Southern Bangladesh Research Articles

Effects of an integrated intervention on the nutritional status and IYCF practices under two years of children in the southern part of Bangladesh

Objective: The significance of appropriate infant and young children feeding (IYCF) to ensure proper nutrition for children is well-documented. Although nutrition interventions with agricultural components have the potential, the evidence for this relationship is insufficient. The objective of this study was to evaluate the effects of an integrated health-based intervention on the dietary pattern and nutritional status of children under two years of age. Methodology: This study was a pre-post analysis of secondary data of the project titled “Integrated Agriculture and Health-Based Interventions for Improved Food and Nutrition Security in Selected Districts of Southern Bangladesh”, which were collected from Barisal and Khulna district. We used data of 268 children aged 0-23 months from baseline and 554 children from endline which comprised the study population to assess socio-demographic, anthropometric and IYCF indicators. Further, horticulture, cooking and hygiene indices were created to analyze the effectiveness of the project interventions. Results: A significant reduction of stunting and underweight and insignificant reduction of wasting were observed from baseline to end line. Compared to baseline, the horticulture index, hygiene index and cooking index differ significantly between the baseline and end line surveys. Further, significant improvement of 6 months exclusive breastfeeding and insignificant improvement of continued breastfeeding up to 1 year were found from baseline to end line. Conclusion: This study shows that integrated agriculture and health-based interventions with nutrition components have a positive impact on stunting and underweight but exert a mixed effect on wasting and IYCF practices. Bioresearch Commu. 8(1): 1077-1087, 2022 (January)

Computational Design Approach to Re-Establish the Urban Fabric of Mongla: A Perspective from Grasshopper

The Padma Multipurpose Bridge Project is the genesis of some subsequent projects in Bangladesh among which developing Mongla Port is one of the priority values. Since Mongla is an integral part of southern Bangladesh, the government has taken initiatives to integrate the port uses for neighboring countries. An agreement was signed (Intra Bangladesh, Butan, India, and Nepal (BBIN) Trade) for offering multi‐modal transit access to India and Port access to Nepal, Bhutan and Eastern India. The objective of this study is to establish a computational way to analyze the existing fabric and restore a potential optimized fabric. The methodology of this study includes developing a computational approach, collecting data from secondary sources, analyzing the data set and adjusting it to the identified existing urban fabric. In this paper, a new tool is introduced named ‘Physarealm’, based on the algorithm of Grasshopper and Rhinoceros.

Availability and utilisation pattern of agricultural waste at household level in selected areas of Bangladesh.

The use of organic fertilisers and soil amendments are almost universally recommended for improving the organic matter levels and maintaining soil health, but few studies documenting the actual availability and quality of such materials on smallholder farms are available. We selected a case study of 300 households from northern and southern Bangladesh to assess the types of waste materials available for recycling and their usage patterns at household level and we applied a novel approach to empirically identify household waste as input inefficiency in a production context. Northern districts have highly intensive farming systems whereas southern districts have low intensity farming. The total amount of agricultural waste produced at household level was estimated at 822 kg per month. Cow dung contributed about 65% of the total waste followed by animal feed refusal waste (11%), garbage (7%) and kitchen waste (6%). Most of the farmers utilised cow dung and wastes as organic fertiliser and lesser amounts as cooking fuel. Econometric analysis shows that the number of cattle and small ruminant per holding, total area of cultivated land and family size were significant factors that influence the amount of waste production at household level. Each household can reduce the chemical fertiliser cost by Tk. 1463 (US$ 17.84) per month by using compost prepared from household waste. There were ample opportunities for compost/vermicomposting and potential markets. The Department of Agricultural Extension from the public sector and private sector agents might motivate farmers to harvest the potential benefits of agricultural waste through effective management and utilisation.

