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Methaemoglobin Levels in Young Children Consuming High Nitrate Well Water in the United States
Abstract
Craun GF [Health Effects Research Laboratory, US Environmental Protection Agency, Cincinnati, Ohio, 45268, USA], Greathouse DG and Gunderson DH. Methaemoglobin levels in young children consuming high nitrate well water in the United States. International Journal of Epidemiology 1981, 10: 309–317.
The EPA limit for nitrate (10 mg/l NO, -N) in drinking water was esteblished to prevent infantile methaemoglo-binemia, an acute condition confined almost exclusively to infants less than three months. This condition is clinically detectable at methaemoglobin levels of approximately 10%. Several studies in the Soviet Union have suggested that elevated methaemoglobin levels from ingested nitrate may not be confined to the young infant and have reported an association between increased methaemoglobin levels of up to 7% in schoolchildren and drinking water with a nitrate concentration of 23–204 mg/l NO,-N. An epidemiologic study of 102 children aged 1–8 conducted in Washington County, Illinois, did not show that ingestion of water with a nitrate concentration of 22–111 mg/l NO, –N was related to increasing methaemoglobin levels nor that the children had high or above normal methaemoglobin levels. The potential for transmission of infectious waterborne disease in this area was demonstrated, however, as a large percentage of the wells used for drinking water contained high numbers of total and faecal conforms.
... Moreover, climate change may intensify the effects of nitrate pollution on temperate rivers if shifts in precipitation regimes increase agricultural run-off [2]. Nitrate toxicity has long attracted the attention of public health agencies after nitrateinduced oxidation of respiratory pigment (methemoglobinemia) was recorded in U.S. babies [19]. Studies have since reported diseases other than respiratory issues in humans and in laboratory and domestic animals after drinking nitrate-polluted water, including mortality, oxidative stress, hypertension, birth defects, diabetes, impaired thyroid function, spontaneous abortions or cancer [11,20,21]. ...
... Even though fish differed in food intake amongst nitrate treatments, we did not observe overt signs of disease, including reduced fish growth. Reduced food ingestion in males may be attributed to fatigue because nitrate forms methaemoglobin, which transports oxygen worse than haemoglobin [19]. However, fish can cope with moderate methaemoglobinemia [72], especially in hard water, such as ours in the laboratory, which may have mitigated nitrate adverse effects [60]. ...
Agricultural intensification and shifts in precipitation regimes due to global climate change are expected to increase nutrient concentrations in aquatic ecosystems. However, the direct effects of nutrients widely present in wastewaters, such as nitrate, are poorly studied. Here, we use multiple indicators of fish health to experimentally test the effects of three ecologically relevant nitrate concentrations (<10, 50 and 250 mg NO3-/l) on wild-collected mosquitofish (Gambusia holbrooki), a species widely introduced for mosquito biocontrol in often eutrophic waters. Overall, biomarkers (histopathology, feeding assays, growth and caloric content and stable isotopes as indicators of energy content) did not detect overt signs of serious disease in juveniles, males or females of mosquitofish. However, males reduced food intake at the highest nitrate concentration compared to the controls and females. Similarly, juveniles reduced energy reserves without significant changes in growth or food intake. Calorimetry was positively associated with the number of perivisceral fat cells in juveniles, and the growth rate of females was negatively associated with δ15N signature in muscle. This study shows that females are more tolerant to nitrate than males and juveniles and illustrates the advantages of combing short- and long-term biomarkers in environmental risk assessment, including when testing for the adequacy of legal thresholds for pollutants.
... The major biological effect of nitrite in humans is its involvement in the oxidation of normal hemoglobin to methemoglobin, which is unable to transport oxygen. When the concentration of methemoglobin reaches 10% of that of hemoglobin, the condition called methemoglobinemia or blue baby syndrome causes cyanosis and, at higher concentrations, asphyxia [25,26]. ...
... On the basis of SAR values, irrigation water is classified into 4 sodium hazard classes: low (<10), medium (10)(11)(12)(13)(14)(15)(16)(17)(18), high (18)(19)(20)(21)(22)(23)(24)(25)(26), and very high (>26). SAR values in the studied area are below 10 and therefore the groundwater of the study area has a very low sodium hazard. ...
Wastewater and groundwater samples of Sanganer were studied to find out the pollution load of wastewater generated from dyeing and printing units and its impact on the quality of domestic wastewater of the Amanishah Nallah and groundwater. The wastewater of these units was found to have high concentrations of sodium, chloride, and sulfate. It has remarkable concentrations of copper, chromium, and iron with low chemical oxygen demand and nearly 7-fold biochemical oxygen demand. The wastewater of these units, discharged on land without any treatment, comes into the Amanishah Nallah through small watercourses. The quality of the domestic wastewater of Nallah deteriorates with the mixing of wastewater from these units. Maximum concentrations of physicochemical parameters were found at the Sanganer Road bridge sampling point. Eleven groundwater samples, collected from various locations of Sanganer, were found polluted due to percolation of wastewater into the ground. Copper and chromium were recorded from some groundwater sources while iron was recorded from almost all sources. Sodium and chloride are the major cation and anion in the groundwater, which is identical to the wastewater of dyeing and printing units. Source G5, near the small watercourse carrying the wastewater of these units, had maximum impact and maximum values of physicochemical parameters.
... NO Previous available studies [10,11] related to MetHb levels in children showed contradictory findings ( Table 1), suggesting the involvement of potential extraneous factors on the relationship between nitrate in drinking water and MetHb level. As well-waters in rural areas may be contaminated with both nitrate as a consequence of agricultural activities, and microorganisms particularly ...
... The strengths of the current study include a larger sample size than in previous studies [10,11] and complete data and covariate information. The study power was sufficient (>20%) to determine a relationship between exposure to nitrate and abnormal MetHb if it exists. ...
Previous studies showed contradictory findings regarding the relationship between nitrate in drinking well-water and abnormal methemoglobin (MetHb) level (>2%) among children. We studied the effect of water chlorination in this relationship in children aged up to 7. 240 subclinical children participated in this cross-sectional study. Water nitrate was analyzed for each participant, and so was blood MetHb. Analysis of two water nitrate exposure levels (50 mg/L as )-other extraneous factors (Breslow-Day-Test for interaction), bivariate and multivariate analyses were performed. Abnormal MetHb levels (up to 7.9%) were associated (p-value = 0.020) with exposure to drinking water nitrate. Only water chlorination was an effect modifier. Among those who do not disinfect water, the prevalence of ab- normal MetHb for those with nitrate level >50 mg/L was 4.95 (p-value = 0.001, 95% CI = [1.92 - 12.79]) times the prevalence for those with nitrate level <50 mg/L. Whereas, among those who do disinfect water, the prevalence for those with high nitrate levels was only 1.38 (p-value = 0.435, 95% CI = [0.62 - 3.07]) times the prevalence of those with low nitrate levels. The biological plausibility of a relationship between waterborne microorganisms, drinking water nitrate, drinking water chlorination, and development of an abnormal MetHb level needs to be further explored.
... This excess of nitrates often indicates anthropogenic pollution around several structures located in Yayéme, Samba Dia, Fimela, Keur Moussa Diarra … The use of high nitrate water for drinking reduces the oxygen carrying capacity of the blood and can lead to "blue disease" (methemoglobinemia) in babies[28] [29] [30][31]. This may be due to the reduction of nitrate to nitrite which reacts with hemoglobin in the blood to form methemoglobin. ...
