Gastric cancer
Pat Price, Karol Sikora in Treatment of Cancer, 2014
H. pylori eradication has been demonstrated to reverse many of the findings regarded as pre-malignant in the stomachs of infected individuals. There is, however, only indirect evidence that eradication may prevent gastric cancer. Other interventional studies have looked at increasing dietary antioxidants and COX2 inhibitors in at-risk populations, but such studies have had inconclusive results to date. These were low intake of animal fat and protein, high intake of complex carbohydrates, nitrate or salt and a low intake of salads, fresh greens and fruit. When the pH of the stomach is higher than usual, bacteria can survive and may reduce dietary nitrate to nitrite to form N-nitroso compounds through nitrosation of dietary amines. N-nitroso compounds are known to be carcinogenic in animals. The source of dietary nitrites is preservatives and colouring agents, especially in home-cured meats, dried fish and sausages. Nitrates are found in crop fertilizers and recycled sewage and they can be converted to nitrites by bacterial action in the food or in the stomach. The protective effect of greens may be explained by the possibility that ascorbic acid may increase gastric acidity and block the bacterial conversion of ingested nitrate to nitrite thereby decreasing the concentration of nitrosanes. This may also explain the role of diffuse H. pylori infections associated with achlorhydria. Other conditions associated with reduced gastric acid production such as pernicious anaemia and previous gastric surgery have also been linked with a higher incidence of gastric cancer.
Epidemiology of Childhood Brain Tumors
David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack in Brain and Spinal Tumors of Childhood, 2020
There is a limited number of studies that show a possible, but tentative, link between nitrate in drinking water and increased risk of childhood brain tumors126–128 One study from California and Washington state showed conflicting evidence. Overall, there was no association with nitrate. However, there was increased risk for childhood brain tumors in the offspring of women who only used well water.126 Another multicenter, international case-control study found no overall association. However, increased risk of astrocytoma was associated with higher levels of nitrate in the drinking water.127 Another study from Taiwan found increased risk of brain tumors in areas with high nitrate exposure in the water.128 Overall, studies show a possible association with nitrate in drinking water and increased risk of childhood brain tumors (Table 2.15).
Personal Protective Equipment (PPE): Practical and Theoretical Considerations
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
Nitrates are a major component of fertilizers and explosive materials. Since newborns have a higher pH (less acid) in their gastrointestinal tract, they transform ingested nitrates into nitrites more efficiently than adults. While nitrates have no effect on hemoglobin, nitrites oxidize hemoglobin from the ferrous (Fe+2, oxyhemoglobin) to the ferric state (Fe+3, i.e., methemoglobin). While the former (Fe+2, oxyhemoglobin) easily carries oxygen, the later (Fe+3, methemoglobin) is incapable of carrying oxygen, and cellular hypoxia (lack of oxygen in the cells) and tissue acidosis is the result. Fetal hemoglobin, present in young infants, is much more easily oxidized to the ferric state (methemoglobin) than is adult hemoglobin. Although the human body possesses two enzyme systems capable of transforming methemoglobin back into its oxygen-carrying predecessor, babies possess only 50% as much of one of these enzyme systems as do adults (WHO Training, 2008, Slide 21). Hence, babies are more capable of producing methemoglobin and less capable of transforming it back into oxyhemoglobin than adults: a lose–lose situation for the baby.
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.
The concentration and health risk assessment of nitrate in vegetables and fruits samples of Iran
Published in Toxin Reviews, 2021
Fereshteh Mehri, Ali Heshmati, Mehdi Moradi, Amin Mousavi Khaneghah
There is a direct correlation between the degree of toxicity of nitrate and daily intake. In this regard, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) specified the acceptable daily intake (ADI) values for nitrates equal to 3.70 (mg/kg bw/day) (Authority 2008). The estimated daily intake (EDI) values calculated for each one of the samples were shown in Table 2 while the EDI values were decreased in the following order: lettuce > leek > carrot > tomato > watermelon > potato > melon > onion. The lettuce sample had highest EDI value (0.89 mg/kg bw/day) which provided 24.02% of ADI and while the onion sample had lowest EDI value (0.05 mg/kg bw/day) which provided 1.24% of ADI. In our study, the EDI values of potato, onion, was lower, and carrot and lettuce were higher in comparison with findings of Suh et al. (2013) in Korea (Suh et al.2013). EDI values of carrot and tomato samples reported by Gruszecka-Kosowska and Baran (2017) were higher than our findings while EDI of onion and potato samples in mentioned study was lower than the results of the current study (Gruszecka-Kosowska and Baran 2017). Based on our results, the total daily intake of nitrate (2.25 mg/kg bw/day) was lower than the ADI (3.70 mg/kg bw/day).
Multi-parametric groundwater quality and human health risk assessment vis-à-vis hydrogeochemical process in an Agri-intensive region of Indus basin, Punjab, India
Published in Toxin Reviews, 2022
Vijay Jaswal, Ravishankar Kumar, Prafulla Kumar Sahoo, Sunil Mittal, Ajay Kumar, Sunil Kumar Sahoo, Yogalakshmi Kadapakkam Nandabalan
(NO3−) in groundwater was observed high in the south-east part of the study area, unlike (SO42−) that showed elevated level in the central part of the study area. Around 20% of groundwater samples of the study area exceeded the recommended limit of 45 mgL−1 for NO3−. This region of Punjab that is well known for intensive agriculture practices and plantation of wheat and cotton as major crops might be the possible reason for increased NO3− in groundwater. According to Huang (2013), wheat requires high N− based fertilizers. According to ENVIS Centre of Punjab (2018), about 99,000 Tonnes of NPK (68,000 Tonnes of N, 28,000 Tonnes of P2O5 and 3,000 Tonnes of K2O) fertilizers were used during the year 2017. Leaching of nitrate released from the oxidation of organic matter, ammonification and nitrification of nitrogen-containing animal and human excreta might also be the reason for the elevated levels of nitrate in groundwater (Shukla and Saxena 2020a, 2020c, CGWB and GYBI 2012). Moreover, sandy soil in the study area's southern region might facilitate rapid infiltration and minimal evapotranspiration (Nakhaei et al. 2015). According to Ahada and Suthar (2018), elevated levels of SO4 in groundwater samples could be due to both natural (dissolution of sulfate and oxidation of sulfide containing minerals) and anthropogenic sources (power plants, phosphate processing refineries, metallurgical processes, etc.).
Related Knowledge Centers
- Atom
- Nitric Acid
- Oxygen
- Nitrogen
- Chemical Formula
- Salt
- Ion
- Bismuth Oxynitrate
- Conjugate
- Trigonal Planar Molecular Geometry