Assessment of antibiotic resistance genes in soils polluted by chemical and technogenic ways with poly-aromatic hydrocarbons and heavy metals.

Anthropogenic activities are leaving lots of chemical footprints on the soil. It alters the physiochemical characteristics of the soil thereby modifying the natural soil microbiome. The prevalence of antimicrobial-resistance microbes in polluted soil has gained attention due to its obvious public health risks. This study focused on assessing the prevalence and distribution of antibiotic-resistance genes in polluted soil ecosystems impacted by industrial enterprises in southern Russia. Metagenomic analysis was conducted on soil samples collected from polluted sites using various approaches, and the prevalence of antibiotic-resistance genes was investigated. The results revealed that efflux-encoding pump sequences were the most widely represented group of genes, while genes whose products replaced antibiotic targets were less represented. The level of soil contamination increased, and there was an increase in the total number of antibiotic-resistance genes in proteobacteria, but a decrease in actinobacteria. The study proposed an optimal mechanism for processing metagenomic data in polluted soil ecosystems, which involves mapping raw reads by the KMA method, followed by a detailed study of specific genes. The study's conclusions provide valuable insights into the prevalence and distribution of antibiotic-resistance genes in polluted soils and have been illustrated in heat maps.

Human health impacts attributable to inhalation exposure of particulate matter (PM10 and PM2.5) during the Holi festival.

OBJECTIVE: The present study focuses on residential areas of Delhi to identify the elevated levels of ambient PM10 and PM2.5 due to biomass burning followed by the coloring activity in the Holi festival celebrated at the end of the winter season. This study also focuses on the health risk assessment and mortality among different age groups due to the change in particulate matter levels during the Holi festival in Delhi, India. MATERIALS AND METHODS: Secondary data of particulate matters have been procured from the Central Pollution Control Board (CPCB), Delhi Pollution Control Committee (DPCC), and Indian Institute of Tropical Meteorology (IITM), Pune for the period of the pre-, during, and post-Holi period for the year 2018-2020 at four selected residential locations in Delhi, India. The health impacts of particle inhalation were quantified using the AirQ + models. RESULTS: The results indicated the levels of PM10 and PM2.5 rise about 3-4 times higher during the Holi festival than on normal days, resulting in health risks and causing an excess number of mortality and Asthma cases in Delhi. Such cases were also found to be higher in 2018, followed by 2019 and 2020 at all the selected locations in Delhi. CONCLUSIONS: The study linked the increasing particulate levels in the Holi festival with the increased health risk through short-term exposure of the population. The excess number of cases (ENCs) of mortality, all causes of mortality among adults (age > 30 years) associated with short-term exposure to particulate were also identified.

A critical review on fate, behavior, and ecotoxicological impact of zinc oxide nanoparticles on algae.

The rapid inclusion of zinc oxide nanoparticles (ZnO NPs) in nanotechnology-based products over the last decade has generated a new threat in the apprehension of the environment. The massive use of zinc nanosized products will certainly be disposed of and be released, eventually entering the aquatic ecosystem, posing severe environmental hazards. Moreover, nanosized ZnO particles owing the larger surface area per volume exhibit different chemical interactions within the aquatic ecosystem. They undergo diverse potential transformations because of their unique physiochemical properties and the feature of receiving medium. Therefore, assessment of their impact is critical not only for scavenging the present situation but also for preventing unintended environmental hazards. Algae being a primary producer of the aquatic ecosystem help assess the risk of massive NPs usage in environmental health. Because of their nutritional needs and position at the base of aquatic food webs, algal indicators exhibit relatively unique information concerning ecosystem conditions. Moreover, algae are presently the most vital part of the circular economy. Hence, it is imperative to understand the physiologic, metabolic, and morphologic changes brought by the ZnO NPs to the algal cells along with the development of the mechanism imparting toxicity mechanism. We also need to develop an appropriate scientific strategy in the innovation process to restrain the exposure of NPs at safer levels. This review provides the details of ZnO NP interaction with algae. Moreover, their impact, mechanism, and factors affecting toxicity to the algae are discussed.