What Influences the Implementation and Sustainability of Nutrition-Sensitive Agriculture Interventions? A Case Study from Southern Bangladesh

Nutrition-sensitive agriculture (NSA) provides a promising pathway for addressing malnutrition. Fulfilling this promise needs a better understanding of the implementation and sustainability of NSA interventions because of their highly complex nature. This study aimed to explore the factors affecting the implementation and sustainability of NSA interventions. A case study design was employed using two focus group discussions with beneficiaries (n = 15), semi-structured interviews with beneficiaries (n = 13), and actors involved in implementation (n = 18). Factors were thematically analyzed using both deductive and inductive approaches adapting the consolidated framework for implementation research. A complex interaction of the factors across the five domains was found: outer setting—nutrition sensitivity of policies, institutional framework; inner setting—culture, social and economic environment, biophysical environment, local capacity, other programs or projects; characteristics of actors—beneficiaries, family members, household capacity, implementers; intervention characteristics—adaptability, design quality, cost of interventions; and, implementation process—fit-to-context, integration and multisectoral collaboration, continuous motivation through engagement, monitoring. Implementing and sustaining NSA needs consideration of multiple factors, with careful analysis of the absorptive capacities of local institutions and beneficiary households. Future studies should explore which mechanisms created for adoption can be continued beyond the project funding cycle, and how.

Exploring the Major Climate-smart Agricultural Practices for Dry Season Crop Production in Salinity Affected Fallow Land in the Coastal Areas of Bangladesh

The landmasses of the coastal areas of Bangladesh still remains under-utilized, thus cropping intensity is much less than the national average. Most areas remain fallow during dry (rabi) season from December to May due to presence of higher concentration of salts in soil and water, and scarcity of suitable irrigation water. Available adaptation options or technologies are not capable to solve these problems at all. Nevertheless, the areas receive a lot of water from monsoon rain, most of that rainwater is drain-out as surface runoff. The present study results suggest that the use of harvested rainwater and conservation agriculture either in combination or alone could mitigate the problem for bringing huge areas under crop cultivation. The public social safety net programmes such as cash-for-work, food-for-work etc. can be deployed for excavating or re-excavating the abandoned coastal ponds, ditches or canals for storing rainwater. Salt-, drought- and/or heat-tolerant crop varieties with short life span can also be cultivated to get the better results. Early plantation or growing crops with early-maturing varieties can ensure safer harvest in ahead of stress arrives. The avenues have immense potential as climate-smart practices for growing crops preferably non-rice crops during dry season in vast fallow land that will not only ensure food security for coastal people but could turn the entire southern Bangladesh as a food surplus zone. The findings refer the broad recommendation, therefore, specific research works based on the locations and resources available are necessary.

Integrating gender and farmer's preferences in a discussion support tool for crop choice

CONTEXTIn northern West Bengal and southern Bangladesh, Rabi crops, sown in winter and harvested in the spring, are an important source of income and nutrition for the target communities. In the study areas, NGOs and extension services have been engaging with farming communities on selecting suitable crops for the upcoming season. This engagement took place in the absence of quantitative tools to discuss trade offs and what-if scenarios to support an informed discussion. OBJECTIVEThe objective of this study was to design a crop-choice model to support extension agronomists in engaging with the farming communities more effectively using a quantitative analysis tool. In this process, we explored how agricultural system models can be inclusive and allow participation and eventual application by NGO and government extension agents, using a process of gender sensitive contribution. MethodsThe crop-choice model includes several constraints related to available resources, including land, labour, capital and technologies to calculate optimal crop areas within the Rabi season. The crop choices are determined considering gender specific community perceptions of risks, labour use, market, price-volatility, self-consumption, water use and cash flow. The model was used to explore the consequences of different crop choices on income, gender specific labour, use of inputs and markets, and to reveal the trade-offs of pursuing different crop choice pathways in the context of agricultural intensification. The initial model was demonstrated to the farmers and the extension agents, and based on their reflections, it was fine-tuned further to make the engagement process more effective. For better communication with the participating farmers, the model related questions and findings were translated in the local language (Bengali). RESULTS AND CONCLUSIONSWe found that the modelling process can be made more inclusive from the outset by including farmers, NGO and extension agents as co-contributors of the model at each of the modelling steps and incorporating their reflections. Such an inclusive and reflective approach provides easy-to-use interfaces and enables translation of model results in ways that more effectively benefit farming communities. The process of engagement with farmers during tool development has been very valuable to farmers and researchers alike and the use of the tool has made the farmers informed about alternative scenarios and led to actual benefits for crop choice decision making. Inclusive farming systems models need to consider the gender dimension and its critical role in farm decision making and how this can be included in models to reflect the diversity of decision process. To maximise relevance of the model for next users and farmers, it was important that these key stakeholders were part of the model development from the beginning, this study has focused on the same throughout. SIGNIFICANCEThis study demonstrated that appropriate design and development principles enabled bioeconomic farming systems models to be used by NGO and government extension agents to engage with farming communities as discussion support tools in farming decisions. Such an approach would make the engagement process more convincing and effective. Besides, it would also provide useful insights to the NGO and extension agents in revising their intervention strategies.

