Heavy metals contamination in green leafy vegetables and its effect on human health: A review

Abstract

Heavy metal contamination in green leafy vegetables has emerged as a critical environmental and public health issue due to increasing industrialization, urbanization and agricultural practices. Heavy metals such as lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) are introduced into the soil, water, and atmosphere through industrial emissions, mining, sewage sludge application, pesticide and fertilizer use, and wastewater irrigation. Green leafy vegetables, owing to their high surface area and efficient nutrient absorption mechanisms, tend to accumulate these toxic metals, leading to bioaccumulation and biomagnification within the food chain. Regular consumption of contaminated vegetables poses serious health risks to humans, including oxidative stress, neurotoxicity, nephrotoxicity, hepatotoxicity, carcinogenic effects, and developmental disorders. Heavy metal exposure is linked to severe chronic illnesses, including cardiovascular diseases, kidney related problems and compromised immune responses. This review provides an in-depth analysis of the sources and pathways of heavy metal contamination in green leafy vegetables, the mechanisms of metal uptake and accumulation in plants, and the associated health risks for human consumers. Additionally, it discusses potential mitigation strategies such as phytoremediation, organic amendments, biochar application, and strict regulatory measures to minimize heavy metal contamination in agricultural produce. This review also explores global regulatory frameworks and future research directions to mitigate heavy metal exposure in agricultural produce. Understanding the interplay between environmental pollution, food safety, and human health is essential for formulating effective policies and sustainable agricultural practices.