Exploring the molecular underpinning of psoriasis and its associated comorbidities through network approach: cross talks of genes and pathways.

Patients with psoriasis often complain of several linked disorders including autoimmune and cardiometabolic diseases. Understanding of molecular link between psoriasis and associated comorbidities would be of great interest at the point of patient care management. Integrative unbiased network approach, indicates significant unidirectional gene overlap between psoriasis and its associated comorbid condition including obesity (31 upregulated and 26 downregulated), ischemic stroke (14 upregulated and 2 downregulated), dyslipidaemia (5 upregulated, 5 downregulated), atherosclerosis (8 upregulated and 1 downregulated) and type II diabetes (5 upregulated, 5 downregulated). The analysis revealed substantial gene sharing among the different psoriasis-associated comorbidities. Molecular comorbidity index determining the strength of the interrelation between psoriasis and its comorbidities indicates prevalence of dyslipidaemia followed by type II diabetes among psoriasis patients. The Jaccard coefficient indices revealed psoriasis shared maximum number of biological pathways with dyslipidaemia followed by type 2 diabetes, ischemic stroke, obesity and atherosclerosis. Moreover, pathway annotation highlighted nearly 45 shared pathways amongst psoriasis and its comorbidities and a substantial number of shared pathways was found among multi-morbidities. Overall, the present study established conceivable link between psoriasis and comorbid diseases. The shared genes and overlapped pathways may be explored as a common productive target for psoriasis and its comorbid conditions. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03533-y.

Toxicity of boron nitride nanoparticles influencing bio-physicochemical responses in freshwater green algae.

Boron nanoparticles have emerged as promising nanomaterials with a wide array of applications in the biomedical, industrial, and environmental fields. However, the potential impact of these nanoparticles on aquatic organisms is not yet known. In the present study, the comparative impact of boron nitride nanoparticles and its bulk form is investigated on two freshwater algae. For this purpose, the effect on the physiological index, cellular morphology, and biochemistry profiles are examined. In Chlorella vulgaris, nano form of boron nitride is found to reduce the growth more (40%) than its bulk form (with ~ 25% growth reduction) at 50 mgl-1 treatment level. While in case of Coelastrella terrestris, 40% reduction under nano form and 33.33% reduction under bulk form is observed at 100 mgl-1 of boron nitride. Chlorophyll and carotenoid levels were also reduced under nanoparticles compared to the bulk. Proline, lactate dehydrogenase, and malondialdehyde assay were found significantly high under nanoparticle exposure. Additionally, increased catalase and superoxide dismutase enzyme activity under nanoparticle exposure revealed that the antioxidant system was activated in both the algae to eliminate the adverse influence of reactive oxygen species. The shading effect and aggregation of nanoparticles over the surface of algal cells are also important factors in attributing toxicity which are confirmed through the compound, TEM, and SEM micrographs. The study suggests that the nano form is more toxic than the bulk form and toxicity is concentration-dependent.