... 6 However, a higher percentage is found in individuals who suffer from methemoglobinemia due to genetic diseases [9][10][11][12] or exposure to certain chemicals and drugs. [13][14][15][16][17] Severe untreated methemoglobinemia is life-threatening and may cause death when methemoglobin levels in the blood stream exceed 70%. 6,18 There are many case reports of potentially serious methemoglobin levels induced by topical anesthesia with lidocaine and benzocaine. ...
Significance:
Untreated methemoglobinemia may cause severe hypoxemia and even death when methemoglobin levels in the blood stream exceed 70%. Although CO-oximetry can be used to monitor the response to treatment for methemoglobinemia, it is costly and requires an invasive procedure for collecting blood samples from patients. A pulse CO-oximeter with a contact probe can be used to continuously and non-invasively measure the percentage of methemoglobin, as well as the percutaneous oxygen saturation. In terms of the prevention of infectious diseases, however, it is desirable to monitor methemoglobin and oxygen saturation levels in a non-contact manner. Diffuse reflectance spectral imaging is promising as a non-contact, non-invasive, and cost-effective clinical diagnostic tool for methemoglobinemia.
Aim:
To demonstrate the feasibility of visible spectral diffuse reflectance for in vivo monitoring of hemoglobin derivatives and evaluating methemoglobin production and reduction as well as hypoxemia during methemoglobinemia in rats.
Approach:
A new imaging approach based on the multiple regression analysis aided by Monte Carlo simulations for light transport was developed to quantify methemoglobin, oxygenated hemoglobin, and deoxygenated hemoglobin using a hyperspectral imaging system. An in vivo experiment with rats exposed to sodium nitrite (NaNO2) at different doses was performed to confirm the feasibility of the method for evaluating the dynamics of methemoglobin, oxygenated hemoglobin, and deoxygenated hemoglobin during methemoglobinemia. Systemic physiological parameters, including the percutaneous arterial oxygen saturation, heart rate (HR), and pulse distention, were measured by a commercially available pulse oximeter, and the results were compared to those obtained by the proposed method.
Results:
Both the methemoglobin concentration and methemoglobin saturation rapidly increased with a half-maximum time of <20 min. They reached their maximal values nearly 60 min after the administration of NaNO2. Tissue oxygen saturation dramatically dropped to a minimum of 33.7 % ± 0.4 % , 23.1 % ± 5.6 % , 8.8 % ± 1.7 % , and 9.7 % ± 5.1 % on average for NaNO2 doses of 25, 37.5, 50, and 75 mg/kg, respectively. Changes in methemoglobin concentration and tissue oxygen saturation are indicative of the temporary production of methemoglobin and severe hypoxemia during methemoglobinemia. Profound increases in the HR and pulse distention implied an elevated cardiac output caused by tachycardia and the resultant increase in peripheral blood volume to compensate for the hypoxia and hypoxemia during methemoglobinemia. This was in agreement with the time course of the peripheral hemoglobin volume concentration obtained by the proposed method.
Conclusions:
The proposed method is capable of the in vivo non-contact simultaneous evaluation of methemoglobin levels and hypoxemia during methemoglobinemia, and that it has potential as a tool for the diagnosis and management of methemoglobinemia.
... The major biological effect of nitrite in human is its involvement in the oxidation of normal hemoglobin to methaemoglobin, which is unable to transport oxygen. When the concentration of methaemoglobin reaches 10% of that of hemoglobin; the condition called mathaemoglobinaemia or blue baby syndrome, cause cyanosis and at higher concentration asphyxia (Sallman, 1957;Craun et al., 1981). Such reports of other health disorder namely non Hodgkin's lymphoma (Weisenbeage, 1991) has increased infant mortality (Super et al., 1981) and hypertension (Malberg et al., 1978) have also been recorded. ...
... In the bloodstream, NO 2 is involved in the oxidation of haemoglobin Hb to methaemoglobin metHb ; the Fe 2+ present in the haem group is oxidized to the Fe 3+ form, and the remaining NO 2 binds firmly to this oxidized haem. The Fe 3+ form does not allow oxygen transport due to the strong binding of oxygen Jaffé, 1981;Craun et al., 1981 . The toxicity of NO 3 -N to humans is due primarily to its reduction to NO 2 -N. ...
Nitrate-nitrogen (NO3-N) and nitrite-nitrogen (NO2-N) are constituents of the nitrogen cycle. NO3-N is toxic to humans, primarily due to its reduction to NO2-N. In Japan, NO3-N and NO2-N levels in tap water must not exceed 10 mg/L and only NO2-N alone not 0.04 mg/L, respectively. In this study, we verified the effect of microorganisms and ultraviolet (UV) to increase of NO2-N in water. First, all tested drinking-waters including tap water and commercial mineral water in PET bottles had < 2 mg/L NO3-N and undetectable levels (< 0.01 mg/L) of NO2-N. However, we found that NO2-N was generated in tap water left to stand at room temperature for several days, leading to increases in CF and TC counts and reduction of NO3-N. We also demonstrated that direct UV and sunlight irradiation of NO3-N-containing drinking water generated NO2-N in 1-2 h, with NO2-N reaching > 0.04 mg/mL by 4-6 h. On the other hand, NO3-N and NO2-N were undetectable in commercially purified water.
... A significant part of this load is associated with the supply of nitro compounds (primarily nitrates) with drinking water. According to WHO, in some countries up to 10% of the population consumes water containing nitrates at concentrations above the permissible level (50 mg / l for NO 3 ) (Craun et al., 1981). Nitrates that come from outside or are formed endogenously are partially converted into nitrites, which are 10 times more toxic than their predecessors. ...
The problem of pollution with nitrates and nitrites of the natural environment is very relevant nowadays. The purpose of this research was to study the morphological features of the myocardium in pregnant rats and their newborn pups exposed to chronic hemic hypoxia induced by sodium nitrite. The changes in the contractile apparatus of cardiomyocytes were atrophy and lysis of myofibrils which were most pronounced at the periphery of the cardiomyocytes, near the capillaries. A similar condition of the microcirculatory vessels accompanies absolutely all types of cardiomyopathies, regardless of the genesis of the disease. Cell-stromal relationships on the background of chronic myocardial ischemia cause destructive processes of myocardial remodeling. The final morphological outcome of prolonged hypoxic heart damage can be focal dystrophy of the myocardium, which leads to the development of chronic heart failure and the appearance of life-threatening arrhythmias.
... Sodium nitrite reacts with Hb, leading to methemoglobinemia which reduces O 2 transport causing organ's injury. 18 An imbalance of the redox state induced by S.nit is considered the main cause of the alteration in liver function. 2 Pretreatment with L-argin, carno, or their combination markedly mitigated the reduced blood Hb matched with S.nit-intoxicated rats, which was attributed to their marked antioxidant index. ...
