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ФЕРУМ У ВОДНИХ ЕКОСИСТЕМАХ: ФОРМИ ЗНАХОДЖЕННЯ, БІОЛОГІЧНЕ ЗНАЧЕННЯ ТА ТОКСИЧНІСТЬ ДЛЯ РИБ

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Е. А. Рабченюк, В. А. Хоменчук, В. З. Курант

Тернопольский национальный педагогический университет имени Владимира Гнатюка

ЖЕЛЕЗО В ВОДНЫХ ЭКОСИСТЕМАХ: ФОРМЫ НАХОЖДЕНИЯ, БИОЛОГИЧЕСКОЕ ЗНАЧЕНИЕ И ТОКСИЧНОСТЬ ДЛЯ РЫБ

В обзоре проанализированы роль железа в природных водах, особенности его метаболизма и токсичности для рыб. Охарактеризованы основные методы экоаналитического контроля железа в гидроэкосистемах. Отмечено, что металл может встречаться в природных водах в растворимой и нерастворимой форме, в виде соединений двух- и трехвалентного железа. Отмечено, что потребности рыб в железе могут значительно варьировать в зависимости от видовых особенностей рыб, однако они значительно ниже по сравнению с млекопитающими. Отмечено, что токсическое действие металла обусловливается не только концентрацией и формами нахождения металла в водной среде, но и физико-химическими показателями воды и физиологическим состоянием организма рыб, которые сильно влияют на биодоступность и скорость усвоения металла.

Ключевые слова: гидроэкосистемы, железо, токсичность, метаболизм, рыбы

 

O. O. Rabchenyuk, V. O. Khomenchuk, V. Z. Kurant

Ternopil Volodymyr Hnatyuk National Pedagogical University, Ukraine

IRON IN AQUATIC ECOSYSTEMS: THE FORMS OF EXISTENCE, BIOLOGICAL SIGNIFICANCE AND TOXICITY FOR FISH

The role of iron in natural waters, especially its metabolism and toxicity for fish, is analysed. Methods of ecoanalytical control of iron in aquatic ecosystems are described. It is noted that iron may occur in natural waters in the following forms: a true solution (compound Fe (II)), insoluble form (compound Fe (III)), organic and inorganic ironcolloids, complex compounds and in the form of finely dispersed suspension (Fe(OH)3, Fe(OH)2, FeS. The relation between forms of iron in natural waters depends on temperature, pH, the presence of chelating agents and oxygen. Bivalent iron (Fe (II)) is more soluble than its trivalent form (Fe (III)). It is noted that for determining the concentration of metals in water the following methods are often used: atomic absorption spectrometry (AAS) with fiery detector, atomic absorption spectrometry in a graphite furnace, atomic emission spectroscopy with inductively coupled plasma (ICP-AES), mass spectrometry with inductively combined plasma. For separating different forms of metal, the above mentioned methods are combined with the separation and concentration techniques, such as extraction, ions selective, liquid, gas chromatography, electrochemical methods. It is noted that iron is an essential metal for animal life in an environment which is rich in oxygen, and is part of a series of heme (hemoglobin, mitochondrial and microsomal cytochromes, catalase, etc.) and non-heme (transferrin, ferritin, mitoferrin etc.) proteins and plays an important role in redox processes of cells. Needs of fish in iron can vary considerably depending on the specific characteristics of fish, but they are much lower comparing to mammals. The absorption of iron in fish is strictly regulated by highly effective process and is done by two main ways: through the gills and gastrointestinal tract which have a clear interaction. A very small amount of iron in the organism of fish is in an unrelated form. As a rule, storage and transportation of the metal is done in the form of complex metalloproteins. The major Fe containing proteins that provide deposit and transport of iron is ferritin and transferrin. The main regulator of iron absorption and distribution in all organs of animals is the peptide hepcidin – iron-regulating hormone. It is shown that iron toxicity is closely related to its forms of water which is directly interact with the body surface and gills of fish. Metal toxicity is due not only to the concentration of the metal in the aquatic environment, but also the physical and chemical indices of water and physiological state of the organism of fish which are greatly affect on the bioavailability and rate of assimilation of the metal.

Keywords: aquatic ecosystems, iron, toxicity, metabolism, fish

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