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Ghaffari HR, Yunesian M, Nabizadeh R, Nasseri S, Pourfarzi F, Poustchi H, Sadjadi A, Eshraghian A. Assessment of hydrogeochemical characteristics and quality of groundwater resources in relation to risk of gastric cancer: comparative analysis of high- and low-risk areas in Iran. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2020; 43:1-21. [PMID: 32458268 DOI: 10.1007/s10653-020-00562-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/10/2020] [Indexed: 12/24/2022]
Abstract
The chemical quality of groundwater supplies in two high-risk area (HRA) and low-risk area (LRA) for gastric cancer in Iran was assessed through hydrogeochemical analysis and water quality indices. For this aim, Piper and Schoeller diagrams and water quality index (WQI) were applied. In addition, exposure to nitrate via drinking water and its corresponding risk were also assessed using Monte Carlo simulation technique. Data on physicochemical properties of groundwater resources were obtained from Iran Water Resources Management Company. Sampling and analysis of tap water for nitrate concentration were conducted in two cities of Shiraz (as a representative of LRA) and Ardabil (as a representative of HRA). According to Piper diagrams, the dominant hydrogeochemical facies of groundwater supplies in HRA and LRA were Na-HCO3 (43.75%) and Ca-HCO3 (41.77%), respectively. The predominant cations in groundwater resources of HRA were found to be Na+ (68.06%) and Ca2+ (31.94%). For LRA, the typical cations were in decreasing trend: Ca2+ (39.64%) > Mg2+ (18.35%) > Na+ (17.26%). For two areas, HCO3-, SO42- and Cl- were, respectively, the most frequent anions. Two-sample Wilcoxon test showed that there were statistically significant difference between two areas in terms of anions and cations concentrations (p value < 0.05). The mean of total hardness (Ca2+ + Mg2+) concentration of water supplies in LRA (528.1 mg/L) was higher than HRA (263.1 mg/L), whereas the mean of Na+ concentration was found to be lower in LRA (90.6 mg/L) compared with HRA (108.1 mg/L). The sum of nitrate intake and its risk in LRA was higher than HRA. WQI results showed that drinking water quality in HRA and LRA ranged from excellent to poor and most water resources were of a good quality class. Further studies are suggested to investigate the role of drinking water in the etiology of gastric cancer in Iran.
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Affiliation(s)
- Hamid Reza Ghaffari
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Masud Yunesian
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
- Center for Air Pollution Research and Department of Research Methodology and Data Analysis, Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
| | - Ramin Nabizadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Air Pollution Research and Department of Research Methodology and Data Analysis, Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
| | - Simin Nasseri
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Water Quality Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Farhad Pourfarzi
- Digestive Diseases Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Hossein Poustchi
- Digestive Oncology Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Sadjadi
- Digestive Oncology Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahad Eshraghian
- Avicenna Center for Medicine and Organ Transplant, Avicenna Hospital, Shiraz, Iran
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Yin J, Wu X, Li S, Li C, Guo Z. Impact of environmental factors on gastric cancer: A review of the scientific evidence, human prevention and adaptation. J Environ Sci (China) 2020; 89:65-79. [PMID: 31892402 DOI: 10.1016/j.jes.2019.09.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 09/17/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Globally, gastric cancer (GC) ranks fifth in prevalence and third in fatalities, and shows a distinct geographical distribution in morbidity and mortality. Such a spatial pattern indicates that environmental factors could be an important contributor to GC. We reviewed a total of 135 relevant peer-reviewed articles and other literature published 1936-2019 to investigate the scientific evidence concerning the effects of environmental factors on GC worldwide. Environmental factors affect GC from the aspects of water, soil, air, radiation, and geology. Risk factors identified include water type, water pollution, water hardness, soil type, soil pollution, soil element content, climate change, air pollution, radiation, altitude, latitude, topography, and lithology; and most of them have an adverse impact on GC. Furthermore, we found that their effects followed five common rules: (1) the leading environmental factors that affect GC incidence and mortality vary by region, (2) the same environmental factors may have different effects on GC in different regions, (3) some different environmental factors have similar effects on GC in essence, (4) different environmental factors often interact to have combined or synergistic effects on GC, and (5) environmental factors can affect human factors to have an impact on GC. Environmental factors have a great impact on GC. Human beings may prevent GC by controlling carcinogenic factors, screening high-risk populations and providing symptomatic and rehabilitative treatments. Furthermore, adaptation measures are recommended to reduce GC risk on private and public levels. Future studies should transcend existing empirical studies to develop causal relationship models and focus on vulnerable population analysis.
