Heavy metals and metalloid contamination and risk evaluation in the surface sediment of the Bakkhali River estuary in Bangladesh.

Current state of contamination and subsequent risk of contaminated sediment of a tidal river of Bangladesh was evaluated in the present study. Sediment samples were collected from five locations in the tributary of Bakkhali River estuary during summer (April) and winter (December) season, 2020. Collected samples were processed using standard protocol and the content of heavy metals (Cd, Cr, Cu, Pb and Zn) and metalloid (As), were analyzed by the Flame Atomic Absorption Spectrometer. Sediment contamination was evaluated by pollution load index (PLI), contamination factor (CF), degree of contamination (Cd), potential ecological risk index (PERI), non-carcinogenic and carcinogenic risk (CR) due to the dermal contact of the sediment. Multivariate statistical analysis such as principal component analysis (PCA) and cluster analysis (CA) were also applied to find out the possible sources of the contaminant in the sediment. Results showed the average concentration of As, Cd, Cr, Pb, Cu and Zn was 9.74 ± 3.57, 2.00 ± 0.85, 48.75 ± 8.92, 29.78 ± 8.39, 5.44 ± 2.03 and 56.94 ± 8.57 mg/kg, respectively. Concentration of Cu, Pb and Zn were within the recommended level whereas the concentration of As, Cd and Cr were suppressed the recommended level of WHO and FAO/WHO standards. PLI, CF and Cd revealed considerably low degree of contamination of the sediment. Geo-accumulation index indicated uncontaminated to moderately contaminated condition of the sediment. Although the values of enrichment factor revealed no potential enrichment for most of the metals, Cd showed a minor enrichment during the winter season. Based on the ecological risk assessment, the sediment from all of the sample locations was found to be of moderate to low risk. PCA and CA analysis revealed the origin of contaminants mainly from anthropogenic sources. Although different metals showed non-carcinogenic risk to the inhabitants, cancer risk values for dermal contact (CRderm) were much lower than 10-6 indicating no cancer risk for adult and child. However, the findings also revealed that children were more susceptible to CRderm compared to adults. The present study concluded that long term dermal contact of the sediment of Bakkhali River estuary will be contagious to the people. Therefore, regular monitoring of the estuarine environment is necessary so that contamination does not get worse.

Moringa-based homestead to achieve Sustainable Development Goals: A case study from Jaintiapur of Sylhet, Bangladesh.

A study was conducted in Sylhet at Jaintiapur Upazila to determine the prospects of Moringa-based homestead concerning Sustainable Development Goals. A household survey was conducted following a simple random sampling of 135 farmers and following a semi-structured questionnaire and interview schedule with 100 farmers (40 identified Moringa-based adopters and 60 non-adopters). The final questionnaire was prepared after pilot testing, which contained data on common species diversity, and the perception of farmers regarding SDGs indicators of "no poverty, zero hunger, good health, and well-being, gender equality, affordable and clean energy, decent work and economic growth". The extent of agreement was recorded following the points Likert scale high (3) to no change (0), and the SDG index (SDGI) value was calculated. The 10 key informant interviews were conducted with non-adopters to get insights into their perception regarding Moringa-based homesteads. The findings revealed that the status of plant species diversity such as betel nut (100 %), mango (100 %), bean (99 %), and arjun (90 %) was higher in comparison to non-adopters where the status of the respective species was 92 %, 99 %, 89 %, and 73 % respectively. The perception assessment revealed that 100 % of adopters and 90 % of non-adopters believed that Moringa-based homesteads had the potential to increase access to food, nutrition, and medicinal resources. While the majority of 70 % of adopters, and 90.5 % non-adopters disagreed that it had the potential to ensure government access and non-government credit resources. Among the Moringa-based homestead adopters, the gross income derived from Moringa sales was 2828.57 ± 1481.45, where 55 % of homesteads were identified to have Moringa plants between 3 and 5, and homesteads solely supplied fuel materials for 40 % of households. Gender participation was quite evident for homestead farming activities, where female participation was higher in planting, weeding, irrigation, and fencing. Homesteads provided both on-farming and off-farming income opportunities where major responses were found for poultry farming (96 %), vegetable farming (95 %), and day labor (97 %). Farmers were found to practice climate-smart practices of homestead agroforestry (100 %), rainwater harvesting (99 %), weeding (98 %), and management of debris (95 %) in their respective homesteads. The results disclosed that Moringa-based homestead in Sylhet can be a potential option for attaining SDGs indicators of escalation of household income (SDGI = 90), access to food, nutrition, and medicinal resources (SDGI = 103.6), facilitation of natural treatment of diseases (SDGI = 104.6), de-escalation of gender discrepancy in terms of production activities (SDGI = 103.64), own source of fuel (SDGI = 58.44), both off-farm and on-farm income opportunity (SDGI = 100.52), ecosystem health maintenance by resilient practices (SDGI = 104.6). Farmers ranked food security capacity as a major motivational factor, while the low economic return was a major demotivational factor. The escalation of Moringa-based homesteads needs to be prioritized while facilitating credit, and institutional support to extend encouragement to non-adopters for wider integration of Moringa-based homesteads, and appropriate utilization of the existing resources for greater profitability.

