Banerjee D.,University of Burdwan |
Das P.P.,Asansol Mines Board of Health |
Fouzdar A.,West Bengal Pollution Control Board
Journal of Urban Health | Year: 2014
Results from studies involving exposure to road traffic noise and risk of hypertension are diverse and have seldom reached statistical significance. This study was designed with the aim of investigating whether there is any association between road traffic noise and prevalence of hypertension in an urban adult population. Similar studies have never been reported from India. A cross-sectional study was performed on 909 adults (533 female and 376 male) aged 18–80 years residing in close proximity to roadways in Asansol City. Time-weighted equivalent noise level (Lden) was estimated using a standard modeling platform. Odds for hypertension in relation to traffic noise exposure were estimated by univariate and multifactorial logistic regression. The adjusted odds ratio (OR) for self-reported hypertension was 1.99 (95 % confidence interval (CI) 1.66–2.39) per 5 dB(A) increase of Lden (range 55.1–77.9). A gender-related risk difference was observed among the male (OR 1.81 (1.42–2.31)) and female (OR 2.18 (1.66–2.88)) respondents. For increase in 9 years of age, the odds of hypertension risk increased by 60 % (OR 1.66 (1.43–1.91) among those exposed above Lden 60 dB(A). Vulnerable subgroups were female aged 35–54 years and male aged 45–54 years. The study suggests that a threshold exposure to road traffic noise at Lden > 65 dB(A) for men and Lden > 60 dB(A) in women may be associated with the occurrence of hypertension. © 2014, The New York Academy of Medicine.
Chatterjee A.,Bose Institute of India |
Sarkar C.,Bose Institute of India |
Adak A.,Bose Institute of India |
Mukherjee U.,West Bengal Pollution Control Board |
And 2 more authors.
Aerosol and Air Quality Research | Year: 2013
The effects of fireworks on air quality was assessed from the ambient concentrations of PM10, water soluble ionic species, metals and SO2 over Kolkata metropolis, India during Diwali festival in November 2010. PM10 concentrations on Diwali night were found to be ~5 times higher than the normal day night-time average. The increase in night-time concentrations of the metals on Diwali night spanned over a wide range (Al, Zn, Pb and Cd showed 5-12 times increases, Cu, Fe and Mn showed 25-40 times and Co and V showed 70-80 times) compared to normal night-time concentrations. The water soluble ionic species showed 1.5-6 times higher concentrations on Diwali night than on normal days. The most significant increases were found for K+, Ca2+, Mg2+ and SO4 2-. The diurnal variations in PM10 and SO2 were also studied at one of the sites, and the results showed that their maximum concentrations were on Diwali night between 8 P.M.-3 A.M., indicating maximum firework activities during this period. PM10 and SO2 concentrations increased by ~5 times compared to those on normal days during this period at this site. The extensive use of firecrackers during Diwali festival thus leads to significant increases in these air pollutants, and since they are associated with serious, adverse health impacts, the use of fireworks during in this kind of festival in a highly populated city, like Kolkata, India, needs to be controlled. © Taiwan Association for Aerosol Research.
Riaz N.,Petronas University of Technology |
Riaz N.,COMSATS Institute of Information Technology |
Chong F.K.,Petronas University of Technology |
Man Z.B.,Petronas University of Technology |
And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2013
Bimetallic Cu-Ni/TiO2 photocatalysts were prepared at different temperatures with varying Cu:Ni mass compositions. The photocatalysts were further calcined at selected temperatures. Characterization procedures were carried out on the photocatalysts to understand the correlation between the photocatalytic activity and the physicochemical and morphological properties. Results from the XRD, FESEM-EDX mapping, and HRTEM analyses were in favor of the metal particles existing in the form of well-dispersed oxides on TiO 2 surface. The surface area of the photocatalysts was almost similar to the bare TiO2 ∼43 m2 g-1 except for 1Cu:9Ni-200-b observed with a higher surface area (53.8 m2 g -1) as compared to other photocatalysts. The photocatalyst performance of the bimetallic system is promising as compared to bare TiO 2 and the monometallic photocatalysts. Results for photodegradation studies showed that 1:9 Cu:Ni mass composition was observed with 100% Orange II removal as compared to other Cu:Ni mass compositions. The 1Cu:9Ni-200-a photocatalyst prepared at lower temperature (8-10 C) displayed 100% Orange II decolorization as compared to 1Cu:9Ni-200-b (prepared at higher temperature of 25 C) with 65.1% dye removal. Although the results from UV-vis spectra showed the disappearance of the visible band (indicating 100% Orange II removal), TOC analysis indicated the presence of organic compounds derived from the dye degradation process. Therefore, longer irradiation time is required to break the chromophore groups in the degradation intermediates to obtain 100% TOC removal. © 2013 American Chemical Society.
