Water quality in the Lachuá Ecoregion Landscape: Comparing streams from Forest, Milpa, and an Oil Palm plantation / Calidad del agua en el paisaje de la Ecorregión Lachuá: Comparando arroyos en bosques, milpa y palma africana

The hydrological network in the Lachuá Ecoregion (EL), Alta Verapaz, Guatemala, hosts high levels of biodiversity and supplies water to 44 Mayan communities. Despite this critical fact, this network has been threatened by scarcely monitored industrial activities including the rapidly expanding oil palm monoculture (Elaeis guineensisJacq). Regardless of Lachua's freshwaters importance, there is little information on how this monoculture impacts them. We compared water-quality properties from streams in oil palm plantations (P), paddock and milpa systems (M), and primary forests (F) in the EL. During 2015-2016, 13 rivers were sampled (5 times) for water temperature, pH, dissolved oxygen (DO), conductivity, hardness, chemical and biochemical oxygen demand (COD and BOD), and concentration of silica, nitrates, phosphates, and ammonia. Several parameters showed significant differences. P were 2.7 ºC and 1.8 ºC warmer than M and F and carried 1.4 mg/L more nitrates than F. F carried 10.8 mg/L and 11.8 mg/L more silica than M and P. M showed intermediate temperatures and silica concentrations, as well as 14.8 µS/cm and 8.9 µS/cm lower conductivities than P and F, respectively. Additionally, COD in M was 9.9 mg/L and 4.6 mg/L lower than P and F, respectively. We believe higher temperatures and lower silica in P are due to the loss of riparian forest and their role in buffering temperatures and recycling silicon. In addition, the existence of secondary forest (guamil) in M might explain the intermediate temperatures and silica concentrations. Our results highlight the contributions of forests to waterways and suggest potential water-quality depletion from the oil palm expansion in the EL.

La red hídrica en la Ecorregión Lachuá (EL), Alta Verapaz, Guatemala, alberga una alta biodiversidad y abastece de agua a 44 comunidades mayas. Sin embargo, recientemente se ha visto amenazada por actividades industriales escasamente monitoreadas, incluido el creciente monocultivo de palma africana (Elaeis guineensis Jacq) del cual se desconocen sus impactos en la EL. Este estudio explora la calidad del agua de arroyos en plantaciones de palma africana (P), bosques primarios (B), y sistemas de potrero y milpa (M) en Lachuá. Durante 2015-2016, se tomaron muestras de 13 ríos (5 veces) para medir la temperatura del agua, pH, oxígeno disuelto (OD), conductividad, dureza, demanda química y bioquímica de oxígeno (DQO y DBO) y la concentración de sílice, nitratos, fosfatos, y amoníaco. Varios parámetros mostraron diferencias significativas. P fue 2.7 ºC y 1.8 ºC más calientes que M y F y portó 1.4 mg/L más nitrato que F. F portó 10.8 mg/L y 11.8 mg/L más sílice que M y P. M mostró temperaturas y concentraciones de sílice intermedias y conductividades 14.8 µS/cm y 8.9 µS/cm menores que P y F. La DQO en M fue 9.9 mg/L y 4.6 mg/L menor que P y F. El aumento de temperatura y la disminución de sílice en P podría deberse a la pérdida de bosques ribereños los cuales amortiguan la tempe-ratura y reciclan el silicio. La presencia de bosque secundarios (guamil) en M podría explicar las temperaturas y las concentraciones de sílice intermedias resaltando la importancia de los bosques en la red hídrica. Se predice un posible deterioro en el agua resultado de la expansión de palma africana en la EL.

