Friday 7 January 2011

DEATH BY SODIUM NITRITE

MY FORENSIC ARTICLES IN SCIENCE REPORTER
THE FOLLOWING ARTICLE APPEARED IN THE
JANUARY 1999 ISSUE
THE POISON SLEUTHS

DEATH BY SODIUM NITRITE

-Dr. Anil Aggrawal

"Good morning doctor. Oh, my God, what are you doing today? You have the dead body of a young woman today. Her whole body seems to have a chocolate brown color. I remember last time too, I had seen a dead body with chocolate brown color. Did this woman also die of the same poison? Please tell me."

"Good morning Tarun. The name of this young woman is Radhika, and she is about 25 years old. She died in her flat at about 9 am today morning. She was a junior executive in a private firm here in Delhi, and was living alone in this flat. Her family members are living in Jaipur. She was living here solely for the purpose of this job. Her parents were looking out for a match for her marriage."

"Oh, I see."

"Yesterday night she was fine. In fact, she met one of her neighbors Shyamala -also a 25 year old girl- at about 9pm, and she tells us that she was perfectly in good spirits. That rules out suicide...."

"Wait a minute doctor. If a person is in good spirits and cheerful a day before his or her death, does it rule out suicide? Is it not possible that she was trying to mislead the neighbors by being cheerful so that nobody gets to know her intentions?"

"There are other indications too. There is no suicide note. Generally a person who commits a suicide, leaves a suicide note."

"Oh, I see"

"Well, the police interrogated Shyamala more about her as she was the only one, who knew Radhika very well. She told the police that she (Radhika) was in love with Chaman, a 26 year old colleague in her office. Recently she had become pregnant by him, and she was pressing him for marriage. However Chaman had lost interest in her, and was trying to avoid her. Only 2 days back she had threatened him to go to his parents if he did not agree for the marriage. Chaman's parents are very religious and God-fearing, and he knew if she approached them, they would force him to marry her. To settle matters he came yesterday to Radhika's flat at about 7 pm. Shyamala knows because when he came, Radhika called her as a mediator. Shyamala tells the police that Chaman was looking very tense and jittery. She thought it was because he had such a difficult matter to resolve. Anyway she just sat there for about an hour. When she saw that the matter is going to take more time, she left the house making an excuse. When she left, Radhika was just preparing to go inside the kitchen to make tea for everyone. She offered Shyamala to go after having tea, but she just left. She however saw Chaman leaving Radhika's house only about 15-20 minutes later. She was sitting idly at her window when she saw him. He looked to be in great hurry."

"Oh, I see. So did you find anything in the post-mortem that corroborates what Shyamala is saying?"

"Yes, I found a 4 month old male baby inside Radhika's uterus, which definitely tells us that she was pregnant. I have kept the tissues of this fetus for his DNA profiling, which will tell us definitely if Chaman was his father or not. More about that later. What interested me was the color of her body. I told you last time (See SR December 1998 issue) that there are certain poisons which can cause methemoglobin to form inside the body. It is this compound which imparts such color to the body. Well one of such poisons is sodium nitrite. I got a hint that she might have died of sodium nitrite poisoning when I went to her flat and saw that she had unfinished breakfast on her table. She was in the habit of having a full meal in the morning itself. She had prepared Dal and Roti and must be eating it. And it was lying there unfinished. Nearby I could see some dried vomitus on the floor. Obviously when she was eating the food, she must have got sick and must have vomited. I saw a salt cellar on her table which was open. I got quite curious, when I glanced underneath the dining table and found lot of white salt like powder spilled over there. As a poison sleuth, I don't want to take chances and intuition told me there was something either in the salt cellar or in the powder spilled over the floor that we were looking for. So I quietly kept the salt cellar in my pocket and also some of the powder spilled over the floor underneath the dining table. I examined both these substances in my lab. And do you know what I found?"

"What? Please tell me doctor. I am getting curious."

"Tarun, I had the most extraordinary finding in the salt cellar. It had a substance looking like salt but it was not sodium chloride. It was sodium nitrite. And the salt like powder which was spilled underneath the table was nothing but sodium chloride. Do you get the picture now?"

"Well, not really. I don't understand how such a curious thing happened."