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Affiliation(s)
- Jie Yin
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
| | - Xiaoxu Wu
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
| | - Suping Li
- The Second People's Hospital of Lanzhou City, Lanzhou 730046, China
| | - Chenlu Li
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
| | - Zhiyi Guo
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
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Taneja P, Labhasetwar P, Nagarnaik P, Ensink JHJ. The risk of cancer as a result of elevated levels of nitrate in drinking water and vegetables in Central India. JOURNAL OF WATER AND HEALTH 2017; 15:602-614. [PMID: 28771157 DOI: 10.2166/wh.2017.283] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The objective of the present study was to determine the effect of nitrates on the incidence of gastrointestinal (GI) cancer development. Nitrate converted to nitrite under reducing conditions of gut results in the formation of N-nitrosamines which are linked to an increased gastric cancer risk. A population of 234 individuals with 78 cases of GI cancer and 156 controls residing at urban and rural settings in Nagpur and Bhandara districts of India were studied for 2 years using a case-control study. A detailed survey of 16 predictor variables using Formhub software was carried out. Nitrate concentrations in vegetables and primary drinking water supplies were measured. The logistic regression model showed that nitrate was statistically significant in predicting increasing risk of cancer when potential confounders were kept at base level (P value of 0.001 nitrate in drinking water; 0.003 for nitrate in vegetable) at P < 0.01. Exposure to nitrate in drinking water at >45 mg/L level of nitrate was associated with a higher risk of GI cancers. Analysis suggests that nitrate concentration in drinking water was found statistically significant in predicting cancer risk with an odds ratio of 1.20.
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Affiliation(s)
- Pinky Taneja
- Academy of Scientific and Innovation Research, Water Technology & Management Division, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Academic Council of Scientific & Innovative Research, Nehru Marg, Nagpur 440020, India
| | - Pawan Labhasetwar
- Water Technology & Management Division, CSIR-National Environment and Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440020, India E-mail:
| | - Pranav Nagarnaik
- Water Technology & Management Division, CSIR-National Environment and Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440020, India E-mail:
| | - Jeroen H J Ensink
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; deceased
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Sohail M, Adeloju SB. Nitrate biosensors and biological methods for nitrate determination. Talanta 2016; 153:83-98. [DOI: 10.1016/j.talanta.2016.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 11/16/2022]
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Rao NS. Nitrate pollution and its distribution in the groundwater of Srikakulam district, Andhra Pradesh, India. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/s00254-006-0358-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bharadwaj L, Dhami K, Schneberger D, Stevens M, Renaud C, Ali A. Altered gene expression in human hepatoma HepG2 cells exposed to low-level 2,4-dichlorophenoxyacetic acid and potassium nitrate. Toxicol In Vitro 2005; 19:603-19. [PMID: 15878651 DOI: 10.1016/j.tiv.2005.03.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 03/15/2005] [Accepted: 03/15/2005] [Indexed: 11/24/2022]
Abstract
2,4-dichlorophenoxyacetic acid (2,4-D) and nitrate are agricultural contaminants found in rural ground water. It is not known whether levels found in groundwater pose a human or environmental health risk, nor is the mechanism of toxicity at the molecular/cellular level understood. This study focused on determining whether 2,4-D or nitrate at environmentally realistic levels elicit gene expression changes in exposed cells. cDNA microarray technology was used to determine the impact of 2,4-D and nitrate in an in vitro model of exposure. Human hepatoma HepG2 cells were incubated with 2,4-D or nitrate alone for 24 h. Cell viability (neutral red assay) and proliferation (BrdU incorporation) were assessed following exposure. Total RNA from treated and control cells were isolated, reverse transcribed and reciprocal labelled with Cy3 or Cy5 dyes, and hybridized to a human cDNA microarray. The hybridized microarray chips were scanned, quantified and analyzed to identify genes affected by 2,4-D or nitrate exposure based on a two-fold increase or decrease in gene expression and reproducibility (affected in three or more treatments). Following filtering, normalization and hierarchical clustering initial data indicate that numerous genes were found to be commonly expressed in at least three or more treatments of 2,4-D or nitrate tested. The affected genes indicate that HepG2 cells respond to environmental, low-level exposure and produce a cellular response that is associated with alterations in the expression of many genes. The affected genes were characterized as stress response, cell cycle control, immunological and DNA repair genes. These findings serve to highlight new pathway(s) in which to further probe the effects of environmental levels of 2,4-D and nitrate.