This study assessed the effect of L-arginine (L-argin), carnosine (carno), or their combination in the amelioration of certain biochemical indices induced in the liver of hypoxic rats. Hypoxia was induced via sodium nitrite (S.nit) injection at a dose of 75 mg/kg. Rats were administered L-argin (250 mg/kg) or carno (250 mg/kg), either alone or in combination, 24 hours and 1 hour prior to S.nit intoxication. Hypoxia significantly elevated serum alanine aminotransferase, in addition to a significant upregulation of hepatic heat shock protein 70 with concurrent reduction in the level of vascular endothelial growth factor. Moreover, hepatic vascular endothelial growth factor 1 (flt-1), hypoxia inducible factor-1α gene expression, and cytochrome P450 levels were elevated, compared with the normoxic group. The antioxidants, administered either alone or in combination, markedly downregulated all of the previously mentioned biomarkers, compared to the hypoxic rats. Histopathological examination revealed hepatocellular degeneration and nuclear pyknosis, in addition to inflammatory cellular infiltration in the hypoxic rats, whereas treatment with the studied antioxidants improved the liver architecture. The present data revealed the efficacy of L-argin and carno in ameliorating the hepatic damage induced via angiogenic markers in response to hypoxia, the combination regimen showing the superior effect.
... Excess chloride in water is usually taken as an index of pollution and reflected as tracer for groundwater contamination [12,13]. Nitrate can reach groundwater as a consequence of agricultural activity, wastewater treatment and oxidation of nitrogenous waste products in excreta [14,15]. Higher contents (up to 3 mg/L) of ammonia are found in strata rich in humic substances or iron or in forests [16]. ...
Objective:
This study aims at assessing the groundwater quality of the three districts of Eastern Terai region of Nepal viz. Morang, Jhapa, Sunsari using physicochemical characteristics and statistical approach so that possible contamination of water reservoir can be understood. pH, temperature, conductivity, turbidity, color, total dissolved solids, fluorides, ammonia, nitrates, chloride, total hardness, calcium hardness, calcium, magnesium, total alkalinity, iron, manganese, arsenic have to be analyzed to know the present status of groundwater quality.
Results:
Results revealed that the value of analyzed parameters were within the acceptable limits for drinking water recommended by World Health Organization except for pH, turbidity, ammonia and iron. As per Nepal Drinking Water Quality Standards, fluoride and manganese too were not complying with the permissible limit. Electrical conductivity, total dissolved solids, chloride, total hardness, calcium hardness, manganese, and total alkalinity show good positive correlation with major water quality parameters. Calcium, magnesium, total hardness, calcium hardness and total alkalinity greatly influences total dissolved solids and electrical conductivity. ANOVA, Tukey, and clustering highlight the significance of three districts. Groundwater can be considered safe, but there is always a chance of contamination through chemical wastes in the heavily industrialized area of Morang and Sunsari Industrial corridor.
... One chemical of major concern is nitrate-nitrogen contamination (NO 3 -N) on surface and ground water as it poses serious health problems (Almasiri and Kaluarachchi, 2007). Methaemoglobinemia in infancy is related to nitrate ingestion resulting in low oxygen intake and consequently causing death (Craun et al., 1981;Aslan and Cakici, 2007). Furthermore, presence of nitrates in drinking water results in the formation of nitrosomines in the stomach, which are carcinogenic (Shuval and Gruener, 1977;Aslan and Cakici, 2007;Speijers and Fawell, 2011). ...
Bio-sand filters (BSFs) are point-of-use (POU) potable water filtration
systems commonly used in low-income communities at household level. The
principle of operation is similar to that of a slow sand filter and the major
difference is that they are operated intermittently at the POU. It
is one of the emerging low-cost technologies which makes use of readily and
locally available construction materials but is poor in the removal of
nitrates. In order to enhance the removal of nitrates through
denitrification, a modified BSF with ethanol as an external
carbon source at C / N ratios of 1.1 and 1.8 was investigated. In the
absence of an external carbon source, the nitrate removal efficiency was
32 %, whilst removal efficiencies at C / N ratios of 1.1 and 1.8
were 44 and 53 % respectively. The inflow rate reduced significantly
from an initial flow rate of 0.04 to 0.01 m3 h−1. The
reduction in the inflow rate was mainly due to the growth of the biological
layer on the filter media. The study showed that the use of an external
carbon source like ethanol in bio-sand filtration enhances the removal of
nitrates in potable water.
... Unlike the ferrous form of hemoglobin, methemoglobin does not strongly bind with oxygen. NaNO 2 is highly reactive with hemoglobin causing methemoglobinemia, a condition in which there is a reduction in hemoglobin stability to transmit oxygen leading to hypoxia (Craun et al., 1981;Knobeloch et al., 2000). Our bodies require oxygen to metabolize glucose. ...
Sodium nitrite (NaNO2) is an inorganic salt used broadly in chemical industry. NaNO2 is highly reactive
with hemoglobin causing hypoxia. Mesenchymal stem cells (MSCs) are capable of differentiating into a
variety of tissue specific cells and MSC therapy is a potential method for improving brain functions. This
work aims to investigate the possible therapeutic role of bone marrow-derived MSCs against NaNO2
induced hypoxic brain injury. Rats were divided into control group (treated for 3 or 6 weeks), hypoxic
(HP) group (subcutaneous injection of 35 mg/kg NaNO2 for 3 weeks to induce hypoxic brain injury), HP
recovery groups N-2wR and N-3wR (treated with the same dose of NaNO2 for 2 and 3 weeks respectively,
followed by 4-week or 3-week self-recovery respectively), and MSCs treated groups N-2wSC and N-3wSC
(treated with the same dose of NaNO2 for 2 and 3 weeks respectively, followed by one injection of 2 ×
106 MSCs via the tail vein in combination with 4 week self-recovery or intravenous injection of NaNO2
for 1 week in combination with 3 week self-recovery). The levels of neurotransmitters (norepinephrine,
dopamine, serotonin), energy substances (adenosine monophosphate, adenosine diphosphate, adenosine
triphosphate), and oxidative stress markers (malondialdehyde, nitric oxide, 8-hydroxy-2′-deoxyguanosine,
glutathione reduced form, and oxidized glutathione) in the frontal cortex and midbrain were measured
using high performance liquid chromatography. At the same time, hematoxylin-eosin staining was
performed to observe the pathological change of the injured brain tissue. Compared with HP group, pathological change of brain tissue was milder, the levels of malondialdehyde, nitric oxide, oxidized glutathione, 8-hydroxy-2′-deoxyguanosine, norepinephrine, serotonin, glutathione reduced form, and adenosine triphosphate in the frontal cortex and midbrain were significantly decreased, and glutathione reduced form/
oxidized glutathione and adenosine monophosphate/adenosine triphosphate ratio were significantly
increased in the MSCs treated groups. These findings suggest that bone marrow-derived MSCs exhibit neuroprotective effects against NaNO2-induced hypoxic brain injury through exerting anti-oxidative effects
and providing energy to the brain.
... Methemoglobinemia prevalence has not increased in America in 64 children of 1 to 8 years of age that used well water contaminated with nitrate at concentrations of 97 to 491 mg per liter. In contrast, in 38 infants, who used well water containing concentrations of 44.3 mg per liter, methemoglobinemia prevalence had increased (56). On the other hand, in the study conducted by WHO, no exact correlation was found between the impact of certain concentrations of nitrates in drinking water and the incidence of methemoglobinemia (57). ...