Integrated bioinformatics approach to unwind key genes and pathways involved in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the fifth leading cause of death in India. Until now, the exact pathogenesis concerning CRC signaling pathways is largely unknown; however, the diseased condition is believed to deteriorate with lifestyle, aging, and inherited genetic disorders. Hence, the identification of hub genes and therapeutic targets is of great importance for disease monitoring. OBJECTIVE: Identification of hub genes and targets for identification of candidate hub genes for CRC diagnosis and monitoring. MATERIALS AND METHODS: The present study applied gene expression analysis by integrating two profile datasets (GSE20916 and GSE33113) from NCBI-GEO database to elucidate the potential key candidate genes and pathways in CRC. Differentially expressed genes (DEGs) between CRC (195 CRC tissues) and healthy control (46 normal mucosal tissue) were sorted using GEO2R tool. Further, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed using Cluster Profiler in Rv. 3.6.1. Moreover, protein-protein interactions (PPI), module detection, and hub gene identification were accomplished and visualized through the Search Tool for the Retrieval of Interacting Genes, Molecular Complex Detection (MCODE) plug-in of Cytoscape v3.8.0. Further hub genes were imported into ToppGene webserver for pathway analysis and prognostic expression analysis was conducted using Gene Expression Profiling Interactive Analysis webserver. RESULTS: A total of 2221 DEGs, including 1286 up-regulated and 935down-regulated genes mainly enriched in signaling pathways of NOD-like receptor, FoxO, AMPK signalling and leishmaniasis. Three key modules were detected from PPI network using MCODE. Besides, top 20 high prioritized hub genes were selected. Further, prognostic expression analysis revealed ten of the hub genes, namely IL1B, CD44, Glyceraldehyde-3-phosphate dehydrogenase (GAPDH, MMP9, CREB1, STAT1, vascular endothelial growth factor (VEGFA), CDC5 L, Ataxia-telangiectasia mutated (ATM + and CDH1 to be differently expressed in normal and cancer patients. CONCLUSION: The present study proposed five novel therapeutic targets, i.e., ATM, GAPDH, CREB1, VEGFA, and CDH1 genes that might provide new insights into molecular oncogenesis of CRC.

A Machine Learning-Based Intrauterine Growth Restriction (IUGR) Prediction Model for Newborns.

Intrauterine growth restriction (IUGR) is a condition in which the fetal weight is below the 10th percentile for its gestational age. Prenatal exposure to metals can cause a decrease in fetal growth during gestation thereby reducing birth weight. Therefore, the aim of the present study was to develop a machine learning model for early prediction of IUGR. A total of 126 IUGR and 88 appropriate-for-gestational-age (AGA) samples were collected from the Gynecology Department, Safdarjung Hospital, New Delhi. The predictive models were developed using the Weka software. The models developed using all the features gave the highest accuracy of 95.5% with support vector machine (SMO) algorithm and 88.5% with multilayer perceptron (MLP) algorithm. Further, models developed after feature selection using 14 important and statistically significant variables also gave the highest accuracy of 98.5% with SMO algorithm and 99% with Naïve Bayes (NB) algorithm. The study concluded SMO_31, SMO_14, MLP_31, and NB_14 to be the better classifiers for IUGR prediction.

Profile of atmospheric particulate PAHs near busy roadway in tropical megacity, India.

Objective: This study focuses on the profile of ambient particulate polycyclic aromatic hydrocarbons (PAHs), their seasonal distribution, source identification and human health risk assessment due to inhalation exposure of ambient PAHs in Delhi, India.Materials and Methods: Two sampling sites were chosen, one at roadway (MH) and other at urban background (JNU) site in Delhi. Determination of PAHs was carried with the help of HPLC with UV detector. Principal component analysis and Molecular diagnostic ratios were used for the source apportionment of PAHs. Health risks associated with inhalation of particulate PAHs were assessed using benzo(a)pyrene equivalent concentration and incremental lifetime cancer risk (ILCR) approach.Results: The results showed that the average mass concentration of Σ16 PAHs near roadway (67.8 ± 40.2 ng m-3) is significantly higher than urban background site (56 ± 30 ng m-3). Moreover, source apportionment study indicated that major PAH-emission sources in Delhi NCR are traffic and coal combustion. ILCR values at both the sites fall in the range of 10-2-10-4 that corresponds to the priority risk level (10-3) and higher than the acceptable risk level (10-6).conclusions: The high PAHs concentration at MH site was due to it's nearness to busy traffic area. Thus, the spatial variations in PAHs were influenced by local emission sources. The high PAHs level during the winter season can be due to their higher emissions from local heating sources, shift of gas/particle partitioning toward the particulate phase at low temperature and reduced photochemical degradation of some PAHs in winter. The low level of PAHs in monsoon season can be attributed to their wet scavenging and higher percentage in vapor phase. PCA showed that the emissions from vehicles predominate at MH site; whereas, coal combustion and traffic both are the significant PAHs sources at JNU site. Health risk assessment revealed that the highest exposure risks occur at busy traffic site, thereby indicating a significantly higher health risk to the population of Delhi.

