Analysis of Trace Element Composition in Leafy Vegetables in Sri Lanka: Implications for Human Diet

Leafy vegetables (LV) are a vital component of the Sri Lankan diet due to their richness in vitamins, minerals, fiber, and other essential nutrients. However, concerns have been raised about their potential contamination with trace elements, including heavy metals, which may pose health risks. Some heavy metals, such as cadmium (Cd), arsenic (As), and lead (Pb), have been controversially associated with health issues, including chronic kidney disease of unknown etiology (CKDu). However, their causal role remains under investigation. This study aimed to analyze the concentrations of As, Cd, and Pb in three commonly consumed leafy vegetables in Sri Lanka—kankun (Ipomoea aquatica), mukunuwenna (Alternanthera sessilis), and gotukola (Centella asiatica)—sourced from local markets in multiple districts. Samples were prepared using microwave digestion and analyzed via Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results revealed that, trace element concentrations in the order of Pb > Cd > As, with gotukola showing the highest Pb (7.24 mg/kg) and Cd (2.45 mg/kg) levels. Over 80% of samples exceeded Codex maximum limits for Pb, while all the samples analyzed were within acceptable limits for As. These findings highlight the need for routine monitoring and regulatory control of trace elements in leafy vegetables to ensure food safety. The study underscores potential dietary exposure risks and supports informed policy decisions regarding agricultural practices and public health interventions.