Ecological and public health risk assessment of potentially toxic elements in the surface sediments of the Pasur river estuary, Bangladesh.

Potentially toxic elements (PTEs) in the surface sediments of the Pasur river estuary was investigated to assess its distribution, potential sources, and current dangers to ecological and public health. The Pasur River is a tidal, meandering, perennial river in south-western Bangladesh with a considerable number of fisheries and industrial activities. Sediment samples were collected from seven sampling points from January to December 2022 to assess the contamination level of six potentially toxic elements (Pb, Cr, Cd, As, Cu and Zn). Flame Atomic Absorption Spectrophotometer was utilized to detect the concentration of PTEs by following some sequential analytical procedure. Concentration of PTEs followed the reducing trend of Zn > Cr > Pb > As > Cu > Cd with the mean value of 61.04 > 49.15 > 26.58 > 10.28 > 6.28 > 1.59 mg/kg, respectively. The principle component and cluster analyses justified the anthropogenic source of the studied PTEs. The mean values of contamination factor (CF), geo-accumulation index (Igeo) and enrichment factor (EFc) showed that Pb and Cd were highly responsible for sediment (uncontaminated to moderate) contamination. Pollution load index (PLI) indicated higher pollution of sediments near the port areas. Potential ecological risk index (PERI) indicated low to moderate risks due to the contaminated sediment. However, the contamination of sediment was not associated with the non-carcinogenic (HQderm and HI < 1) and carcinogenic (CRderm < 10-6) risks due to the dermal contact. Although the risks were within the tolerable limit, regular monitoring is suggested to reduce the risk of PTEs contamination.

Seasonal dynamics of phytoplankton community and functional groups in a tropical river.

Functional classification of phytoplankton could be a valuable tool in water quality monitoring in the eutrophic riverine ecosystems. This study is novel from the Bangladeshi perspective. In this study, phytoplankton cell density and diversity were studied with particular reference to the functional groups (FGs) approach during pre-monsoon, monsoon, and post-monsoon at four sampling stations in Karatoya River, Bangladesh. A total of 54 phytoplankton species were recorded under four classes, viz. Chlorophyceae (21 species) Cyanophyceae (16 species), Bacillariophyceae (15 species), and Euglenophyceae (2 species). A significantly higher total cell density of phytoplankton was detected during the pre-monsoon season (24.20 × 103 cells/l), while the lowest in monsoon (9.43 × 103 cells/l). The Shannon-Wiener diversity index varied significantly (F = 16.109, P = 000), with the highest value recorded during the post-monsoon season. Analysis of similarity (ANOSIM) identified significant variations among the three seasons (P < 0.0001, R = 0.9518). The similarity percentage (SIMPER) analysis pinpointed Ulothrix spp. (Melosira granulate and Cymbella spp.) as the most contributory species are causing such a noticeable difference. Fifty-four phytoplankton species recorded during the study period were classified into 20 functional groups, whereas D/J/M/MP/X1 was considered the most abundant FG in the Karatoya River. FGs of the Karatoya River were influenced mainly by the nutrients (PO4-P and NO3-N) enrichments. As a novel investigation on FGs of phytoplankton in Bangladesh, this study recommends additional surveys in other rivers and floodplains to improve our understanding of phytoplankton diversity and functional groups.

A Comparative Study on the knowledge and attitude of COVID-19 among Urban and Rural populations of Bangladesh.

AimThis study is aimed to identify the awareness and behavioral perspective on COVID-19 between urban and rural people of Bangladesh during the period of outbreak. MethodsA community-based cross-sectional study was conducted in 30 districts of Bangladesh, where 322 participants from urban and 312 from rural area. Participants were selected through convenience sampling. ResultsRural people are found to be much more inter connected to receive information from neighbor. Regarding the incubation periods and the general symptoms, knowledge differs significantly from urban to rural. Even their precautionary and transmission knowledge is found to associate in most of the cases. During this outbreak, urban people significantly increase their religious habits and also believe that there will some major change of life after outbreak. DiscussionThe study reflected that health education program needed to aware about COVID-19 in both urban and rural in Bangladesh that helps in formulating and executing communication and outbreak management.

Leonurus sibiricus L. (honeyweed): A review of its phytochemistry and pharmacology

Leonurus sibiricus is a herbaceous plant found in many countries in Asia and America. This plant is widely practiced as a remedy for the treatment of diabetes, menstrual irregularities, and bronchitis. The approval of therapeutic implications of any drugs depends on the well characterized mode of actions of the compounds. The bioactive compounds like diterpenes, triterpenes, flavonoids and phenolic acids in Leonurus sibiricus show analgesic, anti-inflammatory, anti-oxidant, anti-atherogenic and anti-hemorrhagic, anti-diabetic, anti-bacterial and allelopathic potency. Interestingly, the expression level of some genes is altered by the crude extract treatments, which are effective against cancers, diabetes and cardiovascular diseases where the molecular mechanisms are yet to be explored. Intriguingly, the extracts significantly induce nitric oxide production by endothelial nitric oxide synthase, a signaling molecule of vasodilation in combination with interferon-γ indicating positive effect on atherosclerosis. Further investigations are required to unlock the effects of bioactive compounds found in extracts at clinical settings.