Challenges in Documenting Non-Fatal Drowning Disability in Bangladesh: A Community-Based Survey.

Limited access to health care and the lack of robust data systems means non-fatal drownings are largely missed in low-and middle-income countries. We report morbidity among individuals who experienced non-fatal drowning in the Barishal Division, Bangladesh. A representative household survey was conducted in the Barishal Division in southern Bangladesh between September 2016 and February 2017, covering a population of 386,016. The burden of non-fatal drowning was assessed using the WHODAS 2.0 disability assessment tool, a generic assessment instrument for health and disability. A total of 5164 non-fatal drowning events occurred in the one year preceding the survey. Among these 18% were multiple events. From these, 4235 people were administered the WHODAS 2.0 questionnaire. Non-fatal drowning incidence rates were highest in children aged 1–4 years at 5810 per 100,000 population, and among males. Non-fatal drowning was associated with lower socio-economic status and larger family sizes. Few respondents (6.5%; 95% CI: 4.5–8.4%) reported some level of disability (WHODAS-12 score > 8). Incidence of non-fatal drowning is high in the population, however limited impact on morbidity was found. There is a need to develop tools and methodologies for reliable and comparable data for non-fatal drowning, especially to capture post-event disability in children.

Life‐history traits of Guntea loach, Lepidocephalichthys guntea (Hamilton, 1822) in the Payra River, southern Bangladesh

AbstractThe present study provides the first wide‐ranging elucidation of life‐history traits, including length–frequency distribution (LFD), length–weight and length–length relationship (LWR and LLR), form factor (a3.0), best condition factor (allometric, KA; Fulton, KF; relative, KR; and relative weight, WR), length at first maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of Lepidocephalichthyes guntea from the Payra River in southern Bangladesh. A total of 470 fishes were randomly collected seasonally from February 2019 to January 2020, using several traditional fishing gears (cast nets; drag nets; lift nets; and gill nets). The total length (TL), standard length (SL) and total body weight (BW) of each individual fish were measured with a 0.01 cm and 0.01 g precision, respectively. The TL size classes of 6.00–6.99 cm and 7.00–7.99 cm TL were the numerically dominant groups among the total fish population. Exponential b values of LWR (TL vs. BW) indicate a positive allometric growth (b = 3.20) pattern in the Payra River. The b value of LLR also indicates the same growth pattern. The estimated a3.0 value was 0.007, indicating the fish has an elongated body profile. Among the four types of condition factors, KF is the best‐suited tool for evaluating the well‐being of L. guntea in the Payra River. Additionally, WR exhibited very significant divergence from 100 (p < .0001), designating an imbalanced habitat for L. guntea. The calculated Lm, Mw and Lopt values were 6.54 (~6.5 cm) in TL, 1.16/year and 7.46 cm TL for L. guntea in the Payra River, respectively. Thus, the results of the present study could be used in the future for improved management of this species in Payra River, as well as for linking ecosystems.

Quality assessment and molecular identification of bacteria across the black tiger shrimp (Penaeus monodon) supply chains in Southern Bangladesh

Black Tiger Shrimp (Penaeus monodon) is one of the leading export commodities in Bangladesh. The industry, however, is frequently beset with quality deterioration and microbial diseases owing to various reasons. Here, we analyzed the sensory and nutritional qualities of shrimp, the total bacterial count, and molecular identification of pathogenic bacteria in samples collected from different supply chain actors (SCA), including the gher (farms), depots, wholesalers, retailers, and the processing industry in Khulna, Bangladesh. While the Sensory Quality Indices (SQI) of shrimps collected from farms, depots, and processing plants were found ‘excellent and highly acceptable’, the rating for wholesale and retail markets were ‘good and acceptable’. Nutritionally, higher protein (21.59%), lipid (1.47%), and ash (1.97%) contents were found in shrimps collected from farms than that of other SCAs. Heterotrophic bacterial count (cfu/g) differed in various SCAs: farms 3.75±0.31 (×106), depots 3.95±0.92 (×106), wholesale markets 5.03±0.35 (×106), retail markets 4.82±0.40 (×106), and the processing industry 3.78±0.25 (×106). The presence of Ralstonia spp and Pseudomonas spp, confirmed by 16S rDNA sequencing were found in different SCAs. Overall, the quality of shrimp appeared better in farms than that of other SCAs, indicating that a lack of proper hygiene, sanitation, and post-harvest handling practices could be the likely impediments for quality deterioration.

