Chemical Review and Letters

Priority toxic metals arsenic, cadmium, mercury, and lead in ecosystems: A review of sources, toxicity, and regulatory approaches

Document Type : Review Article

Authors

Usmanova Khilola Umataliyevna 1, 2
Khikmat Shavkatovich Bobojonov 2
Smanova Zulaykho Asanaliyevna 2
Abdullayeva Muborak Muxsimovna 3
Tojiboyeva Feruzakhon Mamadjanovna 4
Atamuratova Malokhat Shavkatovna 5
Akhmadjonov Ulug'bek G'ulom o'gli 2
Gafurov Abdushukur Abdujalol o'g'li 2

1 University of Public Security of the Republic of Uzbekistan, 100109, Tashkent region, Uzbekistan

2 Department of Analytical Chemistry, National University of Uzbekistan, 100174, Tashkent, Uzbekistan

3 Department of Biology and Ecology, National University of Uzbekistan, 100174, Tashkent, Uzbekistan

4 Department of Analytical Chemistry, Tashkent Pharmaceutical Institute, 100015, Tashkent, Uzbekistan

5 Department of General and Inorganic Chemistry Tashkent Institute of Chemical Technology, 100174, Tashkent, Uzbekistan

https://doi.org/10.22034/crl.2025.526745.1616
Abstract
Heavy metals pose a persistent and escalating threat to ecosystems and human health due to their environmental persistence, bioaccumulative potential, and pronounced toxicity. This systematic review synthesizes current knowledge on the distribution, mechanisms of toxicity, regulatory approaches, and analytical strategies concerning four priority toxic metals: arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb). Relevant literature published between 2020 and 2025 was retrieved from Scopus, Web of Science, and PubMed, focusing on peer-reviewed studies. Included publications address contamination sources, toxicodynamics, international standards (WHO, EFSA, EU, Codex), and monitoring practices. Marked discrepancies in permissible exposure limits were identified across jurisdictions, while the neurotoxic, nephrotoxic, and carcinogenic effects of these metals are well documented. Particular concern arises from chronic low-dose exposure, combined metal exposure, and the emergence of nanoparticulate forms—areas where regulatory frameworks remain insufficient. The findings highlight the urgent need for harmonized standards, expanded biomonitoring efforts, and improved risk assessment methodologies to better safeguard environmental and public health

Graphical Abstract

Priority toxic metals arsenic, cadmium, mercury, and lead in ecosystems: A review of sources, toxicity, and regulatory approaches

Keywords

Heavy metals
toxicity
ecotoxicology
human health risk
environmental contamination
regulatory standards
biomonitoring

Subjects

Chemical Review and Letters
Volume 8, Issue 5 - Serial Number 5
September and October 2025
Pages 883-902

  • Receive Date 28 May 2025
  • Revise Date 08 June 2025
  • Accept Date 09 August 2025

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