Elevated fluoride (F⁻) levels in groundwater, primarily due to geogenic processes, pose significant health risks, including dental and skeletal fluorosis and neurological disorders. This study aimed to quantify source-dependent F⁻ exposure at the community level in selected tropical dry regions of Andhra Pradesh, India. These locations include Chintal Cheruvu, Rompicharala, Shantamangalur, Thimmapur, and Nadendla. Community surveys and drinking water sample analyses were conducted in these regions. Dental Fluorosis Index (DFI) was used to estimate exposure levels across age and sex groups. Findings of surveys indicate that groundwater consumption with high F⁻ (4.3 mg/L) results in the highest exposure dose (0.62 mg/kg/day), with Chintal Cheruvu identified as the most affected. A strong positive correlation was observed between exposure dose, water F⁻ content, and the Community Fluorosis Index (CFI), with R² values of 0.98 and 0.97, respectively. Dental fluorosis prevalence exceeded 80% across all age groups, and household surveys revealed 100% unawareness of F⁻ exposure risks. Though there exist many ways to determine the impact of fluoride, the hierarchy of regions may change with the type of parameter chosen. To address this, we developed the Fluoride Impact Index (FII), a multi-criteria index computed considering various parameters indicating the impact of fluoride in a region. The magnitude of FII for Chintal Cheruvu is 0.563 which is highest among the considered regions indicating that it is most impacted region that needs remedial measures first in the hierarchy. Rompicharala with FII as 0.252, Nadendla (0.223), Shantamangalur (0.214), and Thimmapur (0.188) follows the hierarchy. These findings highlight the urgent need to raise awareness about F⁻ exposure risks and to identify sustainable alternative water sources. Immediate interventions, including human health risk assessments using the USEPA approach and the provision of safe drinking water, are critical to achieving SDG-6 of safe drinking water for all by 2030.

Arsenic (As) accumulation in rice plant from arsenic contaminated groundwater has now become an emerging global concern. The main objective of the present study was to evaluate the accumulation pattern of As in different parts of rice plants grown in an As affected area of in order to the make appropriate and safe selection of suitable rice varieties to be cultivated in the As affected areas. The study was conducted by collecting twelve different varieties of rice and soil samples from four arsenic affected villages of Purbasthali II block, West Bengal, India. The soil As level varies between 5.88 and 71.33 mg/kg and soil enzyme activity was recorded 0.215–0.724 µg/24 h/kg soil of amylase, 0.187–4.598 µg/24 h/kg soil of invertase, and 0.103–4.406 µg/24 h/kg soil of cellulose and these activators of soil enzymes were also observed to be affected by arsenic. The highest arsenic accumulation was recorded in root, shoot and leaf of the variety R6 (Voganti) and in rice husk and grain of theR11 (Nayanmoni) and R1 (Miniket), respectively. The overall accumulation pattern of arsenic in different parts of rice plants were in the order of root > shoot > leave > rice husk > rice grain. However, arsenic accumulation varied widely in different cultivars. The mean value of arsenic in rice grain was recorded < 1.0 mg/kg, which was much closer to FAO/WHO prescribed safe limit (1.1 ppm by weight according to FAO, 2019). Our study can be concluded by suggesting varieties like R4 (Miniket) and R8 (Sada Sorno) can be safely cultivated in the As affected areas.

Plastic-aggregates are made up from unused or waste plastic and natural aggregates which have recently been emerged as a significant addition to the existing emerging contaminants list mainly in the coastal environment. The transformation from plastics/microplastics to Plastic-aggregates signifies a crucial shift in our understanding and use of plastics and prompting us to reconsider their fundamental characteristics along with possible environmental threats. When plastic waste is incinerated for the purpose of disposal, it combines with organic and inorganic substances present in the surrounding environment, leading to a new type of material. Besides, some natural factors (physical, chemical, biological or in combination) also act upon discarded plastics to combine with rocks and other earthen materials to form plastic-aggregates. Our research aims to build fundamental knowledge and critically review the possible formation process, classification, and possible degradation of all such polymer-rock compounds along with their impact on the ecosystem. The knowledge gap related to the degradation and release of secondary pollutants from these agglomerates is to be addressed urgently in future research. Development and standardization of proper sampling and reporting procedures for plastic-aggregates can enhance our understanding related to their impacts on human health as well as to the entire environment as these aggregates contain different toxic chemicals.