Stock assessment of Hooghly Croaker Panna heterolepis in the Bay of Bengal (Southern Bangladesh): implications for sustainable management

The study describes growth pattern, growth parameter, mortality, recruitment pattern, exploitation rate (E) and maximum sustainable yield (MSY) to Panna heterolepis from the Bay of Bengal (Bangladesh). About 1223 specimens were collected from commercial fishermen for 12 consecutive months from January to December, 2019. Length–frequency data were analyzed with FAO-ICLARM Stock Assessment Tool. Moreover, our study recorded different water quality and environmental parameters including pH, rainfall, temperature and DO (dissolved oxygen) from the Bay of Bengal. The findings of the study revealed that the allometric co-efficient (b) value indicated negative allometric growth (<3.00) for P. heterolepis population. Whereas, the population dynamic parameters showed growth coefficient (K) 0.13 year−1, life-span (tmax) 3.85 year and growth performance index (Ø′) 2.30. Along with this, P. heterolepis was found to grow rapidly with an asymptotic length (L∞) of 39.08 cm. We found that the natural mortality (M =0.44 year−1) rate was almost similar with fishing mortality (F = 0.42 year−1). Consequently, the standing stock was not quite sustainable with the existing fishing strategy. Furthermore, the maximum allowable exploitation rate (Emax= 0.471) was lower than the recorded exploitation rate (E = 0.490). Subsequently, overfishing is the most focal threat to the wild stock. The recruitment pattern was almost continuous throughout sampling period. Finally, the MSY was assessed at 10234.47 metric tons. Additionally, the environmental parameters denoted that the ecosystem was in a balanced condition for the wild population. The findings would be very useful to introduce appropriate fishing regulations in the Bay of Bengal and nearby ecosystem.

The Scenario of Dengue-like Illness in Paediatric Population of Southern Bangladesh

Dengue is one of the most important mosquito-borne viral diseases affecting humans. Dengue infections can result in a broad spectrum of disease severity ranging from an influenza-like illness (DF) to the life-threatening dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS). Although adults do experience shock, vascular leakage is generally more severe in young children, and in endemic areas, DSS is seen primarily in the pediatric population. The detailed clinical and laboratory profile is crucial for the diagnosis and the successful management of the patients. This study aims to observe the clinical features and laboratory results for the better understanding of patient management to reduce child death in case of dengue fever. A prospective cross-sectional study was conducted at the dengue ward of Khulna Medical College Hospital; 167 suspected dengue patients were enrolled in our research during the period from 7th August to 8th November 2019. Patients attending the emergency department and pediatric outpatient department with complaints of fever and features of dengue with positive NS1 antigen test and/or positive dengue specific antibody IgM or IgG or both were included in this study. Diagnosis of dengue was made on the basis of compatible clinical features and NS1 antigen positivity and/or detection of IgM and IgG antibodies. Patients were classified according to WHO 2012 protocol, and data was analyzed. One hundred sixty patients (95.8%) were diagnosed as having dengue illness, and the rest 7(4.2%) as fever other than dengue. Among the dengue illness, dengue fever (DF) 87(52.1%), DF with warning signs 51(30.5%), DHF 19(11.4%), and DSS 3(1.8%).The most common sign-symptoms of dengue was fever(100.0%),vomiting(52.1%),abdominal pain(38.3%), headache(23.4%),skin rash(13.25%), melena (7.8%), abdominal tenderness(28.7%),palpable liver (24.6%),and palpable spleen(3.0%). NS1 antigen was found positive in 88.6% cases, negative 3.0%, and NS1 antigen test not done 8.4% cases due to time constrain. Anti-dengue antibody IgM positive in 10(6.0%),IgG positive 7(4.2%),both IgM &amp; IgG positive 7(4.2%),both IgM &amp; IgG negative 57(34.1%) and antibody test not done in 86(51.5%) cases due to time constrain. Anti-dengue antibody not done in 86(51.5%) cases; among them most of the cases (98.8%) are found NS1 positive and 1.2% NS1 test negative(P&lt;0.001) in our study which is statistically significant.&#x0D; Observation of clinical and laboratory parameters is helpful for dengue classification and management to reduce child death.&#x0D; TAJ 2021; 34: No-1: 86-96