Evaluation of p16 expression in oral and oropharyngeal squamous cell carcinoma.

Introduction: Oral and oropharyngeal cancers together are the 6th most common cancers in the world and more than 90% are squamous cell carcinomas (OSCC, OPSCC). HPV is an important risk factor. p16 expression apart from indirectly assessing HPV infection, is an independent favorable prognostic marker. Lewis/Modified Lewis criteria of p16 grading identifies a subset of patients with improved overall survival. Aims: (1) To evaluate p16 expression in these cancers. (2) To correlate p16 expression with age, gender, sub-site, histological type and grade. (3) To utilize the Lewis/modified Lewis criteria. Methodology: The study included 70 cases of OSSC's and OPSCC's. Histological features were analyzed. p16 expression was determined and graded. Results were analyzed and evaluated using Chi-square test (value of P < 0.05 was taken significant). Results: p16 positivity was seen in 46/70 (66%) cases (44 OSCC & 26 OPSCC). It was more frequent in younger patients and significantly higher in males. There was no correlation between degree of differentiation and p16 expression. In OSCC, 72.7% were p16 positive, mostly from tongue, buccal mucosa, and hard palate. p16 positivity was seen in 53.8% of OPSCCs, mostly from base of tongue and tonsil. Also, 30.4% of all cases could be included in Lewis criteria and 39.1% in modified Lewis criteria. Conclusion: p16 is an inexpensive, easily available marker, it may be incorporated routinely in all histologically diagnosed cases of OSCC and OPSCC.

Impact of crop residue burning in Haryana on the air quality of Delhi, India.

Crop residue burning (CRB) over northern India is a major air quality and human health issue. The present study assesses the impact of PM10, PM2.5, NO2 and SO2, emitted during CRB activities in Haryana on the air quality of Delhi. The transition from pre-burning to burning period, in both rabi and kharif seasons, shows considerable increase in pollutant concentrations. PM10 and PM2.5 concentrations exceeded NAAQS limits by 2-3 times, while NO2 and SO2 stayed within the limits. MODIS fire observations used to estimate CRB fire counts (confidence ≥80%) shows that rabi (burning period) fires in Haryana are ~3 times higher and more intense than in kharif. Furthermore, backward trajectories shows air mass movement from Haryana, Punjab and Pakistan. Thus, pollutants emitted reach Delhi via air masses, deteriorating its air quality. Meteorological conditions influence pollutant concentrations during both seasons. Frequent dust storms in rabi, and Dusshera and Diwali firework celebrations in kharif season exacerbate air pollution. In rabi, PM10 and PM2.5 have a significant negative association with (relative humidity) RH and positive association with (air temperature) AT. High AT during pre-monsoon, accompanied by low RH, loosens up soil particles and they can easily disperse. Stronger winds in rabi season promote NO2 and SO2 dispersion. In kharif, lower AT, higher RH and slower winds exist. Both PM10 and PM2.5 have a negative association with AT and (wind speed) WS. With lower temperature and slower winds during winter, pollutants are trapped within the boundary layer and are unable to disperse. As expected, NO2 has a significant negative association with AT in Haryana. However, in case of Delhi, the association is significant but positive, and could be due to the odd-even scheme imposed by the Delhi government. More research is needed to determine the health effects of Haryana's rabi CRB activities on Delhi.

Water-insoluble carbonaceous components in rainwater over an urban background location in Northern India during pre-monsoon and monsoon seasons.

