Seasonal variations of trace metals from water and sediment samples in the northern Bay of Bengal.

We aimed to determine the temporal variation of trace metals concentrations in surface water and surface sediment samples at Kutubdia Channel, Bangladesh. Trace metals of samples were detected using energy dispersive X-ray fluorescence (Energy-dispersive X-ray spectroscopy) method. The lowest concentration of metals was found in water samples during post-monsoon season and the highest during pre-monsoon season (Cu: 0.030 ± 0.001 µg/L in pre-monsoon and 0.026 ± 0.002 µg/L in post-monsoon, Zn: 0.087 ± 0.003 µg/L in pre-monsoon and 0.073 ± 0.002 µg/L in post-monsoon, Fe: 0.080 ± 0.001 µg/L in pre-monsoon and 0.055 ± 0.001 µg/L in post-monsoon). In contrast, metal concentration in surface sediment samples were higher in post-monsoon than in pre-monsoon season i.e. Cr 11 mg/kg in pre-monsoon and 12 mg/kg in post-monsoon, Mn 571 mg/kg in pre-monsoon and 606 mg/kg in post-monsoon, As (8 mg/kg in pre-monsoon and 10 mg/kg in post-monsoon, Pb (22 mg/kg in pre-monsoon and 24 mg/kg in post-monsoon, and Fe 2317 mg/kg in pre-monsoon and 2435 mg/kg in post-monsoon. We found a spatial gradient of high to medium to low in trace metal concentration from river to river mouth to offshore area. Considering the sources of metals, land erosion by waves and tidal action, an influx of water and sediment from the surrounding rivers, agricultural waste, industrial effluent and sewage are the most likely sources of metal pollution in the study area. We conclude that proper management strategies should be adopted to control the pollution and conserve the ecosystem health.

Health risk assessment of heavy metal accumulation in the Buriganga and Turag River systems for Puntius ticto, Heteropneustes fossilis, and Channa punctatus.

This study aimed to assess the effects of major ecotoxic heavy metals accumulated in the Buriganga and Turag River systems on the liver, kidney, intestine, and muscle of common edible fish species Puntius ticto, Heteropneustes fossilis, and Channa punctatus and determine the associated health risks. K was the predominant and reported as a major element. A large concentration of Zn was detected in diverse organs of the three edible fishes compared with other metals. Overall, trace metal analysis indicated that all organs (especially the liver and kidney) were under extreme threat because the maximum permissible limit set by different international health organizations was exceeded. The target hazard quotient and target cancer risk due to the trace metal content were the largest for P. ticto. Thus, excessive intake of P. ticto from the rivers Buriganga and Turag could result in chronic risks associated with long-term exposure to contaminants. Histopathological investigations revealed the first detectable indicators of infection and findings of long-term injury in cells, tissues, and organs. Histopathological changes in various tissue structures of fish functioned as key pointers of connection to pollutants, and definite infections and lesion types were established based on biotic pointers of toxic/carcinogenic effects. The analysis of histopathological alterations is a controlling integrative device used to assess pollutants in the environment.

Distribution of polycyclic aromatic hydrocarbons (PAHs) in commonly consumed seafood from coastal areas of Bangladesh and associated human health implications.

Levels, distribution, possible sources and potential risks of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated comprehensively in frequently consumed seafood species collected from the coastal areas of Bangladesh. Samples were collected in winter and summer, 2015. The total concentration of PAHs (∑PAHs) in the examined seafood was 184.5-2806.6 ng/g wet weight (ww) in winter and 117.9-4216.8 ng/g ww in summer, respectively. The levels of ∑PAHs were comparable to or higher than those reported from other coastal areas. Seasonal variation was not significant for the majority of the monitored PAHs. Spatial distribution revealed that the seafood collected from areas with recent urbanization and industrialization (Chittagong, Cox's Bazar and Sundarbans) was more contaminated with PAHs than those from the unindustrialized area (Meghna Estuary). Low-molecular-weight isomers dominated the PAH composition. Molecular ratios suggested the abundance of mixed sources of PAHs in the Bangladeshi coastal areas with a slight imposition toward the petrogenic origin. A preliminary evaluation of human health risk indicated that the dietary PAH exposure from consumption of Bangladeshi seafood would certainly induce adverse health effects. This finding suggests the need to enhance risk management regarding seafood consumption through public advisory in Bangladesh.

