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Diet and Cancer Prevention
Published in James M. Rippe, Lifestyle Medicine, 2019
Nitrites and nitrates are often used as preservatives in meats and other “cured” products. These additives are not carcinogenic in experimental animals; however, nitrate can interact with dietary substances, such as amines or amides, to produce N-nitroso compounds (nitrosamines and nitrosoamides), which are potent carcinogens in animals and probably humans58 Epidemiologic studies have demonstrated a direct relationship between nitrosamine exposure and cancer of the stomach, esophagus, nasopharynx, urinary bladder, liver, and brain.58 When 14 volunteers consumed a high red meat diet (325 g) compared to an isocaloric high fish diet (375 g), there were significantly higher nitroso compounds excreted in the feces (9 μmol/d vs. 1.7 μmol/d, respectively).59 Several naturally occurring foods and their constituents, including tea, garlic, and cruciferous vegetables, may inhibit the formation of endogenous nitrosamines.60 This reduction in carcinogen formation may contribute to the generally protective effect of fruit and vegetables on cancer risk since vitamin C may reduce their formation while other compounds such as allyl sulfur may reduce their bioactivation to agents that bind to DNA and thereby lead to the initiation phase of cancer.
Health and water chemistry
Published in Sandy Cairncross, Richard Feachem, Environmental Health Engineering in the Tropics, 2018
Sandy Cairncross, Richard Feachem
Nitrate concentrations over 50 mg/l (10 mg/l nitrate-N) in drinking water have long been considered to cause a serious blood condition in infants known as methaemoglobinaemia (blue baby disease, or infantile cyanosis). However, the disease is very rare and is more often due to other causes – only two cases due to nitrates in water were reported in more than 30 years in the USA, where more than 60,000 infants annually drink water which exceeds the guideline value. It is also relatively easy to treat. Very high nitrate concentrations also used to be blamed for causing gastric cancer, but the evidence is now against this (WHO 2011).
Pollution by air, water and land
Published in Richard Lawson, Jonathon Porritt, Bills of Health, 2018
Richard Lawson, Jonathon Porritt
There is a suspicion that nitrates in drinking water may be associated with cancer of the stomach. Nitrates may turn into nitrites and then carcinogenic nitrosamines. However, epidemiological studies to date have not linked high levels of nitrate in drinking water with increased rates of stomach cancer.
A case of pseudohyperchloraemia caused by sodium nitrate ingestion
Published in Clinical Toxicology, 2022
Christopher J. Perkins, Gareth E. Wahl, Melissa J. Gillett
The patient’s initial blood gas results contained a number of abnormal findings. His hypernatraemia could be attributed to dehydration in the setting of vomiting, with a possible contribution from ingested sodium nitrate salt. His hypokalaemia likely represents gut losses and kaliuresis secondary to hyperaldosteronism, again expected in the setting of dehydration. Increased pCO2 is consistent with his use of multiple central nervous system depressant medications, whilst the elevated bicarbonate may be due to a metabolic alkalosis of vomiting. The combination of these two disturbances produced a minimal net change in pH. His acute kidney injury was also most likely caused by dehydration. Methaemoglobinaemia is a recognized feature of both nitrite and nitrate poisoning. It was responsible for his cyanosis, and in this case, did not require specific treatment.
Rising incidence and high mortality in intentional sodium nitrite exposures reported to US poison centers
Published in Clinical Toxicology, 2021
Sean D. McCann, Marit S. Tweet, Michael S. Wahl
Sodium nitrite is a highly water-soluble salt commonly used in industrial chemistry, pharmaceutical production, food processing, and as a therapeutic agent in the treatment of cyanide poisoning [1,2]. The reported lethal dose of ingested nitrite salts in humans is highly variable with a broad range reported between 0.7 and 6 g of nitrite component [3]. Nitrites and nitrates are strong oxidizing agents that, when ingested, can lead to profound and potentially fatal methemoglobinemia [4]. Most cases of acquired methemoglobinemia are mild and morbidity and mortality are rare outcomes [5]. However, in severe cases, the resulting impaired oxygen delivery to tissues can lead to significant end organ damage. The clinical manifestations of impaired hemoglobin function can be further compounded by underlying medical conditions that may affect blood oxygenation and oxygen delivery to tissues, such as anemia, cardiac disease, and pulmonary pathology [4]. Presenting symptoms can include cyanosis, decreased oxygen saturation, hypotension, and central nervous system (CNS) depression, among many others. Methylene blue, while also an oxidizing agent, is used to treat xenobiotic induced methemoglobinemia. Methylene blue is reduced to leukomethylene blue, which then reduces methemoglobin to hemoglobin [4,6]. Early recognition of sodium nitrite associated methemoglobinemia and prompt treatment with methylene blue is important when caring for these patients in the emergency department.
Evaluation of zeolite supported bimetallic nanoparticles of zero-valent iron and copper (Z-nZVI/Cu) in the presence of ultrasonic for simultaneous removal of nitrate and total coliforms from aqueous solutions: optimization and modeling with response surface methodology
Published in Toxin Reviews, 2021
Abdolmotaleb Seid-Mohammadi, Ghorban Asgari, Alireza Rahmani, Tayyebeh Madrakian, Amir Karami
Pollution of surface and underground water by nitrate is one of the major environmental problems in various parts of the world (Mohammadi et al.2011). The extensive use of artificial fertilizers and the discharge of industrial and urban wastewater have resulted in large amounts of nitrate penetration into raw water (Öztürk and Bektaş 2004, Cengeloglu et al.2006). The existence of high levels of nitrate in aqueous solutions can lead to problems such as eutrophication in the receiving waters and the development of methemoglobinemia in children (Li et al.2009, Almasi et al.2018). In addition to nitrate, the presence of organisms causing disease such as bacteria, viruses, and parasites in water has led to health and environmental problems in most countries of the world (Zarpelon et al.2016). Coliform bacteria are an indicator of water contaminated with animal and human wastewater and, if this organism is absent, water can be used as safe for drinking purposes. According to reports, these bacteria are generally not harmful, but other microbes which these bacteria are their indicator can cause short-term effects, e.g. diarrhea, nausea, headaches, and other symptoms (Sun et al.2003, Devi et al.2008, Aziz et al.2013). Therefore, the need to remove this pollutant seems necessary for the purpose of water quality, such as maintaining public health.