"To me it is clear like glass. Obviously someone replaced the salt in the cellar with sodium nitrite. And before doing this he spilled the salt underneath the table to empty the cellar so he could fill it with the poison he had brought with him. The only commonly available poison which looks and tastes like salt is sodium nitrite"

"Really? Doctor I am getting curious. Please tell me more about sodium nitrite."

"Tarun, as I told you earlier, sodium nitrite causes methaemoglobinaemia; even small doses of sodium nitrite can kill within a few minutes. Even the nitrates can be dangerous. Organic nitrates in fact are reduced to nitrites in the intestine. Inorganic nitrates, bismuth subnitrate excepted, are not normally reduced to nitrites in the body, but this may occur when the upper digestive tract (stomach and upper part of small intestines) is infected with nitrate-reducing bacteria, e.g. Escherichia coli. Inorganic nitrates are irritants of the stomach and, in large doses, potassium nitrate is a diuretic. A diuretic is a chemical which increases the production of urine. Poisoning by nitrites is actually not very common. It can result from mistaking this salt for common salt or Epsom salts."

"Doctor, under what circumstances can sodium nitrite poisoning occur?"

"Tarun, poisoning can be homicidal, accidental or suicidal. With sodium nitrite, accidental poisoning is probably most common, although homicidal poisoning is also possible as we have seen in the case of Radhika. One of the earliest reports of sodium nitrite poisoning came from Middlesborough, UK in 1936. Two adults and their daughter aged five were suddenly taken ill after the midday meal. The adults died before a doctor could reach them and their daughter died shortly after her admission to hospital. It appears they had complained to neighbors of acute abdominal pain and vomiting. Their faces went blue. Investigation showed very similar results to what I found in Radhika's case. A basin of cooking salt and a salt cellar contained sodium nitrite; the upper layer in the latter was of 98% sodium nitrite and the lower layer 98.2% common salt. Unconsumed food contained sodium nitrite, e.g. cabbage 6.5% and Yorkshire pudding 4.5%. The gastric contents of the man contained 4.275 g and those of the woman contained 1.284g of sodium nitrite. Over a gram of the poison was present in the child's vomit. The vomit of the adults was not available for analysis, but presumably they had ingested considerably more than remained in their stomachs. The source of the poison was not determined, but the man had had access to sodium nitrite in the course of his employment. Nobody knows how the mix up happened. Probably someone filled up a half empty salt cellar either intentionally or mistakenly with sodium nitrite."

"Oh, that is most extraordinary and bears an eerie resemblance to the case we have on our hands."

"Yeah sure. Accidental deaths due to the ingestion of sodium nitrite used in error for common salt in the preparation of soup have also occurred. Several such accidental deaths have been reported. Death in these cases occurred within a few minutes following symptoms which included nausea, headache, vertigo, urgent vomiting, profuse diarrhoea and cyanosis (bluing of the skin). Stomach contents in most of these cases contained sodium nitrite ranging from 1.74 to 84.0 mg/kg of the gastric contents. There was a more consistent concentration in the organs, e.g. in the liver, where the concentration was between 3.0 and 4.35 mg/kg. A quarter of a litre of the soup in most of these cases contained l.5 g of sodium nitrite. I must tell you that the fatal dose of sodium nitrite is from 1 to 2 g. I have already explained you the concept of fatal dose (see "Poisoning by Thallium" SR, October 1997)."

"Yes doctor, I do remember you having mentioned it."

"In another case, eleven men were poisoned after eating oatmeal seasoned with sodium nitrite in mistake for common salt. The men added more salt from salt shakers later shown to contain sodium nitrite. Immediately after the meal they felt sick and vomited. There was dizziness and abdominal cramps. They went blue and five lost consciousness. Methaemoglobin was later demonstrated in their blood. One of these men, aged 82, died the next morning; his organs had a diffuse brown colour. The source of the poison was nitrite used to cure meat. Only eleven of 125 persons who ate of the oatmeal were affected and these eleven had used contaminated salt shakers of which one contained 0.137% of nitrite. It was estimated they had taken at least 163 mg. In yet another case, a boy aged two months suddenly went blue, 'almost black', after his 7.0 am feed. Sodium citrate had been prescribed for the relief of indigestion and two tablets had been added to the feed. When seen in hospital, about five hours later, the appearance of the child simulated those of congenital heart disease; he was neither distressed nor febrile. A diagnosis of toxic methaemoglobinaemia was made and the remaining tablets, fortunately available, were subjected to analysis. They proved to contain 65 mg of sodium nitrite each. The infant, therefore, had ingested 130mg, the maximum dose for an adult. There are a host of other such cases of which I am aware."