Microplastics (MPs) are impacting coastal and ocean ecosystem and also have been linked with ‘blue economy’, which accounts major portion to the total economy of a nation. The ocean serves as a sink for MPs, receiving them from rivers, runoff, industrial effluents, and direct waste discharge. Consequently, marine organisms are impacted, leading to indirect economic losses, and causing irreparable damage to the blue economy. In addition, the presence of chemicals and microorganisms on MPs is causing detrimental effects on marine organisms, leading to economic repercussions. Coastal tourism, a key aspect of the blue economy, relies on a sustainable and visually appealing environment, which is being threatened by rising marine debris, primarily plastic waste generated by tourists. The clean-up cost is very high, whereas the existing removal technologies do not have higher efficiency and are not that much cost effective. Thus, this study reviews the country wise economic effect of plastic pollution, along with existing policies, regulations and the management strategies to control MPs in marine system considering its potential impacts on sectors associated with marine resources vis-à-vis blue economy.

Occurrence of fluoride (F−) at elevated levels in groundwater (GW) has become a major concern as it is associated with serious health issues like dental-skeletal fluorosis, severe neurological disorders, and abnormal enzymatic activities. This study conducted, in Purulia district in West Bengal, India, to understand the factors influencing F⁻ enrichment in GW in the context of hydroclimatic variability, its suitability for drinking water and irrigation purposes, and associated health risks. Results show that 37.5% of collected GW samples (n = 24) exceed the permissible limit of WHO (1.5 mg/L). The average and highest F⁻ concentrations recorded at 1.4 mg/L and 2.2 mg/L, respectively. A positive correlation between F⁻, Ca²⁺, and Na⁺ indicates that rock weathering significantly contributes to F⁻ mobilization. GW in this area is of Na-Mg-Cl type as indicated by the piper plot. The trend of rainfall and temperature shows an inverse relationship with F− content and GW level is one of the major aggravating hydroclimatic factors for mobilization of F− in GW. The study showed that, GW is suitable for irrigation based on geochemical indices, but elevated fluoride and moderate salinity have degraded its quality, raising concerns about increased F− exposure through dietary intake. Consequently, Dental fluorosis prevalence is notably higher among individuals aged 10–20, 21–30, and over 50, with males consuming more F⁻-rich water than females across all age groups. So, it can be concluded that, hydroclimatic variability plays a key role in driving geochemical processes that mobilize fluoride in groundwater. Therefore, identifying safe aquifers while considering demographic and climatic factors is essential for managing fluoride contamination and mitigating health impacts.

Sustainable development goals (SDGs), notably SDG 6, emphasize the need to preserve clean and sustainable water resources for the well-being of current and future generations. Natural water resources, such as lakes, rivers, oceans, and groundwater, play a vital role in sustaining the delicate ecosystems that facilitate life on our planet. Since the presence of contaminants such as heavy metals, agricultural runoff, emergent organic compounds, microplastics (MPs), and microbiological pollutants in the aquatic environment deteriorate the quality of the natural water systems, the progress toward the achievement of SDGs gets challenging and complex. These above stated contaminants follow diverse pathways, including stormwater runoff, agricultural runoff, effluent discharges, and the natural weathering of sediments and solid wastes. The concentration of these contaminants detected in the environment varies largely depending on various factors, such as land use or season, which further add to the difficulties and hence requires proper detection and management strategies. Certain pollutants, such as MPs, are at a very preliminary stage of investigation and their proper detection techniques and classification is the need of the hour. Various mitigation techniques have been explored till date among which many techniques have proved to be beneficial. However, to ensure proper mitigation of contaminants and protection of our valuable natural water resources, integrated efforts of researchers, policy makers, and the community is necessary. Hence, further reinvestigations are required to come up with scalable and economically viable mitigation techniques that will not only focus on contaminant removal but also on reusability of wastewater or resources, which is consistent with the larger goal of promoting sustainability in water resource management.

