Holistic perilous index-based environmental appraisal of Metal(oid)s in the sole coral-bearing island of northeastern bay of Bengal.

This study aimed to evaluate the concentration, distribution, along with the environmental and human health impact of eight heavy metals-Pb, Cr, Cu, Cd, Zn, Mn, Ni, and As-on St. Martin's Island in the northeastern Bay of Bengal, and in doing so to help implement new legislations to protect the island. Focusing on the island's significance as a tourist destination, with seafood being a prominent dietary component, three sample types (sediment, seawater, and crustaceans) were selected for a comprehensive assessment, considering seasonal variations. Concentration of metals was observed to be lower than the established standards in sediment samples, but in seawater samples, Pb, Cr, Cd and Zn were higher than US-EPA values for natural marine water. The metals displayed a decreasing trend of Zn > Ni > Pb > Cu > Mn > As > Cd > Cr in crustacean samples for both seasons. Crustacean samples displayed higher metal concentrations in winter than in monsoon. Pb exceeded the maximum allowable limit for crustaceans with a concentration of about 3 and 4 mg kg-1 in monsoon and winter respectively; being more than 6-8 times the standard for Bangladesh which is only about 0.5 mg kg-1. Health indices displayed that although adults may suffer less from carcinogenic/non-carcinogenic health effects, the risks are far greater for children. For both age groups, As and Ni displayed possibilities of developing cancer. Principal Component Analysis (PCA)shed light on the sources of metals and showed that most of them were from anthropogenic sources. Overall, this study found that the quality of the environment of the island was better in comparison to previous studies made before the pandemic, and so, if the trend continues, it may lead to a better environment for the organisms around the island and help to keep the negative physiological impacts from the consumption of these organisms to a minimal.

Protocol for the Adolescent Menstrual Experiences and Health Cohort (AMEHC) Study in Khulna, Bangladesh: A Prospective cohort to quantify the influence of menstrual health on adolescent girls' health and education outcomes.

BACKGROUND: Menstrual health is essential for gender equity and the well-being of women and girls. Qualitative research has described the burden of poor menstrual health on health and education; however, these impacts have not been quantified, curtailing investment. The Adolescent Menstrual Experiences and Health Cohort (AMEHC) Study aims to describe menstrual health and its trajectories across adolescence, and quantify the relationships between menstrual health and girls' health and education in Khulna, Bangladesh. METHODS AND ANALYSIS: AMEHC is a prospective longitudinal cohort of 2016 adolescent girls recruited at the commencement of class 6 (secondary school, mean age=12) across 101 schools selected through a proportional random sampling approach. Each year, the cohort will be asked to complete a survey capturing (1) girls' menstrual health and experiences, (2) support for menstrual health, and (3) health and education outcomes. Survey questions were refined through qualitative research, cognitive interviews and pilot survey in the year preceding the cohort. Girls' guardians will be surveyed at baseline and wave 2 to capture their perspectives and household demographics. Annual assessments will capture schools' water, sanitation and hygiene, and support for menstruation and collect data on participants' education, including school attendance and performance (in maths, literacy). Cohort enrolment and baseline survey commenced in February 2023. Follow-up waves are scheduled for 2024, 2025 and 2026, with plans for extension. A nested subcohort will follow 406 post-menarche girls at 2-month intervals throughout 2023 (May, August, October) to describe changes across menstrual periods. This protocol outlines a priori hypotheses regarding the impacts of menstrual health to be tested through the cohort. ETHICS AND DISSEMINATION: AMEHC has ethical approval from the Alfred Hospital Ethics Committee (369/22) and BRAC James P Grant School of Public Health Institutional Review Board (IRB-06 July 22-024). Study materials and outputs will be available open access through peer-reviewed publication and study web pages.

Nutrient and heavy metal dynamics in the coastal waters of St. Martin's island in the Bay of Bengal.

Seasonal variation observations were conducted in the coastal waters of St. Martin's Island in the Bay of Bengal to examine the influence of physical processes and the distribution pattern of nutrients in the ocean water. Pollution evaluation indices, health index and statistical techniques were incorporated to assess the heavy metal contamination. Two seasons, cool dry winter and pre-monsoon hot, were considered for sampling from 12 stations around the island. The Cool dry winter season has higher nutrient concentrations than the Pre-monsoon Hot season. The concentration of nutrients appeared as follows: Silicate > Nitrate > Ammonia > Phosphate > Nitrite. PCA and Pearson's Correlation showed that fresh water from nearby rivers, deep water upwelling, and, in some situations, modest anthropogenic sources are crucial. Hence, low DO and phosphate levels during the pre-monsoon hot season indicate there is a planktonic process like photosynthesis prevailing. The island's north-western and south-eastern regions have higher nutrient concentrations, which may be seasonal and due to wind action. Pb, Cu, As, Cr, Cd, and Zn were also considered to comprehend the island's geo-chemical perspectives and ecological and human health risks. The Pre-monsoon Heavy Metal Pollution Index (HPI) and Heavy Metal Evaluation Index (HEI) demonstrated that some places are much higher than the threshold limit, even though no significantly higher value was detected in the cool winter season. The Nemerow Index, the Total Ecological Risk Index (TERI), indicated that heavy metal contamination was severe to moderate and low to moderate. Finally, Pearson's correlation showed the association between physical and chemical characteristics, similar to PCA and Pearson's correlation for nutrients and heavy metals. Thus, this research may help shed light on the state of the seas around St. Martin's Island. This study may also provide explicit insights for the authority to take the necessary measures to preserve marine ecology and the associated terrestrial ecosystem.