Concentrações de nitrato em águas de abastecimento público de 88 municípios da Rede Regional de Atenção à Saúde 13 do estado de São Paulo, Brasil / Concentrations of nitrate in the public water supply of 88 municipalities of the Regional Health Care Network 13 of the São Paulo State, Brazil

Este trabalho apresenta as concentrações de nitrato e suas correlações com as demais variáveis obtidas da análise de 21 parâmetros físico-químicos em 4.347 amostras de águas de abastecimento público de 88 municípios da região nordeste do Estado de São Paulo, Brasil. Os parâmetros analisados foram temperatura, pH, cloro residual livre, cor aparente, turbidez, condutividade e concentrações de lítio, sódio, amônio, potássio, cálcio, magnésio, fluoreto, clorito, bromato, cloreto, brometo, clorato, nitrato, fosfato e sulfato. Análises de componentes principais, incluindo-se as variáveis condutividade e concentrações de nitrato, cloreto, cálcio e magnésio na água, indicaram um grupo de 15 municípios com concentrações relevantes de nitrato. Foi realizada a análise univariada, e foi sugerido o estabelecimento de estratégias no gerenciamento inicial de contaminações de águas subterrâneas. No planejamento de ações entre os diversos atores envolvidos com a gestão da água subterrânea destinada ao consumo humano da região e no monitoramento de sua qualidade, devem ser considerados os níveis de nitrato, assim como os perfis físico-químicos das águas e a complexidade dos sistemas de abastecimento. Estas ações incluem procedimentos para investigar e mitigar contaminações, para garantir a potabilidade da água consumida pela população.

This paper presents the nitrate concentrations and their correlations with other variables obtained by analyzing 21 physical-chemical parameters in 4,347 samples from public water supply of 88 municipalities in the northeast region of the State of São Paulo, Brazil. The analyzed parameters were temperature, pH, free residual chlorine, apparent color, turbidity, conductivity, and concentrations of lithium, sodium, ammonium, potassium, calcium, magnesium, fluoride, chlorite, bromate, chloride, bromide, chlorate, nitrate, phosphate, and sulfate. The principal component analysis, involving the conductivity and the concentrations of nitrate, chloride, calcium, and magnesium, showed a group of 15 municipalities with relevant concentrations of nitrate. As for the univariate analysis it is suggested to apply strategies in the initial management of groundwater contaminations. It has been suggested to plan the actions among the various actors involved in the management of groundwater, which is intended for human consumption in the region, and for its quality monitoring. It has to consider not only the nitrate levels but also the water physical-chemical profiles and the complexity of the supply systems. These actions include the contaminants investigation and mitigation for ensuring the potability of the water consumed by the population.

Relación deltre hipotiroidismo subclínico y bocio con el origen del agua consumida por una población del conurbano bonaerense / Relationship of subclinical hypothyroidism and goiter with the origin of water consumed by a population of the Buenos Aires suburbs

El hipotiroidismo subclínico (HS), elevación de tirotrofina con hormonas tiroideas normales, junto al bocio, aumentó la frecuencia en las últimas décadas. Con el objetivo de relacionar la prevalencia de bocio y HS con el consumo de agua subterránea como factor de riesgo etiológico poblacional, se analizaron 879 historias clínicas de un centro médico de Glew, en el conurbano bonaerense Sur. Se estudió la población según edad (20-60 y 12-19 años) y tipo de agua consumida (potabilizada o napa subterránea). El agua subterránea fue consumida por el 70.5% del grupo de 20 a 60 años (n = 559, 79.9% mujeres) y por el 66.3% del grupo de 12 a 19 años (n = 57, 81.4% mujeres). En el grupo de 20 a 60 años la prevalencia de HS en consumidores de agua potabilizada y subterránea fue del 1% y 57.8% (p < 0.0001) y la de bocio de 3.8% y 38.9% (p < 0.0001), respectivamente; con un riesgo atribuible al agua subterránea de 57% para HS y 35% para bocio. En el grupo de 12 a 19 años, la prevalencia de HS fue 6.9% y 52.6% (p < 0.0001) y de bocio 13.8% y 77.2% para los grupos de agua potabilizada y subterránea, (p < 0.0001) respectivamente; con un riesgo atribuible al agua subterránea de 46% para HS y 61% para bocio. El análisis fisicoquímico mostró presencia de nitratos (entre 24 y 83 mg/l) en aguas de pozos y ausencia en agua potable. La prevalencia aumentada de HS y bocio podrían deberse a la acción disruptora tiroidea de los nitratos.