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Affiliation(s)
- Lalita Bharadwaj
- Department of Medicine and Toxicology Group, Institute of Agricultural Rural and Environmental Health, University of Saskatchewan, 103 Hospital Drive, P.O. Box 120, Royal University Hospital, Saskatoon, Sask., Canada S7N 0W8.
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Ogur R, Coskun O, Korkmaz A, Oter S, Yaren H, Hasde M. High nitrate intake impairs liver functions and morphology in rats; protective effects of α-tocopherol. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 20:161-166. [PMID: 21783584 DOI: 10.1016/j.etap.2004.12.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2004] [Accepted: 12/12/2004] [Indexed: 05/31/2023]
Abstract
The aim of this study was to determine the effect of high dose nitrate ingested in drinking water, on liver enzymes and histopathology, liver weight/body weight (lw/bw) ratio, serum and liver malondialdehyde (MDA) levels and osmotic fragility in Sprague-Dawley rats. These parameters were compared on 40 rats divided into four groups; control animals (group A) drank filtered tap water containing maximum 10mg/L nitrate while treatment groups drank 200mg/L (group B), 400mg/L (group C) and α-tocopherol plus 400mg/L (group D) nitrate containing water ad libitum for 60 days. As a result, lw/bw ratio increased significantly (p<0.05) among rats that consumed water with 400mg/L nitrate. Osmotic fragility increased significantly in treatment groups (p<0.05 versus control). Liver but not serum MDA levels increased in group C (p<0.05 versus control). Group A showed normal hepatic lobular architecture and histology. After nitrate administration, there was hepatocellular degeneration with increased intercellular space of the liver cells in groups B and C. Liver MDA, osmotic fragility and liver histology have returned to nearly normal in group D. These findings show clearly that high nitrate ingestion can cause pathological changes in liver histology and functions. Moreover, α-tocopherol can prevent these effects, possibly through antioxidant properties.
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Affiliation(s)
- Recai Ogur
- Division of Environmental Health, Gulhane Military Medical Academy, Ankara, Turkey
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Zaki A, Chaoui AA, Chait A, Aboussaouira T, Zarrouk K, Himmi T. Impact des nitrates inorganiques sur l’aspect morphofonctionnel du rein chez le rat. Therapie 2005; 60:75-9. [PMID: 15929477 DOI: 10.2515/therapie:2005010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM The aim of our experimental study was to determine the effect of exogenic nitrates on certain biological parameters in relation to renal insufficiency. RESULTS Chronic treatment of rats for 5 months with varying nitrate concentrations (50, 100, 150 and 500 mg/L) induced a dose-dependent reduction in plasma concentrations of total proteins and a dose-dependent increase in plasma urea concentrations and creatinine. DISCUSSION This histological study of the kidney shows that nitrates at doses of 150 and 500 mg/L cause a deterioration in the epithelia of the renal tubules. CONCLUSION In conclusion, a high nitrate intake induces morphofunctional disturbances of the kidney and could thus be regarded as a causative factor in renal insufficiency.
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Affiliation(s)
- Abdelwahab Zaki
- Laboratoire de Physiologie Animale, Faculté des Sciences et Techniques, Béni Mellal, Maroc.
