Abstract

Exposure to heavy metals, including arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg), is a major health hazard. The toxic effects of these heavy metals can exist in a latent state. These metals may accumulate through persistent exposure, causing adverse effects after several years to decades. Heavy metals are found in rice, the main staple food in East Asia. We studied the ecological effects of heavy metals on rice plant roots, straws, and seeds, and the soil and water used for rice cultivation. Food-grade rice grains were also analyzed. The toxicity level of As changed with the chemical form; therefore, species separation analysis of As was conducted. The concentrations of Pb, Cd, and As were analyzed by inductively coupled plasma – mass spectrometry (ICP-MS). The Pb concentration was the highest in soil (59.32 × 10² μg/kg), whereas Cd and As concentrations were the highest in rice roots at 52.36 and 20.65 × 10² μg/kg, respectively. In all samples, Hg was below the detection limit of the employed instrumentation. None of the heavy metal concentrations in the samples exceeded the Korean safety guideline levels. The heavy metal concentrations in the rice samples were the highest near the soil and decreased with distance, particularly As. The concentration of inorganic As was analyzed by high-performance liquid chromatography coupled with ICP-MS. The separation of As species in rice, consumed as food, showed the concentration of inorganic As was 69.51 μg/kg, which is below the Korean safety guideline levels.

摘要

接触重金属，包括砷 (As)、铅 (Pb)、镉 (Cd) 和汞 (Hg)，是一种主要的健康危害。这些重金属的毒性作用可能以潜伏状态存在。这些金属可能会通过持续接触而积累，在数年至数十年后造成不利影响。重金属存在于大米中，大米是东亚的主要主食。我们研究了重金属对水稻根系、秸秆和种子以及水稻种植土壤和水的生态影响。还分析了食品级米粒。As的毒性水平随化学形态的变化而变化；因此，进行了 As 的物种分离分析。Pb、Cd 和 As 的浓度通过电感耦合等离子体质谱法 (ICP-MS) 进行分析。Pb 浓度在土壤中最高（59.32 × 10²  μg/kg)，而水稻根中的 Cd 和 As 浓度最高 ，分别为 52.36 和 20.65 × 10 ² μg/kg。在所有样品中，Hg 均低于所用仪器的检测限。样本中的重金属浓度均未超过韩国安全指南水平。大米样品中的重金属浓度在土壤附近最高，随着距离的增加而降低，尤其是 As。无机砷的浓度通过高效液相色谱结合 ICP-MS 进行分析。作为食物消费的大米中 As 物种的分离显示无机 As 的浓度为 69.51 μg/kg，低于韩国安全指南水平。