... While all spring categories share the same MgCl2 as the primary water salt, the discrepancy between groups lies in the hypothetical composition of secondary and tertiary salts, nitrate and excessive sodium contents and discharge due to dilution and leaching processes, anthropogenic pollution (likely leachate from livestock waste) and other interacting factors that led to decreasing conductivity values. (Craun et al, 1981;Madisonet al, 1985;Avery, 1999;Mesinga et al, 2003;Manassaram et al, 2007;Gatseva et al, 2008;Bryan et al, 2011). ...
This work investigates the water quality characteristics of the Séraïdi springs using old and recently gathered analytical data in order to understand their vulnerability to pollution. The synthesis of analytical and multivariate statistics results allows a hydro geochemical and microbiological characterization of spring water in the Séraïdi region. The results show that this forested, humid and heavily fractured area contains a shallow aquifer highly vulnerable to pollution from anthropogenic sources. Physical and chemical analyzes of major elements indicate that the overall mineralization is low to moderate and is closely related to magnesium, calcium and sodium chloride salts with significant nitrate and sulfate contents. This global mineralization is controlled by soil leaching during high water periods, acid hydrolysis phenomena of underlying rocks and human activities. Recent microbiological test results highlight the presence of Escherichia coli, Clostridia and total coliforms in water. The outbreak of these microorganisms in some spring waters points out that groundwater is exposed to fecal microbiological pollution of human and/or animal origin. This water quality degradation tends to seriously impair the physical-chemical and microbiological quality of water. It constitutes a health risk to the local population and those in search of supposedly fresh and high quality water.
... The higher nitrate concentrations are mainly encountered in the urban area and in the rural area due to agricultural activities. The use of waters with a high nitrate level for drinking purpose reduces the oxygen carrying capacity of the blood and can lead to ''blue disease'' (methemoglobinaemia) in babies (Craun et al., 1981;Gupta et al., 1999;Knobeloch et al., 2000;Zeman et al., 2002). This may be due to the reduction of nitrate to nitrite which reacts with hemoglobin in blood to form methemoglobin. High NO 3 concentrations observed in the study area were mainly due to anthropogenic sources like leakage of septic tanks, sewers, improper disposal of domestic waste, animal and human waste and organic matter (Diédhiou et al., 2012). ...
... The hazardous effect of NaNO2 is derived from the reaction of nitrite with amines and amides in food to produce nitrosamines and nitrosamides, respectively, which play vital roles in posing toxic effects in different organs (Tong et al. 2010;El-Sheikh and Khalil 2011). NaNO2 is highly reactive with hemoglobin causing methemoglobinemia , a condition in which there is a reduction in hemoglobin stability to transport oxygen leading to hypoxia (Craun et al. 1981). The administration of sodium nitrite causes dysregulation of inflammation, hypoxia, ischemia , oxidative stress and impaired energy metabolism which finally aggravate organ damage , including renal damage (El-Sheikh and Khalil 2011;Salama et al. 2013;Abu Aita and Mohammed 2014;Al-Gayyar et al. 2014;. ...
This study aimed to explore the effective role of carnosine and /or L- arginine in down regulation of the inflammatory molecule expression caused renal damage in response to sodium nitrite (NaNO2) induced hypoxia in rats . NaNO2 was administered subcutaneously (s.c.) to rats as a single dose (60 mg/kg body weight ). L-arginine (200mg/Kg body weight) and carnosine (250 mg/ Kg body weight ) were administered (i.p.) as a single dose , 24 h before NaNO2 injection. The results revealed that pre- administration of arginine and /or carnosine to NaNO2 hypoxic rats, significantly modulated the increases in serum markers of renal function (creatinine and urea) as well as the decrease in hemoglobin (Hb) level versus hypoxic rats. The two agents each alone or in a combination, markedly down regulated the serum pro-inflammatory molecules, including tumor necrosis factor-α (TNF- α) , C-reactive protein (CRP), vascular endothelial growth factor (VEGF) and heat shock protein -70 (HSP-70) as well as interleukin-6 (IL-6) in renal tissue compared to NaNO2 hypoxic rats . Also, the two agents successfully down modulated the alteration in the serum hypoxia inducible factor 1α (HIF 1α) . The present biochemical results were also supported by histopathological examination. In conclusion, the current data revealed that although the efficacy of arginine or carnosine each alone, their combination was more effective in ameliorating the renal damage induced by inflammatory molecules in response to NaNO2 hypoxia . This may support the use of this combination as an effective drug to treat hypoxic renal damage
... None of the doses exceeded the chronic reference level of 1.6 mg·kg −1 ·d −1 [11]. Craun et al. [23] performed an experiment in The United States of America with a group of 102 children of 1 -8 years of age. The children drank water with nitrate concentrations of 44 up to 500 mg·L −1 , with exposure doses ranging from 2.2 to 25 mg·kg −1 ·d −1 . ...
There exist potential health risks due to the presence of some elements in groundwater. This study presents measurements of gross alpha and beta activity and chemical concentrations (fluorides and nitrates) in 25 water wells in Aldama municipality, Chihuahua, Mexico. Total alpha and beta emitter analyses were performed at the Academic Unit of Nuclear Studies at the Autonomous University of Zacatecas. Radioactive elements were concentrated by total evaporation. All samples were measured with a Wallac-Oy 1411 liquid scintillate with a pulse separation option (Pulse Shape Analysis) for 6 h. Fluorine and nitrate analyses were performed at the Faculty of Engineering of the Autonomous University of Chihuahua by flow injection-hydride generation collection-atomic absorption spectrometry. Exposure levels were calculated for each well and found to exceed maximum limits allowed under Mexican law in terms of 1) gross alpha and beta activity; and 2) fluoride and nitrate concentrations. Gross alpha activity in two wells exceeded the reference value of 0.56 Bq·L −1. Fluorides and nitrates were found in 40% and 48% of water wells, respectively. Fluoride values were higher than 1.5 mg·L −1 , and the exposure doses for adults and children exceeded the reference value of 0.06 mg·kg −1 ·d −1. Children are the most vulnerable, since their intake doses are near or above of 0.12 mg·kg −1 ·d −1 of the minimum level of risk for the development of skeletal fluorosis or bone fractures. On the other hand, while nitrate concentrations in water wells exceeded the drinking water limit of 10 mg·L −1 , this does not represent a serious health risk, since the calculated exposure doses for adults and children are below the chronic reference level of 1.6 mg·kg −1 ·d −1 established by the USEPA.
... According to WHO (2007), nitrate may have a role in protecting the gastrointestinal tract against a variety of gastrointestinal pathogens since nitrous oxide and acidified nitrite have antibacterial properties, however, nitrate in drinking water is an important risk factor for bottle-fed infants (under three months) given increases in methaemaglobinaemia and possible cyanosis (Greer and Shannon, 2005). Older children are relatively insensitive to the effects of nitrate (Craun, Greathouse & Gunderson, 1981). A number of studies (Gatseva & Argirova, 2008;Radikova et al., 2008;Ward et al., 2010) have reported a correlation between various measures of nitrate intake and effects on thyroid function, but all suffer from methodological and data problems that preclude definitive conclusions being drawn about the effect of nitrates in adults. ...
