#lc50

[learning-living]

Latest cyanide(HCN) concentration in the Hong Kong Polytechnic University: 28.6 ppm

Source: 香城教育電視 HKG ETV

According to the International Cyanide Management Code, cyanide is acutely toxic to humans. Liquid or gaseous hydrogen cyanide and alkali salts of cyanide can enter the body through inhalation, ingestion or absorption through the eyes and skin. The rate of skin absorption is enhanced when the skin is cut, abraded or moist; inhaled salts of cyanide are readily dissolved and absorbed upon contact with moist mucous membranes.

The LC50 (concentration that is lethal to 50% of the exposed population)for gaseous hydrogen cyanide is 100-300 ppm. Inhalation of cyanide in this range results in death within 10-60 minutes, with death coming more quickly as the concentration increases.

The National Institute for Occupational Safety and Health (NIOSH) has recommended that workplace exposures to hydrogen cyanide not exceed 4.7 ppm as a 10-minute ceiling.

The government did nothing to remove the toxic chemicals released from their weapons in the past five months.

[oaresearchpaper]

General bioactivity screening of Homalocladium platycladum (Tapeworm plant) via brine shrimp lethality assay : Janus B. Pansacala : Free Download, Borrow, and Streaming : Internet Archive

This study aimed to evaluate the presence of bioactive compounds in Homalocladium platycladum (Tapeworm plant) through bioactivity screening and toxicity assessment. The powdered mature stems of the plant were extracted using different solvents, namely n-hexane (HEX), dichloromethane (DCM), ethyl acetate (ETA), n-butanol (BUT), and methanol-water (WAT). The resulting fractions were prepared and tested at various concentrations using the brine shrimp lethality assay. The results indicated that the HEX, DCM, and BUT fractions exhibited immediate and acute toxicity, suggesting the presence of bioactive compounds. Furthermore, all fractions demonstrated toxicity at longer exposure times, indicating the potential for chronic toxicity. The median lethal concentration (LC50) analysis using the Miller-Tainter method revealed moderate toxicity for the HEX and DCM fractions, with LC50 values of 199.9 ppm and 457.3 ppm, respectively. Moreover, all fractions, including HEX, DCM, ETA, BUT, and WAT, exhibited bioactivity potential at longer exposure times, with calculated LC50 values of 19.79 ppm, 38.82 ppm, 14.77 ppm, 5.565 ppm, and 131.3 ppm, respectively. Notably, all fractions, except for the methanol-water fraction, displayed high toxicity after 24-hour exposure. These findings suggest that the Tapeworm plant contains bioactive compounds with pharmacological potential. Therefore, further investigation of these compounds is warranted for the development of novel pharmaceutical agents.

[oaresearchpaper]

Tolerance development in termites: A case study of Microtermes obesi Holmgren (Blattodea: Termitidae) from the tea plantations of Darjeeling foothills, West Bengal (India)

Microtermes obesi belong to one such new clad of termite species which damages tea plantations of Darjeeling foothills. To control tea pests, planters use synthetic insecticides that have lead to the much bigger problem of insecticide tolerance in many tea pests. Present study contemplates to investigate the tolerance status of the pest species, collected from organically and conventionally managed tea plantations of Darjeeling foothills to three different commonly used insecticides – Imidacloprid 17.8% SL, Cypermethrin 35% EC and Chlorpyrifos 20% EC, along with the activity of the three major detoxifying enzymes, General Esterases(GE), Glutathion S Transferase (GST) and Cytochrome oxydases (CYP450). Results obtained showed higher level of mean lethal concentration (LC50) for Imidacloprid 17.8% SL = 63.66 ppm, Cypermethrin 35% EC = 31.99 ppm, and Chlorpyrifos 20% EC = 18.57 ppm in M. obesi population collected from conventionally managed tea plantations, as compared to that from organically managed plantations. Even observations on detoxifying enzymes reflected a corresponding enhancement in their activities which were noted as: GE = 2.25 mM mg -1 protein; GST = 120.86 µM min-1 mg-1 protein; CYP450 = 0.75 n mol min-1 mg protein-1 in population of pesticide managed conventional plantation, and at a lower level (GE = 0.23 mM mg -1 protein; GST = 16.73 µM min-1 mg-1 protein; CYP450 = 0.26 n mol min-1 mg protein-1) in population of organically managed tea plantation. Hence, developing an enzyme-based marker for M. obesi populations may be of practical use in titrating an effective pesticide dosage under IPM/IRM strategies.

