THE FOLLOWING ARTICLE APPEARED IN THE

DECEMBER 1998 ISSUE

THE POISON SLEUTHS

DEATH BY SODIUM CHLORATE

-Dr. Anil Aggrawal

"Good morning doctor. Oh, my God, what are you doing today? You have the dead body of a young man today. His whole body seems to have a chocolate brown color. Well, this is the most peculiar color I have ever seen in a dead body. What happened to him? Please tell me."

"Good morning Tarun. The name of this young man is Radhey, and he died in Dr. Gupta's nursing home today morning. Yesterday he and his friend Shyam had a dinner at a 5-star hotel. While they were still having dinner, Shyam got a phone call and had to leave suddenly leaving the dinner unfinished. Radhey became sick immediately thereafter. He started vomiting. Seeing his condition, the hotel staff called the ambulance, and he was shifted to Dr. Gupta's nursing home. The doctors there started a battery of tests to arrive at a diagnosis, but before any diagnosis could be made, he died."

"Oh, looks like he died of some natural disease. You said he had vomiting. May be he died of gastroenteritis."

"Doesn't look like to me. Look at his body. It is so darkly colored. You yourself remarked on that as soon as you came here. One doesn't get that kind of color in gastroenteritis. There may be more to his death, than meets the eye."

"Really? Well, let me know. I am all ears."

"Tarun, I have asked the police investigating this case. It appears, Radhey and Shyam did not have good relations. They were business partners, but lately there had been lot of tussle between the two regarding the ownership of certain business properties, which ran into lakhs of rupees. Naturally each wanted the other out of way. In fact, yesterday's meeting at the 5-star hotel was meant just to sort out these problems...."

"Oh, so you are hinting that probably Shyam killed Radhey. Did he administer some poison to him?"

"Tarun, I have enquired in detail from the police about yesterday's events. They have taken the help of waiters and other staff to find out what exactly happened yesterday evening. Radhey and Shyam arrived in the dinner hall at about 7.30 pm yesterday night, and first of all they started having some drinks. After about two drinks, they called for soups. Just when the soups were brought, a phone call came for Radhey. We know this from the waiter who received the call. Well the waiter tells us that Radhey came back within a minute and started having soup. Soon after Shyam got a phone call and he had to leave. After this Radhey became sick. This peculiar story, coupled with the fact that the body of Radhey is showing this characteristic chocolate brown color, leads me to think that Radhey indeed has been poisoned..."

"Really? With what poison doctor?"

"Tarun, it is a very interesting poison. May be you never realized it is a poison. It is a very common salt available in all chemistry laboratories- sodium chlorate."

"Sodium chlorate? Yeah indeed it is a very commonly available salt. But I never realized it is a poison also."

"Yes, Tarun, it is a very deadly poison. In fact the brown color of Radhey's body led me to that. It causes browning of the body, because it forms a brownish colored compound in the body- methemoglobin."

"Don't really know what methemoglobin is. Please tell me more about it doctor."

"Tarun you know that all of us have hemoglobin in our bodies. It is the basic pigment which picks up oxygen from the lungs and delivers it to all tissues. It resides in the Red Blood Corpuscles or R.B.C.s. If anything were to go wrong with hemoglobin, oxygen transport to the tissues would be seriously hampered and the person may die. Hemoglobin molecule has four iron atoms in it, all of which are in the reduced or ferrous state. This is usually written by the chemical symbol Fe++. Methemoglobin is nothing but a molecule of hemoglobin, in which one or more of iron atoms - may be just one, or all four- are oxidized to Ferric state. Chemically we can represent these iron moieties as Fe+++. Once the hemoglobin molecule is modified in this way, it no more remains useful as an oxygen carrier. It becomes useless in other words, and the person may die for want of oxygen. Sodium chlorate is a strong oxidizing agent. It oxidizes the hemoglobin to methemoglobin and this may cause rapid death."

"Just a minute doctor. You said that normally hemoglobin takes oxygen from the lungs and delivers it to all tissues. Doesn't that too oxidize the hemoglobin and render that useless?"