Basu M.,Indian School of Mines |
Gupta S.K.,Indian School of Mines |
Singh G.,Indian School of Mines |
Mukhopadhyay U.,West Bengal Pollution Control Board
Environmental Monitoring and Assessment | Year: 2011
The main objectives of this study were to investigate the concentration and lifetime cancer risk and hazard index of trihalomethanes (THMs) through multiple routes like oral ingestion, dermal absorption, and inhalation exposure in the water samples collected at water treatment plant endpoints. Bromoform has been found in highest concentration followed by chloroform. A lesser concentration of dibromochloromethane has been found than dichlorobromomethane in most of the studied water, which is an unusual scenario, in spite of the high concentration of bromide in the water which can be attributed to the formation, speciation, and distribution of THMs in the breakpoint chlorination curve. Among the three pathways studied, inhalation contributed 80-90% of the total risk followed by oral exposure and dermal contact. Chloroform was found to be the major THM which is having cancer risk in its gaseous form whereas bromoform contributed highest cancer risk through oral ingestion. The average hazard index of total THMs through oral route was higher than unity, indicating high noncarcinogenic risk. The discrepancy between the three exposure pathways may be attributed to different concentration and speciation of THMs present in the waters. The sensitivity analysis by tornado diagram confirmed the highest positive impact of chloroform to the total cancer risk and, indirectly, confirmed inhalation as the major pathway of exposure. This study suggests the modification of the regulatory issues related to THMs based on the health risk associated with each THM and exposure pathway. © 2010 Springer Science+Business Media B.V.
Chatterjee S.,Indian Association for The Cultivation of Science |
Das S.K.,Indian Association for The Cultivation of Science |
Chakravarty R.,Indian Association for The Cultivation of Science |
Chakrabarti A.,Indian Association for The Cultivation of Science |
And 2 more authors.
Journal of Hazardous Materials | Year: 2010
Adsorption of malathion on Rhizopus oryzae biomass (ROB) with special reference to binding mechanism has been described. ROB has been found to adsorb ∼85% of malathion from its aqueous solution as against 47-68% by other fungal biomasses. Hydrogen ion concentration does not influence the adsorption of malathion by ROB which follows Langmuir-Freundlich dual equilibrium isotherm model (r2 = 0.998). Both physical and chemical interactions are responsible for binding of malathion on ROB. Scanning electron micrographs and EDXA spectra exhibit adsorption of the pesticide on cell surface of ROB. Studies with cell surface polysaccharides show that chitosan through its amine groups contributes largely in the adsorption of malathion. Extraction of lipids from ROB decreases its adsorption capacity to the extent of 36.37-94.02%, depending on the polarity of the solvent. © 2009 Elsevier B.V. All rights reserved.
Narahari M.,Petronas University of Technology |
Dutta B.K.,West Bengal Pollution Control Board
Chemical Engineering Communications | Year: 2012
The effects of thermal radiation and mass transfer on unsteady natural convection flow of an optically dense viscous incompressible fluid near a vertical plate with Newtonian heating have been investigated. Both physically important boundary conditions of uniform wall concentration (UWC) and uniform mass flux (UMF) are considered. Rosseland diffusion approximation is used to describe the radiative heat flux in the energy equation. The governing dimensionless boundary layer equations are solved analytically using the Laplace transform technique. The effects of mass to thermal buoyancy ratio parameter (N), Prandtl number (Pr), Schmidt number (Sc), and the radiation parameter (R) as well as time (t) on the velocity field and skin friction are determined. It is found that velocity increases for aiding flows and it decreases for opposing flows in the cases of both UWC and UMF. The skin friction is reduced with increasing species concentration in the presence of aiding flows for both UWC and UMF. Also, the velocity is greater in the case of UWC than the case of UMF at an early time, whereas the velocity is slightly greater in the case of UMF than that of UWC at a later time in the vicinity of the plate. © 2012 Taylor and Francis Group, LLC.
Mandal P.K.,West Bengal Pollution Control Board |
Bandyopadhyay A.,University of Calcutta
Environmental Quality Management | Year: 2013
Measuring the effects of environmental policies in rapidly changing urban settings ©2013 Wiley Periodicals, Inc.
Bhattacharyya A.,Jadavpur University |
Saha J.,Jadavpur University |
Haldar S.,Jadavpur University |
Bhowmic A.,West Bengal Pollution Control Board |
And 2 more authors.
