Dissertation Title: STUDY ON THE ASSESSMENT OF THE SCALE OF TOXICITY AND HEALTH RISK CAUSED BY THE CONTENT OF TOXIC METALS IN MARINE BIOTA

Author: Kristi HAKA

• Institution: University of Tirana,  Faculty of Natural Sciences, Department of Chemistry.

• Field of study: Applied Chemistry

• Online publication date: 03.03.2026

• The dissertation is published in Albanian.

© Copyright: Kristi HAKA

Published by the University of Tirana
Based on legal acts, regulations and policies of the UT

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ABSTRACT 

This study addresses the assessment of the toxicity and health risk caused by metal concentrations in marine biota, including the analysis of different species and the potential impacts on human health and environmental ecosystems. The main goal is the identification and quantification of heavy metals in biota samples such as cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), chromium (Cr), nickel (Ni), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), aluminum (Al), cobalt (Co), calcium (Ca) and magnesium (Mg) and the assessment of the risk associated with the consumption of these organisms.  

The methodology used involves collecting samples from various areas of marine and lake waters, including coastal, lake and industrially impacted areas. Samples of fish, crustaceans and other organisms were analyzed for heavy metal concentrations using advanced laboratory techniques, including atomic force spectroscopy (AFS). In addition to determining concentrations, the study includes the use of toxicological and health risk models to assess chronic exposure and the potential for harm to consumers of seafood products. 

The results show that some studied areas present significant concentrations of toxic metals, which exceed safe limits for consumption, posing a significant risk to human health. The analyses also show that some marine species have a higher tendency to bioaccumulate, increasing the potential for biomagnification of toxic metals at higher levels of the food chain. Through the health risk assessment, the most exposed groups have been identified, and restrictions and guidelines for the safe consumption of marine products from contaminated areas have been proposed. 

This paper highlights the importance of continuous monitoring of toxic metals in marine biota and the need for clear management measures. The use of sustainable policies, pollution reduction strategies and population education on the risks of exposure to toxic metals is recommended. The study contributes to the scientific literature on the spread of toxic metals and provides a solid basis for the development of risk assessment methodologies in future studies, helping decision-makers and environmental institutions in the protection of public health and marine ecosystems. 

This paper aims to provide a comprehensive framework for understanding heavy metal pollution in marine waters and its impacts, as well as to contribute to the implementation of practical measures for addressing and managing these risks, combining the scientific perspective with environmental and public health needs. 

 

ABSTRACT 

This study presents a comprehensive assessment of the toxicity levels and associated health risks arising from metal concentrations in marine biota. It encompasses the analysis of multiple aquatic species to evaluate their potential implications for human health and environmental ecosystems. The primary objective is to identify and quantify the presence of heavy metals in biotic samples, including cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), chromium (Cr), nickel (Ni), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), aluminum (Al), cobalt (Co), calcium (Ca), and magnesium (Mg), and to assess the risks related to the consumption of these organisms. 

The applied methodology involves the systematic collection of samples from various marine and freshwater environments, including coastal, lacustrine, and industrially influenced areas. Samples of fish, crustaceans, and other aquatic organisms were analyzed to determine heavy metal concentrations using advanced analytical techniques, such as Atomic Absorption Spectroscopy (AAS). Beyond concentration determination, the study employs toxicological and health risk assessment models to evaluate chronic exposure and potential adverse effects on consumers of seafood products. 

The findings indicate that certain sampling areas exhibit elevated concentrations of toxic metals that surpass established safety thresholds, thereby posing significant risks to human health. Furthermore, several marine species demonstrated a higher propensity for bioaccumulation, consequently enhancing the potential for biomagnification of toxic metals across higher trophic levels of the aquatic food web. Through quantitative health risk assessment, the most vulnerable population groups were identified, and specific recommendations and consumption guidelines were proposed for mitigating exposure from contaminated seafood sources. 

This research underscores the critical importance of continuous monitoring of toxic metals in marine ecosystems and highlights the necessity for well-defined management and regulatory measures. The implementation of sustainable environmental policies, pollution mitigation strategies, and public awareness initiatives regarding the dangers of toxic metal exposure are strongly advocated. The study contributes valuable insights to the scientific literature on the distribution and ecological implications of heavy metals, providing a robust foundation for future developments in environmental risk assessment methodologies. 

Overall, this work seeks to establish an integrated framework for understanding heavy metal contamination in marine waters and its multifaceted impacts, while promoting the adoption of practical, science-based measures for the prevention, management, and reduction of associated ecological and public health risks.