"Oh, no Tarun. That is a very loose combination of hemoglobin with oxygen. In fact nature has devised it to be so loose that it readily delivers its oxygen to the tissues. In this combination, all iron atoms remain in the ferrous state. Only the whole molecule simply picks up the oxygen molecule, much as you would pick a hot coal with a tong. But Sodium chlorate really "oxidizes" the molecule rendering it useless. So although Hemoglobin normally carries oxygen around, it doesn't get oxidized in the true sense of the word. In fact, if it were to be oxidized by any means, it would immediately be rendered useless."

"Oh, Sodium chlorate really appears to be an interesting poison doctor. Please tell me more about it."

"Tarun. Two chlorates are very important from a toxicologist's standpoint- Sodium and Potassium chlorate. Chemically we can write them as KClO3 and NaClO3. At one time potassium chlorate was widely used in medicine and being obtainable without restriction, it was a popular household remedy, especially for sore throat. It has now been completely abandoned as a remedy and therefore it is a rare source of poisoning today. Sodium chlorate on the other hand, has a reputation as a safe and effective weedkiller, and is commonly available. Sodium Chlorate is also used as an explosive in many parts of the world. It is still commonly available in the market. Unfortunately many people think that it is non-poisonous, and this wrong belief has given rise to several poisonings."

"Doctor, how can poisoning with sodium chlorate occur usually?"

"Tarun, poisoning with sodium chlorate can occur accidentally, suicidally or even homicidally as seems to be the case I am handling today. Accidental poisoning is perhaps the most common. Sodium chlorate has been mistaken for common salt and Epsom salts..."

"Sorry to interrupt you doctor, but what exactly is Epsom salt?"

"Tarun, it is a bitter, white crystalline powder consisting of hydrated magnesium sulfate. It was once used in medicine as a cathartic and to reduce inflammation such as in sore throat. Its formula is MgSO4.7H2O. It is named after a place called Epsom, in Surrey, England, where it was originally prepared from the water of mineral springs. If magnesium sulfate is prescribed for some disorder, and the person inadvertently took sodium chlorate, which looks very much like it, he may be severely poisoned. In some cases poisoning has occurred when potassium chlorate was taken as a medicine, mainly to treat inflammation or septic spots. In many such cases, potassium chlorate was given for local application, but it was swallowed instead. In one such case, a person was having an ulcer in his mouth. He was given potassium chlorate to gargle his mouth with, but he swallowed it, and was severely poisoned. Illegible prescriptions have also given rise to some poisonings. In one such case, the intended drug to be given was potassium chloride. But on the prescription, only the words "potassium chl." were written. This was misinterpreted by the chemist as potassium chlorate. This drug was dispensed and the patient was severely poisoned!"

"Very interesting indeed!"

"Tarun, I know of several instances when potassium and sodium chlorates have caused inadvertent deaths. In one case, a 5 year old girl had scarlet fever. Inflammation of her throat was treated with repeated sponging with a 2% solution of potassium chlorate. On 7th day, the symptoms of poisoning appeared, and even though the treatment was stopped on that very day, the girl died on the tenth day. In another case, a 61 year old woman sucked daily on 20 tablets of potassium chlorate (324 mg each) for 6 to 10 weeks. She thought that a cancer was developing on her tongue and that she would be cured by this. She was severely poisoned. In one case, a chemist gave his wife several tablets of potassium chlorate for treating her tonsillitis. She died after five days. But probably the most interesting is the case of a 48 year old gardner who was severely poisoned in a curious way. He was using a concentrated solution of sodium chlorate in an atomizer, while a strong wind was blowing. In consequence, spray was blown on to his face and he inhaled and ingested some of the solution. Symptoms of poisoning started the same evening. He could be saved with some heroic effort on the part of the doctors, yet he could only return to full-time work at the end of about a year."

"Doctor, what symptoms does one get on swallowing this poison?"