Subclinical hypothyroidism (SH), elevation of the level of thyrotrophin with normal thyroid hormones, along with goiter (glandular size > 25g), increased in recent decades. In order to relate the prevalence of goiter and SH with the consumption of groundwater, as a population etiological risk factor, we analyzed 879 clinical histories from a medical center in the city of Glew in the South Buenos Aires suburbs. The population was studied according to age (20 to 60 and 12 to 19 years) and type of water consumed (potable water or groundwater). Groundwater was consumed by 70.5% of the group from 20 to 60 years old (n = 559, 79.9% women) and by 66.3% of the group from 12 to 19 years old (n = 57, 81.4% women In the group of 20 to 60 years, the prevalence of SH in potable water and groundwater users was 1% and 57.8% (p < 0.0001) and the goiter rate of 3.8% and 38.9% (p < 0.0001) respectively; with an attributable risk to groundwater of 57% for HS, and 35% for goiter In the group of 12 to 19 years, the prevalence of SH was 6.9% and 52.6% (p < 0.0001) and goiter 13.8% and 77.2% for the water and groundwater groups (p>0.0001) respectively, with an attributable risk of 46% for HS y 61% for goiter. The physicochemical analysis showed the presence of nitrates in the range of 24 to 83 mg/l in groundwater and absence in potable water. The increased prevalence of HS and goiter could be due to the thyroid disrupting action of nitrates.

Oxidative stress assessment in intestine of newborn rats submitted to hypoxia and reoxygenation with tadalafil

Abstract Purpose: To evaluate the functional and structural response of tadalafil effects in the intestinal mucosa, using an experimental model of hypoxia and reoxygenation injury in rats. Methods: The animals were divided into 4 groups: CTL, H/R, H/R+Td and M+Td. The newborn rats allocated in groups H/R, H/R+Td and M+Td were submitted twice a day, to a gas chamber with CO2 at 100% for 10 minutes and afterward reoxygenation with O2 at 98% for 10 minutes, in the three first days of life. Tadalafil dose was given to newborn of group H/R+Td and to the pregnant rat of group M+Td. Histological analysis was made with hematoxylin-eosin technique and oxidative stress through nitrite and nitrate levels and lipid peroxidation. Results: The histological analysis showed a reduction of mucosa alterations in the groups that received tadalafil. In the oxidative stress evaluation, occurred an increase of NO levels and less lipidic peroxidation in the ileum segments that received tadalafil. Conclusion: Tadalafil provides tissue protection when administered independently to both, pregnant or newborns.

Exposición a nitratos en agua y su relación con disfunción de la glándula tiroides: revisión sistemática ¿Existen riesgos para la salud de la población? / Exposure to nitrates in drinking water and its association with thyroid gland dysfunction

Background: Nitrate exposure may be associated with thyroid gland dysfunction. Aim: To review the available evidence about the relationship between nitrates in drinking water and thyroid gland dysfunction. Material and Methods: A wide search was performed using Medline, Cochrane, Lilacs, IBECS and Scielo databases using pertinent keywords, finding a total of 66 related studies. After filtering and in depth reviewing, a total of 12 studies were included in this review. Results: The main results reveal the importance of this ion for human health, finding evidence both in animals and human beings that suggest pathological changes in the gland as its relationship with the occurrence of subclinical hypothyroidism, and potentially cancer of the thyroid gland. In Chile, nitrate is not considered a critical contaminant so its regular measuring and control is not enforced. Conclusions: In light of the present review we believe that there is evidence to consider nitrate as a critical contaminant whose measurement, registration and correct implementation of valid policies would have a direct benefit for the population of this country. Without this information, it is not possible to quantify the damage to human health, especially in vulnerable groups residing in areas at greatest risk of exposure.