[oaresearchpaper]

PPT - General bioactivity screening of Homalocladium platycladum (Tapeworm plant) PowerPoint Presentation - ID:12861434

This study aimed to evaluate the presence of bioactive compounds in Homalocladium platycladum (Tapeworm plant) through bioactivity screening and toxicity assessment. The powdered mature stems of the plant were extracted using different solvents, namely n-hexane (HEX), dichloromethane (DCM), ethyl acetate (ETA), n-butanol (BUT), and methanol-water (WAT). The resulting fractions were prepared and tested at various concentrations using the brine shrimp lethality assay. The results indicated that the HEX, DCM, and BUT fractions exhibited immediate and acute toxicity, suggesting the presence of bioactive compounds. Furthermore, all fractions demonstrated toxicity at longer exposure times, indicating the potential for chronic toxicity. The median lethal concentration (LC50) analysis using the Miller-Tainter method revealed moderate toxicity for the HEX and DCM fractions, with LC50 values of 199.9 ppm and 457.3 ppm, respectively. Moreover, all fractions, including HEX, DCM, ETA, BUT, and WAT, exhibited bioactivity potential at longer exposure times, with calculated LC50 values of 19.79 ppm, 38.82 ppm, 14.77 ppm, 5.565 ppm, and 131.3 ppm, respectively. Notably, all fractions, except for the methanol-water fraction, displayed high toxicity after 24-hour exposure. These findings suggest that the Tapeworm plant contains bioactive compounds with pharmacological potential. Therefore, further investigation of these compounds is warranted for the development of novel pharmaceutical agents.

[mbimphblog]

ACUTE TOXICITY STUDIES OF CADMIUM ON CRAB Sesarma quadratum (Decapoda) |  UTTAR PRADESH JOURNAL OF ZOOLOGY

An estuary is a brackish water feature that is partially contained along the coast, with one or more rivers or streams flowing into it and a free access to the open sea. Estuaries are an example of an ecotone, which is a transition zone between river and maritime habitats. Because many crustacean species live in estuaries, numerous research have been conducted to investigate the bioaccumulation and impact of various toxicants in these creatures. Heavy metals can build up in aquatic organisms' tissues and induce a variety of harmful consequences on all organisms due to biomagnification. The goal of this study was to look at the acute toxicity of cadmium on crabs (Sesarma quadratum). Crab samples were subjected to varying amounts of cadmium (5, 10, 15, 20, and 25g/L) for 96 hours, and cumulative death was calculated in 24-hour intervals. SPSS 20 was used to analyse the data and provide a number of cumulative and fatal mortality rates. Please see the link :- http://mbimph.com/index.php/UPJOZ/article/view/2591

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CHROMIUM SULPHATE INDUCED ALTERATIONS OF GLYCOGEN AND PROTEIN CONTENT IN SOME TISSUES OF A FRESH WATER FISH Heteropneustes fossilis| UTTAR PRADESH JOURNAL OF ZOOLOGY