The carbonaceous content of rainwater was investigated in samples collected at an urban background site in northern India. Sampling was performed on an event basis during two seasons: pre-monsoon (PM) and monsoon (MN) season covering May-June and July-August, respectively, in 2016. The concentrations of different fractions of water-insoluble organic carbon (WIOC) and elemental carbon (EC) were precisely determined, and the sources of WIOC and EC were also analysed. The result revealed that the average WIOC and EC concentration in rainwater ranged from 0.4 to 52 mgC/L and from 0.1 to 15.3 mgC/L, respectively. The concentrations of WIOC and EC were found to be ~ 9 times and ~ 12 times higher, respectively, in the PM season than MN season. The WIOC/EC ratio indicated higher variation in PM season as compared to that of the MN season, suggesting divergent emission sources during the PM season. The formation of water-insoluble secondary organic carbon (WISOC) has also been identified as one of the causes for the extensive difference in the WIOC/EC ratio in different seasons. Results showed that the WIOC and its fractions were efficiently scavenged through rain. While EC and its fractions were less significantly scavenged, due to its hydrophobicity and fine size. The atmospheric scavenging coefficients of selected carbonaceous components were found significantly correlated with rain intensity (RI) during both the seasons. Higher rain intensity caused greater rates of carbonaceous component wash-out and decreasing concentrations of carbonaceous components in the rain.

Mechanism of nanotoxicity in Chlorella vulgaris exposed to zinc and iron oxide.

Usage of nanoparticle in various products has increased tremendously in the recent past. Toxicity of these nanoparticles can have a huge impact on aquatic ecosystem. Algae are the ideal organism of the aquatic ecosystem to understand the toxicity impact of nanoparticles. The present study focuses on the toxicity evaluation of zinc oxide (ZnO) and iron oxide (Fe2O3) nanoparticles towards freshwater microalgae, Chlorella vulgaris. The dose dependent growth retardation in Chlorella vulgaris is observed under ZnO and Fe2O3 nanoparticles and nanoform attributed more toxicity than their bulk counterparts. The IC50 values of ZnO and Fe2O3 nanoparticles was reported at 0.258 mg L-1 and 12.99 mg L-1 whereas, for the bulk-form, it was 1.255 mgL-1 and 17.88 mg L-1, respectively. The significant decline in chlorophyll content and increase in proline content, activity of superoxide dismutase and catalase, indicated the stressful physiological state of microalgae. An increased lactate dehydrogenase level in treated samples suggested membrane disintegration by ZnO and Fe2O3 nanoparticles. Compound microscopy, scanning electron microscopy and transmission electron microscopy confirm cell entrapment, deposition of nanoparticles on the cell surface and disintegration of algal cell wall. Higher toxicity of nanoform in comparison to bulk chemistry is a point of concern.

Investigation of Forest Fire Activity Changes Over the Central India Domain Using Satellite Observations During 2001-2020.

Recurrent and large forest fires negatively impact ecosystem, air quality, and human health. Moderate Resolution Imaging Spectroradiometer fire product is used to identify forest fires over central India domain, an extremely fire prone region. The study finds that from 2001 to 2020, ∼70% of yearly forest fires over the region occurred during March (1,857.5 counts/month) and April (922.8 counts/month). Some years such as 2009, 2012, and 2017 show anomalously high forest fires. The role of persistent warmer temperatures and multiple climate extremes in increasing forest fire activity over central India is comprehensively investigated. Warmer period from 2006 to 2020 showed doubling and tripling of forest fire activity during forest fire (February-June; FMAMJ) and non-fire (July-January; JASONDJ) seasons, respectively. From 2015 JASONDJ to 2018 FMAMJ, central India experienced a severe heatwave, a rare drought and an extremely strong El Niño, the combined effect of which is linked to increased forest fires. Further, the study assesses quinquennial spatiotemporal changes in forest fire characteristics such as fire count density and average fire intensity. Deciduous forests of Jagdalpur-Gadchiroli Range and Indravati National Park in Chhattisgarh state are particularly fire prone (>61 fire counts/grid) during FMAMJ and many forest fires are of high intensity (>45 MW). Statistical associations link high near surface air temperature and low precipitation during FMAMJ to significantly high soil temperature, low soil moisture content, low evapotranspiration and low normalized difference vegetation index. This creates a significantly drier environment, conducive for high forest fire activity in the region.

