A B C D E F G H I J K L M N O P Q R S T U V W X-Z 0-9
close this section of the library Toxicity
View the PDF document Effect of ricin on some biochemical haematological and histopathological variables in mice
Author : Om Kumar, K;Sugendran, K.;Pant, S. C.;Vijayaraghavan, R.
Source : Defence Science Journal ; Vol:54(4) ; 2004 ; pp 493-502
Subject : 57.089 Biomedical Sciences ;57 Biological Sciences ;61 Medical Sciences
Keywords : Ricin;Intraperitoneal route;Oral route;Toxicity;Leukocytosis;Median lethal concentration;Uric acid;Piloerection;Mice;Proteineous toxin
Abstract : Acute toxicity studies of ricin were carried out in Swiss albino male mice. The median lethal concentration (LD50) values were determined for mice through intraperitoneal and oral routes and were found to be 1.01 mg/kg and 28.29 mg/kg, respectively. The ricin (1.0 LD50) was administered in mice through intraperitoneal route and various toxicity related clinical variables were studied on the 1st, 3rd, and the 7th day of post-exposure. The prominent symptoms before death, were diarrhoea with black sticky vent and piloerection. The body weight decreased significantly in a dose-dependent manner. No significant change was observed in organ-to-body weight ratio on the 1st, 3rd, and the 7th day of post-exposure except kidney weight. On the 7th day, kidney weight increased significantly. The levels of blood urea, uric acid, and glucose increased, while total protein level decreased. However, activities of transaminase and phosphatases were not altered. Leukocytosis was also observed. The ricin also affected blood coagulation parameters. There was a significant increase in the clotting time. However, prothrombin time, bleeding time, and erythrocyte sedimentation rate were not altered. Histopathological studies showed degenerative changes in various visceral organs, viz, lungs, liver, spleen, kidney, and testis. Acute toxicity studies of ricin revealed that it is a highly toxic toxin. The ricin intoxication caused alterations in biochemical, haematological variables, and degenerative changes in various visceral organs.
View the PDF document Depleted Uranium Penetrators : Hazards and Safety
Author : Bhat, T. Balakrishna ;Rao, S.S.
Source : Defence Science Journal ; Vol:47(1) ; 1997 ; pp 97-105
Subject : 623.4 Armaments and Ballistics
Keywords : Kinetic energy ;Superior ballistic;Open air firing;Airborne particles;Inhalation;Contaminated environment;Toxicity;Urinary excretion
Abstract : "The depleted uranium (DU) alloy is a state-of-the-art material for kinetic energy penetrators due to its superior ballistic performance. Several countries use DU penetrators in their main battle tanks. There is no gamma radiation hazard to the crew members from stowage of DO rounds. Open air firing can result in environmental contamination and associated hazards due to airborne particles containing essentially U/sub 3/0/sub 8/ and UO/sub 2/. Inhalation of polluted air only through respirators or nose masks and refraining form ingestion of water or food materials from contaminated environment are safety measures for avoiding exposure to uranium and its toxicity. Infusion of sodium bicarbonate helps in urinary excretion of uranium that may have entered the body. "
View the PDF document Low cost adsorbents for the removal of Mercury (II) from aqueous solution : A comparative study
Author : Meena, Ajay Kumar;Mishra, G. K.;Kumar, Satish;Rajagopal, Chitra;Nagar, P. N.
Source : Defence Science Journal ; Vol:54(4) ; 2004 ; pp 537-548
Subject : 504 Environmental Sciences
Keywords : Hazardous heavy metals;Waste water;Evironmental pollution;Toxicity;Mercury;Adsorbents;Water contamination
Abstract : The establishments of the Ministry of Defence, specifically ordnance factories and public sector undertakings (like Bharat Electronics Ltd), carry out operations like electroplating, metal/surface finishing, solid-state wafer processing, and initiatory manufacturing (lead azide, mercury fulminate), which generate waste water contaminated with hazardous heavy metals. Mercury and its compounds are known to be highly toxic, both for the living organisms and the environment. To protect public health, a regulatory discharge standard of mercury, as low as 0.01 mg/l, has been imposed and is expected to be even stricter in the future. A promising method for effective mercury discharge control is to employ suitable adsorbents for the removal of mercury from the contaminated aqueous stream. This paper describes the effectiveness of low cost and locally available, untreated and chemically-treated adsorbents for the removal of mercury from the aqueous solution. Their effectiveness has been compared with that of chemically treated granular activated carbon. Treated sawdust and untreated weathered coal were found to be the most suitable low-cost adsorbents in addition to treated granular activated carbon for the removal of mercury from aqueous solution. Under the optimised conditions, ie, adsorbent dose 10 g/l, pH 6, contact time 48 h, and initial concentration of mercury 3 mg/l, the removal of mercury was found to be 99.8 per cent, 99.8 per cent, and 99.7per cent, using treated granular activated carbon, treated sawdust, and untreated weathered coal, respectively. The adsorption parameters were determined using both Langmuir and Freundlich isotherm models. Surface complexation and ion exchange were the major removal mechanisms involved. The adsorption isotherm studies clearly indicated that the Langmuir model is in good agreement with the experimental data on the adsorptive behaviour of mercury on treated granular activated carbon, whereas, the experimental data on adsorptive behaviour of mercury on weathered coal and treated sawdust follow both Langmuir and Freundlich isotherm models. The paper presents the results of the experimental studies as well as the model parameters.