"Doctor please tell me a few interesting ones out of these."

"In one case, two children aged two and three months respectively took feeds to which from 35 to 40g of sodium nitrite had been added in error for sodium citrate. The elder infant died. Cyanosis and blackening of the mouth were outstanding features. In another case, a boy aged two years vomited while playing with his elder brother aged nine. After a second vomit he was given a glass of water to drink. Vomiting continued and he was taken to hospital. He was deeply cyanosed, collapsed and crying with spasms of pain. Poison was taken out from the stomach with the help of a tube and oxygen was administered, but the child died at about three hours after being poisoned. Sodium nitrite was detected by analysis of his stomach contents. There was methaemoglobin in the blood. It is probable that the boy had ingested and absorbed appreciably more of the poison. The source of the poison in this case was a bottle of sodium nitrite, now nearly empty, which the elder boy had brought for the purposes of a chemical experiment. The dead child had licked the bottle. I must tell you that sodium nitrite is highly soluble in water and its taste resembles that of common salt and that is what makes it such an attractive homicidal poison. Interestingly sodium nitrite is used in machine oil also as a corrosion inhibitor, and deaths have occurred when someone accidentally drank machine oil. There is a case of a girl on record who died in this way. She was eleven years old, and drank a mouthful of machine oil accidentally, some of which she immediately spat out...."

"Just a minute doctor. I think sodium nitrite is an oxidizing agent, and if I remember my chemistry alright, corrosion is an oxidative process. Then how can nitrite be used as a corrosion inhibitor?"

"Tarun, sometimes oxidizers are also reducing agents. Such is the case of nitrite, which can be further oxidized to nitrate. I must tell you that the tendency of nitrite to act as an oxidizer is increased in an acid environment such as that found in the stomach. At higher pH levels its oxidizing potential is greatly decreased. Corrosion can be inhibited by using a sacrificial reducing agent such as nitrite. Sodium nitrite is also commonly put into packaged foods like meat to keep oxidation from happening. So I was telling you about that little girl. Within an hour she was unconscious and deeply cyanosed. Fortunately she recovered after proper treatment. Analysis showed that the oil contained 36.5% sodium nitrite, 7.5% of an emulsifying agent and 56.0% water. Her stomach washings contained 7-8mg/ 100 ml of sodium nitrite."

"Oh, that is certainly most extraordinary!"

"Tarun, sodium nitrite poisoning has happened in other ways too. Poisoning by well water drawn from badly constructed wells near farmyards may contain an appreciable amount of nitrate which makes it unfit for drinking and a source of poisoning newborn infants. This illness is however rarely fatal. About 30 cases are on record and only one, it appears, was fatal. It is apparent that the risk is only to infants of under 90 days old, who live in rural communities..."

"Doctor, can boiling the water make such water safe? I have heard that boiling the water makes it cleaner."

"Yes boiling the water does make it free of infective micro-organisms, because they get killed by boiling, but when the water is contaminated with a chemical substance, it gives no protection whatsoever. On the contrary, it concentrates the nitrates, which can get concentrated upto 3 times on boiling the water! Older children are unaffected, probably because they can tolerate the amount of nitrate likely to be present in their normal fluid intake. It does appear that poisoning in these circumstances is not dependent only upon the amount of nitrate ingested· It has been suggested that poisoning by nitrate will only occur in those whose gastric juice exceeds pH 4.0 and when nitrate-reducing bacteria are present in the upper digestive tract."

"Doctor, this is a most extraordinary fact that you have told me. Can you tell me what is the concentration of nitrites in such contaminated water coming from wells?"

"The contaminated water, usually drawn from shallow wells, of not over 75 feet deep, usually contains over 20 ppm (parts per million) of NaN03. Methaemoglobinaemia (the existence of too much methemoglobin in the blood) does not normally occur unless the water contains 30 ppm. The upper limit of nitrate should not exceed 10 ppm because as I told you earlier, if boiled the water could be concentrated threefold and thus to a dangerous concentration. Even cows which feed on beet tops rich in nitrates develop methaemoglobinaemia. This is known as the condition of 'purple' cows and is well recognized. Purple is the color the cows get when there is lot of methemoglobin in their blood."