This study was conducted to investigate the potability of 15 samples of water, three each from boreholes (BH1-BH3) and hand-dug wells (HD1-HD3), and nine brands of sachet water (SW1-SW9) that were regularly patronized by the students of Osun State University, main campus, residing in private hostels in Osogbo metropolis. The objective of the study was to determine the quality of such water samples. Borehole and well water samples from selected areas and samples of sachet water regularly vended by different manufacturers and vendors were collected, and subjected to physical, chemical and bacteriological analysis. For physical and chemical analysis Wagtech's photometer plus chemical reagents were used. Total heterotrophic bacteria, total coliforms, and feacal coliforms in the water samples were obtained using, respectively, the pour plate method, membrane filtration and growth on MacConkey agar as well as Eosin Methylene Blue agar. The results showed that all of the samples of sachet water exhibited values of physical / organoleptic parameters, inorganic constituents, and mean coliform and E. coli counts per 100 ml below the WHO/SON maximum permissible levels; and were therefore, considered safe for drinking. There were slightly elevated levels of iron in water samples from the borehole category, BH2 and BH3 with no known health impacts. This is because iron is an essential element in human nutrition. Taste is not usually noticeable at iron concentrations below 0.3 mg/l. Although iron concentrations of 1–3 mg/l can be acceptable for people drinking well-water, no health-based guideline value for iron has been proposed. However, there were slightly elevated nitrate levels in samples from hand-dug wells, HD1 and HD3, suggesting that these water sources were not safe for consumption by infants under three months old. In addition, evidence of feacal coliform in water samples from hand-dug wells HD1 and HD2 suggest that they were not safe for human drinking. It is recommended that water from hand dug wells should be boiled before consumption to ensure public health and safety.
... In one study, chloride in liquid swine manure in open manure storage tanks was found to range from 1208 to 1482 mg/l (Ausable Bayfield CA, 1991) Nitrate: Evidence that nitrate is a significant threat to groundwater has been available for over 50 years (Fitzgerald et al. 1997, Fleming 1992, Frank et al. 1991. Nitrate in excess of 10 mg/l causes blue-baby syndrome (Shuval and Gruener 1972, Comly 1945, Craun et al. 1981). ...
... Craun et al. studied 102 children of ages varying between 1 and 8 years that used water with nitrate concentrations of 97 -492 mg NO 3 -/l. 105 In these cases no abnormal methaemoglobin levels were measured in the blood. All values found were within the normal range. ...
A Heidelberg Appeal Nederland Report
... The U.S. national drinking water standard sets a maximum nitrate-N concentration as 10 mg/L. Above this level it is considered harmful, especially to infants, causing a condition called methemoglobinemia (Craun et al., 1981). ...
... There has also been some debate about the linkage between "high" nitrate concentrations in water, and the development of methaemoglobin in children. Craun et al. (1981) report evidence from Washington County Illinois which did not show that ingestion of water with a nitrate concentration of 22-111 mg/l NO3-N was related to increasing methaemoglobin levels, nor that the children had high or above normal methaemoglobin levels. Shuval's work also failed to identify higher methaemoglobin levels among children in areas with nitrate concentrations varying between 50 and 90 mg/l. ...
... The cyanotic condition, known as methaemoglobinaemia, occurs when iron in hemoglobin is oxidized in tandem with nitrite reduction, producing methaemoglobin (MeHb). The MeHb binds oxygen tightly, preventing its release for bodily function (Craun et al., 1981). Infants (less than 3 months of age) are particularly susceptible to the condition because the high pH of their stomachs causes nitrate to occur as nitrite. ...
... Craun et al. studied 102 children of ages varying between 1 and 8 years that used water with nitrate concentrations of 97 -492 mg NO 3 -/l. 105 In these cases no abnormal methaemoglobin levels were measured in the blood. All values found were within the normal range. ...
... An estimate of the total body pool of V 5+ in healthy individuals is from 100 to 200 mg (Byrne and Kosta, 1978). Samples from the drinking water supplies in the USA showed that the concentration of V 5+ can reach 10 mg l À1 (Craun et al., 1981). Moreover, concentration ranges have been reported at 4.1–13 mg l À1 for the rural UK (Galloway et al., 1982) and 0.12–0.65 mg l À1 in Switzerland (Atteia, 1994) . ...
We recently reported that vanadium (V(5+) ) was able to decrease the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated induction of Cyp1a1 and Nqo1 at mRNA, protein and catalytic activity levels in mouse hepatoma Hepa 1c1c7 and human hepatoma HepG2 cells. However, little is known regarding the in vivo effects. Thus, the objective of this study was to investigate whether similar effects would occur at the in vivo level. Therefore, we examined the effect of exposure to V(5+) (5 mg kg(-1) ) with or without TCDD (15 µg kg(-1) ) on the AhR-regulated genes in kidney, lung and heart of C57BL/6 J mice. Our results demonstrated that V(5+) alone significantly decreased Cyp1b1 protein and catalytic activity levels in kidney at 24 h. Moreover, it significantly potentiated Nqo1 and Gsta1 gene expression in the heart, and only Gsta1 gene expression in the lung. Upon co-exposure, we found that V(5+) significantly inhibited the TCDD-mediated induction of Cyp1a1, Cyp1a2 and Cyp1b1 mRNA, protein and catalytic activity levels in the kidney at 24 h. On the other hand, V(5+) significantly potentiated the TCDD-mediated induction of Nqo1 and Gsta1 protein and activity levels in the kidney. Cyp1a1, Cyp1b1, Nqo1 mRNA, protein and catalytic activity levels in the lung were significantly potentiated at 6 h. Interestingly, all tested genes in the heart were significantly decreased at 6 h with the exception of Gsta1 mRNA. The present study demonstrates that V(5+) modulates TCDD-induced AhR-regulated genes. Furthermore, the effect on one of these enzymes could not be generalized to other enzymes even if it was in the same organ. Copyright © 2012 John Wiley & Sons, Ltd.
... Foods contain V 5+ in the concentration of 10–60 μg (Evangelou, 2002). Samples from the drinking water supplies in the U.S.A. showed that the concentration of V 5+ can reach up to 10 μg V 5+ /L (Craun et al., 1981). Furthermore, weight training athletes are reported to use up to 18.6 mg V 5+ per day (Barceloux, 1999). ...
Recent data suggest that vanadium (V5+) compounds exert protective effects against chemical-induced carcinogenesis, mainly through modifying various xenobiotic metabolizing enzymes. In fact, we have shown that V5+ down-regulates the expression of Cyp1a1 at the transcriptional level through an ATP-dependent mechanism. However, incongruously, there is increasing evidence that V5+ is found in higher amounts in cancer cells and tissues than in normal cells or tissues. Therefore, the current study aims to address the possible effect of this metal on the regulation of expression of an enzyme that helps maintain endogenous antioxidants used to protect tissues/cells from mutagens, carcinogens, and oxidative stress damage, NAD(P)H:quinone oxidoreductase 1 (Nqo1). In an attempt to examine these effects, Hepa 1c1c7 cells and its AhR-deficient version, c12, were treated with increasing concentrations of V5+ in the presence of two distinct Nqo1 inducers, the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and isothiocyanate sulforaphane (SUL). Our results showed that V5+ inhibits the TCDD- and SUL-mediated induction of Nqo1 at mRNA, protein, and catalytic activity levels. At transcriptional level, V5+ was able to decrease the TCDD- and SUL-induced nuclear accumulation of Nrf2 and the subsequent binding to antioxidant responsive element (ARE) without affecting Nrf2 protein levels. Looking at post-transcriptional level; we found that V5+ did not affect Nqo1 mRNA transcripts turn-over rates. However, at the post-translational level V5+ increased Nqo1 protein half-life. In conclusion, the present study demonstrates that V5+ down-regulates Nqo1 at the transcriptional level, possibly through inhibiting the ATP-dependent activation of Nrf2.