There has been a growing concern over the occurrence of fluoride (F−) in groundwater and the impact of F− exposure on human health issues over the past decades. So, this study conducted a regional–scale assessment of the occurrence and trend of groundwater F− distribution [2014–2018] integrated with locally field–based investigations on F− exposure to a few selected families (10 households and 35 respondents) and reason behind their consumption of F− containing water (n = 18). In the local study, water samples were collected from multiple sources around the selected households by dividing them into consumptive and non–consumptive use. Results revealed that across the state of Andhra Pradesh, the occurrence of F− is more than the permissible limit in groundwater, and it has been increasing over the years (2014–2018) (average SD is 0.55), and the local study showed that the groundwater had an average of 1.5 mg/L F−, while other sourced water had an average of <1 mg/L F−. Most interestingly, nine families are consuming non–F− containing water (<0.52 mg F−/day) which is commercially available, while only one family is consuming F− containing groundwater and being exposed to >3 mg F−/day. This disparity in fluoride exposure is dependent on economic stability and health exposure policies.

Drinking water sources with groundwater arsenic (As) contamination face multifaceted challenges in the removal and supply of fresh drinking water resources. To eradicate this problem, bioremediation has evolved to become more effective than other chemical and physical removal processes in its cost-effectiveness, high removal efficiency, and lesser production of secondary by-products or waste. Thus, this study aimed to treat As from aqueous media and to detoxify highly toxic forms of As by the isolated bacteria from As-affected areas. We isolated two new Gram-positive bacteria, which are reported here (Bacillus sp. and Bacillus cereus), with As5+ minimum inhibitory concentrations (MICs) of 4500 mg/L for the Bacillus sp. and 1000 mg/L for Bacillus cereus; meanwhile, for As3+, the MICs are 600 mg/L for both isolates. Bacillus sp. and Bacillus cereus can also effectively convert the highly toxic and easily mobile As3+ to As5+ in aqueous media. This study also demonstrates that these bacteria can remove a significant proportion of As3+ and As5+ (averaging 50% for both) from aqueous media. These As-resistant bacteria from the As-affected area can be used and upscaled for the treatment of As for a safer drinking water supply.

Microplastics, small sized plastic particles having size <5 mm are formed through primary process including production of beauty products, microbeads and microfibres as well as secondary process including mechanical weathering, friction, aberration and fragmentation of large plastics. The major sources of microplastics are land-based and ocean-based sources. Microplastic pollution is a serious concern due to the persistent, low biodegradability and bio-accumulative behaviour. Microplastics can bioaccumulate in the food chain and can cause ecological and human health risk. Hence, it is important to remove from the aquatic ecosystems. Microplastics are removed from aquatic systems and wastewater through a series of processes such as physical, chemical and biological treatments. In the present articles, >250 articles are reviewed to collect the information regarding the various physical, chemical and biological methods for the removal of microplastics. Also, the probable control strategies to combat with plastic pollution were assessed. It was concluded that recent water treatment methods are efficient in removing microplastic pollution. The efficiencies to remove microplastic from the water ranged between 74 %-99.2 %, 65 %-99.20 % and 77 %-100 % for physical, chemical and biological treatment methods, respectively. Among the three treatment methods, physical methods especially the filtration of water from biochar is the most efficient way (efficiency up to 100 %) to remove microplastics. It was also concluded that creating public awareness, promoting reusing, recycling and reducing, and application of bioplastics can control the production of microplastics from plastic wastes. This review will be useful to add current knowledge regarding the abatement of microplastic pollution, and finding novel solution to control microplastics. This review will also help the policymakers to implement most effective and cost-efficient method to remove microplastics, and to find out new methods to reduce, reuse and recycle plastic wastes.

