Kawser Ahmed

Potential ecological risk of hazardous elements in different land-use urban soils of Bangladesh

Soil pollution, influenced by both the natural and anthropogenic factors, significantly reduces environmental quality. In this study, six hazardous elements (Cr, Ni, Cu, As, Cd and Pb) in 12 different land-use urban soils from Bangladesh were assessed. The ranges of Cr, Ni, Cu, As, Cd and Pb in studied soils were 2.4-1258, 8.3-1044, 9.7-823, 8.7-277, 1.8-80 and 13-842 mg/kg, respectively. More than 70% of soil samples exceeded the Dutch target value for Ni, Cu, As, Cd and Pb concentration in soil, indicating a potential risk to the environment. Certain indices, including the enrichment factor (EF), pollution load index (PLI) and contamination factor (Cf(i)), were used to assess the ecological risk posed by hazardous elements in soils. The mean range of PLI was 1.5-10, indicating progressive deterioration of soil due to metal contamination. However, the Cf(i) values of Cd ranged from 3.7 to 35 revealed that the examined soils were strongly impacted by Cd. Considering the severity of potential ecological risk for single metal (Er(i)), the descending order of contaminants was Cd>As>Cu>Pb>Ni>Cr. In view of the potential ecological risk (PER), soils from all land uses showed considerable to very high potential ecological risk.

Arsenic and lead in foods: a potential threat to human health in Bangladesh

The non-carcinogenic and carcinogenic risk of arsenic and lead to adults and children via daily dietary intake of food composites in Bangladesh was estimated. The target hazard quotients (THQs), hazard index (HI) and target carcinogenic risk (TR) were calculated to evaluate the non-carcinogenic and carcinogenic health risk from arsenic and lead. Most of the individual food composites contain a considerable amount of arsenic and lead. The highest mean concentrations of arsenic were found in cereals (0.254 mg kg–1 fw) and vegetables (0.250 mg kg–1 fw), and lead in vegetables (0.714 mg kg–1 fw) and fish (0.326 mg kg–1 fw). The results showed the highest THQs of arsenic in cereals and lead in vegetables for both adults and children which exceeded the safe limit (> 1) indicating that cereals and vegetables are the main food items contributing to the potential health risk. The estimated TR from ingesting dietary arsenic and lead from most of the foods exceeded 10−6, indicating carcinogenic risks for all adult people of the study area.

Reactive transport modeling of subsurface arsenic removal systems in rural Bangladesh.

Subsurface Arsenic Removal (SAR) is a technique for in-situ removal of arsenic from groundwater. Extracted groundwater is aerated and re-injected into an anoxic aquifer, where the oxygen in the injected water reacts with ferrous iron in the aquifer to form hydrous ferric oxide (HFO). Subsequent extraction of groundwater contains temporarily lower As concentrations, because As sorbs onto the HFO. Injection, storage, and extraction together is called a cycle. A reactive transport model (RTM) was developed in PHREEQC to determine the hydrogeochemical processes responsible for As (im)mobilization during experimental SAR operation performed in Bangladesh. Oxidation of Fe(II) and As(III) were modeled using kinetic-rate expressions. Cation exchange, precipitation of HFO, and surface complexation, were modeled as equilibrium processes. A best set of surface complexation reactions and corresponding equilibrium constants was adopted from previous studies to simulate all 20 cycles of a SAR experiment. The model gives a reasonable match with observed concentrations of different elements in the extracted water (e.g., the r(2) value of As was 0.59 or higher). As concentrations in the extracted water are governed by four major processes. First, As concentration decreases in response to the elevated pH of injection water and likewise increases when native neutral pH groundwater flows in. Second, the sorption capacity for As increases due to the gradual buildup of HFO. Third, As sorption is enhanced by preferential removal of As(V). Fourth, competitive sorption of Si limits the capacity of freshly precipitated HFO for As sorption. Transferability of the developed reactive transport model was demonstrated through successful application of the model, without further calibration, to two additional SAR sites in Bangladesh. This gives confidence that the model could be useful to assess potential SAR performance at locations in Bangladesh based on local hydrogeochemical conditions.