Temporal Variations of Condition Factor and Relative Weight For Mystus Gulio (Hamilton, 1822) From the Coastal Water in Bangladesh

The long whiskers catfish, Mystus gulio (Hamilton, 1822), is a valuable, delicious food fish in coastal areas of Bangladesh. It is found in fresh and brackish water of South Asian region. The present study illustrates the temporal variation of condition factor (KF) and prey-predator through relative weight (WR) along with length-weight relation (LWR) of M. gulio in the Maloncho River at southern Bangladesh. There were a total of 1200 individuals collected between January-December 2017 and October 2019 to June 2020. Different traditional gears (such as cast net, seine net, square lift net) were used for collecting the fish samples. There were 35% males and 65% females. The total length of fish ranged 7.8-18.3 cm for males and 9.3-22.1 cm for females. The body weight ranged 8.80–72.34 g for males and 8.09-128.82 g for females. LWR was significant with r2 value &gt;0.950. The calculated co-efficient (b) were negative allometric growth in male and female (b&lt;3.0, p&lt;0.001). The KF indicated the best condition of this species. WR revealed no significant difference from 100 for both sex (p = 0.441) and females (p = 0.221), indicating a suitable habitat for growth. From conservation point of view, the findings of this present study on M. gulio will be helpful in Bangladesh (Maloncho River) and neighboring countries. J. Bio-Sci. 29(1): 111-122, 2021 (June)

Quality assessment of freshwaters from a coastal city of southern Bangladesh: Irrigation feasibility and preliminary health risks appraisal

The present study was conducted for the first time to appraise the water quality, irrigation feasibility, and human health risk of surface water in heavy industrial and urban establishments from a coastal city of Bangladesh. Surface water samples were collected from the hilly terrain comprised of Plio-Pleistocene to Miocene-sediments throughout the study area. The ranges of pH were 5.35 to 7.58, EC values were 42.3 to 2440 µS cm−1, and turbidity were 2.53 to 1570 NTU, respectively. The overall physicochemical condition of water samples revealed that the water was unsuitable and also unsafe for domestic use. A bias-free systematic sampling and analyzed parameters invoke that surface water quality is deteriorated by Cr (52.2), Mn (532), Fe (4797), Mg (31445), K (29213), Co (69.0), Ni (39.5), and Pb (22.4 µg L−1) contamination and make the surface water unsuitable for drinking, cooking, fisheries, and other purposes. Anthropogenic activities (e.g., domestic, industrial, agricultural, etc.) intensified by climate change-induced sea-level rise are mainly responsible for the source apportionment of metal pollution in the study region. However, the surface waters of the studied sites are allowed to use for irrigations, except for Karnaphuli river due to high alkali hazards. Furthermore, the existence of toxic metal-induced non-carcinogenic and carcinogenic risks does not allow inhabitants to use this water for household works.

Vulnerability assessment of seawater intrusion in coastal aquifers of southern Bangladesh: Water quality appraisals

Overexploitation of groundwater, sea level rising, shrimp cultivation, etc. are the main causes of seawater intrusion in the coastal aquifers which is a growing concern around the globe. So to evaluate the seawater intrusion in the coastal aquifers of southern Bangladesh (Paikgachha, Khulna), water quality parameters such as pH (7.75–8.82), EC (371–5320 µS cm−1), TDS (182–2790 mg L-1), salinity (0.1–2.8 ppt), Na+ (14.8–1376 mg L-1), K+ (2.71–19.4 mg L-1), Ca2+ (33.2–192 mg L-1), Mg2+ (25–138 mg L-1), Cl- (18.2–3168 mg L-1), HCO3− (205–840 mg L-1), and CO32− (6.22–149 mg L-1) for 20 composite water samples, along with the hydro-geo-physical entities were utilized. Additionally, groundwater quality distributions were also appraised for identifying the suitable water sources for drinking and irrigation. Most of the sampling sites possessed mainly NaCl-type groundwater where Na+ and Cl- contents were 2–6 times higher than the recommended limits. Indices-based calculations indicated that only 35% of the sampling sites can provide good quality drinking water whereas groundwaters from >50% of sampling sites were unsuitable for irrigation. Statistical approaches reveal the potential seawater intrusion with trivial evidence of carbonate mineralization. Distributions of seawater intrusion vulnerability among the studied area were specified by the GALDIT index. The central (30%), southern (25%), and northern (45%) parts were identified as high, moderate, and low vulnerable zones, respectively due to saline water. Thus, considering the heterogenic distribution of seawater intrusion vulnerability among the studied unconfined aquifers, more intimate and detailed groundwater investigations are required on a periodical basis to explore water for drinking and irrigation.