Qualidade da água em escolas públicas municipais: análise microbiológica e teor de nitrato em Araçatuba, estado de São Paulo – Brasil / Quality of water in municipal public schools: microbiological analysis and nitrate content in Araçatuba, state of São Paulo – Brazil

A potabilidade da água de consumo em escolas públicas de Ensino Infantil do município de Araçatuba/SP foi avaliada procedendo-se à pesquisa de coliformes totais, de Escherichia coli e ao teor de nitrato em amostras coletadas, nos seguintes pontos: cavalete de distribuição da rede pública ou de poço; torneira da cozinha e bebedouro. Das 25 escolas analisadas, 12% não atenderam aos padrões de potabilidade da água perante parâmetro microbiológico; entretanto, quanto ao nível de nitrato, todas as amostras apresentaram resultados dentro do Valor Máximo Permitido pela legislação vigente. Os dados obtidos sugerem correlação positiva entre a concentração de nitrato e o NMP de coliformes totais. A presença de coliformes totais e de E. coli, especialmente em escolas da zona rural, cuja a água é proveniente de poço, aponta a necessidade da implantação de medidas de saneamento da água em escolas públicas de Educação Infantil do município de Araçatuba, SP.

The potability of water for consumption in public childhood education schools of the city of Araçatuba/SP was evaluated by carrying out a survey of total coliforms, Escherichia coli and nitrate content, in collected samples at the following points: cross connection control manual of public main or wells; kitchen faucet and watercooler. Of the 25 schools analyzed, 12% did not meet the standards of water potability to the microbiological parameter; but referring to nitrate content, all remained within the maximum value allowed by vigent legislation. Obtained data guggest a positive correlation between the nitrate concentration and the NMP of total coliforms. The presence of total coliforms and E. coli, especially in rural schools, whose water comes from well, points out the need to implement water sanitation measures in public schools of Early Childhood Education in the city of Araçatuba, SP.

Método espectrofotométrico na região UV a 205 nm para determinação de íon nitrato em água: validação / Spectrophotometric method in UV region at 205 nm for determination of nitrate ion in water: validation

Este estudo teve por objetivo validar o método espectrofotométrico na região ultravioleta(205 nm) para determinação de nitrato em água para consumo humano e de diálise, bemcomo calcular sua incerteza associada. A linearidade, seletividade, precisão, exatidão, limitede detecção (LD) e limite de quantificação (LQ) foram avaliados de acordo com o documentode orientação INMETRO DOQ-CGCRE-008. Os resultados obtidos utilizando água deabastecimento indicaram que a matriz não tem efeito significativo sobre a seletividade dométodo. A exatidão e a repetitividade foram avaliadas com três níveis de concentração doanalito na água de abastecimento, na água de diálise e em material de referência certificado,apresentando resultados satisfatórios para todas as matrizes utilizadas. Os limites de detecção equantificação foram de 0,074 e 0,248 mg/L de nitrato, respectivamente. O método mostrou-seadequado para determinação de nitrato em água de abastecimento e em água de diálise.

This study validated the spectrophotometric method in ultraviolet region (205 nm) fordetermining nitrate in water used for human consumption and dialysis procedure and tocalculate its associated uncertainty. The linearity, selectivity, precision, accuracy, limit ofdetection (LD) and limit of quantification (LQ) were evaluated according to the INMETRODOQ-CGCRE-008. The results obtained using water supply indicated that the matrix has nosignificant effect on the selectivity of the method. Accuracy and repeatability were evaluatedusing three different levels of analyte concentration in the supply water, in the dialysis waterand in the certified reference material, showing satisfactory results at all matrices used.The limits of detection and of quantification were 0.074 and 0.248 mg/L of nitrate, respectively.The method proved to be adequate for determining nitrate in water supply and dialysis water.

Nitric oxide and asymmetric dimethyl arginine (ADMA) levels in an experimental hydronephrotic kidney caused by unilateral partial ureteral obstruction

