Summary of Chemistry doctoral thesis: The accumulation, elimination and effect of heavy metals (As, Cd, Pb) on cortisol levels in Oreochromis sp.

Research scope and content: Study on Lethal Concentration 50 (LC50 - 96 hours) of As and Cd and Pb in Oreochromis sp.; the accumulation, elimination of heavy metals (As, Cd, Pb) in Oreochromis sp. in exposure phase and elimination phase; the effects of heavy metals (As, Cd, Pb) on plasma cortisol levels in Oreochromis sp.
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Summary of Chemistry doctoral thesis: The accumulation, elimination and effect of heavy metals (As, Cd, Pb) on cortisol levels in Oreochromis sp. MINISTRY OF EDUCATION VIETNAM ACADEMY AND TRAINING OF SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY ---------------------------- NGUYEN QUOC THANG THE ACCUMULATION, ELIMINATION AND EFFECT OF HEAVY METALS (As, Cd, Pb) ON CORTISOL LEVELS IN OREOCHROMIS SP. Major: Inorganic Chemistry Code: 9.44.01.13 SUMMARY OF CHEMISTRY DOCTORAL THESIS Ho Chi Minh City - 2018 The dissertation was completed at: Graduate University of Sciences and Technology, Vietnam Academy of Science and Technology; Institute of Applied Materials Science; Industrial University of Ho Chi Minh City, Korea Instite of Toxicology – Gajeong-ro, Yuseong-gu, Daejeon; The Department of Biology and Chemistry - Changwon National University; HoChiMinh City Institute of Resources Geography. Scientific Supervisors: 1. Assoc. Prof. Dr. Le Van Tan 2. Assoc. Prof. Dr. Nguyen Thi Kim Phuong 1 st Reviewer: ........................................................................... .................................................................................................... 2 nd Reviewer: .......................................................................... ................................................................................................... 3 rd Reviewer:........................................................................... ................................................................................. …………….. The dissertation will be defended at Institute of Applied Materials Science, Graduate University of Science And Technology, Vietnam Academy of Science and Technology, 01A, Thanh Loc 29, Thanh Loc ward, 12 District, Ho Chi Minh City. At ….. hour….. date….. month …..2018. The dissertation can be found in National Library of Vietnam and the library of Graduate University of Science And Technology, Vietnam Academy of Science and Technology. 1 INTRODUCTION 1. The necessity of the thesis Heavy metals are particularly significant in ecotoxicology because of their toxicity, persistence, and bioaccumulation in the food chain. Among aquatic organisms, fish are particularly sensitive to many toxicants and are valuable bioindicators for an estimation of the metal pollution level. Fish typically occupy higher positions in the aquatic food chain and may accumulate metals and pass them to human beings through food, which can cause chronic or acute diseases. It is well known that heavy metals easily accumulate in bones, gills, kidneys, and the liver of fish and can cause various detrimental effects. Heavy metals can induce histological changes and can cause changes in enzymatic activity, carbohydrate metabolism and electrolyte levels; they can also introduce metallothionein and reduce glycogen content, leading to disturbances in neuromuscular transmission and contraction, and can alter metabolic functions and impair detoxification mechanisms. The routes of metal uptake in fish are through the gills, the digestive system and the skin. Therefore, the importance of studies of heavy metal bioaccumulation in fish, which represent a valuable source of food for humans, in the context of environmental pollution, seems unquestionable. 2. Objectives Study on the accumulation, elimination of heavy metals (As, Cd, Pb) and its effects on plasma cortisol levels in Oreochromis. sp in waterborne. 3. Research scope and content - Study on Lethal Concentration 50 (LC50 - 96 hours) of As and Cd and Pb in Oreochromis sp. -The accumulation, elimination of heavy metals (As, Cd, Pb) in Oreochromis sp. in exposure phase and elimination phase. - The effects of heavy metals (As, Cd, Pb) on plasma cortisol levels in Oreochromis sp. 4. Structure of the thesis The dissertation has 112 pages, including the Preface, Chapter 1: Overview, Chapter 2: Experiment, Chapter 3: Results and discussions, 2 Conclusions, Publications, with 43 images, 17 tables and 194 references. Chapter 1. OVERVIEW Cadmium belongs to a group of toxic metals which have no function in the physiological processes of human, thus its bioaccumulation in different organs and tissues of living organisms exposed to Cd is a common occurrence. Lead can enter the human and cause several unwanted effects, such as: Disruption the biosynthesis of haemoglobin and anaemia, a rise in blood pressure, kidney damage and subtle abortions, disruption of nervous systems, brain damage. The LC50 values of Pb was vary from species to species and organism age. Main effect of As were coagulation of protein, reaction coenzym to complex, destroys the phosphate. Arsenic combinate with sulfhydryl groups of mitochondrial enzymes and prevents cellular respiration. Inorganic As (III) was the most toxicity. The major routes of toxic chemistry uptake in organism are through the respiratory system, the digestive system and the skin. Metals enter to the cell via membrane protein transporters and passive diffusion through the cell membrane. The accumulation of heavy metals in fish tissue is dependent on numerous of factors including water concentrations of metals, exposure period, water temperature, oxygen concentration, pH, hardness, salinity, alkalinity and dissolved organic carbon, …The elimination of metals from the tissues depends on time, age, metabolic activity, interacting agents, the biological half- life of the metals and aquatic species. Toxic chemistry got into the other organs from the blood, in here, it was bio-transformed, eliminated or accumulated. The rate of ...