty bottle. It containes a strong tincture of iodine. It is the medicine which one applies to abrasions and wounds. It is used as an antiseptic. Iodine has a strong odor and a very bad taste. This poison can not be given to anyone as a poison...."

"Do you think Ramlal never ingested the contents of the bottle, and died by some other means?"

"No, Tarun, Ramlal did ingest the contents of the bottle. In fact, I have found signs on his dead body, which point to death by iodine. Not only this I have recovered some iodine from his stomach too. But the iodine was not given to him with homicidal intention. He ingested it himself with suicidal intentions. He probably did it so, because he was very depressed. He was not able to pay up his debts. Yesterday night Mahto visited him and demanded his money again. It dawned upon Ramlal, that he would not be able to stall his creditors for long, so after Mahto left, he consumed iodine to kill himself."

"So iodine is such a strong poison, that it can kill? Well, can you tell me a little bit about iodine, so that I understand better how you detected iodine in his body?"

"Tarun, Iodine was discovered by the French Chemist Bernard Courtois (1777-1838) in 1811. It might interest you to know that he was not interested in discovering a new element at all. He was actually in the buisiness of manufacturing potassium nitrate which was needed for making gunpowder. He used to get potassium nitrate from potassium carbonate (potash), which in turn he got from seaweed. As one of the steps to get the potassium carbonate, he had to heat the seaweed in acid. One day in 1811, he added too much acid and, on heating, obtained a beautiful violet vapor. On condensing the vapor, he produced dark lustrous crystals. This was in fact iodine. Courtois had in fact unwittingly discovered a new element! The element was given its name 3 years later by Sir Humphry Davy from the Greek iodes (like the violet). The name clearly refers to its unique color. It was originally prepared from the ashes of kelp and other seaweeds, just as Courtois had done. However at the present time, the major sources of iodine are natural and oil field brines, from which they are separated by a special process known as ion exchange chromatography. Kelps are very rich in iodine. I may tell you that although iodine in large amounts is poisonous to our body, it does need iodine in very small quantities. It is needed by the thyroid gland to make the hormone thyroxine. If someone's diet is deficient in iodine, his thyroid gland may enlarge. This disease is known as goitre. Kelps are so rich in iodine, that people who consume kelps don't suffer from goitre at all."

"Oh, I see. How much iodine is required by our body daily?"

"Tarun, the daily requirement of iodine is about 150 micrograms/day in adults, of which the thyroid gland takes up about 70 micrograms. Rest of the iodine is used for some other essential purposes. Some commercial preparations containing iodine are povidone-iodine and tincture of iodine. These are basically used as antiseptics and disinfectants. Ramlal probably kept the tincture of iodine in his general medical chest, as most of us do. Povidone-iodine is primarily used as a vaginal disinfectant. Tincture of iodine is usually applied on cuts and abrasions, to prevent them from getting infected. Tincture of iodine consists of 2% iodine, 2.4% sodium iodide, 47% ethyl alcohol and rest is water. Then there is the strong iodine tincture, which was found in Ramlal's house. It consists of 7% iodine, 5% potassium iodide, 83% ethyl alcohol, and water. It might interest you to know that the word tincture comes from the Latin tinctura (dyeing), which in turn comes from tingere (to dye). This Latin word also gives us the common English word tint. It is interesting that the word tincture is applied only to alcoholic solutions. Medicine and dyeing may appear to have no connection at all, but in fact there is an interesting link. In pharmacy alcoholic solutions are commonly called tinctures because many dyes will dissolve in alcohol but not in water. Tincture of iodine is reddish brown in color. In addition to tincture iodine, another preparation, Lugol's iodine is also available which consists of 5% iodine and 10% potassium iodide and the rest is water."

"Oh, the information is interesting indeed. Can you tell me what symptoms does one experience if he is given iodine?"

"I would like to tell you, it is not easy for someone to give iodine to others for homicidal purposes, because it has a characteristic color, odor and taste. Iodine vapors too have a characteristic odor and taste and are intensely irritating to the eyes, mucous membranes, and skin. In several countries, such as the US, the maximum allowable concentration is 0.1 ppm (1 mg/m3). Ppm, as you know stands for Parts Per Million. Even at this concentration, i.e. 0.1 ppm, some people may experience eye irritation. Higher concentrations may lead to excessive tearing, tightness in the chest, sore throat, headaches, irritation of the respiratory tract, and water-logging in the lungs, similar to that seen with chlorine gas exposure. Iodine is a powerful irritant and vesicant, which means it can cause skin eruptions. Symptoms may occur through inhalation, skin or eye contact, or ingestion. Iodine vapor may cause brown staining of the cornea. A 7% solution of iodine, which as you know now is the strong iodine tincture, is corrosive to the eye and the skin. Owing to its strong oxidizing action, iodine acts as an acid corrosive, precipitating cell proteins. Symptoms of iodine ingestion include unpleasant metallic taste, brownish-colored vomit, diarrhea, weak pulse, and retention of urine. There may be corrosion of skin and and mucus membrane with brownish yellow stains. Finally there may be delirium, stupor, and collapse. Changes in the body involve staining of the walls of food pipe and of stomach walls and rapid development of pneumonia-like symptoms."

"Doctor, how much iodine is sufficient to kill a person?"

"Tarun, about 3-4 g of elemental iodine or 30-250 mL of strong ticture can kill a person. Death usually occurs in the first 48 hours. However death can occur as early as about ½ hour after ingestion to as late as 52 days."

"Oh, I see. Well, in the current case how can you prove to the court that Ramlal did die of iodine poisoning?"

"As I told you, I found Iodine in his stomach. Iodine can be detected in stomach by some deceptively simple tests. If the stomach contents contains iodine, it may be made to sublime, by taking the stomach contents in a beaker and warming it gently. The purplish iodine vapours may be made to condense on a watch glass placed on the top of the beaker. Another test involves adding 1 ml of starch solution to 10 ml of stomach contents. A blue-black colour will develop immediately due to the formation of starch iodide. If death has occurred after 2-3 hours, some iodine may have reached urine too. To detect iodine in the urine, we add 5 ml of chloroform and a few drops of nitric acid to 10 ml of urine and allow to stand for 3 minutes. A pinkish violet chloroform layer forms, which confirms the presence of iodine in the urine. I have done all these three tests on Ramlal's body and have found iodine in stomach contents as well as in the urine."

"You said you found some signs on Ramlal's body also which pointed towards iodine poisoning. What are those signs?"

"Tarun, the main sign is the brownish or yellowish stains of skin, which you can see on Ramlal's body. Furthermore all internal organs such as liver and spleen are found engorged with blood. Sometimes there is a characteristic odor too from the body, but this is very rarely perceptible. Now since we have proved that this is a case of death due to iodine, we can easily prove that Mahto couldn't have given this solution to Ramlal. Come, let us tell the police about it, so they can release Mahto."

"Oh, how very clever of you doctor. This was a most interesting discussion. It is doubtful if Mahto could have been proved innocent without your excellent detective work. Tell me what are you going to tell me the next time?"

"Tarun, next time, I would tell you about a very interesting poison- Barium "