The concentration, source and potential human health risk of heavy metals in the commonly consumed foods in Bangladesh.

Seven food items, namely, meat, egg, fish, milk, vegetables, cereals and fruits were collected from Bogra district, Bangladesh to evaluate the levels of heavy metal and associated health risk to the adults and children. The samples were analyzed for the quantification of selected heavy metals (Cr, Ni, Cu, As, Cd and Pb) on inductively coupled plasma mass spectrometer followed by acid digestion. In general, the highest concentrations of the studied metals were detected in vegetables, cereals, and fruits. The range of Cr, Ni, Cu, As, Cd, and Pb in the foods were 0.058-10, 0.036-25, 0.045-40, 0.005-7.1, 0.001-5.5 and 0.005-13 mg/kg fw, respectively. Multivariate principal component analysis (PCA) revealed three major groups of the studied metals and showed significant anthropogenic contributions of the Ni, Cu, and As in foods. Health risk assessment was evaluated in terms of target hazard quotient and target carcinogenic risk (TR) which showed that the intake of some metals through foods were higher than the recommended values, consequently consumption of the foods may be associated with non-carcinogenic health risks. Nonetheless, elevated levels of As and Pb were also found to be associated with lifetime carcinogenic risk to the consumers.

Metal speciation in sediment and their bioaccumulation in fish species of three urban rivers in Bangladesh.

Six trace metals (chromium [Cr], nickel [Ni], copper [Cu], arsenic [As], cadmium [Cd] and lead [Pb]) were measured in sediments and soft tissues of three commonly consumed fish species (Channa punctatus, Heteropneustes fossilis, and Trichogaster fasciata) collected from three urban rivers around Dhaka City, Bangladesh. The abundance of total metals in sediments varied in the decreasing order of Cr > Ni > Pb > Cu > As > Cd. Sequential extraction tests showed that the studied metals were predominantly associated with the residual fraction followed by the organically bound phase. The range of metal concentration in fish species were as follows: Cr (0.75-4.8), Ni (0.14-3.1), Cu (1.1-7.2), As (0.091-0.53), Cd (0.008-0.13), and Pb (0.052-2.7 mg/kg wet weight [ww]). The rank of biota-sediment accumulation factor for fish species were in the descending order of Cu > As > Pb > Ni > Cr > Cd. Metal concentrations in fish exceeded the international permissible standards suggesting that these species are not safe for human consumption.

Metal speciation in soil and health risk due to vegetables consumption in Bangladesh.

This study was conducted to investigate the contamination level of heavy metals in soil and vegetables, chemical speciation, and their transfer to the edible part of vegetables. Metals were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd, and Pb in agricultural soils were 3.7-41, 3.9-36, 3.7-46, 2.3-26, 0.6-13, and 4.5-32 mg/kg, respectively. The metals were predominantly associated with the residual fractions of 39, 41, 40, 40, 34, and 41 % for Cr, Ni, Cu, As, Cd, and Pb, respectively. Considering the metal transfer from soil to the edible part of vegetables, the mean transfer factors (TFs) were in the descending order of Cu > Ni > Cr > Pb > As > Cd. In the edible tissues of vegetables, the concentrations of As, Cd, and Pb in most vegetable samples exceeded the maximum permissible levels, indicating not safe for human consumption. Total target hazard quotient (THQ) of the studied metals (except Cr) from all vegetables were higher than 1, indicated that if people consume these types of vegetables in their diet, they might pose risk to these metals. Total values of carcinogenic risk (CR) were 3.2 for As and 0.15 for Pb which were higher than the US Environmental Protection Agency (USEPA) threshold level (0.000001), indicating that the inhabitants consuming these vegetables are exposed to As and Pb with a lifetime cancer risk.

Trace elements in different land use soils of Bangladesh and potential ecological risk.

