Potential Health Risk Assessment of Heavy Metals via Garlic Consumption from Cultivation Areas in Northern Thailand

Heavy metal (HM) contamination in agricultural soils may lead to plant uptake from roots to edible parts, posing risks to food safety. This study assessed the health risks from garlic consumption in Chiang Mai and Lampang, Thailand’s major garlic-producing provinces. Detected HM concentrations in soil followed the order: Pb > Cr > Cu >As > Cd, respectively. All measured levels were within acceptable limits. Heavy metal concentration in Chiang Mai soil was 7.08 ± 4.72 mg/kg (As); 0.84 ± 0.32 mg/kg (Cd); 19.25 ± 7.18 mg/kg (Cr); 14.64 ± 6.51 mg/kg (Cu); and 20.45 ± 6.70 mg/kg (Pb). By comparison, average concentrations in Lampang soil were 14.20 ± 2.81 mg/kg (As), 2.25 ± 0.24 mg/kg (Cd); 28.00 ± 3.87 mg/kg (Cr); 26.34 ± 2.33 mg/kg (Cu); and 28.62 ± 3.84 mg/kg (Pb). Elevated Pb levels in soils cultivated with garlic and other crops likely stemmed from agricultural chemical use, with Pb concentrations in garlic exceeding the Codex Alimentarius Commission (CODEX) guideline value.