"Tarun, immediately there is acute digestive upset. Vomiting is usual. It may persist for upto 48 hours. There may be severe pain behind the breast bone or in the abdomen. Red Blood Cells begin to break down and may reduce in number to half. Red cells may only be 2.5 x 1012/L in this poisoning, while normally they are 5 x 1012/L. Heinz bodies are seen in the red cells...."

"What are Heinz bodies doctor?"

"Tarun, Heinz bodies are nothing but denatured hemoglobin. I told you that sodium chlorate destroys hemoglobin. This destroyed or denatured hemoglobin, also known as methemoglobin precipitates in the RBCs as Heinz bodies. These bodies were first described by a German doctor Robert Heinz. Hence the name. Besides these symptoms, acute renal failure also occurs in sodium chlorate poisoning. This is in part due to direct action of chlorate on the kidney and in part due to mechanical obstruction of tubules of the kidney by hemoglobin set free from the red cells. Urine is scanty and dark brown. Total stoppage of urine may also occur."

"Doctor, how much sodium chlorate is needed to kill an adult robust man?"

"Tarun, about 20-35 grams would be required. And the person would die in about 4-5 days, although death can be quicker as in this case."

"Oh, Doctor, now I know all about sodium chlorate. Tell me how you deduced that Radhey died of sodium chlorate poisoning?"

"Tarun, the color of Radhey's body gave away the poison to me. You will agree the color is very peculiar. It is chocolate brown. This is the color of methemoglobin. So the moment I saw the chocolate color of Radhey, I knew I was looking for some poison, which converts hemoglobin to methemoglobin, and sodium chlorate is one such poison. Then I made a blood film of Radhey and saw it under the microscope. RBCs were broken, and they showed fragmentation which was expected in sodium chlorate poisoning. Numerous Heinz bodies were also seen in the RBCs. His kidneys as you can see are enlarged, as we would expect in sodium chlorate poisoning. I have made a microscopic examination of the kidneys too. And I have found that the tubules of the kidney are occluded with broken red cells and brown pigment granules. You surely know what the tubules of the kidney are. They are the microscopic tubes through which filtered blood - or urine- passes forwards. These tubules are dilated and many are completely blocked by debris. This is exactly the change that we would expect in sodium chlorate. There is no doubt that Shyam has given Sodium chlorate to Radhey."

"But how could he do that? They were both having dinner together."

"Tarun, Shyam was probably working with some accomplice, who was sitting outside the dinner hall probably with a mobile phone. Just when the soups were served, the accomplice phoned from his mobile to the reception desk of the dinner hall, asking for Radhey. When Radhey went to pick up the phone, Shyam quickly mixed the sodium chlorate which he already had in his possession. Radhey discovered that it was a blank call and returned to his table and started having his soup. The taste of sodium chlorate is somewhat similar to that of common salt, so one may not discover any change in taste, especially when he is already drunk as Radhey was. When he had finished his soup, Shyam and his accomplice knew it was not safe to remain there any more. So according to their pre-arranged plan, the accomplice phoned again- this time to Shyam. He took the call, came back to Radhey and told him that he had to leave as he had got some important call. The idea was to leave the scene immediately to remain out of trouble. You know the rest of the story."

"Very clever indeed. But how do you know the story with such gory details?"

"Tarun you will be surprised but Shyam has told us this story himself. Actually when I conducted the post-mortem, I immediately suspected I was looking for sodium chlorate. I told the police about it. They raided Shyam's house and recovered a small sachet, containing a white powder. When I examined it chemically, I discovered it was nothing but sodium chlorate. Faced with this fact, police renewed their interrogation of Shyam. Faced with all the scientific evidence against him, Shyam broke down and told these details to the police. The police are now looking for his accomplice, who is on the run."

"Very clever doctor. This was a most interesting discussion doctor. Without your masterly deduction, Shyam could never have been caught. Every one would have thought that it was a case of death due to gastroenteritis. Tell me what are you going to tell me the next time?"

"Tarun, next time, I would tell you about a very interesting poison- Sodium nitrite. " "