Bogra city is highly susceptible to environmental pollution due to overpopulation, rapid industrialization, and urbanization during the last decades. The levels of six trace elements (chromium, nickel, copper, arsenic, cadmium, and lead) in seven different land use soils in Bangladesh were assessed. The ranges of Cr, Ni, Cu, As, Cd, and Pb in studied soils were 6.3-256, 8.3-271, 13-279, 7.5-87, 0.09-29, and 5.3-624 mg/kg, respectively. The pollution load index (PLI) values for all land uses were higher than 1, indicating the progressive deterioration of soil due to trace elements contamination. In view of the potential ecological risk (PER), soils from all land uses showed moderate to very high potential ecological risk. Among the elements, As and Cd showed a higher potential ecological risk than the others.

Trace elements in two staple cereals (rice and wheat) and associated health risk implications in Bangladesh.

Concentrations of fourteen trace elements (Cd, As, Pb, Cr, Ni, Zn, Se, Cu, Mo, Mn, Sb, Ba, V and Ag) in the composite samples of most frequently consumed two staple foods, i.e. rice and wheat (collected from 30 different agroecological zones for the first time in Bangladesh) were measured by ICP-MS. The mean concentrations (mg/kg fresh weight) of Cd, As, Pb, Cr, Ni, Zn, Se, Cu, Mo, Mn, Sb, Ba, V and Ag were found as 0.088, 0.321, 0.713, 0.183, 0.213, 13.178, 0.0256, 1.985, 0.102, 4.654, 0.0033, 0.144, 0.081 and 0.007 and 0.011, 0.281, 0.221, 0.352, 0.145, 15.472, 0.245, 1.894, 0.209, 22.077, 0.0012, 3.712, 0.023 and 0.0013 in rice and wheat samples, respectively. Dietary risk of human health (non-carcinogenic and carcinogenic risks) was assessed by USEPA deterministic approaches. Total target hazard quotient (THQ) values for As and Pb were higher than 1, suggesting that people would experience significant health risks from consuming rice and wheat. However, the THQ of other metals were all less than 1. Also, the estimation showed that the target carcinogenic risk (TR) of As and Pb exceeded the accepted risk level of 1 × 10(-6). Moreover, concerning the nutritional requirements of essential elements for a sound health, the recommended doses for the daily intake of Mn was conveniently supplied by the studied cereals; however, Cr, Zn, Se, Cu and Mo were below the recommend daily allowances (RDAs). Thus, the carcinogenic and non-carcinogenic risk of As and Pb with lower supplementation of essential elements via staple foods for Bangladeshi people is a matter of concern.

Trace metals in soil and vegetables and associated health risk assessment.

The objective of this study was to assess the contamination level of trace metals in soil and vegetables and health risk to the urban population in Bangladesh. The range of Cr, Ni, Cu, As, Cd, and Pb in agricultural soils was 158-1160, 104-443, 157-519, 41-93, 3.9-13, and 84-574 mg/kg, respectively. Sequential extraction tests revealed that the studied metals were predominantly associated with the residual fraction, followed by the organically bound phase. Concerning Cu, Ni, Cd, and Pb in vegetables, more than 50 % samples exceeded the FAO/WHO recommended permissible limits. Considering the transfer of metals from soil to vegetables, Cu and Cd exhibited higher transfer factor (TF) values than the other metals. Target hazard quotient (THQ) for individual metal was below 1, suggesting that people would not experience significant health hazards if they ingest a single metal from vegetables. However, total metal THQ signifies the potential non-carcinogenic health hazard to the highly exposed consumers. The carcinogenic risk (TR) of As (1.9 × 10(-4)) and Pb (2.3 × 10(-5)) through consumption of vegetables were higher than the USEPA threshold level (10(-6)), indicating potential cancer risks.

Heavy Metals in Common Fishes Consumed in Dhaka, a Megacity of Asia: A Probabilistic Carcinogenic and Non-Carcinogenic Health Hazard.