Human and livestock waste as a reduced carbon source contributing to the release of arsenic to shallow Bangladesh groundwater

Recent studies have demonstrated that the supply of relatively young organic carbon stimulates the release of arsenic to groundwater in Bangladesh. This study explores the potential role of human and livestock waste as a significant source of this carbon in a densely populated rural area with limited sanitation. Profiles of aquifer sediment samples were analyzed for phytosterols and coprostanol to assess the relative contributions of plant-derived and human/livestock waste-derived organic carbon at two well-characterized sites in Araihazar. Coprostanol concentrations increased with depth from non-detection (<10m at Site B and <23m at Site F) to maxima of 1.3 and 0.5ng/g in aquifer sands recovered from 17m (Site B) and 26m (Site F), respectively. The commonly used sewage contamination index ([5β-coprostanol]/([5α-cholestanol]+[5β-coprostanol])) exceeds 0.7 between 12 and 19m at Site B and between 24 and 26m at Site F, indicating input of human/livestock waste to these depths. Urine/fecal input within the same depth range is supported by groundwater Cl/Br mass ratios >1000 compared to Cl/Br <500 at depths >50m. Installed tube wells in the areas study sites may act as a conduit for DOC and specifically human/livestock waste into the aquifer during flood events. The depth range of maximum input of human/livestock waste indicated by these independent markers coincides with the highest dissolved Fe (10-20mg/L) and As (200-400μg/L) concentrations in groundwater at both sites. The new findings suggest that the oxidation of human/livestock waste coupled to the reductive dissolution of iron-(oxy)-hydroxides and/or arsenate may enhance groundwater contamination with As.

Reduction in exposure to arsenic from drinking well-water in Bangladesh limited by insufficient testing and awareness

This study considers potential policy responses to the still very high levels of exposure to arsenic (As) caused by drinking water from shallow tubewells in rural Bangladesh. It examines a survey of 4,109 households in 76 villages of Araihazar upazila conducted two years after a national testing campaign swept through the area. The area is adjacent to the region where a long-term study was initiated in 2000 and where households are periodically reminded of health risks associated with well-water elevated in As. Results confirm that testing spurs switching away from unsafe wells, although the 27% fraction who switched was only about half of that in the long-term study area. By village, the fraction of households that switched varied with the availability of safe wells and the distance from the long-term study area. Lacking follow-up testing, two years only after the campaign 21% of households did not know the status of their well and 21% of households with an unsafe well that switched did so to an untested well. Well testing is again urgently needed in Bangladesh and should be paired with better ways to raise awareness and the installation of additional deep community wells.

Enhancing the capacity of local drillers for installing arsenic-safe drinking water wells—experience from Matlab, Bangladesh

Nearly 90% of the estimated 10 million tubewells in Bangladesh are installed privately by local drillers for rural drinking water supplies in Bangladesh. The awareness of local drillers on elevated Arsenic (As) concentrations in tubewell water at shallow depths have made them change their practice of installation of tubewells. Using the visual color attributes of the shallow sediments (<100 m) and content of dissolved iron, generally associated with high As concentrations, the local drillers presently install community tubewells at depths targeting red/brownish or off-white sediments. This study recognizes the local tubewell drillers as important stakeholder in the business of tubewell installation. A Sediment Color Tool has been developed to enhance the local driller’s capacity to identify the As-safe aquifers that would bring significant change to reduce As exposure and scale-up safe water access in rural Bangladesh.

Geochemical Speciation and Risk Assessment of Heavy Metals in Sediments of a River in Bangladesh

The surface sediment of a downstream river (Paira) connected to the marine ecosystems of the Bay of Bengal was assessed by sequential extraction technique. The objectives of this study were to evaluate the mobility and dynamics of heavy metals and their probable ecological risks. The results revealed high environmental risk of Cd due to higher availability in the exchangeable fraction (21%) and a considerable portion in the carbonate bound fraction due to the special affinity towards carbonate and co-precipitation with its minerals. Toxic metals like Cr, Ni, and Cd are of concern, and can occasionally be associated with adverse biological effects. The risk assessment code (RAC) suggests that the highest mobility of Cd poses a higher environmental risk and threat to the aquatic biota, as well.