Microplastics (MPs) have already been detected in various environmental matrices like soil, sediment, and surface water, and recently in groundwater also. The occurrence of MPs in groundwater depends up on the transportation through recharge and may controlled by source and local hydrogeology, and partly on the process of surface water-groundwater interaction (SW-GW). Based on the available studies, we intended to establish a hypothetical overview on the source and process-dependent occurrence of MPs in groundwater across terrestrial and coastal aquifers. Groundwater recharge from agricultural stagnant water, losing streams near dumping sites and agricultural fields, effluents from wastewater treatment plants, septic system failure etc. are the potential sources of MPs in groundwater. The factors like sea level rise and tidal pumping are among the major factors which may control the migration of MPs in coastal aquifer along with the physical and chemical properties of the aquifer media. These MPs have another ecological concern as they can adsorb persistent organic pollutants as well as heavy metals and transfer them to animal tissues through food chain. Studies are being conducted mainly focusing the MP contamination in surface water, marine environment and soil, and very limited studies are available to address the source of MPs in groundwater. However, no such study has been done on the existence, profusion, or environmental factors that contribute to MP pollution in the groundwater in relation to the present climate change scenario. Understanding the extent of MP contamination in groundwater systems is necessary for developing effective management strategies and minimizing their impact on the environment and human health. This study focusses on the source along with the controlling factors of the migration of MPs towards groundwater including the effect of climate change.

Access to clean water has been identified as one of the primary Sustainable Development Goals. Rapid urbanization is going on in developing nations creating additional pressure on water resources in most of these places which in turn also affects individuals which is largely reliant on proper sanitation and drinking water quality. In addition, open sanitation practice is becoming major public health problem in rural and in some urban areas in India. Groundwater contamination by pathogenic bacteria sourced from both sanitation system and surface water is becoming one of the major concerns now-a-days. The residents of the Ganges river basin in India are already stressed with natural arsenic pollution as well as other various types of water pollution, and microbial pollution from sanitation is a new addition to it. A field-based hydrogeological investigation with the identification of sanitation sites (surface and subsurface) was conducted in some parts of the Ganges basin, in and around a lower order distributary river, River Churni in West Bengal state, to identify the natural and human influences on sanitation drinking water pollution in a highly populated part of South Asia. Groundwater was found to be contaminated severely with total (TC) and fecal (FC) coliform bacteria. The abundance of TC was found to be the highest in monsoon season (78%) than in pre-monsoon (48%) and post-monsoon (29%) seasons. The results revealed that the groundwater samples from shallow depths and close to sanitation sites were highly contaminated with coliform bacteria than the deeper and higher distant (>30 m distance) ones. Shallow groundwater samples near to surface water (River Churni) source, other than sanitation sites, showed elevated TC levels. The occurrence of coliform bacteria in studied groundwater samples was observed to be positively correlated with conductivity, TDS, TOC, chloride, and sulfate, while the abundance was restricted by pH and temperature of groundwater. Thus, improper sanitation systems and contaminated surface water were identified as one of the major sources of pathogenic contamination of groundwater-sourced drinking water in the studied area, whereas improper human practices further complicate the scenario which needs to be managed properly.

The global climate patterns like El Niño Southern Oscillation (ENSO) cycle and Indian Ocean Dipole (IOD) have impacts on surface water quality and groundwater recharge patterns. But the ENSO and IOD impacts on surface water-groundwater (SW-GW) interaction in terms of quality have not been studied. Therefore, the present study was conducted to delineate the impacts of ENSO and IOD on the SW-GW interaction process-induced groundwater quality of coastal aquifers of Sundarbans, by the application of isotopic signature, salinity content of groundwater and seawater in relation to rainfall variability. Study results revealed that the declining trend of rainfall potentially increases the seawater salinity. The rainfall pattern also positively correlates with the groundwater level (GWL) at a 5% level of significance observed from the wavelet analysis. The deficit in rainfall due to the El Niño is the possible reason for the declining GWL, which is giving rise to groundwater salinity. El Niño also affected the nearshore seawater salinity which was increased from 19 to 24 ppT. The study provides a surrogate understanding of the potential impact of El Niño in one of the most climatically vulnerable parts of the planet, while IOD impacts are not conclusive. In the scenario of depleted rainfall amount, groundwater abstraction practices need to be managed, otherwise, it could create a potential threat to the available drinking water resources in the present and future climate change scenarios.

