438 research outputs found

    Chemical simulation of greywater

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    Sustainable water resources management attracts considerable attention in today’s world. Recycling and reuse of both wastewater and greywater are becoming more attractive. The strategy is to protect ecosystem services by balancing the withdrawal of water and the disposal of wastewater. In the present study, a timely and novel synthetic greywater composition has been proposed with respect of the composition of heavy metals, nutrients and organic matter. The change in water quality of the synthetic greywater due to increasing storage time was monitored to evaluate the stability of the proposed chemical formula. The new greywater is prepared artificially using analytical grade chemicals to simulate either low (LC) or high (HC) pollutant concentrations. The characteristics of the synthetic greywater were tested (just before starting the experiment, after two days and a week of storage under real weather conditions) and compared to those reported for real greywater. Test results for both synthetic greywater types showed great similarities with the physiochemical properties of published findings concerning real greywater. Furthermore, the synthetic greywater is relatively stable in terms of its characteristics for different storage periods. However, there was a significant (p<0.05) reduction in 5-day biochemical oxygen demand (BOD5) for both low (LC) and high (HC) concentrations of greywater after two days of storage with reductions of 62% and 55%, respectively. A significant (p<0.05) change was also noted for the reduction (70%) of nitrate‒nitrogen (NO3‒N) concerning HC greywater after seven days of storage

    Atrazine and Breast Cancer: A Framework Assessment of the Toxicological and Epidemiological Evidence

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    The causal relationship between atrazine exposure and the occurrence of breast cancer in women was evaluated using the framework developed by Adami et al. (2011) wherein biological plausibility and epidemiological evidence were combined to conclude that a causal relationship between atrazine exposure and breast cancer is “unlikely”. Carcinogenicity studies in female Sprague-Dawley (SD) but not Fischer-344 rats indicate that high doses of atrazine caused a decreased latency and an increased incidence of combined adenocarcinoma and fibroadenoma mammary tumors. There were no effects of atrazine on any other tumor type in male or female SD or Fischer-344 rats or in three strains of mice. Seven key events that precede tumor expression in female SD rats were identified. Atrazine induces mammary tumors in aging female SD rats by suppressing the luteinizing hormone surge, thereby supporting a state of persistent estrus and prolonged exposure to endogenous estrogen and prolactin. This endocrine mode of action has low biological plausibility for women because women who undergo reproductive senescence have low rather than elevated levels of estrogen and prolactin. Four alternative modes of action (genotoxicity, estrogenicity, upregulation of aromatase gene expression or delayed mammary gland development) were considered and none could account for the tumor response in SD rats. Epidemiological studies provide no support for a causal relationship between atrazine exposure and breast cancer. This conclusion is consistent with International Agency for Research on Cancer’s classification of atrazine as “unclassifiable as to carcinogenicity” and the United States Environmental Protection Agency's classification of atrazine as “not likely to be carcinogenic.

    Soil type influences crop mineral composition in Malawi

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    Food supply and composition data can be combined to estimate micronutrient intakes and deficiency risks among populations. These estimates can be improved by using local crop composition data that can capture environmental influences including soil type. This study aimed to provide spatially resolved crop composition data for Malawi, where information is currently limited. Six hundred and fifty-two plant samples, representing 97 edible food items, were sampled from N150 sites in Malawi between 2011 and 2013. Samples were analysed by ICP-MS for up to 58 elements, including the essential minerals calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se) and zinc (Zn). Maize grain Ca, Cu, Fe, Mg, Se and Zn concentrations were greater from plants grown on calcareous soils than those from the more widespread low-pH soils. Leafy vegetables from calcareous soils had elevated leaf Ca, Cu, Fe and Se concentrations, but lower Zn concentrations. Several foods were found to accumulate high levels of Se, including the leaves of Moringa, a crop not previously been reported in East African food composition data sets. New estimates of national dietary mineral supplies were obtained for non-calcareous and calcareous soils. High risks of Ca (100%), Se (100%) and Zn (57%) dietary deficiencies are likely on non-calcareous soils. Deficiency risks on calcareous soils are high for Ca (97%), but lower for Se (34%) and Zn (31%). Risks of Cu, Fe and Mg deficiencies appear to be low on the basis of dietary supply levels

    A screening tool to prioritize public health risk associated with accidental or deliberate release of chemicals into the atmosphere

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    The Chemical Events Working Group of the Global Health Security Initiative has developed a flexible screening tool for chemicals that present a risk when accidentally or deliberately released into the atmosphere. The tool is generic, semi-quantitative, independent of site, situation and scenario, encompasses all chemical hazards (toxicity, flammability and reactivity), and can be easily and quickly implemented by non-subject matter experts using freely available, authoritative information. Public health practitioners and planners can use the screening tool to assist them in directing their activities in each of the five stages of the disaster management cycle