Hydrogeochemical contrasts across the multi-level aquifers of Bengal basin in Matlab, Bangladesh: Implications for arsenic free and low -manganese drinking water sources

Targeting shallow, intermediate-deep and deep aquifers, piezometers nests were installed at 15 locations in the Matlab region, an As hotspot in southeastern Bangladesh. Groundwater levels and water quality were monitored for over a three years period. Stable isotopic composition was used to identify the hydrogeological characteristics of different aquifers, hydraulic connectivity between the contaminated and safe aquifers. Within the shallow depth (up to 100m), two aquifers (Aquifer-1 and Aquifer-2) were identified, and groundwater from Aquifer-1 indicated consistently high As concentration was found to be As-enriched (median As levels upto 714 μg/L). Considerable variability in As concentrations were observed in Aquifer-2 wells (6–30 μg/L) comprising relatively oxidized or less reduced red and off-white sands. The intermediate-deep and deep aquifers were found to contain very low As concentration and these aquifers are hydraulically separated from the shallow aquifers. Groundwater depth and elevation and stable isotope signatures also reflect that intermediate-deep and deep aquifers, in most places belong to the same hydrostratigraphic unit (Aquifer-3).

Heavy metals content of selected key foods in Bangladesh

T epidemic of metabolic syndrome, including a marked increase in the prevalence of obesity and gestational diabetes mellitus among pregnant women, represents a significant public health problem. Both weight gain and body mass index are major predictors of diabetes; for every 1 kg increase in adult weight, the risk of diabetes increases by 4.5 to 9%. Although genetic factors may contribute to selected cases of obesity, environmental and epigenetic factors are likely more important. There is increasing recognition that the risk of adult obesity is clearly influenced by prenatal and infant environmental exposures. This tenet is the fundamental basis of developmental programming. Low birth weight, together with infant catch-up growth, is associated with a significant risk of adult obesity and type II diabetes. As an index of the public health significance, a striking 57% of type II diabetes can be attributed to programmed metabolic syndrome. Animal models have replicated human epidemiologic findings and elucidated potential programming mechanisms that include altered organ development, cellular signaling responses, and epigenetic modifications. Adipose tissue is one of the principal targets of programming that predisposes to offspring obesity. Our studies show that newborns of obese/high fat diet mothers and low birth weight newborns of maternal under-nutrition both exhibit programmed adipocytes that contribute to the development of obesity. These adipocytes have intrinsic trait of increased cell proliferation and enhanced propensity for fat storage. Knowledge of the mechanisms of fetal adipocyte programming will enable the development of novel therapeutics to prevent obesity and glucose intolerance.O is associated with increased classically activated M1 adipose tissue macrophages (ATMs) and reduced alternatively activated M2 ATMs, which contributes to insulin resistance. Epigenetic mechanisms play important roles in complex diseases including obesity and insulin resistance. We find that the expression of DNA methyltransferase 1 (DNMT1) is significantly induced in macrophages exposed to the saturated fatty acid (SFA) stearic acid and the pro-inflammatory cytokine TNFα, is higher in ATMs isolated from obese mice, but is significantly lower in M2 than in M1 ATMs. Inhibiting DNA methylation pharmacologically by 5-aza-2’-deoxycytidine (5-azadC) or genetically using macrophages from myeloid-specific DNMT1 knockout mice (MD1KO) results in M2 macrophage polarization, evidenced by up-regulation of M2 marker, such as arginase 1 (ARG1), mannose receptor, Dectin-1, programmed cell death 1 ligand 2, interleukin 1 receptor antagonist, interleukin 10, and peroxisome proliferator-activated receptor γ1 (PPARγ1), key regulator of M2 macrophage activation; whereas overexpressing DNMT1 profoundly suppresses interleukin 4-induced ARG1 and PPARγ1 expression. PPARγ1 promoter is enriched with CpG sites. Inhibiting DNA methylation in macrophages by 5-azadC or in MD1KO mice significantly decreases, whereas stearic acid and TNFα significantly increase PPARγ1 promoter DNA methylation. Finally, MD1KO mice have lower adipose tissue inflammation and significantly improved insulin sensitivity without altering body