Amit Kumar

Assessment of indoor air concentrations of VOCs and their associated health risks in the library of Jawaharlal Nehru University, New Delhi

The present work investigated the levels of total volatile organic compounds (TVOC) and benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene (BTEX) in different microenvironments in the library of Jawaharlal Nehru University in summer and winter during 2011–2012. Carcinogenic and non-carcinogenic health risks due to organic compounds were also evaluated using US Environmental Protection Agency (USEPA) conventional approaches. Real-time monitoring was done for TVOC using a data-logging photo-ionization detector. For BTEX measurements, the National Institute for Occupational Safety and Health (NIOSH) standard method which consists of active sampling of air through activated charcoal, followed by analysis with gas chromatography, was performed. Simultaneously, outdoor measurements for TVOC and BTEX were carried out. Indoor concentrations of TVOC and BTEX (except benzene) were higher as compared to the outdoor for both seasons. Toluene and m/p-xylene were the most abundant organic contaminant observed in this study. Indoor to outdoor (I/O) ratios of BTEX compounds were generally greater than unity and ranged from 0.2 to 8.7 and 0.2 to 4.3 in winter and summer, respectively. Statistical analysis and I/O ratios showed that the dominant pollution sources mainly came from indoors. The observed mean concentrations of TVOC lie within the second group of the Molhave criteria of indoor air quality, indicating a multifactorial exposure range. The estimated lifetime cancer risk (LCR) due to benzene in this study exceeded the value of 1u2009×u200910−6 recommended by USEPA, and the hazard quotient (HQ) of non-cancer risk came under an acceptable range.

Antihyperglycemic activity with DPP-IV inhibition of alkaloids from seed extract of Castanospermum australe: Investigation by experimental validation and molecular docking.

The antidiabetic actions of Castanospermum australe Cunn., seed (CAS) extract were evaluated in Poloxamer-407 (PX-407) induced T2DM rats. The CAS extract (100 and 150 mg/kg body weight) was administered orally once a day for 5 weeks after the animals were confirmed diabetic. A significant increase in blood glucose, HbA₁c and serum insulin levels were observed in T2DM rats in comparison to citrate control rats. Treatment with CAS extract in T2DM rats reduced the elevated levels of blood glucose, HbA₁c and insulin with significant (p≤0.001) improvement in OGT. The CAS extract treatment also increased (p≤0.001) the K(ITT) and prevented increase in HOMA-R level in T2DM rats. The DPP-IV inhibitory potential of CAS extract showed IC₅₀ value of 13.96 μg/ml whilst the standard Diprotin A displayed the IC₅₀ value of 1.543 μg/ml. Molecular docking of the three reported alkaloids from the seeds of C. australe showed comparable DPP-IV inhibition with berberine. Our data suggest that CAS extract (150 mg/kg body weight) normalizes hyperglycemia in T2DM rats with strong DPP-IV inhibitory potential. The molecular docking showed that among the three alkaloids of seed extract 7-Deoxy-6-epi-castanospermine is a potent DPP-IV inhibitor similar to berberine.

Determination of volatile organic compounds and associated health risk assessment in residential homes and hostels within an academic institute, New Delhi

The purpose of this study was to investigate the concentrations of volatile organic compounds (VOCs) in different indoor microenvironments of residential homes and hostels in an academic institute, in New Delhi, during March-May 2011. Eleven VOCs (aromatic and halogenated) were assessed. Sampling and analytical procedure were based on National Institute for Occupational Safety and Health (NIOSH) standard method. The lifetime cancer and non-cancer risk were calculated for targeted VOCs using US Environmental Protection Agency guidelines. The mean concentrations of ∑ VOCs (sum of monitored VOCs) and individual VOC were found to be higher indoors as compared to outdoors at both types of premises. Indoor to outdoor (I/O) ratios of the targeted VOCs exceeded 1.0, suggesting the significant presence of indoor sources. Strong correlations between I/O concentrations of VOCs in the current study suggest the presence of common sources. Factor analysis (FA) was used for source evaluation separately at two premise types. The estimated lifetime cancer risks in the current study for all occupants at both premises exceeded 10(-6) .

An assessment of ozone levels, UV radiation and their occupational health hazard estimation during photocopying operation.