Predicting risk of low birth weight offspring from maternal features and blood polycyclic aromatic hydrocarbon concentration.

Prenatal exposure to organic pollutants increases the risk of low birth weight (LBW) offspring. Women involved in the plucking of tea leaves can be exposed to polycyclic aromatic hydrocarbons (PAHs) during pregnancy through inhalation and diet. Therefore, the aim of the study was to investigate the association of maternal socio-demographic features and blood PAH concentration with LBW; also to develop a model for predicting LBW risk. The study was performed by recruiting 55 women who delivered LBW and 120 women with NBW (normal birth weight) babies from Assam Medical College. The placental tissue, maternal and cord blood samples were collected. A total of sixteen PAHs and cotinine were analysed by HPLC and GC-MS. Association of PAH concentration with weight was determined using correlation and multiple logistic regression analyses. Predictive model was developed using SVMlight and Weka software. Maternal features such as age, education, food habits, occupation, etc. were found to be associated with LBW deliveries (p-value<0.05). Overall, 9 PAHs and cotinine were detected in the samples. A multiple logistic regression depicted an increased likelihood of LBW by exposure to PAHs (pyrene, di-benzo (a,h) anthracene, fluorene and fluoranthene) and cotinine. Models based on the features and PAHs/ cotinine predicted LBW offspring with 84.35% sensitivity and 74% specificity. LBW prediction models are available at http://dev.icmr.org.in/plbw/ webserver. With machine learning gaining more importance in medical science; our webserver could be instrumental for researchers and clinicians to predict the state of the fetus.

Toxicity evaluation of iron oxide nanoparticles and accumulation by microalgae Coelastrella terrestris.

Uses of iron oxide nanoparticles have increased in the last decade. The increased application marked a concern regarding their fate and behavior in the environment. Especially towards the aquatic ecosystems, as the ultimate descend of these iron oxide nanoparticles are aquatic bodies. The greater surface area per mass compared with larger-sized materials of the same chemistry renders these nanoparticles biologically more active. Therefore, it is imperative to assess their eco-toxicogical impact on aquatic eco-systems. In the present study, comparative assessment of iron oxide nanoparticles and their bulk counterpart have been monitored using Coelastrella terrestris up to 40 days. Interestingly, study reveals the potential of Coelastrella terrestris as tool for the bioremediation of iron nanoparticles to combat nano-pollution. Adsorption/absorption kinetics measured after 25 days of treatments with iron oxide nanoparticle and its bulk counterpart revealed higher absorption levels in comparison to the adsorption with maximum accumulation factor (AF) of 2.984 at 50 mg L-1 in nano-form. Iron oxide absorption was found linearly related with concentration in both cases (y = 11.313x-12.165, R2 = 0.8691 in nano; y = 6.35x-5.74, R2 = 0.8128 in bulk). However, 50-mg L-1 nanoparticle concentration was perceived sub-lethal for the algae with 33.33% algal growth reduction under nano and 27.77% under bulk counterpart. Other biochemical parameters, i.e., SOD, CAT, MDA, and lipid quantification, were also quantified to correlate the state of metabolism of treated algal cells in comparison to the control and these exhibited reduction in algal growth due to oxidative stress. Morphological changes were monitored through SEM and TEM.

Up-regulation of fibroblast growth factor receptor 1 due to prenatal tobacco exposure can lead to developmental defects in new born.