weight. In summary, DNA methylation plays an important role in regulating macrophage polarization. Inhibiting DNA methylation at PPARγ1 promoter promotes M2 macrophage polarization; whereas in obesity, elevated SFAs and pro-inflammatory cytokines enhance PPARγ1 promoter DNA methylation, which contributes to deregulated ATM polarization, inflammation and insulin resistance.D is known cause of endothelial dysfunction that leads to microvascular complications and end organ damage. The molecular mechanisms of these changes are poorly understood, but there is evidence that oxidative stress plays a role. (+)-Catechin (CTN), a polyphenolic compound abundantly found in grapes, wine, and tea, might serve as a supplemental therapy to alleviate impact of high ambient glucose. CTN belongs to a group of polyphenolic compounds, which are believed to have anti-inflammatory and antioxidative properties. Our recent study showed that the effects of CTN are comparable with enalapril for the treatment of diabetic nephropathy in streptozotocin-induced diabetic rats. CTN decrease urinary albumin excretion, improved creatinine clearance, lowered serum concentrations of endothelin-1 and lipid peroxidation markers. Diabetes is a stage of low grade chronic inflammatory process. CTN has been shown significantly decrease levels of inflammatory cytokines. Double blinded ongoing study scrutinizes the effects of flavonoids on endothelial function and inflammatory markers in type 1 diabetic adolescents. Patients between the ages of 1221 years are eligible for the study and are given flavanoid rich supplement or placebo. A non-invasive measurement of endothelial function is analyzed using an Endo-Pat2000 device. The preliminarily data showed that there is significant differences in reactive hyperemia before and after flavanoid treatment. The concentration of TNFα and IL6 in urine is significantly decreased after flavonoid treatment. Flavanols and particularly (+)-catechin, are powerful food supplements with significant impact of endothelial function and might be used to prevent microvascular complications in patients with diabetes.Medical practice is not exempted from complications. This is particularly relevant in the critical care setting. Decisions bearing on patients lives have to be taken amidst tensions dictated by windows of opportunity, progression of the disease, and availability of technological equipment and staff. In spite of all of these factors, medical errors can arise. Critical care medicine has gone through an evolutionary threshold in the last few decades, thanks to the works of dedicated researchers such as Amato, Van de Bergher, and Rivers, among others. The international community has developed several initiatives to implement their findings and recommendations. It is however disturbing that nutritional support has not received equal attention as the advances in medical science. This is also reflected in the education of medical students in some countries where nutrition as a specialist subject is rather brief. All this should be considered with respect to evidence-based data which strengthens the notion that nutritional support generates superior medical care outcomes. To ensure optimal care of the patient, a quality control system relating to nutritional support should be designed and put into effect. This involves the documentation around the nutritional support protocol, which must be strengthening harmoniously integrated into programs. Proper documentation also serves to evaluate the continuing education effectiveness of nutritional and metabolic interventions and has a potential impact on hospital management. In this regard, educative and organizative interventions must be conducted on three levels: (1) increasing the knowledge base of medical and paramedical personnel about current nutritional support practices in the intensive care unit, (2) better documentation and recording practices, and (3) continuous training and education. Adopting these aforementioned procedures will result in a higher fulfillment of nutritional prescriptions, an increased coverage of patients prescribed with nutritional support, and a higher proportion of patients receiving the prescribed energy. List of Abbreviations ICU Intensive care unit International Organization for Standardization Nutritional support ISO NS PN Parenteral nutrition Food, Nutritional, and Metabolic Intervention Program Subjective Global Assessment Standard PRINUMA SGA SOP Operating ProcedureT pattern of human growth is used throughout pediatric science to establish the state of health and wellbeing of children. The