ABSTRACT Aim Our aim is to measure asymmetric dimethyl arginine and nitric oxide levels in rats with induced unilateral acute ureteral obstruction to research the effects on the kidney. Material and Methods The study included 21 adolescent (average age 6 weeks) Sprague-Dawley male rats weighing between 240-290g divided at random into 3 groups. Group-1: Control group (n=6): underwent no procedures. Group-2: Sham group (n=6): underwent the same procedures as the experimental group without ureter and psoas muscle dissection. Group-3: Group with induced partial unilateral ureteral obstruction (n=9). All rats were sacrificed after 12 weeks. Superoxide dismutase enzyme activity and nitrite and nitrate salt levels were measured in renal tissue. Plasma nitrite-nitrate and ADMA levels were examined. Results In the experimental group histopathological changes observed included renal pelvis dilatation, flattened papillae, sclerotic glomerulus and fibrosis. In the experimental group tissue SOD and blood ADMA levels were higher than the control and sham groups (p<0.05) while tissue NO and plasma NO values were lower than in the sham and control groups (p<0.05). Conclusion Oxidative stress and disruption of NO synthesis play an important role in renal function and histopathological changes after obstructive renal disease. To prevent renal complications developing after obstructive nephropathy we believe that a new strategy may be research on reducing ADMA.

Mechanical properties of composites as functions of the syringe storage temperature and energy dose

Objective: To investigate the mechanical properties of different classifications of composites indicated for posterior application as functions of the storage condition and of the energy dose. Material and Methods: Specimens (8x2x2 mm) were obtained according to the factors: I) Composites (3M ESPE): Filtek P60, Filtek Z350XT, and Filtek Silorane; II) Syringe storage conditions: room temperature, aged, oven, refrigerator, and freezer; and III) Energy dose: 24 J/cm2 and 48 J/cm2. After photoactivation, the specimens were stored at 37ºC for 24 h. After storage, a three-point bending test was carried out in a universal testing machine at 0.5 mm/min. Flexural strength (S) and flexural modulus (E) were calculated. Data were analyzed by three-way ANOVA and Tukey's test (α=0.05). Results: Different storage conditions significantly affected the silorane composite for S; conversely, no effects were noted in terms of E. The accelerated aging protocol significantly increased the S of Filtek P60 and Filtek Silorane, whereas storage in the oven significantly decreased the S for all of the composites tested. Filtek P60 was the only composite not affected by the lower storage temperatures tested for S, whereas for the silorane this parameter was impacted at the same conditions. The factor "dose" was not statistically significant. Conclusions: The syringe storage at different temperature conditions proved to influence mostly the flexural strength, a clinically important characteristic considering the posterior indication of the materials tested. The silorane composite should not be stored at lower temperatures. .

Origen y calidad del agua para consumo humano: salud de la población residente en el área de la cuenca Matanza-Riachuelo del Gran Buenos Aires / The origin and quality of water for human consumption: the health of the population residing in the Matanza-Riachuelo river basin area in Greater Buenos Aires

El objetivo del estudio es analizar el origen y la calidad del agua domiciliaria utilizada para el consumo, en una muestra de hogares del área de la cuenca Matanza-Riachuelo del Gran Buenos Aires, Argentina. Según su origen, el 9% de las muestras de agua provenientes de la red pública, el 45% de las de agua envasada y el 80% de las provenientes de perforaciones o pozos individuales resultaron no potables por exceso de coliformes, Escherichia coli o nitratos. Los individuos de la muestra de hogares en los que la fuente principal de agua para el consumo eran pozos individuales presentaron una probabilidad 55% superior de padecer alguna enfermedad de origen hídrico, probabilidad que llegaría al 87% en el caso de las diarreas y al 160% en el de las dermatitis. El agua para consumo humano en este territorio debería provenir de fuentes centralizadas que aseguren el control de la calidad del agua.

The aim of this study is to analyze the origin and quality of water used for consumption in a sample of households in Matanza-Riachuelo river basin area in Greater Buenos Aires, Argentina. The results of drinking water by source indicated that 9% of water samples from the public water system, 45% of bottled water samples and 80% of well water samples were not safe for drinking due to excess content of coliforms, Escherichia coli or nitrates. Individuals living in households where well water is the main source of drinking water have a 55% higher chance of suffering a water-borne disease; in the cases of diarrheas, the probability is 87% higher and in the case of dermatitis, 160% higher. The water for human consumption in this region should be provided by centralized sources that assure control over the quality of the water.