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Criss RE, Davisson ML. Fertilizers, water quality, and human health. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:A536. [PMID: 15238290 PMCID: PMC1247390 DOI: 10.1289/ehp.112-a536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
| | - M. Lee Davisson
- Lawrence Livermore National Laboratory, Livermore, California
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Morris RD, Cole D. Environmental health surveillance: indicators for freshwater ecosystems. CANADIAN JOURNAL OF PUBLIC HEALTH = REVUE CANADIENNE DE SANTE PUBLIQUE 2002; 93 Suppl 1:S39-S44. [PMID: 12425174 PMCID: PMC6980092 DOI: 10.1007/bf03405117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The relationship between the health of human populations and the state of the ecosystems in which they live is profoundly complex. As most environmental indicators relevant to human health depend on evidence of a direct cause and effect relationship, there are few indicators of the less direct consequences of environmental degradation on human health. Indicators of the direct consequence of contaminants in freshwater ecosystems on human health are highlighted in this paper and candidate indicators for environmental health are provided. Many of the indicators included here are from the State Of the Lakes Ecosystem Conference (SOLEC) program. SOLEC conferences in the past (1994 and 1996) examined the state of various components of the ecosystem through the use of ad hoc indicators, and provided subjective assessments of certain environmental conditions. At SOLEC 98, a comprehensive suite of 80 Great Lakes ecosystem health indicators was presented for review, refinement and acceptance. Candidate indicators for freshwater systems and environmental health presented here are organized following the "Pressure-State-Response" framework and cover the areas of drinking water, recreational water, freshwater food sources, and the availability of freshwater for economic activities.
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Affiliation(s)
- Robert D Morris
- Tufts University, School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
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Sandor J, Kiss I, Farkas O, Ember I. Association between gastric cancer mortality and nitrate content of drinking water: ecological study on small area inequalities. Eur J Epidemiol 2002; 17:443-7. [PMID: 11855578 DOI: 10.1023/a:1013765016742] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The carcinogenic feature of N-nitroso compounds has been well established. Similarly, the transformation of ingested nitrate to N-nitroso compounds in the stomach has been thoroughly documented, nevertheless nitrates' carcinogenic effect has not been proved convincingly in human. The present study was aimed to investigate a population of small villages provided by drinking water with high and widely variable nitrate content (72 mg/l median, 290.7 mg/l 95-percentile concentration). Empirical Bayes estimates for settlement-specific age-, sex-, and year-standardised mortality ratios of gastric cancer (GC) were related to the settlement level average nitrate concentrations in drinking water controlling for confounding effects of smoking, ethnicity and education. The log-transformed average nitrate concentration showed significant positive association with stomach cancer mortality in linear regression analysis (p = 0.014). The settlements were aggregated according to the nitrate concentration into 10-percentile groups and the standardised mortality ratios (SMRs) were calculated. Those groups with higher than 88 mg/l average nitrate concentration showed substantial risk elevation and the log-transformed exposure variables proved to be significant predictors of mortality (p = 0.032) at this level of aggregation also. The association seemed to be fairly strong (r2 = 0.46). Although this investigation constituting an ecological study has certain limitations, it supports the hypothesis that the high level of nitrate in drinking water is involved in the development of GC.
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Affiliation(s)
- J Sandor
- Department of Public Health, University of Pecs, Hungary.