National immunisation campaigns with oral polio vaccine may reduce all-cause mortality: Analysis of 2004-2019 demographic surveillance data in rural Bangladesh.

BackgroundWest African studies have suggested that national immunisation campaigns with oral polio vaccine (C-OPV) may non-specifically reduce all-cause child mortality rate by 15–25%. We investigated whether C-OPVs had similar non-specific effects in rural Bangladesh from 2004 to 2019.MethodsChakaria, is a health and demographic surveillance system (HDSS) in Southern Bangladesh. From 2004–2011 the HDSS covered a random sample of households; from 2012 to 2019 it covered a random sample of villages. Using Cox proportional hazards models, we calculated hazard ratios (HR) comparing mortality for children under 3 years of age after C-OPV versus before C-OPV to assess the effect of receiving a C-OPV. We allowed for different baseline hazard function in the two periods (2004–2011, 2012–2019), with separate models for each period.FindingsThere were 768 deaths (2.1%) amongst 36,176 children. The HR after C-OPV was 0.69 (95% confidence interval: 0.52–0.90). National campaigns providing vitamin A or measles vaccine did not have similar effects. Each additional dose of C-OPV was associated with a reduction in the mortality rate by 6% (−2 to 13%). The number needed to treat with C-OPV to save one life between 0 and 35 months of age was 88 (81–96).InterpretationThis is the fourth study to show that C-OPV has beneficial non-specific effects on child survival. All studies have shown a beneficial effect of C-OPV on child health. Stopping OPV as planned after polio eradication without any mitigation plan could have detrimental effects for overall child health in low-income countries.FundingThe Chakaria HDSS was funded by international sponsors. No sponsor had any influence on the preparation of the article.

Opportunities and risks with early sowing of sunflower in a salt-affected coastal region of the Ganges Delta

On low-lying land in the Ganges Delta, waterlogging, salinity, and poor soil structure are constraints to intensifying cropping systems. Early sowing of dry season (rabi) crops in this area is hypothesized to increase yield potential because the current late sowing exposes the crop to less favourable temperature conditions, soil dryness, and salinity stresses. Field experiments were conducted over 2 years to identify the opportunities and challenges of early sowing between mid-November and mid-December for maximizing sunflower yield in Southern Bangladesh. Sunflower was dibbled into untilled wet soil on five occasions (23 and 30 November and 10, 20, and 30 December in 2016–2017 and 25 November, 14 and 25 December, and 10 and 25 January in 2017–2018), with two mulching treatments (rice straw at ~ 5 t ha−1 and 15–20% rice residue retention). Sowing before 15 December was associated with larger heads, more seeds per head, greater seed weight, and higher grain yield (3.5–4 t ha−1) in the first year, but early sowing was also risky since, in the second year, the sunflower sown on 25 November was hampered by heavy rainfall, which depressed yield compared to crops sown on 15 December. Increased yield from early sowing before 15 December was associated with higher soil water, lower soil salinity, and higher solute potential compared to sowing after 15 December. Lower yield in late sown crops was also associated with increased temperature at grain-filling stage. The rice straw mulch significantly improved soil water availability, reduced soil salinity, increased soil solute potential, and increased yield in the second year. In this paper, we show for the first time that sunflower sown before 15 December in the Ganges Delta has higher yield potential, but to gain the benefits of the earliest sowing, growers will need to manage the increased risk of yield loss due to waterlogging.