    Dietary Diversity Predicts the Adequacy of Micronutrient Intake in Pregnant Adolescent Girls and Women in Bangladesh, but Use of the 5-Group Cutoff Poorly Identifies Individuals With Inadequate Intake

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    Background: The Minimum Dietary Diversity for Women (MDD-W) indicator based on a 10-food group women dietary diversity score (WDDS-10) has been validated to assess dietary quality in nonpregnant women. Little is known about its applicability in pregnant women, and specifically pregnant adolescent girls with higher nutrient requirements. Objectives: This study aimed to 1) compare the adequacy of micronutrient intakes between pregnant adolescent girls and women, 2) examine the performance of WDDS-10 in predicting the mean probability of adequacy (MPA) of 11 micronutrients, and 3) assess how well the MDD-W cutoff of 5 groups performed in pregnant adolescent girls and women. Methods: We used data from a 2015 household survey in Bangladesh (n = 600). Nutrient intakes were estimated with a multiple-pass 24-h recall and WDDS-10 was assessed through the use of a list-based method. Multiple linear regression models adjusted for geographical clustering assessed the association between WDDS-10 and MPA. Sensitivity and specificity analysis assessed the accuracy of MDD-W in correctly classifying individuals into high (MPA \u3e0.6) or low MPA. Results: Dietary intakes of pregnant adolescent girls and women were similar in energy intake, WDDS-10 (5.1 ± 1.4), MPA (0.40 ± 0.12), and micronutrient intakes. Probabilities of adequacy were ∼0.30 for riboflavin, vitamin B-12, calcium, and zinc; 0.12-0.15 for folate; 0.16-0.19 for vitamin A; and extremely low for iron at 0.01. The WDDS-10 was significantly associated with MPA in both groups and predicted MPA equally well at population level (SD of residuals 0.11 for both). Use of the 5-food groups cutoff for MDD-W to classify individuals\u27 diets into MPA \u3e0.6, however, resulted in a low correct classification (∼40%). A cutoff of 6 food groups markedly improved correct classification. Conclusions: The WDDS-10 predicted MPA equally well for pregnant adolescent girls and women at population level. The MDD-W indicator performed poorly in classifying individuals with MPA \u3e0.6

    Global mapping of highly pathogenic avian influenza H5N1 and H5Nx clade 2.3.4.4 viruses with spatial cross-validation.

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    Global disease suitability models are essential tools to inform surveillance systems and enable early detection. We present the first global suitability model of highly pathogenic avian influenza (HPAI) H5N1 and demonstrate that reliable predictions can be obtained at global scale. Best predictions are obtained using spatial predictor variables describing host distributions, rather than land use or eco-climatic spatial predictor variables, with a strong association with domestic duck and extensively raised chicken densities. Our results also support a more systematic use of spatial cross-validation in large-scale disease suitability modelling compared to standard random cross-validation that can lead to unreliable measure of extrapolation accuracy. A global suitability model of the H5 clade 2.3.4.4 viruses, a group of viruses that recently spread extensively in Asia and the US, shows in comparison a lower spatial extrapolation capacity than the HPAI H5N1 models, with a stronger association with intensively raised chicken densities and anthropogenic factors

    Association between wasting and food insecurity among children under five years: findings from Nepal demographic health survey 2016

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    Background Wasting is a consequence of food insecurity, inappropriate dietary practices, and inadequate caring and feeding practices. The present study assessed association between wasting and household food insecurity among under 5 years old children, along with other socio-demographic characteristics. Methods This study is a secondary analysis of the Nepal Demographic and Health Survey 2016. The survey is cross-sectional in design with use of standardized tools. The sampling frame used is an updated version of the frame from the 2011 National Population and Housing Census. The participants were children under 5 years of age (n = 2414). Logistic regression was carried out to identify the odds of being wasted for children belonging to different levels of food insecure households using odds ratio and 95% confidence intervals. Results The prevalence of wasting increased with the level of food insecurity, from mild (9.4%) to moderate (10.8%) and to severe (11.3%). The highest proportions of wasted children were in Province 2 (14.3%), from rural areas (10.1%), born to mothers with no education (12.4%) and from a richer quintile (11.3%). Children belonging to severe food insecure households had 1.36 (95%CI 0.72–2.57) adjusted odds of being wasted and those belonging to mild food insecure and moderately food insecure households had 0.98 (95%CI 0.64-1.49) and 1.13 (95%CI 0.65–1.97) odds of being wasted respectively. Province 1 (AOR 2.06, 95%CI 1.01–4.19) and Province 2 (AOR 2.45, 95%CI 1.22–4.95) were significantly associated with wasting. Conclusion Considering the increment in childhood wasting as per level of food insecurity, an integrated intervention should be developed in Nepal that, 1. addresses improving knowledge and behavior of community people with respect to diet and nutrition; 2. reduce the problem of food insecurity through agricultural interventions
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