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Biomedical subjects

S Sadasivan

Publications and source records attributed to S Sadasivan.

17 recordsLinked to original sources
PubMed2004

Precipitation scavenging of polycyclic aromatic hydrocarbons in Mumbai, India.

The concurrent rain and air sampling was conducted for thirteen rain events between the last week of May and end of June 2001. Concentration of total PAHs varied from 84.25 to 777.49 ng/l whereas that in air was in the range of 4.05 to 34.42 ng/m(3). In rainwater the lower molecular weight PAHs (e.g. Phenanthrene, Fluoranthene and Pyrene) were found to be more prominent than the higher molecular weight compounds. The gas phase scavenging ratio (Wg) was found to increase with the molecular weight of the compound. The particle phase scavenging ratio (Wp) values for the more volatile PAHs were generally much higher than those for less volatile PAHs. The higher MW PAHs have Wg values equal to or larger than their Wp values.

Journal Article↗
PubMed2003

Geochronology of Pb and Hg pollution in a coastal marine environment using global fallout 137Cs.

Global fallout 137Cs was used for dating sediment cores and estimation of recent sedimentation rates (up to 1 cm/y) in the Thane Creek, which lies in the southern part of the Deccan belt of India. The residence time of 210Pb in the Thane Creek water was calculated to be 0.7 years. Further, the concentrations of Pb (up to 70 microg/g) and Hg (up to 10 microg/g) in sediment profiles were measured to assess the anthropogenic input of contaminants due to large-scale industrialization, which has taken place in this area over the last two decades. The depth-wise concentration profile of Hg shows positive evidence of continued fresh input into the Creek.

Ecosystem↗
PubMed2002

Daily intake of aluminium by adult population of Mumbai, India.

Electrothermal atomic absorption spectrophotometry (ET-AAS) has been used for the determination of Al in environmental and food samples with a detection limit of 0.3 ng ml(-1). The reliability of estimation is assessed through the analysis of Standard Reference Materials (IAEA SRMs) of Soil-7, SL-3, SD-M2/TM and Hay (V-10). The results indicate that the average concentration of aluminium in air particulate samples is 5.3 microg m(-3). The daily intake of Al by the adult population of Mumbai is 6.4 mg day(-1).

Adult↗
PubMed2002

Selenium levels in biological matrices in adult population of Mumbai, India.

Selenium (Se) levels in whole blood, serum, urine, muscle and saliva of Mumbai adults have been estimated by differential pulse cathodic stripping voltammetry (DPCSV); the detection limit of Se is 0.05 ng ml(-1). The reliability of estimation is further assessed through the analysis of Standard Reference Materials. The Se levels in whole blood (n = 35) and blood serum (n = 201) of the Mumbai adult population is 99.6 and 100 ng ml(-1); approximately 34.8% of the population have serum Se levels between 80 and 100 ng ml(-1). The blood serum levels of Se for Mumbai adults are comparable to those of whole blood. The mean concentration of Se in urine on a 24-h basis is 5.2 ng ml(-1). Muscle and saliva of the Mumbai adult population contain 195.4 ng g(-1) and 2 ng ml(-1) of Se, respectively. A good correlation between serum Se and dietary Se is observed with a correlation coefficient of 0.89.

Adult↗
PubMed2002

Atmospheric dust loads and their elemental composition at a background site in India.

Air particulate samples collected during 1995-96 at a background site situated on the east coast of Thar Desert in Rajsthan State of India were analysed for atmospheric dust loads (Suspended Particulate Matter) and elemental composition. The values of SPM ranged from 9 microg M(-3) to 97 microg M(-3) with an average of 43 microg M(-3) except a few episodic values, which were 3 to 5 times higher than the average during summer months. The results for elemental composition of the particulate samples showed that the concentrations of anthropogenic toxic trace elements viz. Br, Cr, Pb, Sb, Se and Zn are lower by a factor of 2 to 10 as compared to urban areas. The high enrichment factors for anthropogenic elements viz. Br, Pb, Sb and Zn show an input from coal/wood fuel burning and vehicular pollution at the sampling site. The depletion of Si in SPM samples shows long distance transport of dust to the sampling site.

Air Pollutants↗
PubMed2002

Behaviour and fluxes of trace and toxic elements in creek sediment near Mumbai, India.