Heavy metal contamination of fish is a serious public health concern worldwide, including in Bangladesh. In this study, six commonly consumed fish species namely Hilsha (Tenualosa ilisha), Kachki (Corica soborna), Punti (Puntitus ticto), Taki (Channa punctatus), Meni (Nandus nandus), and Tengra (Mystus tengara) were analyzed for arsenic (As), cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mn), and nickel (Ni), by inductively coupled plasma mass spectrometry. The fish samples were collected from wholesale markets in Dhaka city, the main business hub of Bangladesh where the fishes converged from countrywide and are redistributed to the whole city. The metal concentration varied among the studied fish species. Hilsha, the national fish of Bangladesh, contained the highest As among the other fishes of this study, whereas Zn, Cd, Cu, Mn, and Ni were the highest in Kachki, and Pb and Cr were the highest in Tengra. The probable source of metal accumulation in the fish species may be the river or marine water that can be contaminated by industrial waste, pesticide, and/or fertilizer use in agriculture and/or commercial fish feeds. All analyzed fish species showed serious heavy metal pollution, having high average pollution load index (APLI) values (> 1). The estimated daily intake (EDI) values for the metals were lower than the maximum tolerable daily intake (MTDI). The hazard index (HI) for all the fish species was above 1 for adults, showing non-carcinogenic health risks. The target carcinogenic risk (TCR) values were below the acceptable limit (10-4) for most of the metals, indicating safe for consumption with respect to the risk of cancer.

Carcinogenic and non-carcinogenic health hazards of potentially toxic elements in commonly consumed rice cultivars in Dhaka city, Bangladesh.

The study aimed to assess the level of potentially toxic elements (As, Cd, Pb, Zn, Cu, Cr, Mn, and Ni) and associated health implications through commonly consumed rice cultivars of Bangladesh available in Capital city, Dhaka. The range of As, Cd, Pb, Zn, Cu, Cr, Mn, and Ni in rice grains were 0.04-0.35, 0.01-0.15, 0.01-1.18, 10.74-34.35, 1.98-13.42, 0.18-1.43, 2.51-22.08, and 0.21-5.96 mg/kg fresh weight (FW), respectively. The principal component analysis (PCA) identified substantial anthropogenic activities to be responsible for these elements in rice grains. The estimated daily intake (EDI) of the elements was below the maximum tolerable daily intake (MTDI) level. The hazard index (HI) was above the threshold level, stating non-carcinogenic health hazards from consuming these rice cultivars. The mean target cancer risk (TCR) of As and Pb exceeded the USEPA acceptable level (10-6), revealing carcinogenic health risks from the rice grains.

Spatiotemporal distribution of microplastic debris in the surface beach sediment of the southeastern coast of Bangladesh.

This study undertakes a spatiotemporal analysis of microplastic pollution in surface beach sediments, covering 7 coastal beaches in Bangladesh and two seasons-monsoon and winter. The concentration of microplastics extracted from the surface beach sediment is 242.86 particles/kg dw. The results showed both significant seasonal (p value = 0.001) and spatial (p value = 0.004) variation. The abundance and polymer types were significantly higher (57 %) in winter than in the monsoon season (43 %). Touristic and commercial beaches showed higher levels of microplastic pollution than the non-touristic beaches. Polyethylene (28.8 %) and Polypropylene (27.6 %) were the most abundant polymer. The most dominant coloration of microplastics was white (42.6 %). The majority of the microplastics were fibers (33.5 %). Smallest particles measuring <1 mm constituted nearly half of the total microplastics load (48.5 %). This baseline data can be useful in terms of coastal zone management for the southeastern coastal beaches of Bangladesh.

The pervasiveness of microplastic contamination in the gastrointestinal tract of fish from the western coast of Bangladesh.

This study investigated the prevalence of microplastics (MPs) in the gastrointestinal tract (GIT) of fish from the western coast of Bangladesh, the world's largest mangrove ecosystem. Altogether, 8 different species of fish (5 demersal and 3 pelagic) were examined. Microplastics were detected in every individual fish with an average abundance of 7.1 ± 3.14 particles per specimen. The demersal species were observed to consume more microplastics (7.78 ± 3.51) than the pelagic species (5.92 ± 2.06). Moreover, small-sized fish was found to accumulate higher MPs/body weight than large-sized fish. Polypropylene was the most abundant polymer type (45 %) and fiber was the most prevalent shape (71 %). SEM analysis revealed cracks, pits, and foreign particles on the microplastics' surface, representing their ability to bear organic pollutants and heavy metals. This study will be a source of information for future research and a guide for policy-makers to take better actions to protect and restore marine resources.