"Oh, this is most extraordinary."

"There are more interesting facts Tarun. Nitrite poisoning from spinach has also occurred. During 1959-65 in Germany there were 15 cases of nitrite poisoning in infants, aged two to ten months, who had eaten spinach. Nitrite and the remains of spinach were found in the stomach contents of one of the infants. Two factors were responsible. First, the excessive use of nitrate fertilizer, which should not, but often did, exceed 80 kg/hectare. Second, bacterial activity converted the nitrate in spinach into nitrite. Samples of spinach, fresh, frozen and tinned, showed a nitrate contamination of from 40 to 2100 mg/kg. The risk arose when the feed was prepared in advance and stored overlong at room temperature. Even after cooking, a sufficient number of bacteria remained to produce nitrite. The maximum nitrate content of spinach should not exceed 200mg/kg. It has even been recommended that during the first three months infants should not be given spinach."

"Doctor, such an interesting poison must have caught the fancy of suicides also. Have there been cases of suicidal poisoning too with sodium nitrite?"

"Yes, sure. Suicidal poisoning with sodium nitrite has also occurred. A medical practitioner, aged 51, committed suicide in 1942 by ingesting sodium nitrite. He had been mentally ill for some time. On the night of his death he awoke his son, a medical student, and told him that his mother had suddenly been taken ill during the night. A doctor was summoned and while he was attending to the woman a bump was heard in the passage. The deceased was then found lying on the floor; he died within five minutes of his fall. Poisoning was suspected, but a search revealed only a glass of brandy and another which appeared to contain water. Toxicological analysis demonstrated 2g of sodium nitrite in the gastric contents. The blood was 'dark'. Unfortunately no analysis was made of the brandy or water, otherwise I am sure they would have found nitrite in the brandy. The deceased had given his wife some of the brandy during the night and this may have been the vehicle of poison responsible both for her illness and his death. I feel he first gave brandy laced with nitrite to his wife and then consumed the poison himself, but of course it is only a guess. But sure enough, it is possible to kill someone by lacing his or her drink with as little as 2 grams of sodium nitrite. It was believed that the poison was taken within an hour prior to his death. It was suggested by the relatives that he had died of a heart attack, but the doctor said that he had died of nitrite poisoning."

"Oh, doctor. We could go on and on with such interesting stories. Tell me how you can prove Radhika died of nitrite poisoning?"

"Tarun, I told you I examined both the contents of the salt cellar as well as the powder spilled over the floor. Now I will tell you what happened. Chaman came to Radhika's house not for reconciliation, but for killing her. He was sure, killing her was his only way out. He got sodium nitrite from a chemistry lab. We have still to find out, how he got hold of it, and who gave it to him. He came fully armed with this poison in a packet. When Shyamala left and Radhika went inside the kitchen to make a cup of tea, he quickly picked up the salt cellar, spilled the salt in it on the floor underneath the table and refilled it with the powder that he had brought. He knew that sometime she would consume the contents of the salt cellar thinking it was salt and she would die. It was no doubt a very clever plan, but thankfully we could catch it. The color of Radhika's body at once told me we were looking for a poison which produces methemoglobinemia, and that was Chaman's undoing. I have found an appreciable quantity of Sodium nitrite from Radhika's stomach contents, and to top it all, the police has found some left over sodium nitrite from Chaman's house too. Initially he denied having any hand in Radhika's death, but when he was told of all the medical and circumstantial evidence against him, he broke down and admitted his guilt."

"Very clever doctor. This was a most interesting discussion doctor. Without your masterly deduction, Chaman could never have been caught. People might have thought, it was an accidental death. Tell me what are you going to tell me the next time?"

"Tarun, next time, I would tell you about a very interesting poison. You may not have even thought that it was a poison. I will tell you about death by Potassium Permanganate. " "



***

1 comment:

  1. Thankyou for sharing such as nice blogpost. Great collection, Keep it sharing.
    We have supplied Pineapple powder at affordable rates ta large no. of customers. Our products are fully tested for use in home and office.
    Sunflower lecithin

    ReplyDelete