Development of modern, innovative and cost effective technologies for the decontamination of arsenic contaminated water is an interesting and popular research topic. The main objective of the present study was to isolate arsenic resistant bacteria from arsenic contaminated groundwater and soil, which can be used as an effective agent to remove arsenic from the contaminated water in order to provide clean drinking water to the people. In the present investigation, three Gram positive, rod shaped bacteria, namely, S4, S7 and S8, isolated from arsenic contaminated soils and two from contaminated groundwater, namely, SW2 and SW4, of Purbasthali II block of Burdwan, West Bengal, India, are being reported, which can tolerate high concentrations of both arsenate and arsenite. These bacteria are able to remove more than 50% of arsenate and arsenite from arsenic amended media. From biochemical tests and scanning electron micrograph, all the isolates were identified as different strains of Bacillus sp. These bacteria, having unique properties can be used for the bioremediation of arsenic contaminated water, which will be highly beneficial for human population as well as for livestock and vegetation of the affected area.

An interesting and popular topic of research is the development of modern, innovative and cost effective technologies for the decontamination of arsenic contaminated water. The main objective of the study was to isolate arsenic resistant bacteria which can be used to remove arsenic from the contaminated water of an arsenic affected area, so that clean drinking water can be provided to the affected people. In this present investigation, we are reporting three Gram positive, rod shaped bacteria, namely, S4, S7 and S8, isolated from arsenic contaminated soils of Purbasthali I block of Burdwan, West Bengal, India, which can tolerate high concentrations of both arsenate and arsenite. These three bacteria can remove more than 50% of arsenate and arsenite from arsenic amended media. The isolate S8 is an arsenic oxidizing bacterium which can oxidize arsenite to the less toxic form of arsenate. This particular strain, having both characteristics of removing and oxidizing arsenic was identified through 16S rRNA gene sequence analysis, as Aneurinibacillus aneurinilyticus DM-TSB-1. This particular bacterium, having these unique properties can be used for the bioremediation of arsenic contaminated water which will be highly beneficial for the human population as well as the livestock and vegetation of the affected area.

In the present work, the possibility of using a non-conventional finely ground (250 μm) Azadirachta indica (neem) bark powder [AiBP] has been tested as a low-cost biosorbent for the removal of arsenic(III) from water. The removal of As(III) was studied by performing a series of biosorption experiments (batch and column). The biosorption behavior of As(III) for batch and column operations were examined in the concentration ranges of 50–500 µg L−1 and 500.0–2000.0 µg L−1, respectively. Under optimized batch conditions, the AiBP could remove up to 89.96 % of As(III) in water system. The artificial neural network (ANN) model was developed from batch experimental data sets which provided reasonable predictive performance (R2 = 0.961; 0.954) of As(III) biosorption. In batch operation, the initial As(III) concentration had the most significant impact on the biosorption process. For column operation, central composite design (CCD) was applied to investigate the influence on the breakthrough time for optimization of As(III) biosorption process and evaluation of interacting effects of different operating variables. The optimized result of CCD revealed that the AiBP was an effective and economically feasible biosorbent with maximum breakthrough time of 653.9 min, when the independent variables were retained at 2.0 g AiBP dose, 2000.0 µg L−1 initial As(III) concentrations, and 3.0 mL min−1 flow rate, at maximum desirability value of 0.969.