A comprehensive review on sustainable coastal zone management in Bangladesh: Present status and the way forward.

Bangladesh, a coastal developing nation with a diverse sustainable biodiversity of natural resources is currently focused upon by international communities as a result of its high potential of the coastal zone (CZ) with natural gas. Sustainable Coastal Zone Management (SCZM) is key to its national development. SCZM refers to the management of coastal resources in order to provide secure and alternative livelihoods, as well as to manage all types of coastal hazards and social and cultural well-being in order to ensure long-term productivity and minimize environmental impact. This paper aims to delineate the current initiatives and status of coastal management in Bangladesh, highlighting key issues such as climate changes, sea level rise, tropical cyclones, coastal and marine pollution, coastal erosions, saltwater intrusions, and mangrove degradations as well as the future trend in Bangladesh which will facilitate sustainable development by emphasizing the social, ecological, and economic pillars of sustainability. Unsustainable coastal development practices in Bangladesh are going to damage the coastal ecosystems, particularly mangrove forests and coral reefs, which provide protection against tropical cyclones caused by global climate change and coastal erosions. The paper concludes by outlining a roadmap toward achieving SCZM in Bangladesh. The road to achieving SCZM requires collaboration, integration of scientific research, policy frameworks, community engagement, capacity building, and long-term commitment from all stakeholders involved. So, it is required to address all kinds of coastal issues and reframes all existing coastal management practices to ensure a healthy productive ecosystem to achieve SCZM as well as the sustainable development of the country.

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.

Effects of microplastic and heavy metals on coral reefs: A new window for analytical research.

In the modern world, plastic trash has been recognized as a global issue, and studies on microplastics (MPs) in the marine and inland environments have previously been conducted. Marine ecosystems act as a bio-diverse ecosystem where coral reefs contribute to make a sound living of the coastal people by gathering natural resources. The current study indicates that MPs and heavy metals (HMs) accumulation to biofilm and organic matter through sedimentation, precipitation, adsorption, and desorption that may have potential effect on growth and development of coral reefs in the marine ecosystems. However, the knowledge of distribution, impact, mechanism, degradation, and association mechanisms between MPs and HMs in the natural environment may open a new window for conducting analytical research from an ecological viewpoint. The current study thus summarizes the types of marine samples with the analytical techniques, polymers of MPs, and their impact on corals and other marine biota. This study also identifies existing knowledge gaps and recommends fresh lines of inquiry in light of recent developments in MPs and HMs research on the marine ecosystems. Overall, the present study suggests a sustainable intervention for reducing MPs and HMs from the marine ecosystems by demonstrating their existence in water, sediment, fish, corals, and other biota, and their impending ecotoxicological impacts on the environment and human health. The impacts of MPs and HMs on coral reefs are critically assessed in this study in light of the most recent scientific knowledge, existing laws, and new suggestions to minimize their contamination in the marine ecosystems.

Nursing Care Systematization with Case-Based Reasoning and Artificial Intelligence.

Of the most popular applications of artificial intelligence (AI), those used in the health sector are the ones that represent the largest proportion, in terms of use and expectation. An investigative systematization model is proposed in the scientific training of nursing professionals, by articulating epistemological positions from previous studies on the subject. In order to validate the model proposed, a prototype was created to present an application that could help nurses in their clinical processes, storing their experiences in a case base for future research. The prototype consisted of digitizing paediatric nursing diagnoses and inserting them into a case base in order to assess the effectiveness of the prototype in handling these cases in a structure conducive to retrieval, adaptation, indexing, and case comparison. This work presents as a result a computational tool for the health area, employing one of the artificial intelligence techniques, case-based reasoning (CBR). The small governmental nursing education institution in Bangladesh used in this study did not yet have the systemization of nursing care (NCS) and computerized support scales.

Distribution and source apportionment of toxic and trace elements in some benthic and pelagic coastal fish species in Karnaphuli River Estuary, Bangladesh: Risk to human health.