It has been estimated that we obtain over three quarters of dietary nitrate from vegetables and fruits. Nitrate-rich vegetable types include leafy greens and certain root vegetables (e.g., beetroots and radishes). The salivary glands actively concentrate plasma nitrate, leading to high salivary nitrate concentrations (5–8 mM) after a nitrate-rich meal. Nitrate is an ecological factor that can induce rapid changes in structure and function of polymicrobial communities. However, the effects on the oral microbiota have not been clarified, whilst a limited number of previous studies did indicate that nitrate is likely to be beneficial for oral health. The aim of this thesis was therefore to study nitrate-induced microbiome changes and identify potential mechanisms for nitrate-induced homeostasis, in order to determine if nitrate can be considered a prebiotic compound for oral health. A second aim was to isolate nitrate-reducing isolates and test their probiotic potential in vitro. In chapter 1, an in vitro study was set up testing the effect of 6.5 mM nitrate on oral communities grown from saliva of 12 healthy individuals. In chapter 2, fifty-three nitrate-reducing isolates were obtained and the effect of six probiotic candidates was tested on healthy oral communities grown from saliva of different donors with or without 6.5 mM nitrate. In chapter 3, the effects of nitrate-rich beetroot extracts on oral acidification after sugar rinsing was tested in 24 individuals without active caries. Supernatants (chapters 1 and 2) or saliva samples (chapter 3) were taken for nitrate, nitrite, ammonium, lactate and pH measurements. Additionally, the bacterial composition of in vitro biofilms and salivary pellets were determined using 16S rRNA gene Illumina sequencing and/or qPCR of the nitrate-reducing genus Rothia. We showed that nitrate stimulates the growth of the beneficial genera Rothia and Neisseria in our in vitro model, while potentially decreasing caries-, halitosis- and periodontal disease-associated bacteria. Additionally, the in vitro and in vivo data presented in this thesis indicate that nitrate can limit or prevent pH drops when sugars are fermented by the oral microbiota – a mechanism of resilience that could be stimulated by the consumption of nitrate-rich vegetable extracts. The main pH buffering mechanisms of nitrate were lactic acid usage during denitrification (observed both in vivo and in vitro) and during the reduction of nitrite to ammonium, as well as the potential production of ammonia (observed in vitro). In this thesis, the effects of nitrate were observed after short periods, i.e., after 5-9 h incubation in vitro and/or after 1-4 hours after nitrate supplement intake in vivo. Future studies should focus on the longitudinal effects of daily nitrate intake. In chapter 2, nitrate-reducing species belonging to the genera Rothia and Actinomyces were isolated. A selection of Rothia isolates increased lactate usage and nitrate reduction capacities of oral communities, potentially benefitting dental health and systemic health, respectively. The in vitro and in vivo data presented in the current thesis suggest that nitrate can modulate the oral microbiota in ways that are beneficial for the host and could thus be considered a prebiotic substance for the oral microbiota. Additionally, nitrate-reducing isolates can stimulate certain beneficial effects of nitrate metabolism. Nitrate and nitrate-reducing bacteria are thus promising components for future oral care products to prevent or treat oral diseases and this should be further investigated.
FIA is a very successful method in simplifying chemical assays. The main reasons for the success are the following advantage of FIA over conventional manual techniques: High sampling rate, smaller sample and reagent consumption and waste generation, simplicity and low cost instrumentation, Availablability of instrumentation in all laboratories, increased precision compared to batch methodologies and Automation in sample preparation and detection. A Study was conducted monthly to estimate the levels of some nitrogen and phosphorous species : Nitrite (NO2-), Nitrate (NO3-) Ammonium (NH4 +) and phosphate (PO4-3) in waters of shatt Al-Arab from nine stations: (1) Qurnah\ (Tigris) (2) Qurnah \Euphrates (3) Saad bridge (4) Qarmat Ali (5) Al-Najeebia(6) Ashar(7) Abu Al-khasib(8) Seeba and (9) Fao for the period October 2009 to September 2010. The higher concentrations of nitrite were recorded in the station 5 (Al-Najeebia) in march 2010 was 0.110 µg\ml and station 8) Seeba(in Jan 2010 was 0.095 µg\ml while the higher concentrations of Nitrate were recorded in station 7 (Abu Al-khasib) in Jun, July 2010 were 0.225,0.275 µg\ml respectively. The results indicated that (NH4 +) concentrations increasing during May, June and July 2010 especially in stations 5 and 6 was (0.95, 1.35),(1.30, 1.25) and (1.45, 1.40 µg\ml) respectively. phosphate concentrations increasing during winter and spring 2010 especially in stations (Ashar, Abu Al-Khasib, Seeba,and Fao) 1.566, 2.033, 0.966, 1.266 µg\ml respectively. This can be attributed to increasing in temperature in summer, salinity of Shatt Al-Arab water and decay of organic and inorganic compounds in high temperature.
Nitrate is a naturally occurring compound present in vegetables, the consumption of which can contribute
significantly to nitrate dietary exposure. The European Food Safety Authority Panel on Contaminants in the
Food Chain (CONTAM Panel) issued an opinion on ‘Nitrate in vegetables’ in 2008. The European Commission
subsequently requested more information on potential acute effects of nitrate exposure in infants and young
children consuming lettuce or spinach, taking into account the possibility of establishment of slightly higher
maximum levels as an alternative to local derogations. For infants, cooked spinach is more likely to be a
component of the diet than lettuce. Nitrate exposure at the current or proposed maximum levels for nitrate in
spinach cooked from fresh is unlikely to be a health concern, although a risk for some infants eating more than
one spinach meal in a day cannot be excluded. For children, the CONTAM Panel concluded that levels of nitrate
in lettuce are not a health concern. However the concentrations of nitrate in spinach have the potential to
increase dietary nitrate exposure to levels at which a health concern can not be excluded for some young
children. Enforcing the current maximum levels for nitrate in lettuce and spinach, or proposed maximum levels
at 500 mg/kg higher than the current maximum levels, would have a minor impact compared to the situation of
local derogations from the maximum levels, because only about 1 % of lettuce samples and 5 % of spinach
samples exceeded the respective current maximum levels. Inappropriate storage of cooked vegetables can result in in-situ conversion of nitrate to nitrite, resulting in an increased potential for causing methaemoglobinaemia. The CONTAM Panel noted that infants and children with bacterial infections of the gastrointestinal tract are more sensitive to nitrate, and recommended against feeding spinach to such children.
This study aimed to explore the efficiency of carnosine (Cs) and/or l-arginine (Agn) in the downregulation of apoptotic and inflammatory molecule expression and DNA damage caused hepatic injury in response to sodium nitrite (Sd)-induced hypoxia in rats. Rats were injected with Sd; Agn or/and Cs were administrated prior to Sd intoxication. Sd significantly decreased hemoglobin concentration and Bcl-2 mRNA expression, while increased expressions of apoptotic markers (Bax and caspase), tumor necrosis factor-α, nuclear factor kappa B, and C-reactive protein and the oxidative DNA damage in hepatic tissue. Moreover, administration of Agn or/and Cs exhibited a modulation of the previous parameters. However, concurrent treatment with the forementioned antioxidants modulated these levels. It was concluded that the treatment with the combination of Agn and Cs was the most effective regimen in ameliorating Sd toxicity accompanied by hypoxic stress.