Studies on marine sediments are extremely important since they act as ultimate sink of anthropogenic pollutants. The present study was conducted near Mumbai city of India to understand and assess the behaviour and fluxes of trace and toxic elements in creek sediment. Seven sediment core samples were collected and analysed for trace and toxic elements such as Fe, Cu, Pb, Zn, Rb and Sr in different sections of the core using EDXRF technique. The fluxes of the elements in each section of the core were calculated using the mass sedimentation rates derived from 210Pb dating technique and the sediment density at each location. The estimated depositional fluxes of Fe, Rb and Sr in Zone-1 and Zone-3 are in the ranges of 0.4-0.5% cm(-2) yr(-1); 4-6 microg cm(-2) yr(-1) and 10-20 microg cm(-2) yr(-1) respectively, where as they were about 3-4 times higher in zone-2 for the same elements. The depositional fluxes of elements Cu (40-60 microg cm(-2) yr(-1)), Zn (35-43 microg cm(-2) yr(-1)) and Pb (6-12 microg cm(-2) yr(-1)) were also found to be higher in zone-2 compared to zone-1 and zone-3 which can be attributed to the release from the newly developed chemical zone of Thane-Belapur industrial belt.

Environmental Monitoring↗
PubMed2002

Heavy metal concentration and distribution in a dated sediment core of Nainital Lake in the Himalayan region.

The concentrations and distribution of the elements, including heavy metals such as As, Ba, Br, Co, Cr, Cs, Fe, Ga, K, Mn, Na, Rb, Sc, Sr, Th and Zn, were investigated in dated sediment cores of Nainital Lake located in the Himalayan region, in Uttar Pradesh state of India, which is considered as a remote background area. The concentrations of the elements were measured by instrumental neutron activation analysis using the k0 method. The International Atomic Energy Agency certified reference material SL-3 was used to evaluate the accuracy of the method. The normalized data for a series of elements were used to understand the source of loading. Elements like Br, Co, Cr, Fe, K, Mn and Zn show a negative correlation with increasing depth whereas elements like As, Ba, Cs, Na and Rb show a positive correlation with increasing depth. By considering the concentration for the bottom segments of the core as close to the baseline concentration, recent flux values for different elements were calculated. An increase in the flux value was observed for Br, Cr, Fe, K, Mn and Zn, which can be attributed to anthropogenic contribution in recent years.

Environmental Monitoring↗
PubMed2002

Distribution of HCH and DDT in the coastal marine environment of Mumbai, India.

Organochlorine pesticides (OCPs) in sediment, water and biota samples from the coastal marine environment of Mumbai were analysed to elucidate their distribution in various environmental compartments. HCH isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites were the predominantly identified compounds in all the samples. High ratios of DDT to dichlorodiphenyldichloroethylene (DDE) were found in seawater samples. This indicates the presence of a significant source of DDT in this region. In sediment samples, the gamma-isomer contributed almost 55% to the total HCH, indicating a high affinity of the gamma-isomer towards the sediment. The levels of organochlorines in fish obtained from this region were found to be lower than the levels of organochlorines in fish in temperate regions.

Animals↗
PubMed2001

Blood lead and its effect on Cd, Cu, Zn, Fe and hemoglobin levels of children.

The levels of heavy metals, such as Pb, Cd, Cu, Zn and Fe, in whole blood samples of Mumbai and Hyderabad children have been determined. In the present study, 576 blood samples of children (3-6 years old) were collected during 1996-1998 and analyzed for heavy metal contents by anodic stripping voltammetry and atomic absorption spectrometry. The geometric mean concentrations of Pb, Cd, Cu and Zn in blood of Mumbai children were 8.0, 0.10, 86.5 and 398.9 microg dl(-1), while those for Hyderabad children were 13.3, 0.13, 100.6 and 483.4 microg dl(-1) respectively. The geometric mean concentrations of Fe in the blood of Mumbai and Hyderabad children were 21.9 and 34.5 mg dl(-1), respectively. Of the Mumbai children, 61.8% were found to have a blood lead concentration lcss than 10 microg dl(-1), while the corresponding proportion of Hyderabad children was 27.4%. Higher concentrations of Pb in the children's blood were observed at high traffic areas in both cities. A decreasing trend in the hemoglobin content with increasing blood lead levels was observed for Mumbai children. A good negative correlation (-0.61) between the blood lead and iron has been observed for Mumbai children The hemoglobin content of 85% of the study population was found to vary between 8 and 14 g%.