This study investigates the levels of ozone concentration along with an ultraviolet (UV) and visible spectral radiation at eight photocopy centers in an academic institute, Delhi. Sampling was done in two types of locations, i.e., basement photocopy centers (BPC) and ground floor photocopy centers (GPC) for 8h. Measurements of levels of ozone, UV and visible radiation were done by ozone analyzer, UV radiometer and Field spectra instrument, respectively. Results show that the hourly mean concentration of ozone was observed to be in the range of 1.8-10.0 ppb and 5.3-45.8 ppb for BPC and GPC, respectively. In terms UV radiations, energy lies between 5.0×10(-3) and 7.0×10(-3) mW/cm(2) for ultraviolet A (UVA), 1.0×10(-3) and 2.0×10(-3) mW/cm(2) for ultraviolet B (UVB) and 6.0×10(-3) and 8.0×10(-3) mW/cm(2) for ultraviolet C (UVC). Correlation between the UV radiations and ozone production observed was statistically insignificant. To know the health hazard occurred to the workers, the standard erythema dose (SED) value was calculated for emitting UV radiation. The SED was estimated to be in the range of 0.02-0.04 and 0.02-0.32 for direct and indirect methods which is less than the guideline prescribed by Commission Internationale del Eclairage (CIE). In nutshell, person involved in photocopy operation for their livelihood must be trained and should have knowledge for the long term gradual build up health problems due to ozone and UV production from photocopier. The manufactures should be ultimated with the significant ozone production, so that photocopier machine can be redesigned.

Spatial and temporal variability of surface ozone and nitrogen oxides in urban and rural ambient air of Delhi-NCR, India

Ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), and nitrogen oxides (NOx) were measured continuously at three sites viz. urban background (JN), urban/traffic (CP), and rural (DP) in Delhi-NCR during the years 2013–2014. Meteorological parameters (temperature and relative humidity) were also measured in order to evaluate the relationship with targeted pollutants. The study shows that highest concentration of O3 was in summer while the lowest ones were recorded in winter and autumn for all the three sites. However, the level of NOx was observed maximum in CP (22.6xa0ppb) during winter and minimum in DP (5.3xa0ppb) during autumn. The diurnal variation of O3 was characterized by day-time maxima/(night-time minima) having concentrations 50.2/(17.2), 46.1/(15.7), and 56.7/(23.6)u2009ppb at JN, CP, and DP, respectively. Distinct differences in concentrations were observed for O3 and its precursors during weekends and weekdays for all the three sites. The analysis revealed that higher/(lower) levels of O3 were observed during weekend/(weekdays). The moderate weekend effect was noticed for all the three sites but highest at rural site; DP.O3 was negatively correlated to RH and NOx, while it was positively correlated to temperature. The observed mean concentrations of O3 and NO2 were found to be below the recommended guideline values established by WHO and the European Union.

Antidiabetic activity and molecular docking of fructooligosaccharides produced by Aureobasidium pullulans in poloxamer-407-induced T2DM rats.

This study evaluated the beneficial effects of fructooligosaccharide (FOS) intake from Aureobasidium pullulans using poloxamer-407 (PX-407) induced type 2 diabetes mellitus (T2DM) in rat. Administration of FOS enhanced enzymatic activities of catalase and glutathione reductase in a dose-dependent manner. Significant reduction in fasting plasma triacylglycerol and very low-density lipoprotein level coupled with slight increase in fasting plasma insulin level was observed. Significant decrease in severe glucosuria, proteinuria, blood creatinine, urea and advanced glycation end products was also observed. Supplementation of FOS increased glucagon like peptide-1 content as well as Bifidobacteria and Lactobacilli populations in the caecum. Molecular docking by Gold and Glide software revealed that three sugar types present in the FOS (1-kestose, nystose, and 1-β-fructofuranosyl nystose) are potent dipeptidyl peptidase-IV inhibitors as well as peroxisome proliferator-activated receptor-gamma agonists. This work indicates that FOS can be positioned as a nutraceutical product, beneficial in diabetes-associated metabolic abnormalities.

Spatial and temporal variability of VOCs and its source estimation during rush/non-rush hours in ambient air of Delhi, India

The present study deals with the concentrations of individual and total volatile organic compounds (TVOCs) present in the ambient atmosphere of Delhi. Sampling was done in four different zones, viz. residential, commercial, industrial and heavy traffic density area (HTDA) during rush and non-rush hours. The National Institute for Occupational Safety and Health (NIOSH)-1501 standard method was used for benzene, toluene, ethylbenzene and xylene (BTEX) measurements while real-time monitoring was done for TVOC using a data-logging photoionization detector. Results showed that the mean concentrations of TVOC and ∑BTEX were found to be highest in HTDA as compared to those in other zones. Toluene contributed the most among BTEX as 28.5, 108.6, 129.6 and 104.5xa0μg/m3 at residential, commercial, industrial and HTDA, respectively. However, the concentrations of TVOC were found to be 518.9xa0μg/m3 in HTDA followed by industrial (511.3xa0μg/m3), commercial (429.6xa0μg/m3) and residential areas (199.5xa0μg/m3). It is noted that the concentrations of the pollutants were observed to be higher during rush hours in contrast to non-rush hours due to more number of vehicles plying the road. After examining the seasonal variability, the winter samples showed the highest concentrations of the pollutants which could be due to stable environment. In order to identify the sources, characteristic ratios and correlation analysis were also done. Cancer and non-cancer risks were estimated for BTEX using US Environmental Protection Agency (USEPA) guidelines. The estimated lifetime cancer risk (LCR) in this study exceeded the value of 1.0u2009×u200910−6 recommended by the USEPA for adults and children in all zones. The population groups are in the category of “possible risk” after comparing with the Sexton’s classifications of cancer risk.