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Koparal AS, Öğütveren ÜB. Removal of Nitrate from Aqueous Solutions by Electrodialysis. ACTA ACUST UNITED AC 2002. [DOI: 10.1080/00207230211302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Vermeer IT, van Maanen JM. Nitrate exposure and the endogenous formation of carcinogenic nitrosamines in humans. REVIEWS ON ENVIRONMENTAL HEALTH 2001; 16:105-116. [PMID: 11512627 DOI: 10.1515/reveh.2001.16.2.105] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- I T Vermeer
- Numico Research BV, Wageningen, The Netherlands
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Abstract
The purpose of this study was to determine the effects of administration of high dose nitrate in drinking water on weight gain, hematological parameters and osmotic fragility in rats. We compared these parameters in 40 rats divided into four groups (one control and three treatment groups). Control animals drank filtered tap water containing a maximum of 10 mg/l nitrate while the treatment groups drank 100 mg/l, 200 mg/l and 400 mg/l nitrate-containing water ad libitum for 60 days. Animals in the treatment groups gained less weight than the control group and the differences between the control and treatment groups were statistically significant (p < 0.05). At the concentration of 100 mg/l nitrate, platelet counts and hemoglobin levels were significantly increased compared with the control group (p < 0.05). At the concentration of 200 mg/l nitrate, erythrocyte counts, hemoglobin and hematocrit levels were significantly increased compared with the control group (p < 0.05). At the concentration of 400 mg/l nitrate, platelet counts were decreased significantly when compared with the first two treatment groups (p < 0.05). There were statistically significant differences in osmotic fragility ratios between treatment groups and the control group (p < 0.05). We concluded that high nitrate intake in drinking water decreases weight gain, affects hematological parameters by inducing bone marrow activity at low doses and inhibiting it at high doses, and increases erythrocyte osmotic fragility.
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Knobeloch L, Salna B, Hogan A, Postle J, Anderson H. Blue babies and nitrate-contaminated well water. ENVIRONMENTAL HEALTH PERSPECTIVES 2000; 108:675-8. [PMID: 10903623 PMCID: PMC1638204 DOI: 10.1289/ehp.00108675] [Citation(s) in RCA: 227] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The use of nitrate-contaminated drinking water to prepare infant formula is a well-known risk factor for infant methemoglobinemia. Affected infants develop a peculiar blue-gray skin color and may become irritable or lethargic, depending on the severity of their condition. The condition can progress rapidly to cause coma and death if it is not recognized and treated appropriately. Two cases of blue baby syndrome were recently investigated. Both cases involved infants who became ill after being fed formula that was reconstituted with water from private wells. Water samples collected from these wells during the infants' illnesses contained nitrate-nitrogen concentrations of 22.9 and 27.4 mg/L.
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Affiliation(s)
- L Knobeloch
- Wisconsin Department of Health and Family Services, Madison 53703-3044, USA.
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Abstract
Based on the premise that dietary nitrate is detrimental to human health, increasingly stringent regulations are being instituted to lower nitrate levels in food and water. Not only does this pose a financial challenge to water boards and a threat to vegetable production in Northern Europe, but also may be eliminating an important non-immune mechanism for host defence. Until recently nitrate was perceived as a purely harmful dietary component which causes infantile methaemoglobinaemia, carcinogenesis and possibly even teratogenesis. Epidemiological studies have failed to substantiate this. It has been shown that dietary nitrate undergoes enterosalivary circulation. It is recirculated in the blood, concentrated by the salivary glands, secreted in the saliva and reduced to nitrite by facultative Gram-positive anaerobes (Staphylococcus sciuri and S. intermedius) on the tongue. Salivary nitrite is swallowed into the acidic stomach where it is reduced to large quantities of NO and other oxides of N and, conceivably, also contributes to the formation of systemic S-nitrosothiols. NO and solutions of acidified nitrite, mimicking gastric conditions, have been shown to have antimicrobial activity against a wide range of organisms. In particular, acidified nitrite is bactericidal for a variety of gastrointestinal pathogens such as Yersinia and Salmonella. NO is known to have vasodilator properties and to modulate platelet function, as are S-nitrosothiols. Thus, nitrate in the diet, which determines reactive nitrogen oxide species production in the stomach (McKnight et al. 1997), is emerging as an effective host defence against gastrointestinal pathogens, as a modulator of platelet activity and possibly even of gastrointestinal motility and microcirculation. Therefore dietary nitrate may have an important therapeutic role to play, not least in the immunocompromised and in refugees who are at particular risk of contracting gastroenteritides.