Effects of tree species diversity and stand structure on carbon stocks of homestead forests in Maheshkhali Island, Southern Bangladesh

BackgroundThe homestead forests of Bangladesh occupy 0.27 million hectares (10% of the total forested area) and have potential to store carbon (C) and conserve biodiversity. Small scale forestry practices, however, are lacking reliable estimation of C stocks and tree species diversity. This may hinder successful implementation of REDD + and similar mechanisms as they concentrate on large-scale forests. This study aimed to estimate the above- and below-ground carbon stocks in homestead forests of Maheshkhali Island in Bangladesh and how tree species diversity and stand structural variation affect these C stocks. We randomly surveyed a total of 239 homestead forests in the hillside, beachside, and inland in 2019.ResultsTree biomass C stocks were 48–67% greater in the inland and hillside forests than in the beachside due to significantly greater stand density, basal area, tree diameter. In total we found 52 tree species, but most abundant species in the inland and hillside forests, Mangifera indica, Samanea saman, and Artocarpus heterophyllus stored the most C in tree biomass. Greater tree species richness and diversity index in the inland and hillside forests indicated greater above- and below-ground tree biomass C stocks. An increase in tree species richness and diversity index by one unit was found to increase the tree biomass C stock by 22 and 30 Mg C ha−1, respectively. The total soil C stock was also affected by tree species diversity, stand density, and their interaction with soil properties. Total soil C stocks were greatest (51 Mg ha−1) in the inland forests, having also the greatest stand density and tree species richness. C stock in soil surface was greatest in the hillside forests due to the greatest litterfall, but the average share of litterfall from the total biomass C was only 0.1%.ConclusionsHomestead forest ecosystems could store 96 Mg C ha−1 in total, which can contribute to climate change mitigation by generating C credits for small-scale homestead forests owners. Above- and below-ground tree biomass C stocks were found to correlate with tree species diversity, which may also contribute to biodiversity conservation in the REDD + in Bangladesh and countries alike.

SARS-CoV-2 molecular identification and clinical data analysis of associated risk factors from a COVID-19 testing laboratory of a coastal region in Bangladesh

Background and aimOutbreak of COVID-19 seems to have exacerbated across the globe, including Bangladesh. Scientific literature on the clinical data record of COVID-19 patients in Bangladesh is inadequate. Our study analyzes the clinical data of COVID-19 positive patients based on molecular identification and risk factor correlated with three variables (age, sex, residence) and COVID-19 prevalence in the four districts of Chattogram Division (Noakhali, Feni, Lakshmipur and Chandpur) with an aim to understand the trajectory of this pandemic in Chattogram, Southern Bangladesh. MethodsA cross-sectional study is conducted in the context of RT-PCR-based COVID-19 positive 5,589 individuals diagnosed with SARS-CoV-2 infection from the COVID-19 testing laboratory, Abdul Malek Ukil Medical College, Noakhali-3800, Bangladesh. For molecular confirmation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), standard diagnostic protocols through real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) were conducted. Different patient demographics were analyzed using SPSS version 22 for exploring the relationship of three factors – age, sex, and residence with a cumulative number of COVID-19 positive cases and prevalence of COVID-19 in four districts in Chattogram division. The data was recorded between May to July, 2020. ResultsAmong the three parameters, the present study revealed that 20–40 cohort had the highest incidence of infection rate (51.80%, n = 2895) among the different age groups. Among the infected individuals, 56.8% (n = 3177) were male and 43.2% (n = 2412) were female, denoting males being the most susceptible to this disease. Urban residents (52.7%, n = 2948) were more vulnerable to SARS-CoV-2 infection than those residing in rural areas (47.3%, n = 2641). The prevalence of COVID-19 positive cases among the four districts was recorded highest in the Noakhali district with 36.8% (n = 2057), followed by the Feni, Lakshmipur and Chandpur districts with 25.9% (n = 1448), 20.8% (n = 1163) and 16.5% (n = 921), respectively. ConclusionsThis study presents a statistical correlation of certain factors linked to Bangladesh with confirmed COVID-19 patients, which will enable health practitioners and policy makers to take proactive steps to control and mitigate disease transmission.

A Risk Exchange: Health and Mobility in the Context of Climate and Environmental Change in Bangladesh-A Qualitative Study.