Heavy metal contamination of aquatic resources poses a major hazard to aquatic creatures, particularly fish, which are at a higher trophic level in the aquatic food chain. Fish is an important bio-resource for humans because it contributes to our economy and provides a source of income for millions of people throughout the world. The effects of chromium (III) sulphate (Cr2(SO4).18H2O) on tissue metabolite levels of the freshwater fish Heteropneustes fossilis were investigated in this work. For 24, 48, 72, and 96 hours, the LC50 values were recorded. The glycogen content of the liver, muscles, testis, and ovary of fish subjected to sub-lethal concentrations of 5.0 mg/l for 10 and 20 days showed a reduction, while protein depletion was observed in the liver, testes, and ovary. According to the findings, chromium (III) sulphate induces metabolic disruptions and, as a result, changes in tissue metabolite levels, which have a negative impact on fish health. Please see the link :- http://mbimph.com/index.php/UPJOZ/article/view/1769

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EFFECT OF SUBLETHAL CONCENTRATION OF FORMALIN ON HAEMATOLOGICAL AND BIOCHEMICAL PARAMETERS OF Oreochromis niloticus | UTTAR PRADESH JOURNAL OF ZOOLOGY

Even though formalin is a highly toxic substance, it has long been used for conventional treatment of fish ectoparasites. Aside from that, formalin is a key component of plywood mill effluent. Perumbavoor, Kerala's Ernakulam (district), is a prominent plywood industrial belt, with hundreds of plywood firms operating in a small region. All of these plywood mills discharge their effluents directly into neighbouring bodies of water without any treatment. As a result, a thorough investigation into the effects of formalin on aquatic creatures, particularly fish, is required. A study was conducted to examine haematological and biochemical alterations in Oreochromis niloticus after exposure to sub lethal quantities of formalin (1/80th (0.175 ml), 1/70th (0.2 ml), and 1/50th (0.28 ml) dilution of formaldehyde LC50) during periods of 20 hours, 100 hours, and 300 hours. When the concentrations and exposure time were increased, the total count of RBC, haemoglobin, PCV, MCH, MCHC, and MCV decreased as compared to the control. The number of WBCs rose as the concentration and exposure time increased. The amount of blood glucose increased as the dosage and exposure duration increased. When compared to control fish, total protein, globulin, and albumin were lower in exposed fish. According to the findings of this study, haematological and biochemical markers can be utilised as indicators of formalin-related stress in fish. The recent study underscored the importance of regulating formaldehyde leakage into aquatic systems from both home and industrial sources. For the control of parasite infection in aquaculture, a very low concentration (0.37 ml) is ideal; otherwise, it may harm the health of the fish and, eventually, humans.

Please see the link :- http://mbimph.com/index.php/UPJOZ/article/view/2152

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HISTOLOGICAL STUDY OF MALATHION SUB-LETHAL TOXICITY IN GILLS OF Clarias batrachus | UTTAR PRADESH JOURNAL OF ZOOLOGY

Malathion (organophosphorus pesticide) is used worldwide in the agricultural field due to its biodegradability and non-persistent properties to control the harmful pest. However their range of harmful effects on animals extends far beyond the agricultural pest. The main objective of this study is to observe the impact of sub-lethal concentration (96 hours) of organophosphorus malathion on the gills of freshwater fish Clarias batrachus. The organophosphorus pesticide malathion (50% EC) was purchased from the local market of Jhansi. After volumetric experimentation and selection of required dose of biomarker (malathion) as per experimental protocol, value of malathion LC50 96 hours calculated 0.25 ppm. The sub-lethal concentration of 0.025 ppm was determined by using 1/10th of LC50 at 96 hours. The effect of malathion on sub-lethal concentration (1/10 of 96 hours of LC50) and histological observation were recorded on the gills of treated fishes. Some reasonable alterations were observed in the gills sections of treated fishes as compared to the control group. These histological changes were characterized as:- Thickening of secondary lamellae, hemorrhage at primary lamellae, deformation of the cartilage core, erosion of secondary lamellae, blood congestion in the secondary lamellae, shortening of the secondary lamellae. This study indicates that the deformation of the gills depended on the duration of exposure and concentration of Malathion dose.

Please see the link :- https://mbimph.com/index.php/UPJOZ/article/view/1668