The role of atomic absorption spectroscopy in heavy metal contamination and human health risk assessment: A comprehensive review

Abstract

Heavy metal contamination of the environment having a substantial and growing threat to human health worldwide. Atomic Absorption Spectroscopy (AAS) has seemed as one of the most powerful, reliable, and broadly applied analytical techniques for the quantitative determination of heavy metals in complex environmental, biological, food, and clinical matrices. This review provides a comprehensive overview of AAS principles, instrumentation variants including Flame AAS (FAAS), Cold Vapour AAS (CV-AAS), Graphite Furnace AAS (GFAAS) and Hydride Generation AAS (HG-AAS), their application to heavy metal analysis across multiple samples. The review critically studies the role of AAS in human health risk assessment, covering exposure pathways, toxic mechanisms of import heavy metals including arsenic (As), cadmium (Cd), mercury (Hg), chromium (Cr), nickel (Ni), and lead (Pb), and the application of internationally recognized risk assessment frameworks. Recent methodological advances including high-resolution range source AAS (HR-CS AAS), hyphenated techniques, and automation are discussed. Current limitations and future directions for AAS in environmental health research are also identified.