Nowadays, heavy metal pollution has become a serious environmental problem on global scale. The heavy metals are non-biodegradable in nature, which can easily accumulate in the organisms of lower trophic level, and enter to the human body system through food chain. From this backdrop, the present experiment highlighted the effect of three heavy metals (Cr, Pb, and Mn) in different concentrations (25, 50, and 75 ppm) on Cicer arietinum in terms of growth physiology, metal uptake, biochemistry, and ultrastructural deformation. The results showed that with increasing metals (Cr and Pb) concentrations from 25 ppm to 75 mg/L both root and shoot length decreased along with root and shoot biomass. However, Mn showed little improvement in all growth physiological parameters at 50 ppm concentration. Biochemical parameters also revealed that both Cr and Pb reduced 64.94 and 69.61% total chlorophyll, respectively, with respect to control. Chlorophyll “a” to “b” ratio was highest in Mn followed by Cr and Pb at higher concentration (75 ppm). Metal accumulation pattern indicated that Cr is less accumulated in root shoot and leaf compared to Mn and Pb in all the studied concentrations. However, accumulation of Mn in shoot was always higher compared to Pb in all studied concentrations. Ultrastructural damage was recorded highest for Cr in root, shoot and leaf at both 25 and 50 ppm concentration. However, at 75 ppm Pb showed highest deformation in root and leaf was observed.

Ground water arsenic contamination is a widespread problem in many developing countries including Bangladesh and India. In recent years development of modern innovative technologies for the removal of arsenic from aqueous system has become an interesting topic for research. In this present study, two rod shaped Gram-positive bacteria are being reported, isolated from arsenic affected ground water of Purbasthali block of Burdwan, West Bengal, India, which can tolerate arsenate concentration up to 4500 ppm and 550 ppm of arsenite concentration. From biochemical analysis and 16S rRNA sequencing, they were identified as Bacillus sp. and Aneurinibacillus aneurinilyticus respectively. The isolates SW2 and SW4 can remove 51.45% and 51.99% of arsenite and 53.29% and 50.37% of arsenate, respectively from arsenic containing culture media. Both of the isolate can oxidize arsenite to less toxic arsenate. These two arsenic resistant bacteria can be used as a novel pathway for the bioremediation of arsenic.

Fluoride contamination and other physicochemical parameters in groundwater of Simlapal block of Bankura district were investigated. A total of 50 deep tube well (DTW) samples were collected from 18 villages of Simlapal. The higher concentration of iron values was recorded, 9.40 mg/L with an average value of 2.11 mg/L. Drastically, 58 % of water samples exceed the permissible limit of 1.5 mg/L (Guidelines for drinking water quality, World Health Organization, Geneva, 2004). Spatial distribution of F− (Guidelines for drinking water quality, World Health Organization, Geneva, 2004) concentration classes is represented by the simple Inverse Distance Weighting (IDW) interpolation method. The affinity between the pH and F− in groundwater suggests the dissolution of fluoride-bearing minerals in groundwater. Furthermore, the pH has a good positive correlation with HCO3− (r = 0.224). This indicates a prevailing condition of alkalinity (caused by HCO3 only here) in the groundwater, which promotes a mineral dissolution. The F− shows a significant positive correlation with pH (r = 0.313, p < 0.05) and HCO3− (r = 0.224), while it has a negative correlation with Ca and Mg ions (r = −0.225 and −0.226). PCA accounts for 74.21 % of the variability for the first four components. F1 values have high loading (32.71 %), second component (F2) exhibits 19.98 %, third component (F3) shows 12.74 %, and fourth component (F4) shows only 8.72 % of the total variability to justify the significant correlation between chemical constituents. In terms of quality of water, sodium adsorption rate (SAR) showed that all the samples are from the group of excellent to good. With respect to permeability, sodium percentages show that 18 % are permissible but doubtful and 2 % are unsuitable for irrigation purposes.

The present study was conducted in some randomly selected area of Malda and South Dinajpur district of West Bengal to find out the level of fluoride in groundwater and its association with other inorganic constituents through statistical modeling and chemical indices. Results revealed that the considerable variation of different parameters, among them 7.90% sample showed F- levels beyond the WHO recommended value. Moreover, F- shows positive correlation with Na+ (p < 0.467*) and negative correlation with Ca2+ (p < -0.289) which is again well supported by factor analysis study. From the results of Multiple linear regression model and piper diagram revealed the significant relationship of F- with Na+, alkaline pH and Ca2+ and dominancy of F- due to high Na-HCO3 enrichment respectively. The higher level of F- in groundwater is the consequence of fluoride containing sedimentary rock weathering.

