Heavy Metals Contamination in Vegetables Grown in Polluted Soils and Their Health Implications for Humans in South Asia: A Systematic Review

Background: This review aimed to investigate vegetable contamination with heavy metals and their associated health impacts on humans.Methods: Data was collected from websites, journals, and published reports on heavy metals contamination in vegetables over the last 30 years using various search engines, including Google Scholar, ResearchGate, Scopus, Google Scholar, DOAJ, PLOS ONE, etc. Results: The analysis results illustrated that heavy metal concentrations in common vegetables, such as tomatoes, eggplants (brinjal), spinach, red spinach, carrots, and radishes, of different countries often exceeded the permissible limits of the World Health Organization (WHO), the Codex Alimentarius Commission, China's Ministry of Health, and the State Environmental Protection Administration (SEPA) standards.This review showed that the higher concentrations of heavy metals, especially cadmium, copper, chromium, lead, and manganese, are linked to numerous health disorders in humans, including cardiovascular diseases, low birth weight, spontaneous abortions, gastrointestinal issues, liver damage, and renal dysfunction. Conclusion:The excessive use of chemical fertilizer and irrigation with contaminated groundwater and industrial discharge wastewater are the causes of higher levels of heavy metal accumulation in vegetables.Thus, relevant authorities must take initiatives to monitor industrial effluent discharge, ensure compliance with regulatory frameworks, and build public awareness for food safety, soil, water, and environmental sustainability.