The Karnaphuli River is one of the prime and most important streams in the southeastern part of Bangladesh. The favorable water current and the geographic location have rendered the Karnaphuly River estuary a suitable habitat and a breeding ground for diverse fish species. Reversely, this estuary has been polluted by discharges from many point and non-point sources due to its location in the catchment area of a heavily industrialized area, Chattagram port city. However, published research concerning the status of toxic and trace elements in some commercially important benthic and pelagic coastal fish species in Karnaphuli River estuary was not found in the existing literature. Therefore, it's an important field of study on the assessment of toxic and trace elements concentration in the commercially important benthic and pelagic coastal fish species and their health taxation in the Karnaphuli River Estuary. Energy dispersive X-ray fluorescence (ED-XRF) was used to quantify trace metal concentration in edible parts of the fish species. This study revealed that the rank of the trace metals concentration was as follows (mg/kg): Zn (37.1) > Mn (16.12) > V (11.16) > Cu (9.49) > Rb (5.62) > Pb (2.98) > Cr (1.59) > Co (1.17). The F-test showed that a significant difference at 95 % confidence level in the distribution pattern of trace metals concentration among the examined fish species in the study area. The metal pollution index (MPI) in the muscle of fishes were found to be in the following order: L. bata > P. monodon > T. cirratus > M. bleekeri > O. pabda > H. nehereus > L. calcarifer > P. argenteus > P. paradiseus > T. toli, and the MPIs for most of the benthic fish species were higher compared to the pelagic fishes. On the other hand, the examined fish species were significantly bio-accumulative with the highest bio-accumulation factor value for benthic species. The multivariate analysis identified that the sources of the trace metals were associated with anthropogenic activities. For the human health risk assessment concern, estimated daily intake, target hazard quotient and cancer-causing risk were estimated. The results for non-cancer hazardous index values were found to be lower than unity. On the other hand, the total cancer risk data ranging from 1.24E-05 to 1.70E-05 were fallen within the range for the threshold values (1.0E-06 to 1.0E-04). However, considering the suggested values set by the environmental and regulatory agencies, it has been recommended that no significant non-carcinogenic and cancer-causing health risk for humans was seen due to the consumption of the studied fish species.

Artificial Intelligence Technique of Synthesis and Characterizations for Measurement of Optical Particles in Medical Devices.

The aim of this study is to demonstrate the effect of particle size on semiconductor properties; artificial intelligence is being used for the research methods. As a result, we picked cadmium sulfide (CdS), which is a unique semiconductor material that is employed in a broad variety of current applications. Given that CdS has distinct electrical and optical characteristics, it may be employed in the production of solar cells, for example. Solar cells, as is also well known, have become an essential source of energy in the world. Within the visible range (500-700 nm), we create one layer of bulk CdS and one layer of nano-CdS air bulk CdS air and air nano-CdS air. We used a number of instrumentation methods to investigate the naked CdS nanoparticles, including XRD, SEM-EDX, UV-Vis spectroscopy, TEM, XPS, and PL spectroscopy, among others. The results show that for bulk CdS at normal incidence, the transmittance is T = 45, and for nano-CdS with particle size 3 nm, the transmittance is T = 85.8, with transverse-electric (S-polarized) and transverse-magnetic (P-polarized) transmittances of TE = 75 and TM = 80, respectively.

Genetic damage induced by lead chloride in different tissues of fresh water climbing perch Anabas testudineus (Bloch).

The present investigation was undertaken to study the induction of DNA damage by lead chloride (PbCl(2)) in freshwater climbing perch Anabas testudineus using alkaline single cell gel electrophoresis (comet assay). Based on the LC(50) values of lead chloride of A. testudineus three different concentrations viz., 0.1, 1.0 and 2.0 mg/L were selected to expose fish. The DNA damage was observed in the gill, kidney and liver tissue as the percentage of DNA in comet tails and comet heads in the tissue of the exposed fish. DNA damage at different concentrations showed sensitivity to particular tissue. The liver tissue exhibited significantly (p < 0.01) higher DNA damage, followed by kidney and gill. However, the DNA damage was found to be dose dependent; at 2 mg/L of PbCl(2) the tail and head DNA of liver tissue were 57.84% and 39.49%, in kidney tissue the values were 52.36% and 44.97% whereas in gill tissue the values were 48.86% and 48.96% respectively. The current study explored the utility of the comet assay for in vivo laboratory studies using A. testudineus species for screening the genotoxic potential of lead chloride.