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Biomedical subjects

S D Soman

Publications and source records attributed to S D Soman.

At least 19 recordsLinked to original sources
PubMed1991

A cancer mortality study in Bombay-based atomic energy community: 1975-1987.

Cancer deaths recorded by the centralised health services of the Department of Atomic Energy (DAE) among its employees and their families stationed in Bombay during 1975-1987 have been analysed. Expected number of deaths due to cancer in the study group has been estimated by using the age-sex-specific cancer death rates reported for Bombay resident population for the year 1983. The size of the database for the entire DAE community is about 702,000 person years and the number of cancer deaths observed in 154. Analysis has been done separately for employees and their families, individually for important groups of cancer sites such as respiratory organs, digestive organs, breast, genito-urinary organs and lymphatic and haematopoietic systems. The standardised mortality ratios are generally lower than 100, which may partly be due to the 'healthy worker effect' in the DAE community and partly because of its differences in the social class distribution and the concomitant differences in lifestyle with respect to the comparison group of Bombay city.

Adolescent↗
PubMed1989

A sensitive method for the determination of Th in body fluids.

A method involving neutron activation followed by simple radiochemical separation was developed and applied to determine the concentrations of Th in blood serum and urine. The method is sufficiently sensitive to detect 0.025 ng of 232Th. The average concentration of Th found in the blood serum and urine of subjects from normal environments is 7.9 ng L-1 and 2.7 ng L-1, respectively.

Humans↗
PubMed1987

Environmental radiation and cancer in India.

The hormesis hypothesis, which suggests that ecologically realistic low levels of ionising radiations may be beneficial to humans, seems to be substantiated significantly by the data available on cancer incidence/mortality rates and environmental radiation levels in various cities and states of India. Where the radiation level is greater, cancer risk is invariably less. The annual cancer incidence rate (per 100,000 population) seems to decrease by 0.03/microSv increase in the external background radiation dose from a hypothetical incidence level of 79 per 100,000 corresponding to "zero environmental radiation".

Background Radiation↗
PubMed1987

Measurement of 14C emission rates from a pressurised heavy water reactor.

Carbon-14 is produced in pressurised heavy water reactors (PHWR), mainly as an activation product in the fuel. It is also produced in the heavy water used as the primary coolant and moderator, and is produced in the air in the annular space between the pressure tube and calandria tubes as well as in the free space in the calandria vault. The production rates in different systems of a PHWR are calculated on the basis of design parameters. During a period of 3 y, 14C released through the gaseous route has been measured at Rajasthan Atomic Power Station, Kota, India, a PHWR unit. These releases have been found to be mainly 14CO2. This reduced form of 14C is less than 5% of the releases. The normalised releases of 14C have a geometric mean of 5.17 TBq GWe-1 y-1 and a geometric standard deviation of 1.52. The 14C present in the form of carbonates in liquid effluents has also been measured and is 0.14% of the gaseous releases.

Air Pollutants, Radioactive↗
PubMed1986

The distribution of mercury in the Indian population.

Data have been obtained for the distribution of mercury in a non-occupationally exposed Indian adult group and compared with data available from other regions. The biological elimination half time for mercury of 33 days obtained here is in good agreement with the corresponding value for inorganic mercury compounds. The present work indicates that the relationship between dietary intake and blood concentration is only meaningful when long-term blood concentrations are measured.

Air Pollutants↗
PubMed1983

Concentrations of morphologically normal, motile spermatozoa: Mg, Ca and Zn in the semen of infertile men.

Semen from infertile men (n = 23) has been compared with that of control subjects (n = 25). Whereas the concentrations of morphologically normal, motile sperms, Mg, Ca and Zn fell within the acceptable limits for all the control subjects, only two infertile men qualified by all five parameters. Of the patient group, seven were abnormal on all counts; sperm motility, Mg and Zn were low in 16, Ca in 19 and abnormal morphology was encountered in 12. Since there was no linear correlation between any two parameters, it is possible that each factor may singly or jointly influence the physiological integrity of the spermatozoa. The results are discussed from a consideration of pathological manifestations known to occur in deficiency of these trace elements à propos their role in determining the fertility index of the semen.

Calcium↗
PubMed1983

Nutritional status and the serum levels of Mg, Ca, Zn and Cu.

Serum Mg, Ca, Zn and Cu levels of 65 Indian children aged 5 months to 3 y 7 months, living in Bombay city, were estimated by atomic absorption spectrometry. Twenty-five well nourished controls exhibited the following serum levels: Mg 2.5 +/- 0.3 mg%, Ca 9.7 +/- 0.6 mg%, Zn 103.2 +/- 9.7 micrograms % and Cu 148.7 +/- 26 micrograms %. The remaining 40 patients were divided into four categories depending on the status of their nutrition; Group I was minimally undernourished, whereas Group IV was the worst effected. Group I (n = 6) had serum values of 2.5 +/- 0.2 mg% Mg, 8.9 +/- 0.6 mg% Ca, 85 +/- 18 micrograms % Zn and 108 +/- 25.8 micrograms % Cu. Group II (n = 20) levels were 2.2 +/- 0.3 mg% Mg, 8.3 +/- 0.9 mg% Ca, 82.6 +/- 16.5 micrograms %, Zn and 89.2 +/- 27.6 micrograms % Cu. Group III (n = 9) were 2.1 +/- 0.3 mg% Mg, 8.3 +/- 0.8 mg% Ca, 88.3 +/- 22.6 micrograms % Zn and 93 +/- 26.9 micrograms % Cu, whereas the most severely undernourished (Group IV) children had serum levels of 2.2 +/- 0.4 mg% Mg, 7.6 +/- 0.8 mg% Ca, 78.4 +/- 15.7 micrograms % Zn and 62.8 +/- 17.5 micrograms % Cu.

Calcium↗
PubMed1982

Altered sensorium in neurological infections and the homeostasis of Mg, Zn, Cu and Ca.

In a grave illness the homeostasis of some elements may be upset either by the disease process per se, or by the therapy adopted. Patients with pyogenic, viral and tubercular meningo-encephalitis were targets of interest. 108 subjects' serum and cerebrospinal fluid (CSF) compartments were assayed for magnesium, calcium, zinc and copper, by atomic absorption spectrometry. Results showed that the serum pool was more intensely altered than the CSF pool in the case of magnesium and calcium but the reverse occurred for zinc and copper. No organism-dependent change was noted, but comatosed patients were the worst effected. These findings are discussed with respect to the relative brain and CSF content of each element and the patho-physiology which could alter the compartments studied.

Brain↗
PubMed1982

Passive measurement of radon and thoron using TLD or SSNTD on electrets.

An electret is an electrical analogue of a permanent magnet and it carries a permanent electric charge. Our previous work has shown that such electrets are suitable for collecting decay products of radon and thoron in passive chambers. In the present work, the decay products are directly collected on the surface of a TLD or SSNTD providing in situ registration of the radiation from the decay products of radon and thoron. A 101. chamber, the sides of which were covered with a layer of Whatman No. 1 (W-1) filter paper, showed the following responses: (i) SSNTD (CR-39) recorded 92 +/- 13 tracks per cm2 per pCi/l, hr for radon and 9 +/- 1.5 tracks per cm2 per pCi/l. hr for thoron; (ii) for similar levels TLD (CaF2(Dy)) chips recorded an equivalent of 1.35 +/- 0.16 mR for radon and 0.30 +/- jk0.09 mR for thoron. Taking advantage of the differential response of the two chambers (one covered with a layer of W-1 filter paper and the other with a 75 mm polyurethene foam), simultaneous measurement of radon and thoron could be achieved.

Radiation Monitoring↗