A study was conducted to assess the seasonal variations of soil enzymes (amylase, invertase, cellulase, and urease), and physicochemical parameters of soil in an arsenic (As)-contaminated area. Ten different sampling sites of Purbasthali, West Bengal, India, were chosen for this experiment, and the collected data were compared with that of the control area, Burdwan University Farm, Burdwan. The As concentrations were found to be high in all experimental soil samples. Only urease and amylase activities were found to vary significantly (p < 0.01) with organic carbon content during pre-monsoon season but nonsignificant (p > 0.05) relationships were recorded between soil enzyme activities and organic carbon content during the post-monsoon period. Again urease and cellulase activities were found to vary significantly (p < 0.05) with soil As content in both pre- and post-monsoon periods, respectively. Similar observations were recorded from cluster analysis in both the seasons. Moreover, all tested soil enzymes activities except urease in post-monsoon period have shown significant relationship (p < 0.01, p < 0.05) with soil moisture in both pre- and post-monsoon periods. Therefore, it is suggested that the study of enzymatic activities and physicochemical parameters of soil may be helpful in assessing the effects of As on the biochemical quality of soils.

Herbal products are cheaper and effective than chemical based mosquito repellent, therefore an attempt has been madeto prepare a 100% herbal product based on traditional practices and rural wisdom. Present study was conducted for effectiveutilization of Basak (Adhatoda zeylanica Medik. syn. A. vasica Nees) as a mosquito repellent. Seven varieties of productswere prepared from its leaves with different natural compositions. Study results revealed that maximum percentage ofweight loss with V7 variety followed by V1 and lowest in variety V6. Almost all varieties of bio-cake burned within 35 – 45minutes except variety V5, which took 60 minutes to complete burning. Variety V6 showed highest ash content (7.70 g) andlowest ash was recorded for V5 (1.67 g) after complete burning. The emission of CO2, CO and O3 was recorded as V2>V4>V3>V5 ≈ V7>V1>V6; V5>V6>V1>V7>V4>V2>V3 and V5>V3 ≈ V4 ≈ V7>V2>V1>V6, respectively during burning ofbio-cake. On the other hand knock down experiment demonstrated that almost all varieties of bio-cakes are effective asmosquito repellent. But only two varieties (V6 and V7) caused more than 50% knock down. Finally the emission of gaseousproduct was compared with a synthetic mosquito coil.

Silver nanoparticles are receiving increasing attention in the field of agriculture. This study aims at evaluating the antifungal properties of green synthesised silver nanoparticles (AgNPs) from Aloe vera leaf extract against two pathogenic fungus Rhizopus sp. and Aspergillus sp. Results revealed that synthesised nanoparticles showed strong absorption maximum at 400 nm corresponding to the surface plasmon resonance. The prepared nanoparticles were characterized by SEM, FT-IR and UV–Vis spectroscopy. From the scanning photograph it is clear that particles are heterogeneous in shape such as rectangular, triangular and spherical with uniform distribution. FT-IR study showed sharp absorption peaks at 1,631 and 3,433 cm−1 for amide and alcoholic hydroxide groups, respectively. On the other hand, synthesised silver nanoparticles showed highest antifungal activity against Aspergillus sp. than Rhizopus sp. by application of 100 μL of 1 M silver nanoparticles with maximum inhibition of the growth of fungal hyphae. However, microscopic observation revealed that synthesised nanoparticles caused detrimental effects on conidial germination along with other deformations such as structure of cell membrane and inhibited normal budding process of both the tested species. Therefore, it has been concluded that Aloe vera leaf extract origin silver nanoparticles have tremendous potentiality towards controlling pathogenic fungus. However, further research is needed to check the efficacy of size-dependent AgNPs on different species of fungus.