Medición de nitratos y nitritos en agua y saliva de población rural precordillerana de la VIII región / Nitrate and nitrite in water and saliva of rural population in the Andes foothills of the VIII Region

Introducción: Un factor de riesgo para las neoplasias escamosas de faringe son las nitrosaminas, las que derivan de los nitratos salivales que provienen de la dieta y en especial del agua si los niveles están por sobre la norma. Objetivos: Conocer y comparar los niveles de nitratos y nitritos en agua y saliva de habitantes de la región precordillerana y en población urbana de Concepción. Material y método: Estudio prospectivo, tipo caso y control. Determinan niveles de nitratos y nitritos en agua de la zona precordillerana y en agua de Concepción y en saliva de habitantes de la zona rural y de grupo control de Concepción. Resultados: Se obtienen 10 muestras de agua del sector rural y 1 muestra de agua potable de Concepción. Nivel de nitratos en agua rural 23,29 mg/L, en agua urbana 3,6 mg/L (p <0,05). En saliva, grupo estudio (n =15) con nivel de nitritos de 9,58 mg/ml, grupo control (n =24) nivel de 3,8 mg/ml (p <0,05). Conclusión: En la zona rural hay niveles significativamente mayores de nitratos en el agua y nitritos en saliva. Los niveles en agua son superiores a normas nacionales e internacionales. Nuestros resultados resaltan la posible importancia de las nitrosaminas y sus precursores como elementos carcinogónicos en los carcinomas escamosos orofaríngeos.

Introduction: A risk factor for squamous carcinomas of the oropharynx are the nitrosamines, which are derived from salivary nitrate coming from diet and water, especially if the levels are above the allowed levels. Aim: To determine and compare the levels of nitrates and nitrites in drinking water and saliva of people at the foothills of our region and urban population of Concepcion. Material and method: A descriptive cross sectional study. Determination of levels of nitrates and nitrites in drinking water in the Andean foothills and Concepcion and in saliva of people from same locations. Results: We obtained 10 rural water samples and 1 from Concepcion drinking water. Nitrate levels in rural water were 23.29 mg/L and 3.6 mg/L (p <0.05) in urban water. In saliva, the study group (n =15) had 9.58 mg/ml nitrite in saliva, the control group (n =24) 3.8 mg/ml (p <0.05). Conclusion: In rural areas there are significantly higher levels of nitrates in drinking water and saliva. The water levels are higher than national and international standards. Our results confirm high amounts of nitrogen cycle products (nitrites and nitrates) in drinking water and in saliva so it could be considered as carcinogenic elements in oropharyngeal squamous cell carcinomas.

Correlation between total nitrite/nitrate concentrations and monoamine oxidase (types A and B) and semicarbazide-sensitive amine oxidase enzymatic activities in human mesenteric arteries from non-diabetic and type 2 diabetic patients

The aim of this study was to determine the correlation between total nitrite/nitrate concentrations (NOx) and the kinetic parameters of monoamine oxidase enzymes (MAO-A and MAO-B) and semicarbazide-sensitive amine oxidase (SSAO) in human mesenteric arteries. Arteries were from non-diabetic and type 2 diabetic patients with sigmoid or rectum carcinoma for whom surgery was the first option and who were not exposed to neo-adjuvant therapy. Segments of human inferior mesenteric arteries from non-diabetic (61.1 ± 8.9 years old, 7 males and 5 females, N = 12) and type 2 diabetic patients (65.8 ± 6.2 years old, 8 males and 4 females, N = 12) were used to determine NOx concentrations and the kinetic parameters of MAO-A, MAO-B and SSAO by the Griess reaction and by radiochemical assay, respectively. The NOx concentrations in arteries from diabetic patients did not differ significantly from those of the non-diabetic group (10.28 ± 4.61 vs 10.71 ± 4.32 nmol/mg protein, respectively). In the non-diabetic group, there was a positive correlation between NOx concentrations and MAO-B parameters: Km (r = 0.612, P = 0.034) and Vmax (r = 0.593, P = 0.042), and a negative correlation with the SSAO parameters: Km (r = -0.625, P = 0.029) and Vmax (r = -0.754, P = 0.005). However, in the diabetic group no correlation was found between NOx concentrations and the three kinetic parameters of the enzymes. These results suggest an important function of sympathetic nerves and vascular NOx concentrations in arteries of non-diabetic patients. Thus, these results confirm the importance of a balance between oxidants and antioxidants in the maintenance of vascular homeostasis to prevent oxidative stress.