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Affiliation(s)
- G M McKnight
- Department of Medicine and Therapeutics, Medical School, University of Aberdeen, Foresterhill, UK
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van Loon AJ, Botterweck AA, Goldbohm RA, Brants HA, van Klaveren JD, van den Brandt PA. Intake of nitrate and nitrite and the risk of gastric cancer: a prospective cohort study. Br J Cancer 1998; 78:129-35. [PMID: 9662263 PMCID: PMC2062934 DOI: 10.1038/bjc.1998.454] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The association between the intake of nitrate or nitrite and gastric cancer risk was investigated in a prospective cohort study started in 1986 in the Netherlands, of 120,852 men and women aged 55-69 years. At baseline, data on dietary intake, smoking habits and other covariates were collected by means of a self-administered questionnaire. For data analysis, a case-cohort approach was used, in which the person-years at risk were estimated from a randomly selected subcohort (1688 men and 1812 women). After 6.3 years of follow-up, 282 microscopically confirmed incident cases of stomach cancer were detected: 219 men and 63 women. We did not find a higher risk of gastric cancer among people with a higher nitrate intake from food [rate ratio (RR) highest/lowest quintile = 0.80, 95% CI 0.47-1.37, trend-P = 0.18], a higher nitrate intake from drinking water (RR highest/lowest quintile = 0.88, 95% CI 0.59-1.32, trend-P = 0.39) or a higher intake of nitrite (RR highest/lowest quintile = 1.44, 95% CI 0.95-2.18, trend-P = 0.24). Rate ratios for gastric cancer were also computed for each tertile of nitrate intake from foods within tertiles of vitamin C intake and intake of beta-carotene, but no consistent pattern was found. Therefore, our study does not support a positive association between the intake of nitrate or nitrite and gastric cancer risk.
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Affiliation(s)
- A J van Loon
- University Masstricht, Department of Epidemiology, The Netherlands
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Abstract
BACKGROUND Although considerable evidence suggests that Helicobacter pylori infection plays a crucial role in the pathogenesis of gastric carcinoma, a striking difference exists between the number of infected individuals and the proportion of those developing gastric carcinoma. The purpose of this article is to review the available evidence supporting the existence of identifiable risk factors for the development of gastric carcinoma. METHODS We performed a critical review of the pertinent literature, which forms the basis for this study. RESULTS In terms of treatment strategies for prevention of gastric carcinoma, cure of H. pylori infection in all infected patients seems unfeasible, mainly for economic reasons. However, the final and definite step to prove that infection with H. pylori is a preneoplastic condition for the development of gastric cancer would be the observation that cure of the infection leads to a significant reduction in gastric cancer incidence rates in comparison with an untreated population. Therefore, in 1997 a multicenter preventive interventional study on gastric carcinoma will be started in Germany. The target group in this study includes patients with a specific pattern of H. pylori gastritis who will be summarized by a "gastric cancer risk index." CONCLUSIONS It is hoped that long-term follow-up of these patients will reveal whether preventive treatment of H. pylori infection is capable of reducing the risk for development of gastric cancer.
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Affiliation(s)
- S Miehlke
- Department of Gastroenterology, Hepatology, and Infectious Diseases, Otto-von-Guericke University, Megdeburg, Germany
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van Maanen JM, Welle IJ, Hageman G, Dallinga JW, Mertens PL, Kleinjans JC. Nitrate contamination of drinking water: relationship with HPRT variant frequency in lymphocyte DNA and urinary excretion of N-nitrosamines. ENVIRONMENTAL HEALTH PERSPECTIVES 1996; 104:522-8. [PMID: 8743440 PMCID: PMC1469364 DOI: 10.1289/ehp.96104522] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We studied peripheral lymphocyte HPRT variant frequency and endogenous nitrosation in human populations exposed to various nitrate levels in their drinking water. Four test populations of women volunteers were compared. Low and medium tap water nitrate exposure groups (14 and 21 subjects) were using public water supplies with nitrate levels of 0.02 and 17.5 mg/l, respectively. Medium and high well water nitrate exposure groups (6 and 9 subjects) were using private water wells with mean nitrate levels of 25 and 135 mg/l, respectively. Higher nitrate intake by drinking water consumption resulted in a dose-dependent increase in 24-hr urinary nitrate excretion and in increased salivary nitrate and nitrite levels. The mean log variant frequency of peripheral lymphocytes was significantly higher in the medium well water exposure group than in the low and medium tap water exposure groups. An inverse correlation between peripheral lymphocyte labeling index and nitrate concentration of drinking water was observed. Analysis of N-nitrosamine in the urine of 22 subjects by gas chromatography-mass spectrometry revealed the presence of N-nitrosopyrrolidine in 18 subjects. Analysis of the mutagenicity of well water samples showed that a small number of the well water samples were mutagenic in the Ames Salmonella typhimurium test after concentration over XAD-2 resin. In conclusion, consumption of drinking water, especially well water, with high nitrate levels can imply a genotoxic risk for humans as indicated by increased HPRT variant frequencies and by endogenous formation of carcinogenic N-nitroso compounds from nitrate-derived nitrite.
