N-Nitrosodimethylamine (NDMA), also known as dimethylnitrosamine (DMN), is a semi-volatile organic chemical, produced as by-product of several industrial processes and present at very low levels in certain foodstuffs, especially those cooked, smoked, or cured. NDMA is water-soluble, colorless, and its taste and odor are weak or absent. It is toxic to the liver and other organs, and is a suspected human carcinogen.
Video N-Nitrosodimethylamine
Properties
NDMA is an industrial by-product or waste product of several industrial processes. Manufacturing of unsymmetrical dimethylhydrazine (UDMH), which is a component of rocket fuel that requires NDMA for its synthesis. Of more general concern, water treatment via chlorination or chloramination of organic nitrogen-containing wastewater can lead to the production of NDMA at potentially harmful levels. Further, NDMA can form or be leached during treatment of water by anion exchange resins. Finally, NDMA is found at low levels in numerous items of human consumption including cured meat, fish, beer, and tobacco smoke It is, however, unlikely to bioaccumulate.
Maps N-Nitrosodimethylamine
Toxicity
N-Nitrosodimethylamine is highly toxic, especially to the liver, and is a suspected human carcinogen. The US Environmental Protection Agency has determined that the maximum admissible concentration of NDMA in drinking water is 0.7 ng L-1. The EPA has not yet set a regulatory maximum contaminant level (MCL) for drinking water. At high doses, it is a "potent hepatotoxin that can cause fibrosis of the liver" in rats. The induction of liver tumors in rats after chronic exposure to low doses is well documented. Its toxic effects on humans are inferred from animal experiments but not well-established experimentally.
NDMA's contamination of drinking water is of particular concern due to the minute concentrations at which it is harmful, the difficulty in detecting it at these concentrations, and to the difficulty in removing it from drinking water. It does not readily biodegrade, adsorb, or volatilize. As such, it cannot be removed by activated carbon and travels easily through soils. Relatively high levels of UV radiation in the 200 to 260 nm range breaks the N-N bond and can thus be used to degrade NDMA. Additionally, reverse osmosis is able to remove approximately 50% of NDMA.
It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.
As a poison
On April 13, 1978, a teacher in Ulm, Germany was convicted for the murder of his (then living) wife using NDMA. As a teacher of chemistry, the perpetrator could easily order the substance and did so three times--a total of 85 grams (3 oz). He mixed the poison into blackberry jam, which was a favorite dessert of his wife. The victim became seriously ill and was taken to the hospital, where her husband continued to supply her the poisoned jam. The victim became suspicious when her husband called her asking if she had eaten all of the jam. The blackberry jam was then analyzed in a forensic lab. Mice that were fed it died within two days. NDMA was detected. The teacher was sentenced to life in prison; his wife died soon after the trial. The perpetrator died two years later of cancer of the liver. The NDMA was named "N" in the trial and in all press publications in Germany at the time, to prevent copy-cat murders.
On September 10, 1978, Steven Roy Harper, a jealous former boyfriend of Sandra Johnson, spiked lemonade with NDMA at the Johnson family home in Omaha, Nebraska. Harper had acquired NDMA working at the UNMC Eppley Cancer Center in March 1978. At the time, this substance was in common use in the laboratory to induce cancer in mice for study. The incident resulted in the death of 11-month-old Chad Sheldon and 30-year-old Duane Johnson from, ultimately, massive liver damage. NDMA produced very characteristic lesions in the liver, rapidly declining platelet count, and highly elevated SGOT levels. Other symptoms included headache, fever, vomiting, abdominal pain, scattered intradermal hemorrhage, lethargy, nausea, and diarrhea. Harper was sentenced to death for his crime but committed suicide before his execution could be carried out.
Huang Yang (Chinese: ??; pinyin: Huáng Yáng, 1985 - April 16, 2013), age 28, a postgraduate medical student at Fudan University, was the victim of a N-Nitrosodimethylamine poisoning in Shanghai, China. Huang is believed to have been poisoned by his roommate via a dispenser in his dormitory on April 1, 2013. Huang was critically ill within hours. A few days later, investigators established Huang had ingested NDMA. He died in 15 days after getting sick. His roommate, another medical student who had written several papers on NDMA, was detained and is the only suspect. In the progression of the poisoning, his liver function had been damaged in Day 2, blood platelet levels fell in Day 3, nose first started bleeding in Day 5, and he fell into a coma in Day 8. His pupils dilated in Day 14, and he suffered from pulmonary fibrosis in Day 15.
References
External links
- Nitrosodimethylamine (NDMA) Information
- CDC - NIOSH Pocket Guide to Chemical Hazards
- Method Development for the Determination of N-Nitrosodimethylamine (NDMA) in Drinking Water
- SFPUC NDMA White Paper
- Public Health Statement for n-Nitrosodimethylamine
- Toxicological Profile for n-Nitrosodimethylamine CAS# 62-75-9
Source of article : Wikipedia
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