Hydrogeochemical characterization and quality assessment of groundwater resource in Savar - an industrialized zone of Bangladesh.

Savar Upazila in the Dhaka District is a rapidly expanding city with a diverse range of industries and agricultural activities. This expansion poses environmental challenges including the threat to groundwater contamination. Based on these considerations, the objective of this research is to carry out a shallow groundwater hydrogeochemical characterization and an assessment of the suitablity of the groundwater for drinking and irrigational purposes using a geochemical approach, multivariate statistical techniques, and some indices of groundwater quality. The hydrogeochemical analyses of 42 groundwater samples from shallow depths (18 - 76 m) showed that the order of concentrations of cations, anions, and metals was Ca2+ > Na+ > Mg2+ > K+, HCO3- > Cl- > SO42- > NO3-, and Cr > As > Pb > Mn > Fe, respectively. Weathering of silicates was found to be the most significant hydrogeochemical process governing the chemistry of groundwater. Cation exchange also plays a significant role in the evolution of the groundwater chemistry. Principal component analysis and hierarchical cluster analysis suggested that anthropogenic activities are influencing groundwater quality. A drinking water quality index map showed that about 91% of the groundwater samples were in the excellent category and suitable for human consumption, with only a few samples exceeding the standards of the WHO and Bangladesh for concentrations of Ca2+, Mg2+, HCO3-, Fe, Mn, and As. An analysis of irrigation quality parameters found that most of the groundwater samples were either excellent or good for agricultural uses, except for one sample in the Tetuljhora Union that was unsuitable based on residual sodium carbonate. This finding may be useful to local governments in understanding the current status of groundwater quality, tracking potential threats of contamination, and initiating appropriate measures for long-term groundwater resource management.

Are the rights of people with disabilities included in international guidance on WASH during the COVID-19 pandemic? Content analysis using EquiFrame.

PURPOSE: People with disabilities are at increased risk from COVID-19. Access to water, sanitation and hygiene (WASH) services and facilities is a fundamental right for all, and is vital in stopping the transmission of COVID-19. However, people with disabilities often face difficulties accessing WASH. Various international organisations have published guidance and recommendations on WASH service provision during the COVID-19 pandemic, and this must include information of relevance to people with disabilities. This study aimed to investigate the inclusion of core concepts of rights for people with disabilities in guidance on WASH during the COVID-19 pandemic. METHOD: We used the EquiFrame content analysis tool to analyse the inclusion of 21 core concepts of rights for people with disabilities in international guidance documents on WASH during the pandemic. 29 documents were included from multilateral entities, international consortiums and non-governmental organisations. Key information from the included guidance documents was extracted for each of the 21 core concepts. RESULTS: One-third of the WASH guidance did not include any reference to the rights of people with disabilities, and the majority of information was provided by just one guidance document. Most commonly referenced across all was access to WASH, including details on accessible infrastructure (eg, handwashing stations) and communication strategies. Information on many important rights and considerations, such as the affordability of services and caregiver support, was rarely included. CONCLUSION: Although some information is provided in international WASH guidance, this often has a narrow focus on access, rather than the full array of rights and considerations that are important for people with disabilities. International guidance should continue to be reviewed and updated to include further information of relevance to people with disabilities, informing a disability-inclusive approach to WASH during the remainder of the COVID-19 pandemic and future crises.

The Inclusion of Rights of People with Disabilities and Women and Girls in Water, Sanitation, and Hygiene Policy Documents and Programs of Bangladesh and Cambodia: Content Analysis Using EquiFrame.

People with disabilities and as women and girls face barriers to accessing water, sanitation, and hygiene (WASH) services and facilities that fully meet their needs, especially in low- and middle-income countries. Women and girls with disabilities experience double discrimination. WASH policies should support and uphold the concepts of disability and gender inclusion, and they should also act as a guide to inform WASH programs and service delivery. Using a modified version of the EquiFrame content analysis tool, this study investigated the inclusion of 21 core concepts of human rights of people with disabilities and women and girls in 16 WASH policy documents and seven end-line program reports from Bangladesh and Cambodia. Included documents typically focused on issues of accessibility and neglected wider issues, including empowerment and support for caregivers. The rights of children and women with disabilities were scarcely focused on specifically, despite their individual needs, and there was a disconnect in the translation of certain rights from policy to practice. Qualitative research is needed with stakeholders in Bangladesh and Cambodia to investigate the inclusion and omission of core rights of people with disabilities, and women and girls, as well as the factors contributing to the translation of rights from policy to practice.

Photo-active and dynamical properties of hematite (Fe2O3)-water interfaces: an experimental and theoretical study.