Introduction: Tobacco-smoking is one of the most important risk factor for preterm delivery, pregnancy loss, low birth weight, and fetal growth restriction. It is estimated that approximately 30% of growth-restricted neonates could be independently associated with maternal smoking.Methods: In this study, gene expression profile, GSE11798, was chosen from GEO database with an aim to perceive change in gene expression signature in new born due to maternal smoking. Enrichment analysis was performed to annotate differentially expressed genes (DEGs) through gene ontology and pathway analysis using DAVID. Protein-protein interactions and module detection of these DEGs were carried out using cytoscape v3.6.0. Thirty umbilical cord tissue samples from 15 smokers and 15 non-smokers pregnant women were included in this analysis.Results: Twenty-six differentially expressed genes (DEGs) between two groups were selected using GEO2R tool. The DEGs were observed to be participating in biological processes/pathways related to growth releasing hormone, angiogenesis, embryonic skeletal, and cardiac development. Fibroblast growth factor receptor-1 (FGFR1) was identified to be the hub node with 348 interacting partners, which regulates transcription, cell growth, differentiation, and apoptosis. The up-regulation of FGFR1 in umbilical cord tissue may lead to reproductive and developmental complications such as encephalocraniocutaneous lipomatosis, osteoglophonic dysplasia, and Pfeiffer syndrome in new-borns.Conclusion: The findings manifests the possibility of overcoming these adverse health effects in new born through FGFR1 modulating treatments during pregnancy.

Toxicity assessment of ZnO nanoparticles to freshwater microalgae Coelastrella terrestris.

Commercial usage of ZnO nanoparticles has increased recently due to its versatile applications, raising serious environmental concern because of its ultimate release of nanoparticles in aquatic ecosystem. Therefore, it is important to understand the impact of ZnO nanoparticle toxicity especially on algal flora, which is the primary producer in the aquatic food chain. In the current study, algal growth kinetics was assessed after the exposure of zinc oxide nanoparticles and its bulk counterpart to Coelastrella terrestris (Chlorophyceae). Zinc oxide nanoparticles were found to be more toxic (y = 34.673x, R2 = - 0.101, 1 mg L-1 nanoparticle (NP)) than bulk (y = 50.635x, R2 = 0.173, 1 mg L-1 bulk) by entrapping the algal cell surface. Higher toxicity may be due to oxidative stress within the algal cell as confirmed through biochemical analysis. Biochemical parameters revealed stressful physiological condition in the alga under nanoparticle exposure, as lactate dehydrogenase release (18.89 ± 0.2 NP; 13.67 ± 0.2 bulk), lipid peroxidation (0.9147 ± 1.2 NP; 0.7480 ± 0.8 bulk), and catalase activity (4.77 ± 0.1 NP; 3.32 ± 0.1 bulk) were found higher at 1 mg L-1 in the case of nano-form. Surface adsorptions of nanoparticles were observed by SEM. Cell organelle damage, cell wall breakage, and cytoplasm shrinkage were found as responses under toxic condition through SEM and TEM. Toxicity was found to be influenced by dose concentration and exposure period. This study indicates that nano-form of ZnO is found to be more toxic than bulk form to freshwater alga.

Ornamental plants as sinks and bioindicators.

Mitigation of urban air pollution is a big challenge, especially for the metropolitan cities of the world. In an Indian metropolis like Delhi, even after the implementation of several control policies, no such remarkable change has been observed in its air quality. Globally, afforestation or greenbelt development is an effective and well-recognized pollution abatement process. The aim of our present study was to examine the biochemical response of some naturalized ornamental plant species, viz. Dracaena deremensis, Tagetes erecta, Rosa indica and Dianthus caryophyllus. During experimental study, plants were kept at selected sites which were categorized in terms of traffic density (emission source) and vegetative pattern during winter months for 120 days. Four biochemical parameters, viz. total chlorophyll, ascorbic acid, pH, relative water contents along with Air Pollution Tolerance Indices were determined from foliar samples at each selected site. D. deremensis and T. erecta were classified under tolerant while R. indica and D. caryophyllus were marked as in sensitive category. Based on the sensitivity of selected plant species, it has been recommended that D. deremensis and T. erecta may be used as sinks for the abatement of air pollution at highly polluted sites whereas R. indica and D. caryophyllus can be used as bioindicators.