Objective: To synthesize and characterize silver nanoparticles from aqueous root extract of Parthenium hysterophorus (P. hysterophorus) and also to evaluate the potentiality of synthesized silver nanoparticles as larvacidal agent against Culex quinquefasciatus (Cx. quinquefasciatus). Methods: The silver nano particles were generated using root extract of P. hysterophorus. The characterization of synthesized nanoparticles was done by visual color change, UV-Vis spectrum, scanning electron micrograph, fluorescent microscope and Fourier transform infrared spectroscopy. Results: It was found that aqueous silver ions can be reduced by aqueous root extract of P. hysterophorus to generate extremely stable silver nanoparticles in aqueous medium. Larvae were exposed to varying concentrations of plant extracts, aqueous silver nitrate solution and synthesized silver nanoparticles for 0, 24 and 48 h separately. Aqueous root extract showed moderate larvicidal effects; however, the maximum efficacy (60.18%) was observed with the synthesized silver nanoparticles against the larvae of Cx. quinquefasciatus. Conclusions: These results suggest that the green synthesis of silver nanoparticles have the potential to be used as an ideal eco-friently approach for the control of the Cx. quinquefasciatus. This is the first report on the mosquito larvicidal activity of the nano particle synthesized by P. hysterophorus. © 2014 Asian Pacific Tropical Medicine Press.

A survey was conducted in the remote area of Laxmisagar village of Simlapal Block, Bankura District, West Bengal, India, of the fluoride (F) concentration in ground water and dental fluorosis in children, 66 boys and 83 girls, aged 6 - <8 yr, 8 - 10 yr, and >10 yr. The ground water F concentration range was 0.25-9.30 mg F/L and the mean 2.02 mg F/L. Using Dean's Index, the severity of dental fluorosis tended to increase with age, particularly for girls but the result was not significant (boys: r=0.474, p=0.893; girls: r=0.949, p=0.146). In the >10 yr groups, severe dental fluorosis was present in 15.79% of boys and 35% of girls. Copyright © 2013 The International Society for Fluoride Research Inc.

The effects of 4.0, 8.0, 10.0, and 20.0 mM aqueous sodium fluoride (NaF) were studied on Bengal gram seedlings, Cicer arietinum L. A significant decrease (p<0.01) in the physiological growth parameters (root and shoot length, fresh root and shoot weight, dry root and shoot weight, number of primary leaves, and number of root branches) was observed with increasing F concentration after seven days of treatment. However, separate addition of aqueous calcium chloride (CaCl2) to the NaF growth media gave little or only minor improvement in the growth physiology of the seedlings. On the other hand, the pigment, protein, and proline content showed good agreement with F stress, and addition of CaCl2 caused improvement in all biochemical parameters. The concentration of F in the plant body increased with increasing NaF concentration, but maximum reduction of plant body F occurred with the addition of 10.0 mM CaCl2 to the 20mM NaF growth medium. © 2012 The International Society for Fluoride Research Inc.

Since most of the equipments are usually installed in rooms or enclosed plants, the effect of an enclosure is important. Absorptive surface of the enclosure can reduce levels to the extent of 5 dB(A) which is quite significant. Effectiveness of enclosures in sound varies with the frequency of sound and the shape, size, laying pattern of sound absorbing material, which is put on the walls of the enclosure. The sound absorbing material accomplishes little shielding if there is no acoustical absorption within it. Acoustical absorbents when applied to the interior surface of the enclosure adsorb some of the energy and the noise level within the enclosure builds up only by the energy not absorbed. This paper elucidates the procedure of developing an enclosure to study its performance in attenuating sound at varying conditions. The results found encouraging and such enclosures can be developed for plant machineries by the plant personnels without getting confused by the claims and rhetoric of advertisements of big companies engaged in developing such items.

This paper elucidates the effect of environmental stressors, viz. noise and illumination, on operator's performance. The effect of environmental stressor on the performance of tasks is studied in a workshop where work situations are simulated. The study was conducted on two machines, namely a lathe and a shaper, to explore the individual as well as combined effect of noise and illumination levels on operator's performance. The performance was found to decrease slowly as either the illumination level or noise level increased while keeping the other one fixed. But the performance level decreased more rapidly as both the noise and illumination level were increased simultaneously. The relationship between the equivalent noise level or illumination level and workers performance was found to be statistically significant as the correlation coefficients of all the relations were high. © 2007 Institute of Noise Control Engineering.