Extremophiles | Year: 2014
Haloferax mediterranei holds promise for competitive industrial-scale production of polyhydroxyalkanoate (PHA) because cheap carbon sources can be used thus lowering production costs. Although high salt concentration in production medium permits a non-sterile, low-cost process, salt disposal after process completion is a problem as current environmental standards do not allow total dissolved solids (TDS) above 2000 mg/l in discharge water. As the first objective of this work, the waste product of rice-based ethanol industry, stillage, was used for the production of PHA by H. mediterranei in shake flasks. Utilization of raw stillage led to 71 ± 2 % (of dry cell weight) PHA accumulation and 16.42 ± 0.02 g/l PHA production. The product yield coefficient was 0.35 while 0.17 g/l h volumetric productivity was attained. Simultaneous reduction of BOD5 and COD values of stillage by 83 % was accomplished. The PHA was isolated by osmotic lysis of cells, purification by sodium dodecyl sulfate and organic solvents. The biopolymer was identified as poly-3-(hydroxybutyrate-co-15.4 mol%-hydroxyvalerate) (PHBV). This first report on utilization of rice-based ethanol stillage for PHBV production by H. mediterranei is currently the most cost effective. As the second objective, directional properties of decanoic acid together with temperature dependence of water solubility in decanoic acid were applied for two-stage desalination of the spent stillage medium. We report for the first time, recovery and re-use of 96 % of the medium salts for PHA production thus removing the major bottleneck in the potential application of H. mediterranei for industrial production of PHBV. Final discharge water had TDS content of 670 mg/l. © 2014 Springer Japan.
Banerjee D.,University of Burdwan |
Das P.P.,Asansol Mines Board of Health |
Foujdar A.,West Bengal Pollution Control Board
Environmental Monitoring and Assessment | Year: 2014
There is an established evidence that exposure to high levels of road traffic noise is associated with elevated risk of coronary heart disease (CHD). The results however have been heterogeneous and mostly inconclusive. The present investigation aimed to examine this association in adult subjects, with a secondary aim of identifying potentially vulnerable sub-populations. Similar studies have never been reported from Indian population. For exposure assessment, the time-weighted road traffic noise indicator, L den, was used as a continuous and categorical predictor. A cross-sectional study was designed, and sociodemographic and lifestyle- and health-related characteristics were recorded for 909 (533 females and 376 males) subjects aged 18-80 years. The respondents living in areas with L den<60 dB(A) were designated as the reference group. Odds for self-reported CHD in relation to traffic noise exposure were estimated by univariate and multifactorial logistic regression with adjustments for potential confounders and effect modifiers. The adjusted odds ratio (OR) for self-reported CHD was 1.72 (95 % CI 1.36-2.19) per 5 dB(A) increase of L den (range 55-80 dB(A)). A gender-related risk difference was observed among male (OR 1.47 (1.07-2.02)) and female (OR 1.83 (1.27-2.65)) respondents. A stronger effect for subjects in the age group 55-64 years old was found, with age, residence period, body mass index, and self-reported stress being significant confounders. This study suggests epidemiological evidence that exposure to road traffic noise of L den>65 dB(A) may be associated with occurrence of CHD in adult subjects. A trend was observed indicating increasing risk with higher exposure levels. The study results are also suggestive of higher risk of outcome among those with other chronic ailments (diabetes, pulmonary, or renal issues) and residing in the same location in excess of 15 years. Orientation of bedroom windows was identified as a significant effect modifier. © 2013 Springer Science+Business Media Dordrecht.
Nasir R.,Petronas University of Technology |
Mukhtar H.,Petronas University of Technology |
Man Z.,Petronas University of Technology |
Dutta B.K.,West Bengal Pollution Control Board |
And 2 more authors.
Journal of Membrane Science | Year: 2015
Mixed matrix membranes (MMMs) containing diethanolamine (DEA) and carbon molecular sieve (CMS) in polyethersulfone (PES) were synthesized and characterized to study the efficiency of CO2 separation from CH4. The membranes were fabricated by adding fixed amount of CMS and polymer into a solvent with DEA at different concentrations. These membranes were characterized for physicochemical properties by employing field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The permeability and selectivity studies were carried out by using pure carbon dioxide and methane in a small laboratory test cell. The characterization results revealed that the structure of the membranes was dense and non-porous. It was also found that carbon molecular sieve was uniformly distributed in the polymer matrix. The addition of DEA significantly enhanced the performance of the investigated MMMs such that the CO2 permeance and CO2/CH4 selectivity were enhanced up to 172.41% and 283.21% respectively at a pressure of 6bar. A comparison with the performance of a few other membranes decisively establishes the superiority of the membranes prepared and tested in this study. © 2015 Elsevier B.V.