pattern of normal growth is described by a decaying polynomial curve during infancy and childhood and a sigmoidal curve during adolescence. On an individual level this pattern may vary depending on environmental factors, the most important of which during infancy and early childhood, is nutrition. However, evidence has been accumulating for the last three decades to demonstrate the importance of growth rate during intrauterine life and the long term consequences of the magnitude of subsequent birth weight combined with infant growth rates. Low birth weights and rapid early growth, sometimes referred to as catch-up growth; result in increased risk for obesity, CVD, CHD and the metabolic syndrome. Considerable uncertainty exists about the timing, duration and magnitude of infant growth rates in weight and length that maximize later risk and the magnitude of risk in different ethnic groups. This paper reviews evidence from birth cohort studies in South Africa (Birth to Twenty) and the UK (ALSPAC and Born in Bradford) that relates size at birth to early, nutritionally dependent, infant growth rates and the subsequent appearance of risk factors for the metabolic syndrome and obesity. It stresses the importance of accurately assessing infant and child growth and the subsequent analysis of the pattern of growth in relation to appropriate growth charts, both references and standards, in order to accurately monitor child health and wellbeing.C in diet pattern and lifestyle have resulted in a dramatic increase in the prevalence of obesity and metabolic syndrome in western countries and many Asian countries. This has resulted in a significant increase in the incidence of nonalcoholic fatty liver disease (NAFLD), which is considered to be a hepatic manifestation of metabolic syndrome. NAFLD has become an important public health issue because of its high prevalence. NAFLD consists of 2 clinical entities: simple steatosis, which generally follows a benign non-progressive clinical course, and nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis and hepatocellular carcinoma (HCC). The development of cirrhosis in NAFLD is 5% to 8% during 7-21 year follow-up periods. Survival in NASH is lower than the expected survival of the matched general population due to the higher incidence of cardiovascular and liver-related death. In patients with cirrhotic NASH, HCC and liver failure are the main causes of morbidity and mortality (5-year cumulative HCC development rate 11.3%, 5-year survival rate 75.2%, respectively). Recently, obesity and diabetes have been revealed as risk factors for HCC by clinical studies and experimental studies. The risks of obesity and diabetes for HCC are likely conferred by two factors: the increased risk of development of NAFLD and the carcinogenic potential of themselves. It is conceivable that the nutritional habit play a key role in the development of NAFLD and treatment for it. Further study is needed to define the pathogenesis of NAFLD and to develop effective treatment. Etsuko Hashimoto, J Nutr Food Sci 2013, 3:4 http://dx.doi.org/10.4172/2155-9600.S1.010F more than fifteen years, serious efforts have been made to make a dent towards reducing the high infant and high maternal mortality rates in Nigeria. According to the National Demographic Survey (NDHS), the infant mortality rate in Nigeria in 1992 stood at 114/1000 live births which has come down to 86/1000 as shown in a survey carried out in 2010.This statistics is considered very high and Nigeria can certainly do better if the right approach and strategy using a combination of Community Management of Acute Malnutrition (CMAM) and promotion of Infant and Young Child Feeding Programs to tackle the problem are adopted. The most recent NDHS statistics in Nigeria (2009) shows that under-5 mortality was 138/1000 live birth which is considerably high and according to the Paediatric Association of Nigeria, 90% of child deaths in Nigeria are preventable! The underlying cause of high infant and child mortality figures is poor nutritional practice which has become exacerbated by the fast degradation of Nigeria’s health facilities. It has been globally established that 53% of child deaths is as a result of preventable malnutrition. Until a few years ago, the high prevalence of Severe Acute Malnutrition (SAM) in Northern Nigeria was not reported. Studies carried out in Kebbi, Katsina, Gombe, and Jigawa states have revealed the existence of a silent nutritional emergency that threatens the attainment of the UN Millennium Development Goal number 4 in Nigeria. SAM prevalence in many of the Local