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Affiliation(s)
- J M van Maanen
- Department of Health Risk Analysis and Toxicology, University of Limburg, Maastricht, The Netherlands
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Mirvish SS. Role of N-nitroso compounds (NOC) and N-nitrosation in etiology of gastric, esophageal, nasopharyngeal and bladder cancer and contribution to cancer of known exposures to NOC. Cancer Lett 1995; 93:17-48. [PMID: 7600541 DOI: 10.1016/0304-3835(95)03786-v] [Citation(s) in RCA: 584] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The questions of whether and how N-nitroso compounds (NOC) may be inducing cancer in humans are discussed. The principal subjects covered include nitrite-derived alkylating agents that are not NOC, reasons for the wide tissue specificity of carcinogenesis by NOC, the acute toxicity of nitrosamines in humans, mechanisms of in vivo formation of NOC by chemical and bacterial nitrosation in the stomach and via nitric oxide (NO) formation during inflammation, studies on nitrite esters, use of the nitrosoproline test to follow human gastric nitrosation, correlations of nitrate in food and water with in vivo nitrosation and the inhibition of gastric nitrosation by vitamin C and polyphenols. Evidence that specific cancers are caused by NOC is reviewed for cancer of the stomach, esophagus, nasopharynx, urinary bladder in bilharzia and colon. I review the occurrence of nitrosamines in tobacco products, nitrite-cured meat (which might be linked with childhood leukemia and brain cancer) and other foods, and in drugs and industrial situations. Finally, I discuss clues from mutations in ras and p53 genes in human tumors about whether NOC are etiologic agents and draw some general conclusions.
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Affiliation(s)
- S S Mirvish
- Eppley Institute for Research in Cancer, Department of Pharmaceutical Sciences, Omaha, NE, USA
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Gangolli SD, van den Brandt PA, Feron VJ, Janzowsky C, Koeman JH, Speijers GJ, Spiegelhalder B, Walker R, Wisnok JS. Nitrate, nitrite and N-nitroso compounds. Eur J Pharmacol 1994; 292:1-38. [PMID: 7867685 DOI: 10.1016/0926-6917(94)90022-1] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A risk assessment has been made on nitrate, nitrite and N-nitroso compounds encountered in the human diet. Vegetables constitute a major source of nitrate providing over 85% of the average daily human dietary intake. Nitrite and N-nitroso compounds present in the diet contribute relatively small amounts to the body burden and the major source of these biologically reactive compounds is derived from the bacterial and mammalian metabolism of ingested nitrate. Additionally, endogenous synthesis provides an important source contributing to the body burden of nitrate. Data from animal toxicological studies, human effects and epidemiological surveys have been reviewed and evaluated. It is concluded that there is no firm scientific evidence at present to recommend drastic reductions beyond the average levels of nitrate encountered in vegetables grown in keeping with good agricultural practice. Recommendations have also been made for further animal and human studies to be carried out to elucidate the potential risks to man from ingested nitrate.
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Affiliation(s)
- P I Reed
- Lady Sobell Gastrointestinal Unit, Wexham Park Hospital, Slough, Berkshire, United Kingdom
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