View the PDF document Studies on contact toxicity Part IV
Author : Cheema, P.S. ;Misra, J.N. ;Paul, R.K. ;Ranganathan, S.K.
Source : Defence Science Journal ; Vol:9(3) ; 1959 ; pp 222-232
Subject : 632.9 Pest Control
Keywords : Toxicity ;DDT ;Glue ;Potassium ;Dichromates ;Mosquitoes ;Flies
Abstract : The use of starch and a mixture of glue and potassium dichromate as pretreatment for the enhancement of the residual activity of DDT has been investigated using mosquitoes, Cluex fatigans Weid. and flies, Musca nebulo Linn. The DDT deposits were derived either from an emulsifiable concentrate or a water dispersible powder concentrate. As substrate, cement, brick and mud surfaces were investigated both as they were in the lime-washed conditions. Pretreatment with glue-dichromate considerably enhanced the residual activity of DDT against both the species of insects on all the three surfaces and proved very much superior to pretreatment with starch. The deposits derived from DDT emulsion showed residual activity for a longer period than those derived from DDT water dispersible powder on mud surfaces pretreated with glue-dichromate.
View the PDF document Amifostine : An effective prophylactic agent against sulphur mustard toxicity
Author : Pathak, Uma ;Raza, S. K.;Vijayraghavan, R. ;Jaiswal, D. K. ;Kumar, P.
Source : Defence Science Journal ; Vol:52(4) ; 2002 ; pp 439-444
Subject : 57.089 Biomedical Sciences ;57 Biological Sciences
Keywords : Amifostine ;Sulphur mustard ;Prophylactic agent ;Radioprotector ;Toxicity ;Alkylating agent
Abstract : Amifostine, S-2-(aminopropylamino) ethylphosphorothioate and two of its analogues have been evaluated as prophylactic agent against SM toxicity. The compounds were administered intraperitoncally (i.p.) at 0.2 LD/sub59 dose in mice 30 min prior to dermal application of SM. The protective efficacy was determined by observing the mortality for 14 days. The protection offered by amifostine was better than its analogues. Subsequent study on time-dependent protection, carried out with amifostine (0.2 LD/sub50, i.p.) provided significant protection when the drug was administered as 30 min pre-treatment and simultaneous treatment against SM at 155 mg.kg/-1 dose (equal to 19-fold LD/sub50). Furthermore, oral administration of amifostine (30 min pre-treatment) showed similar results. These findings suggest that amifostine is a promising prophylactic agent against SM toxicity.
View the PDF document Respiratory Effects of Amifostine and DRDE-07: Probable Prophylactic Agents of Sulphur Mustard in Rats
Author : Singh, Seema;Malviya, Vimal;Gautam, Anshoo;Singh, Ram;Pathak, Uma;Raza, S. K.;Vijayaraghavan, R.
Source : Defence Science Journal ; Vol:56(4) ; 2006 ; pp 531-541
Subject : 57.089 Biomedical Sciences ;623.459 Chemical Weapons
Keywords : Amifostine;DRDE-07;Toxicity;Respiratory frequency;Tidal volume;Prophylactic agents;Sulphur mustard antidote;Cytoprotective drug;Sulphur mustard
Abstract : Amifostine (S-2[3-aminopropylamino]ethyl phosphorothioate) and one of its analogues, DRDE-07 (S-2[2-aminoethylamino]ethyl phenyl sulphide) are promising prophylactic agents for sulphur mustard (SM; a blistering agent) toxicity. When given orally, DRDE-07 was more effective than amifostine as a prophylactic agent against SM administered percutaneously. Various pharmacological and toxicological studies are required before the introduction of a chemical as a drug. The respiratory effects of amifostine and DRDE-07 were carried out in rats using a body plethysmograph fitted with a volumetric pressure transducer for sensing the respiratory flow signals. The signals were amplified, digitised, and stored on a personal computer for further analysis. After taking control recordings of respiratory signals, different doses (0.5 LD50, 1.0 LD50 and 2.0 LD50) of amifostine and DRDE-07 were administered orally (LD50 amifostine = 2262 mg/ kg; DRDE-07 = 1599 mg/kg), and the respiratory changes were monitored for 4 h. Amifostine and DRDE-07 showed a uniform breathing pattern even in 2.0 LD50 dose. However, a significant dosedependent decrease in respiratory frequency was observed following amifostine administration. DRDE-07 did not show any significant change. The tidal volume was not altered significantly both in amifostine and DRDE-07 administered animals. The study shows that DRDE-07, even in lethal doses, may not affect the respiration immediately, whereas, amifostine may decrease the respiratory frequency.
View the PDF document Quick Semi-quantitative Test for Lead in Processed Foods
Author : Premavalli, K. S.;Majumder, T. K.;Bawa, A. S.
Source : Defence Science Journal ; Vol:57(2) ; 2007 ; pp 243-247
Subject : 61 Medical Sciences
Keywords : Lead detection;Quick test;Dithizone reagent;Atomic absorption spectrophotometer;Processed foods;Lead poisoning;Toxicity;Canned foods
Abstract : A simple, quick semi-quantitative test for the determination of lead metal in canned fruits, vegetables other than dehydrated onion, fish, and meat products, has been developed using the optimised concentration of dithizone reagent under alkaline pH as the test solution, which on reaction with the sample solution gives green to blue to violet to red colour, depending on the lead concentration in the sample. The quick test results were compared with atomic absorption spectrophotometric analysis. A total of 80 samples were analysed and it was found that the lead content ranged from 0.001 ppm to 10.35 ppm in all the samples.