Nitrate and chloride concentrations in groundwater beneath a portion of the trinity group outcrop zone, Texas

Using a geographic information system and statistics, we evaluated spatial distributions of nitrate and chloride concentrations in groundwater in an area of north-central Texas with agricultural activity, in addition to oil and natural gas exploration and production. Data were compiled from 40 water wells sampled in 2007. Nitrate concentrations in three wells exceeded the maximum contaminant level [44 mg/L] for drinking water. The highest nitrate concentration was 149 mg/L, and concentrations were generally higher in shallower wells. Chloride concentrations exceeded the 250 mg/L secondary drinking water standard in two wells, with no significant association between chloride concentration and well depth. Results of this study suggest localized human impacts, especially for nitrate, and identify areas warranting future monitoring

[Nitrate and nitrite level of drinking water and the risk of upper gastrointestinal cancers in urban areas of Golestan province, northeast of Iran]

Esophageal and gastric cancers are among prevalent cancers in the world and it is believed that nitrate and nitrite contaminations of drinking water are important factors in increasing the risk of these cancers. This study was designed to determine the correlations between these factors and upper gastrointestinal cancers. In this ecologic study, mean concentrations of nitrite and nitrate of drinking waters in Golestan urban areas were obtained during 2004-2005. All patients with esophageal and gastric cancers during this period who resided in urban areas were recruited to estimate the incidence rate and Age Standardized Rate [ASR] of these cancers. The province was divided into three regions of low, intermediate and high incidence based on 33% and 66% quartiles of both cancers. Spearman Correlation Coefficient and regression line were used to analyze data

Seasonal variations in physico-chemical characteristics of Pichavaram mangroves, southeast coast of India.

All the physico-chemical parameters such as temperature, salinity pH, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate were studied in Pichavaram mangroves, southeast coast of India, for a period of two years (April 2000-March 2002). Air and surface water temperatures varied from 27 degrees C to 38 degrees C and from 26 degrees C to 37 degrees C. Salinity varied from 3.0 per thousand to 33.0 per thousand and the pH ranged between 7.2 and 8.2. Variation in dissolved oxygen content was from 2.4 to 5.0 ml l(-1). Concentrations of nutrients viz nitrates (9.50 to 32.12 microM), nitrites (1.07 to 5.99 microM), phosphates (0.73 to 2.36 microM) and reactive silicates (22.1 to 89.8 microM) also varied independently.

Hydrochemical assessment of the pollutants in groundwaters of Vrishabhavathi Valley Basin in Bangalore (India).

The present study aims at the assessment of groundwater quality in and around the Vrishabhavathi Valley, the erstwhile fresh water stream, today carrying huge quantities of industrial, agricultural and domestic effluents from the western part of Bangalore metropolis. Groundwater samples were collected from both bore wells and open wells along the Vrishabhavathi watershed and subjected to a comprehensive physico-chemical and bacteriological analysis. The study revealed that 57% of the samples were non-potable due to their values when compared to the BIS standards. The concentrations of nitrate and total hardness were found higher than the standards in 43.33% and 40% of the samples respectively. 50% of the samples examined, indicated bacterial contamination in the groundwater.

Evaluation of physical, chemical and microbiological properties of lake Uluabat, Turkey.

