U.C. Mishra
Bhabha Atomic Research Centre
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Atmospheric Environment | 1967
B.S. Negi; S. Sadasivan; U.C. Mishra
Abstract The elemental composition of aerosols over four cities in India was determined by EDXRF over a 1-year period and the results are presented. The crustal element levels in air in all the cities are found to be similar to those reported for urban areas elsewhere in the world while that of anthropogenic elements are lower. The aerosol compositions show a seasonal variation. The levels of crustal elements are higher during summer and decrease with rainfall. The anthropogenic elements are generally higher during winter. The lead levels are essentially from non-auto exhaust sources such as refuse burning, smelter etc., and in three of the cities they are strongly correlated to zinc. The crustal elements are from local soils and no significant crust-air fractionation is seen. Factor analysis of the data suggests between four and six aerosol source types for the four cities. Soil dust accounts for the major fraction of the measured mass. About 68–80 % of the aerosol mass comprising the residuals seems to consist of C, O 2 and N, in particular, which were not measured.
Science of The Total Environment | 1987
R.N. Khandekar; R. Raghunath; U.C. Mishra
Levels of lead, cadmium, zinc and copper were measured in the blood of normal children and adults of Greater Bombay, India using differential pulse anodic stripping voltammetry. The median concentrations of Pb, Cd, Zn and Cu in the whole blood of children and adults were 11.54, 0.21, 484.2 and 86.2 micrograms dl-1, respectively. The blood lead concentration showed an increase with age. Children living in industrial zones with high vehicular traffic have significantly higher blood lead concentrations than their counterparts living in the cleaner suburban parts of the city. The mean levels of Pb, Cd, Zn and Cu in blood of Bombay children and adults are compared with those from other countries.
Science of The Total Environment | 1986
R.N. Khandekar; R. Raghunath; U.C. Mishra
The lead content of teeth of Bombay residents has been determined using differential pulse anodic stripping voltammetry. The median tooth lead concentrations for adults and children in Bombay are estimated to be 8.31 and 3.01 micrograms/g of tooth, respectively. The data indicate that the lead concentration of a tooth increases with the age of the donor. For children the tooth lead content varies with the type of tooth. Further, children living in industrial areas have a higher tooth lead content than children living in the cleaner suburbs of Greater Bombay.
Science of The Total Environment | 1984
R.N. Khandekar; U.C. Mishra; K.G. Vohra
Environmental lead exposure of the Greater Bombay population has been estimated by measuring lead concentrations in air particulates, water, food and cigarette smoke. Atmospheric lead concentrations in different zones of the city varied between 82 and 605 ng m-3. The dietary intake of lead is estimated to be 245 micrograms day-1 and is calculated from the lead content in different food groups and the amount of that group consumed by an average resident of the city. The uptake by a non-smoker living in the city area is estimated to be 33 micrograms of lead per day, 75% of which comes from food, 15% from air and 10% from water. For a suburban resident 85% of the lead intake comes from food. The blood lead measurements and the contribution of atmospheric lead to the blood lead level are discussed.
Journal of Radioanalytical and Nuclear Chemistry | 1986
U.C. Mishra; G. N. Shaikh; S. Sadasivan
Trace elements in tobacco and tobacco smoke of a large number of commonly available brands of cigarettes were analyzed by energy dispersive X-ray fluorescence. This work supplements the data on same samples gathered by INAA and reported earlier. Data on some toxic elements like Pb, Cu and Ni that could not be measured by INAA are presented here. A number of chewing and snuff tobacco samples were also analyzed. The concentrations of Ca, K, Cl, Br, Cu, Fe, Ni, Pb, Rb, Sr, Ti and Zn in all these samples are presented and their relative hazards are discussed.
Science of The Total Environment | 1988
R.M. Tripathi; R.N. Khandekar; U.C. Mishra
Particle size distribution of atmospheric aerosols was measured at different locations in Moradabad and Bombay, India, using an Andersen cascade impactor. The size distributions of lead, cadmium, copper and zinc were found to be bimodal. The respirable fraction of the particulates (less than 4.7 microns) was calculated. The fraction of fine particles was found to be greater in Bombay than in Moradabad. The mass median aerodynamic diameter (MMAD) for lead, cadmium, copper and zinc was calculated. The atmospheric concentrations of these elements were also measured at the two locations. The analysis of samples was carried out by differential pulse anodic stripping voltammetry.
Journal of Radioanalytical and Nuclear Chemistry | 1992
A. N. Shaikh; R. N. Khandekar; S. J. S. Anand; U.C. Mishra
Toxic trace metals like mercury, arsenic and cadmium have been determined in widely used Indian chewing tobacco and cigarette tobacco by neutron activation followed by sequential radiochemical separation (RNAA). Differential Pulse Anodic Stripping Voltammetry (DPASV) has been used for the estimation of lead, cadmium and copper in cigarette tobacco and its smoke aerosols. The reliability of the data has been assured by analyzing standard reference materials, bovine liver (NBS-1577) and orchard leaves (NBS-1571), and intercomparison of the Pb, Cd and Cu values by three techniques, namely, RNAA, DPASV and Energy Dispersive X-ray Flourescence technique (EDXRF). The levels of Hg, Cd, As, Pb and Cu in cigarette and chewing tobacco and the estimated intake of Cd, Cu and Pb to the smoker are presented and discussed.
Atmospheric Environment | 1989
R.M. Tripathi; R.N. Khandekar; R. Raghunath; U.C. Mishra
Abstract Atmospheric concentrations of Pb, Cd, Cu and Zn have been measured at different locations in Bombay. The concentration levels of these metals in blood and teeth of Bombay residents were also measured to assess the current and integrated exposure. Higher atmospheric concentrations were observed in higher vehicular traffic zones in Bombay. Environmental monitoring of Pb, Cd, Cu and Zn was also carried out at Moradabad, the largest production and exporting centre of brass wares in India. Surface soil concentrations of these metals were also measured in Moradabad and Bombay. The analysis of samples was carried out by differential pulse anodic stripping voltammetry (DPASV). The study indicates that automobile exhaust is the dominant source for heavy metals in the environment of Bombay whereas the brass industry is responsible for enhanced concentrations of these metals in Moradabad.
Journal of Radioanalytical and Nuclear Chemistry | 1986
U.C. Mishra; G. N. Shaikh
Trace elements present in Indian cigarette tobacco and cigarette smoke have been reported earlier. This paper presents trace element concentrations in chewing and snuff tobaccos determined by Instrumental Neutron Activation Analysis. The levels of Br, Co, Cr, Fe, Mn, Zn, etc., present in different brands of chewing and snuff tobaccos are compared in two types of tobacco as well as with similar data from other countries.
Science of The Total Environment | 1984
U.C. Mishra; G.N. Shaikh
It has been well established that smoking causes lung cancer and many other chest diseases. To study the harmful effects of smoking, an automatic smoking machine was developed in this laboratory. Cigarette smoke contains many known carcinogens. The amounts of various carcinogens are proportional to the total particulate matter. Hence variation in total particulate matter (TPM) of different brands of cigarettes, bidis and cheruts (Indian cigars) was studied for various smoking parameters. An attempt has been made to arrive at some intake values of TPM from cigarettes and bidis smoked by the automatic smoking machine under different simulated smoking conditions.