Hamadan University of Medical Sciences Avicenna Journal of Environmental Health Engineering 2423-4583 11 2 2024 12 29 Investigation of Heavy Metals Contamination in the Soil of Landfill Sites of Iran: A Systematic Review 115 125 10.34172/ajehe.5467 EN Sepideh Sahragard https://orcid.org/0009-0003-3014-5841 Roqiyeh Mostafaloo https://orcid.org/0000-0002-5415-0755 Farzaneh Fanaei https://orcid.org/0000-0001-5390-3295 Senobar Imanian https://orcid.org/0000-0001-6153-9251 Monireh Dehabadi https://orcid.org/0000-0002-2333-5394 Amir Adibzadeh https://orcid.org/0000-0002-5703-0759 Negin Nasseh https://orcid.org/0000-0001-8898-630X Journal Article 10.34172/ajehe.5467 2024 02 20 2024 10 30 Heavy metals from hazardous waste, such as batteries, electronics, cleaning products, and cosmetics, can be transported to soil through landfill leachates. Due to their persistent structure, toxic metals such as chromium (Cr), cobalt (Co), lead (Pb), and cadmium (Cd) accumulate in the soil and can cause various ecological and health risks. Hence, this study aimed to assess the extent of heavy metal pollution in the soil of landfill sites in Iran. The present study reviewed previous research on the assessment of heavy metal contamination such as Pb, arsenic (As), Cr, Cd, zinc (Zn), Co, and nickel (Ni) in soils of landfill sites. For this purpose, "Magiran", "SID", «IranMedex», "Scopus», "PubMed", "ScienceDirect" and "Web of Science" databases were searched for related articles published until 2024. Persian and English keywords including heavy metals, waste disposal sites, soil, and Iran were used for search. Eventually, out of 206 articles, 21 studies met our inclusion criteria and were included in the study. The concentrations of heavy metals, including Pb, As, Cr, Cd, Zn, Co, and Ni, were found to be higher than national and international standards in some soil samples. Therefore, landfill sites, as an anthropogenic resource, have the potential to transmit pollution to the soil. Contamination levels depend on waste composition, hazardous content, leachate production and migration, landfill age and design, soil characteristics, and operating conditions. Health and ecological risks can be mitigated by reducing hazardous waste, recycling heavy metal-containing wastes, installing anti-seepage systems, and maintaining continuous monitoring.