The aim of the current study is to evaluate the efficacy of pretreatment with either l-arginine (L-arg) or Carnosine (Car) and their combination in ameliorating some of the biochemical indices induced in the lung of sodium nitrite (NaNO2)-intoxicated rats. The results revealed that NaNO2 significantly increased serum tumor necrosis factor-α, C-reactive protein, heat shock proteins-70, vascular endothelial growth factor, and Interleukin 6. Moreover, transforming growth factor-β, hypoxia-inducible factor, Smad-2, Protein Kinase B (AKT), and Bax were overexpressed, whereas Bcl2 protein was downregulated compared with the normoxic group. The administration of the fore mentioned antioxidants, either alone or in combination, markedly downregulated the previously mentioned inflammatory, apoptotic, as well as the fibrotic markers in lung tissue compared with the NaNO2-intoxicated rats. The histopathological examination reinforced the previous results. In conclusion, the current data revealed the efficacy of l-arg and Car in ameliorating the pulmonary damage via suppression of the inflammatory markers in response to NaNO2-intoxication. Interestingly the combination regimen showed the most significant effect.
Nitrogen occurs in the biosphere in oxygenation states ranging from 3- (ammonia) to 5+ (nitrate). The most important inorganic forms of nitrogen are ammonia (NH3), nitrate (NO3-), nitrite (NO2-), and molecular nitrogen (N2). All of these forms are interrelated in the environment by the nitrogen cycle, a complicated series of transformations (described in Chemistry section). Naturally occurring organic nitrogen compounds occur in surface waters and contain amino and amide nitrogen, and some heterocyclic compounds such as purines and pyrimidines.
Nitrate and nitrite have a variety of commercial uses. The major use of nitrate is in inorganic fertilizers. It is also used in the manufacture of explosives, in glassmaking, and as a heat-transfer fluid and a heat-storage medium for solar heating applications. Both nitrate and nitrite are used in curing meats. The properties of potassium nitrate and nitrite, two commonly used compounds, are shown in Table 1 (USEPA 1985). Potassium nitrate is also known as saltpeter (Windholz 1976).
Es werden Studien zu möglichen gesundheitlichen Auswirkungen von folgenden Trinkwasserinhaltsstoffen diskutiert:
1)
die Wasserhärte bestimmende Leichtmetalle (Ca, Mg)
2)
Nitrat
3)
Schwermetalle (Pb, Cd)
4)
Organische Verunreinigungen, insbesondere halogenierte Kohlenwasserstoffe
The U.S. Environmental Protection Agency (EPA) recently reanalyzed the noncancer toxicity data for nitrate in order to reevaluate the nitrate reference dose (RfD). This re-analysis was prompted by questions concerning the comprehensiveness of previous toxicity evaluations, the adequacy of the uncertainty factors used to estimate the RfD, and the need to incorporate new research findings. The EPA reaffirmed its position that increases in methemoglobin associated with early clinical signs of cyanosis represent the critical toxic effect, and that infants represent the sensitive population because of their disposition for methemoglobin formation. An RfD of 1.6 mg/kg/day was verified by the EPA’s Intra-agency Reference Dose Work Group. This RfD supports the existing standard of 10 mg NO3-N/L of water.
The water samples collected from the bore wells were analysed for important physico-chemical parameters. This study helps in assessing the ground water quality in Arsikere taluk, Hassan district, Karnataka, which is the only source of drinking water. The ground water analysis shows that few of the parameters are higher than the maximum permissible limits when compared with the prescribed Indian Standard limits for drinking water. Chloride, electrical conductivity, alkalinity, etc., were high in some of the study site in Arsikere taluk. Fluoride concentration was very high in all the samples. The presence of very high quantity of fluoride in the bore well water samples is significant as there is fluorosis; caries of teeth affected people in Arsikere taluk. The study indicates that the ground water quality is not suitable for drinking purpose without prior treatment.
11 sources from 8 villages situated in the down stream area of Banas river, Rajasthan from industrial area was studied for evaluation of their suitability for drinking purposes. The results were compared with Indian Drinking Water Standard (IS: 10500, 1991). From the results it was clear than no source have all analyzed parameters within maximum desirable limit but 3 sources (OW 4, OW 8 and OW 11) have all parameters within maximum permissible limit, therefore groundwater of these source may be used for drinking purposes in absence of any other suitable source, but a prolonged use of this water may be harmful. Although the parameters, which are out of maximum desirable limit, are not so much health hazardous but the effects on health may increases in absence of nutrient diet. 4 sources (OW 1, OW 5 and OW 7) have only one parameter out of maximum permissible limit. OW 1 and OW 5 have fluoride concentration out of maximum permissible limit, so that the groundwater of these sources may be used with an intake of extra calcium dose. OW 7 have total dissolved solids just above maximum permissible limit. Total dissolved solids have no health effect so that the groundwater of this source may also be used for drinking purposes. One more source that can be used for drinking purpose is OW 9 of Kacholiya village. This source has TDS and magnesium out of maximum permissible limit. Both parameters have no harmful effect on human health but the use of the water for domestic purpose is doubtful. The use of groundwater of other 4 sources (OW 3, OW 4, OW 6, and OW 9) is harmful as they have more than 2 parameters out of maximum permissible limit. No source was found to have heavy metal concentration out of maximum desirable limit.
The aim of this research was to review the effects of nitrate and nitrite intake through drinking water and food on humans, especially in infants. To this purpose, we examined environmental levels of those ions in drinking water, food, their metabolism in humans, acute toxicity (methaemoglobinaemia), long-term toxicity (carcinogenicity, spontaneous miscarriage, diabetes mellitus...). Finally, it is described the origin and prevention of water contamination by nitrate.
In recent years, Nitrate absorption by plants, has greatly been concerned about in different countries. Some of them, have stablished standards for the amount of Nitrate concentration in edible plants. In Iran, there are few researches on this matter and because of high rate of vegetable consumption , it is necessary to be noticed. So, the primary goal of this project is to determine the concentration of Nitrate in edible parts of different plants , and then, to introduce the plants, which have the most potential for absorbing Nitrate. In this survey, samples of Spinach (Spinacea oleracea), Leek (Allium pooum), Sweet basil (Ocimum basilicum), Fenugreek (Trigonella foenum), Onion (Allium cepa), Cabbage (Brasica deracea), Lettuce (Lactuca sativa), Radish (Ruphanus sativens), Cucumber (Cucumis sativa), Tomato (Lycopersicum esculentum), Potato (Solanum toberosum) and Carrot (Daucus carota) were gathered from farms of Dorcheh, Dashti, Ziar, Falavarjan, Khomieni shahr, Najaf abad (Isfahan), Khorasgan in 1999 (July, Aug., Nov.) and 2000 (May, June). In some cases , some samples with defined harvesting place were purchased from market and added to this collection. Then, Nitrate concentration in edible parts , was measured in each sample . The averages were 2865, 412, 328, 450, 428, 673, 639, 819, 30, 14, 171 and 736 mg/kg (wet weight) in spinach, leek, sweet basil, fenugreek, onion, cabbage, lettuce, radish, cucumber, tomato, potato and carrot, respectively. In these samples spinach had the highest nitrate concentration and tomato , the lowest. Nitrate concentration in Spinach was more than the WHO standard, so it's recommended to delete it from under one year old children's food, in order to prevent Methemoglobinemia suffering.