Background: Climate change influences patterns of human mobility and health outcomes. While much of the climate change and migration discourse is invested in quantitative predictions and debates about whether migration is adaptive or maladaptive, less attention has been paid to the voices of the people moving in the context of climate change with a focus on their health and wellbeing. This qualitative research aims to amplify the voices of migrants themselves to add nuance to dominant migration narratives and to shed light on the real-life challenges migrants face in meeting their health needs in the context of climate change. Methods: We conducted 58 semi-structured in-depth interviews with migrants purposefully selected for having moved from rural Bhola, southern Bangladesh to an urban slum in Dhaka, Bangladesh. Transcripts were analysed using thematic analysis under the philosophical underpinnings of phenomenology. Coding was conducted using NVivo Pro 12. Findings: We identified two overarching themes in the thematic analysis: Firstly, we identified the theme “A risk exchange: Exchanging climate change and health risks at origin and destination”. Rather than describing a “net positive” or “net negative” outcome in terms of migration in the context of climate change, migrants described an exchange of hazards, exposures, and vulnerabilities at origin with those at destination, which challenged their capacity to adapt. This theme included several sub-themes—income and employment factors, changing food environment, shelter and water sanitation and hygiene (WaSH) conditions, and social capital. The second overarching theme was “A changing health and healthcare environment”. This theme also included several sub-themes—changing physical and mental health status and a changing healthcare environment encompassing quality of care and barriers to accessing healthcare. Migrants described physical and mental health concerns and connected these experiences with their new environment. These two overarching themes were prevalent across the dataset, although each participant experienced and expressed them uniquely. Conclusion: Migrants who move in the context of climate change face a range of diverse health risks at the origin, en route, and at the destination. Migrating individuals, households, and communities undertake a risk exchange when they decide to move, which has diverse positive and negative consequences for their health and wellbeing. Along with changing health determinants is a changing healthcare environment where migrants face different choices, barriers, and quality of care. A more migrant-centric perspective as described in this paper could strengthen migration, climate, and health governance. Policymakers, urban planners, city corporations, and health practitioners should integrate the risk exchange into practice and policies.

Assessment of river water\u2013groundwater\u2013seawater interactions in the coastal delta of Bangladesh based on hydrochemistry and salinity distribution

A synchronization study among hydrochemistry, hydrochemical facies evaluation, EC observation, salinity distribution and groundwater flow direction has been addressed to assess river water–groundwater–seawater interactions in the coastal delta of southern Bangladesh. The findings show that river water, shallow groundwater and deep groundwater interact with seawater at various intensities within the complex dynamics of hydrochemical facies evaluation. Deep groundwater is intensively influenced by seawater, where shallow groundwater is moderately affected and river water is very negligibly affected. Major cation and anion have been plotted in the Piper diagrams and hydrochemical facies diagrams (HFE-D) to clarify the result. More than 60% of the water samples of the river lie on the Ca-HCO3 (or Mg-HCO3) facies quadrant, and more than 70% of the shallow groundwater samples and more than 95% of the deep groundwater samples lie on the Na-Cl facies quadrant of the HFE-D diagram. River water types are dissimilar, and approximately 82% of facies are characterized by freshening phases and 18% by intrusion phases. Mixed water types with predominate of Na-Cl were observed in shallow groundwater where the hydrochemical facies are characterized by 53 percent freshening phases and 47 percent intrusion phases. Deep groundwater hydrochemistry clearly indicates the dominant Na-Cl type of water in the study area where only four hydrochemical facies are observed and 78 percent correspond to the intrusion phases and 22 percent to the freshening phases. Both direct and reverse cation exchange reactions take place in shallow groundwater, where deep groundwater is predominantly characterized by reverse cation exchange reactions. Two end members: seawater of Bay of Bengal and freshwater, contribute to the exchange reactions in the coastal aquifer of the study area. In terms of nitrate contamination, river waters are affected by negligible to low concentrations, shallow groundwater is affected by moderate to high concentrations and deep groundwater is affected by moderate to very high nitrate concentrations. Dissimilarity in electrical conductivity (EC) values, variation of salinity distribution maps and groundwater flow direction suggest the possible interconnections among river water, groundwater and aquifer sediments. Significant concentrations of Na+ and Cl− ions lead to seawater contamination in groundwater, and HCO3− along with Na+, Ca2+, Mg2+ in river water suggests mixing of freshwater and seawater, which could have adverse effects both in coastal delta aquatic life and in agriculture.