The dynamical properties of physically and chemically adsorbed water molecules at pristine hematite-(001) surfaces have been studied by means of equilibrium Born-Oppenheimer molecular dynamics (BOMD) in the NVT ensemble at 298 K. The dissociation of water molecules to form chemically adsorbed species was scrutinised, in addition to 'hopping' or swapping events of protons between water molecules. Particular foci have been dynamical properties of the adsorbed water molecules and OH(-) and H3O(+) ions, the hydrogen bonds between protons in water molecules and the bridging oxygen atoms at the hematite surface, as well as the interactions between oxygen atoms in adsorbed water molecules and iron atoms at the hematite surface. Experimental results for photoelectrical current generation complement simulation findings of water dissociation.

Photolytic water oxidation catalyzed by a molecular carbene iridium complex.

The complex IrCl(2)(Cp*)(trz) (trz = triazolylidene), 2, was prepared from readily available 1,3-dimethyl-4-phenyl-1,2,3-triazolium salt. Under basic conditions, the C-bound phenyl group readily cyclometalates, while under acidic conditions, cyclometalation is reversed. The sensitivity of the C(aryl)-Ir bond but not the C(trz)-Ir bond towards acidolysis provided a basis for using 2 as a catalyst in Ce(IV)-mediated water oxidation. The catalytic activity is characterized by a robust catalytic cycle, affording excellent turnover numbers (TON > 20,000). Under cerium-free conditions and in the presence of hematite as a photoelectrode, light-induced activity was observed. The photoelectrochemical reaction is strongly pH-dependent, which requires pH adjustments when running multiple cycle experiments to regenerate the catalytic activity. Analogous chelating complexes display better stability and higher catalytic activity than the monodentate complex 2.

Novel, nanoporous silica and titania layers fabricated by magnetron sputtering.

Composite asymmetric membranes are fabricated through the deposition of submicrometer thick (100 nm) silica (SiO(2)) and titania (TiO(2)) films onto flat nanoporous silica and zirconia substrates by magnetron sputtering. The deposition conditions for both coating types were systematically altered to determine their influence on the deposited coating morphology and thickness. Ideal He/N(2) gas selectivity was measured for all of the membranes. The TiO(2) coatings, when deposited onto a ZrO(2) support layer with a pore size of 3 nm, formed a long columnar grain structure with average column diameter of 38 nm. A similar columnar structure was observed for TiO(2) coatings deposited onto a SiO(2) support layer with a pore size of 1 nm. Under the same conditions, SiO(2) coatings, deposited onto the same SiO(2) supports, formed a closely packed spherical grain structure whereas, when deposited onto ZrO(2) supports, the SiO(2) coatings formed an open grain structure. The average SiO(2) grain diameter was 36 nm in both cases. This preliminary investigation was aimed at studying the effect of sputtering parameters on the density and morphology of the deposited coatings. For the depositions carried out, the coating material was found to be very dense. However, the presence of grain boundaries resulted in poor ideal He/N(2) separation efficiencies.

Deposition of hybrid organic-inorganic composite coatings using an atmospheric plasma jet system.

The objective of this study is to investigate the influence of alcohol addition on the incorporation of metal oxide nanoparticles into nm thick siloxane coatings. Titanium oxide (TiO2) nanoparticles with diameters of 30-80 nm were incorporated into an atmospheric plasma deposited tetramethylorthosilicate (TMOS) siloxane coating. The TMOS/TiO2 coating was deposited using the atmospheric plasma jet system known as PlasmaStream. In this system the liquid precursor/nanoparticle mixture is nebulised into the plasma. It was observed that prior to being nebulised the TiO2 particles agglomerated and settled over time in the TMOS/TiO2 mixture. In order to obtain a more stable nanoparticle/TMOS suspension the addition of the alcohols methanol, octanol and pentanol to this mixture was investigated. The addition of each of these alcohols was found to stabilise the nanoparticle suspension. The effect of the alcohol was therefore assessed with respect to the properties of the deposited coatings. It was observed that coatings deposited from TMOS/TiO2, with and without the addition of methanol were broadly similar. In contrast the coatings deposited with octanol and pentanol addition to the TMOS/TiO2 mixture were significantly thicker, for a given set of deposition parameters and were also more homogeneous. This would indicate that the alcohol precursor was incorporated into the plasma polymerised siloxane. The incorporation of the organic functionality from the alcohols was confirmed from FTIR spectra of the coatings. The difference in behaviour with alcohol type is likely to be due to the lower boiling point of methanol (65 degrees C), which is lower than the maximum plasma temperature measured at the jet orifice (77 degrees C). This temperature is significantly lower than the 196 degrees C and 136 degrees C boiling points of octanol and pentanol respectively. The friction of the coatings was determined using the Pin-on-disc technique. The more organic coatings deposited with octanol and pentanol exhibited friction values of 0.2, compared with approx. 0.8 for the coatings deposited from TMOS/TiO2 mixture (with and without methanol). Wear performance comparison between the two types of coating again indicated a significant organic component in the coatings deposited from the higher boiling point alcohols.