We review types of public drinking water and bottled water and provide recommendations on the composition of water for infants. Water used with any of the commercial infant formulas in Spain should contain less than 25 mg/l of sodium. Drinking water must be boiled for a maximum of one minute (at sea level) to avoid excessive salt concentration. Bottled water need not be boiled. Fluoride content in drinking water should be less than 0.3 mg/l in first year of life to prevent dental fluorosis. Nitrate content in water should be less than 25 mg/l to prevent methemoglobinemia. Water with a calcium concentration of between 50 and 100 mg/l is a dietary source of calcium since it provides 24-56% of the required daily intake in infancy.
An 8-year-old girl visited the emergency room with perioral cyanosis and dyspnea, which had developed 20 hrs prior to the hospital visit. She had taken a Chinese herbal medication for 3 days prior to the onset of the symptoms. A co-oximeter examination revealed a methemoglobin level of 23.7%. An intravenous infusion of methylene blue was administered. Chemical analysis of the herbal medication revealed an ammonia (NH3) level of 239.41 mg/ L. More studies are needed on the correlation between methemoglobinemia and the components of Chinese herbal medicines.
There were analyzed the results of laboratory investigations of samples of different vegetal food — stuffs for determination
of nitrates made in the Center of Preventive Medicine of municipe Chisinau during the last 5 years (2003–2007). In general,
the average parts of samples with increased quantities of nitrates were 8.8%; 5.9%; 2.2%; 5.9% and 6.4% in the years 2003,
2004, 2005, 2006 and 2007, respectively. Every year were established nitrates over norms in samples of radish, beet — roots,
potatoes and autumn cabbage, during 4 years — in vegetable marrows and melons, during 3 years — in green onions and green
grocery. Quantities of nitrates over norms never were revealed during the period of the study in fruits, grapes, mushrooms
and different berries. It was proposed some recommendations.
A major problem with on-site sanitation is nitrate pollution of the groundwater. A tentative nitrogen budget is established
for pit latrines in eastern Botswana. The ammonia volatilisation was found to be negligible while leaching varied largely
from about 1 to 50%. Leaching of nitrate was assessed by using chloride as tracer, assuming two sources of chloride, atmospheric
deposition and the use of common salt in food. The initial content of nitrogen in excreta was assessed from nutritional data.
The residual nitrogen in abandoned latrines as found by analysis, was 15–20%. The remainder should be denitrification which
would then be in the order of 30–70%. That denitrification is important is supported by an elevated N-isotope ratio in groundwater
and in deep-rooted non-N-fixing trees. The varying leaching rate provides a possibility of checking it by sealing the latrines.
Since about 95% of the nitrogen in human excreta is present in the urine, an even more attractive solution would be urine-separating
latrines with surface near percolation of the urine in the root zone of the vegetation, utilising it for crop growth. Since
such latrines are used elsewhere in the world the problem is not technical but social acceptability.
Over the last 20 years, dietary nitrate has been implicated in the formation of methemoglobin and carcinogenic nitrosamines in humans. This has led to restrictions of nitrate and nitrite levels in food and drinking water. However, there is no epidemiological evidence for an increased risk of gastric and intestinal cancer in population groups with high dietary vegetable or nitrate intake. A reevaluation of our currently very negative perception of dietary nitrates comes from recent research into the metabolism and enterosalivary circulation of nitrate in mammals. These studies showed that nitrate is converted to nitrite in the oral cavity that then "fuels" an important mammalian resistance mechanism against infectious diseases. Moreover, there is now evidence that the conversion of nitrate into oxides of nitrogen prevents the formation carcinogenic nitrosamines.
The contamination of groundwater and rural drinking water supplies by nitrates from livestock and human excrement, other organic waste, or chemical fertilizers is a potential hazard throughout the world. Infant illness and death from nitrate-induced methemoglobinemia is probably often misdiagnosed, perhaps as sudden infant death syndrome, and certainly contributes to the national infant death rate statistics. A 1950 report listed 144 cases of infant methemoglobinemia with 14 deaths in one 30-month period in Minnesota. Infant deaths resulting from misdiagnosis of this preventable, treatable intoxication were still occurring as recently as 1986 in South Dakota. In this state, about 39% of dug or bored wells were unsafe due to high nitrate content, compared with 22% of drilled wells and 16% of driven wells. Properly constructed wells more than 30 m deep are more likely to be safe. Groundwater concentrations of nitrate may be unsafe for consumption, and standards are needed to regulate such contamination. Such standards could serve as guidelines and could be enforceable in the case of water systems dependent on wells.
The effect of sodium nitrite, amyl nitrite and nitroglycerin (glyceryl trinitrate) on the hemoglobin of adult erythrocytes was examined in vitro. Both amyl nitrite and nitroglycerin reacted immediately with oxyhemoglobin to effect oxidation into methemoglobin while sodium nitrite required an inductionary period (lag phase) prior to the reaction. Kinetic studies of the biomolecular rate law for each of the preceding reaction's reactionary periods (log phases) allowed rate constant calculations to be made. The values are 1.14 x 10(4) M-1 min-1, 7.45 x 10(4) M-1 min-1, and 3.50 x 10(1) M-1 min-1 for sodium nitrite, amyl nitrite and nitroglycerin, respectively. A comparison of the amyl nitrite and nitroglycerin rate constants reveals that amyl nitrite is approximately 2000-fold more toxic to oxyhemoglobin than nitroglycerin. These oxidant's effect on in vitro hemoglobin solutions are comparable since both reactions approximate to rectangular hyperbolae. Sodium nitrite reacts about 300-fold faster with oxyhemoglobin than does nitroglycerin. However, the sodium nitrite reaction proceeds in a sigmoidal fashion which makes a strict comparison between these compounds relative toxicities less clear cut.
Several epidemiological studies in California have yielded data on percentage methaemoglobin in healthy individuals. The population groups represented include infants, elementary and high school children, and adults. The distributions of values in each group are described, as well as the differences between groups. Factors affecting the distributions are discussed.
In the study of infants, the factors assessed include respiratory and gastrointestinal disease, and food and water intake. In schoolchildren, the effect of age and location of residence within Southern California are evaluated, and in adults, smoking, gender and time of day.
Among infants in the 31 to 60 day age range, 33 per cent had methaemoglobin levels of 3 per cent or above, while 8 per cent had methaemoglobin levels of 4 per cent or above. Among adults, 15 per cent had levels of 3 per cent or above, while 2 per cent had levels of 4 per cent or above. Among both elementary and high school students, 3 per cent had methaemoglobin levels of 3 per cent or above, while less than 1 per cent had levels of 4 per cent or greater.
National Interim Primary Drinking Water Regulations Survey of community water supply systems
- Lj Mccabe
- Symons
- Jm
- Lee
REFERENCES US Environmental Protection Agency, National Interim Primary Drinking Water Regulations, EPA 570/9-76-003, GPO, Washington, DC 1977. McCabe LJ, Symons JM, Lee RD and Robeck GG. Survey of community water supply systems. J Am Water Works Aisoc. 1970; 62. 670-^87.