Lake Uluabat, known for its scenic beauty and richness of aquatic life, is situated in Marmara Region, Bursa (Turkey). On account of its importance, lake Uluabat was designated by the Ministry of Environment as a Ramsar site in 1998. Physical, chemical and microbiological parameters of the aquatic ecosystem in lake Uluabat were measured monthly at five stations from February 2003 to January 2004. The results showed that lake Uluabat can be classified as Class I with respect to temperature (16.36 +/- 7.47 degrees C), nitrate nitrogen (0.63 +/- 0.50 mgl(-1)), sodium (9.64 +/- 2.78 mgl(-1)), chloride (20.45 +/- 4.59 mgl(-1)), sulphate (54.80 +/- 29.97 mgl(-1)); as Class II with respect to dissolved oxygen (7.62 +/- 1.99 mgl(-1)), ammonium nitrogen (0.52 +/- 0.49 mgl(-1)), chemical oxygen demand (35.74 +/- 10.66 mgl(-1)), total coliform (2027 MPN100 ml(-1) (average value)); as Class III with respect to pH (8.69 +/- 0.16) and as Class IV with respect to total nitrogen (84.94 +/- 66.13 mgl(-1)), total phosphorus (1.11 +/- 3.01 mgl(-1)), biochemical oxygen demand (21.21 +/- 6.60 mgl(-1)) according to TWPCR (Turkey Water Pollution Control Regulation). The nutrient content of lake waterapparently indicated that lake had an eutrophic characteristic. Phosphorus was determined as a limiting factor in lake. The measured hardness values (140.94 +/- 14.61 CaCO3 mgl(-1)) indicated that lake water was classified as soft/hard during the study period. Eutrophic characteristic of the lake and contaminant accumulation in water will probably affect the future use of the lake. Therefore, pollution parameters must be regularly monitored and evaluated according to aquatic living and local regulations.

Water pollution of oued msn a under catchments, in Algerian Tiaret region

This work concerns with the evaluation of the hydrous pollution evaluation of Industrial effluents, in the principal manufacturing units of Tiaret industrial park, as well as in the receiving dam of worn water of this city. Collected data were treated by correspondent factorial analysis between sites and sampling periods, in summer and winter. This analysis made us possible to focus obvious signs of pollution with the following evolutionary tendencies: On the level of Giplait: We have recorded an increase in the COD and the BODS during the two periods of sampling, as well as increasing rate of suspended solids. On the level of Sotrefit: We have recorded a strong phosphates concentration during the summer and winter periods, as well as a raised rate of Chromium [in winter] and Copper [in summer]. On the level of the ENF: We have noted that heavy metals prevail in these site effluents. On the level of the Barrage: We have noted a high concentration of nitrates, organic matter and suspended matter, as a source of pollution of the dam, which is currently used for the supply drinking water in Tiaret region. This work proved that Tiaret region become polluted

Environmental impact of nitrogen fertilization in tea eco-system.

To quantify the nitrogen losses through runoff and leaching under a tea plantation in hilly soil, a field experiment was conducted from October 2001 to October 2002 at United Planters Association of Southern India (UPASI), Coonoorin Nilgiri district. Runoff water was collected in the collection tub on most rainy days but the leachate was collected in the soil water sampler when the rainfall exceeded 150 mm. Higher nitrogen fertilization levels significantly influenced the NO3-N concentration in both the runoff and leachate and it was likely to cause adverse environmental impact at the delivery end. The NH4-N and NO3-N concentrations in runoff decreased with the days after fertilizer application. NH4-N concentration reduced from 10.27 mg/l on the 9th day to 1.72 mg/l on the 34th day after fertilizer application. NO3-N concentration reduced from 23.5 mg/l on the 9th day to 4.32 mg/l on the 34th day after fertilizer application. Nitrogen loss varied depending on the quantity of rainfall and runoff. The NO3-N concentration in the leachate increased with increase in depth (18.06 mg/l at 22.5 cm depth to 20.98 mg/l at 45 cm depth) whereas NH4-N concentration decreased with increase in depth (6.32 mg/l at 22.5 cm depth to 5.79 mg/l at 45 cm depth.

Physico-chemical characteristics of water samples of Bantwal Taluk, south-western Karnataka, India.

Quality of water is an important criterion for evaluating the suitability of water for irrigation and drinking. In the present study the analysis of water samples from different sources like open wells, bore wells, farm ponds and streams/rivers of twenty villages of Bantwal taluk of Dakshina Kannada district, South-western Kamataka has been carried out. The physico-chemical characteristics of this water showed that it is suitable for irrigation and agricultural purposes.