Government Areas in Gombe state was as high as 7% and all these happening in the absence of emergencies such as natural disaster (drought, famine, earthquake, or war). This silent emergency in Northern Nigeria is being tackled by the efforts of UNICEF through the supply of plumpy nuts and basic medicines.T major causes of death in industrialized countries are the chronic diseases such as heart disease, cancers, diabetes which all have to do with lifestyle choices. The majority of these chronic diseases could be prevented if wise choices were made beginning at an early age. Education is critical in terms of providing people access to this information so that they will be able to make informed choices to promote wellness and prevent chronic diseases from developing. In order for education to be successful it has to be multi-faceted and have a positive, engaging and fun angle. Schools are therefore an ideal place in which to launch a comprehensive program that will motivate people to make positive lifestyle choices for wellness. Dr. Demas will discuss her work in the public schools and some of her research results that clearly demonstrate that the most effective way to promote positive behavior change regarding nutrition is to educate students who will bring the message home and will educate their families.G epithelium provides a physical barrier against external environment. Barrier defects resulting in the permeation of luminal inflammatory substances induce an abnormally robust inflammatory response. The barrier integrity depends on the coordinated expression and interaction of proteins in cell-cell junctional complexes, including the tight junctions (TJs). Recently, we have demonstrated that some dietary polyphenols have potentials to regulate the intestinal TJ barrier. Among the polyphenols tested, a citrus polyphenol, naringenin, promotes and protects the intestinal TJ barrier in human epithelial Caco-2 cells and a murine model of colitis. In Caco-2 cells, naringenin enhances the intestinal TJ barrier, indicated by epithelial electrical resistance and dextran permeability. Immunoblot analysis and confocal microscopy demonstrate that naringenin increases the assembly of TJ proteins, ZO-2, occludin, claudin-1, and claudin-4, at TJs. The increased claudin-4 by naringenin is mediated by its transcriptional regulation. Luciferase reporter assays with mutagenesis and pharmacological inhibitors show that the naringenin-mediated claudin-4 up-regulation occurs in part through a transcriptional factor, Sp-1. The naringenininduced occludin assembly correlates with its phosphorylation, indicating the important role of the occludin phosphorylation. In a murine model of colitis, the naringenin ingestion suppresses the colon damage and inflammation, indicated by clinical score, colon shortening, and inflammatory cytokine expression. This naringenin-mediated suppression occurs simultaneously with protection of TJ barrier in colons. Taken together, some polyphenols such as naringenin have roles in intestinal barrier regulation and that the supplemental feeding might provide us with an alleviative effect on diseases associated with the intestinal barrier defect.T ReninAngiotensin System (RAS) is one of the most important biological systems involved in cardiovascular and hydroelectrolytic balance regulation. ClassicallyAngiotensin II acting through AT1 receptor produces vasoconstriction and proliferative effects while Angiotensin-(1-7) [Ang-(1-7)] acting through Mas receptor produces vasodilation and antiproliferative effects. Recently was demonstrated that Ang-(1-7)/Mas axis also can improve lipid and glycemic profile preventing and reversing diabetes and obesity. Sirtuins are the most known enzymes activated by caloric restriction, which also can be activated for natural compounds such as Resveratrol. Recent studies showed that both RAS and Sirtuins could be modulated by diet composition. Our group recently demonstrated that high-fat diet produces RAS unbalance and increases Sirt4 expression in adipose tissue. Furthermore, our recent study showed that high-fat feed mice treated with resveratrol and (or) an oral formulation of Ang-(17) associated to the food, present an improved metabolic profile with reduced body-fat and improved glucose metabolism. The same study pointed out for a cross talk between RAS and Sirtuins in adipose tissue, once one system was able to modulate each other in adipocytes. In conclusion we recently demonstrated that RAS and Sirtuins are key biological enzymes modulated by dietcomposition and able to improve metabolism when selectively activated.