STUDY OF HEAVY METAL CONTAMINATION AND ITS POTENTIAL IMPACT ON AGRICULTURAL SOILS AND HUMAN HEALTH IN MINING AREAS OF THAI NGUYEN PROVINCE

Abstract

Mineral extraction generates undeniable economic benefits; however, this activity has been and continues to be a principal contributor to environmental contamination in the vicinity of mining operations. This study evaluated heavy metal contamination in soils from mining areas and adjacent agricultural lands in Thai Nguyen province. Soil samples were collected from four locations: Tan Long lead-zinc mine, Ha Thuong tin mine, Trai Cau iron mine and Thai Nguyen city. Heavy metals including arsenic (As), zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb) were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results showed alarming levels of heavy metals exceeding Vietnamese national technical regulations (QCVN 03-MT:2015/BTNMT), particularly at three mining sites. Lead concentrations reached 38,441.6 mg/kg at Trai Cau (exceeding standards by 128 times), cadmium reached 172.9 mg/kg at Ha Thuong (17 times above limits) and zinc reached 40,124.9 mg/kg at Trai Cau (133 times above limits). No significant difference was found between mining soils and adjacent agricultural soils (p > 0.05), indicating contamination spread. Comparison with previous studies showed increasing contamination trends over time at multiple sites. The findings highlight serious environmental and health concerns, including potential bioaccumulation in food chains and impacts on agricultural productivity. The study recommends establishing buffer zones between mining and agricultural areas, implementing soil remediation techniques, monitoring heavy metal concentrations, and raising community awareness about associated health risks.