OsAlba1, a dehydration-responsive nuclear protein of rice (Oryza sativa L. ssp. indica), participates in stress adaptation.

Alba proteins have exhibited great functional plasticity through the course of evolution and constitute a superfamily that spans across three domains of life. Earlier, we had developed the dehydration-responsive nuclear proteome of an indica rice cultivar, screening of which led to the identification of an Alba protein. Here we describe, for the first time, the complete sequence of the candidate gene OsAlba1, its genomic organization, and possible function/s in plant. Phylogenetic analysis showed its close proximity to other monocots as compared to dicot Alba proteins. Protein-DNA interaction prediction indicates a DNA-binding property for OsAlba1. Confocal microscopy showed the localization of OsAlba1-GFP fusion protein to the nucleus, and also sparsely to the cytoplasm. Water-deficit conditions triggered OsAlba1 expression suggesting its function in dehydration stress, possibly through an ABA-dependent pathway. Functional complementation of the yeast mutant ΔPop6 established that OsAlba1 also functions in oxidative stress tolerance. The preferential expression of OsAlba1 in the flag leaves implies its role in grain filling. Our findings suggest that the Alba components such as OsAlba1, especially from a plant where there is no evidence for a major chromosomal role, might play important function in stress adaptation.

Dynamic interaction of trace gases (VOCs, ozone, and NOx) in the rural atmosphere of sub-tropical India

The atmospheric chemistry and health implications of pollutants are important scientific concerns in the rural atmosphere. The current study investigates the estimation of seasonal and diurnal variability of VOCs, ozone, and NOx in the rural area located in a tropical region of India during the year 2013–2014. Results showed that most of the targeted VOCs were higher in winter followed by summer and autumn. The diurnal variability of aromatic hydrocarbons showed similar pattern with different amplitudes as maxima and minima during morning (07:00–10:00xa0h) or evening (16:00–19:00xa0h) and daytime (10:00–16:00xa0h), respectively. The sum of aromatic VOCs are found to be in the range from 27.3 to 87.9xa0μg/m3. In addition to this, O3 and NOx were observed as 45.04xa0±xa015.19xa0μg/m3 and 12.41xa0±xa03.49xa0μg/m3, respectively, during the observation period. The estimated VOC/NOx ratios (ranged from 3.4 to 3.7) indicated that the selected rural area was VOC limited in terms of ozone sensitivity. The sources of the VOCs have been explained by characteristic ratios, correlation, and principal component analysis. Further, ozone-forming potential (OFP) of the targeted aromatic VOCs has been evaluated using maximum incremental reactivity which suggested toluene (benzene) contributed the largest (lowest) in the ozone formation. Exposure assessment in terms of lifetime cancer and non-cancer risks lies within the acceptable range of USEPA guidelines.

Distribution of VOCs in urban and rural atmospheres of subtropical India: Temporal variation, source attribution, ratios, OFP and risk assessment

This paper reports the first study which comprises the seasonal, diurnal variability, source characterization, ozone forming potential and risk assessment of volatile organic compounds (VOCs) at three sites (two urban and one rural) in the National Capital Territory of Delhi, India. The study was performed during three seasons of the year 2013-14 and two different categories of VOCs (aromatics and halogenated) have been selected. The study used the sampling and analytical procedures of NIOSH methods. Results showed that the mean concentration of sum of VOCs (∑VOC) is significantly higher at urban sites (110.0 and 137.4μg/m3 for JN and CP, respectively) as compared to the rural site, DP (56.5μg/m3). The contribution of individual to total VOC concentrations is noticed to be very similar at all the three sites. Most of the VOCs are observed to be significantly higher in winter followed by summer and autumn. Diurnal cycles of aromatic VOCs are highly influenced by the vehicular traffic and photochemical oxidations which showed higher and lower levels during morning/evening and daytime, respectively. Diagnostic ratios of the toluene/benzene (ranged from 0.65 to 13.9) infers the vehicular traffic might be the main contributing source in the urban sites while xylene/benzene ratio (ranged from 0.7 to 2.8) confirms the VOCs are transported to rural site from the nearby urban areas. Correlation and factor analysis suggested the sources are group of different species (traffic emissions, solvent usage and industrial) rather than single gas. The analysis of reactivity in terms of Prop-Equiv concentrations and ozone forming potential indicated that m/p-xylene and toluene are the main VOC contributing to the total ozone formation in urban and rural sites, respectively. Hazard ratios and lifetime cancer risk values exceeded the permissible standards established by USEPA and WHO suggests that the people are at significant risk.