Child↗
PubMed2001

Daily intake of Se by adult population of Mumbai, India.

The atmospheric Se levels in Mumbai varied between 0.02 and 1.92 ng m(-3) with a mean concentration of 0.21 ng m(-3). The daily intake of Se by the adult population of Mumbai is 61.9 microg day(-1). Differential pulse cathodic stripping voltammetry (DP-CSV) has been used for the determination of Se in air particulate and food samples. The detection limit of Se using DPCSV was found to be 0.05 ng ml(-1). The reliability of estimation was further assessed through the analysis of standard reference materials (SRMs), tuna fish, animal blood, milk powder and fish tissue obtained from IAEA. The frequency distribution of dietary intake levels of selenium for Mumbai adults showed that approximately 61% of the studied population have a dietary intake of 30-90 microg day(-1). Ingestion was found to be the main route of Se exposure for Mumbai adults. The turn over time of Se through blood is 17 days.

Air Pollution↗
PubMed2001

Atmospheric and children's blood lead as indicators of vehicular traffic and other emission sources in Mumbai, India.

Average concentration of Pb in atmospheric air particulates in different suburbs of Mumbai was studied for almost a decade and its spatial and temporal profiles are discussed in relation to emission sources. In general the concentration of Pb in all the residential suburban atmosphere is well below the Central Pollution Control Board (CPCB, 1994) prescribed limit of 1.5 microg m(-3) barring a few exceptions for some residential/industrial sites, such as those of Thane and Kurla scrap yards. The correlation between blood lead of children and air lead reveals that the blood Pb level in children could increase by 3.6 microg dl(-1) for an incremental rise of 1.0 microg Pb m(-3) of air. The temporal profile of air Pb values indicates a decreasing trend in residential suburbs (Khar: 1984, 0.39 microg m(-3); 1996, 0.17 microg m(-3)) as well as in suburban residential areas with low traffic (Goregaon: 1984, 0.53 microg m(-3); 1996, 0.30 microg m(-3)).

Air Pollutants↗
PubMed1997

Compact Fiber Optic Dynamic Light Scattering System

Fiber optic dynamic light scattering (FODLS) is fast developing as a technique for sizing particles in concentrated dispersions. Fiber optic systems have the potential to be made into online particle size measuring equipment in process industries. Two different laser light sources were used to study monodisperse polystyrene latex dispersion with different particle sizes and volume fractions. The apparent diffusion coefficients were a function of particle size, volume fraction, and signal to noise ratios. The apparent diffusion coefficient data showed that FODLS probes collective diffusion for smaller particles and self diffusion for larger particles. It was observed that for a polydisperse concentrated dispersion, both self and collective diffusion were probed by FODLS. This means that the apparent diffusion coefficient can be used only as a relative quantity. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMedDate not supplied

Natural course of asymptomatic pancreatic pseudocyst: a prospective study.

AIM: To study the natural course of asymptomatic pseudocysts of the pancreas. METHODS: Thirty patients (age range 18-68 years, mean 44; 24 men) with asymptomatic pseudocysts of the pancreas were enrolled between December 2001 and December 2003, and were followed up every month. Those who developed symptoms due to pseudocyst (increasing pain or features of obstruction such as vomiting or jaundice) were subjected to an endoscopic or surgical drainage procedure. End point of the study was either spontaneous resolution of pseudocyst or drainage procedure. RESULTS: Eighteen (60%) of 30 patients had resolution of the pseudocyst over an average duration of 5 months. Maximum diameter of less than 7.5 cm and cyst volume less than 250 mL were significantly more frequent in patients with resolution of pseudocyst than in those without (14/18 vs 2/12 [p=0.001] and 15/18 vs 2/12 [p=0.0003], respectively). Presence of internal debris was associated with non-resolution (9/12 vs 2/18; p=0.001). CONCLUSION: Pseudocysts with less than 7.5 cm diameter, volume less than 250 mL, and absence of internal debris were associated with spontaneous resolution within an average duration of 5 months.

Abdominal Pain↗