School of Environmental, Resources and Development, Asian Institute of Technology, Pathumthani, Thailand.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2010 Nov;45(13):1702-14. doi: 10.1080/10934529.2010.513232.
There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities. To better understand current status of Pb contamination and accumulation in the surrounding environment and potential health impact, surface sediment, soil and plant samples were collected seasonally from representative monitoring sites along the aquatic track or flow regime. Potential health risk was determined using hazard quotient (HQ) as an index for local inhabitants who consume rice. Environmental monitoring illustrated that Pb concentrations in the surface sediment was as high as 869.4 mg kg(-1) dry weight and varied differently among stations sampled. Lead content in agricultural soil ranged between 137.8 to 613.5 mg kg(-1) dry weight and was inversely proportion to the distance from the point source. Moreover Pb was transported from the point source to down hill areas. At the highly polluted monitoring stations (S1, S2, and S3), concentrations of Pb exceeded the maximum allowable concentration for Pb in agricultural soil (300 mg kg(-1)) by 1.7-2 times. The Pb in soil was primarily associated with Fe/Mn oxides bound fraction (46-56%) followed by the organic bound fraction (25-30%). Lead uptake by plant varied and was species dependent. However root and tuber crops like cassava (19.92 mg Pb kg(-1) dry weight) and curcumin (3.25 mg Pb kg(-1) dry weight) could have removed Pb from the soil which suggest growing root crops in Pb contaminated soils should be avoided. However Cd, a co-contaminant at one of monitored stations (S4) yielded rice grain with Cd exceeding the maximum allowable concentration suggesting some potential health risk (HQ = 5.34) if people consume rice grown at this station. Overall result shows a low risk associated with Pb release into the environment.
泰国山区有许多废弃和现存的矿山（锡、铅和锌矿）。有毒元素，包括重金属如铅（Pb）、镉（Cd）和砷（As），已经从矿区释放出来并迁移到相邻的景观中。在泰国北碧府的通帕蓬区，附近矿区发生了铅污染，这可能会给下游社区带来潜在的健康问题。为了更好地了解当前周边环境中铅污染和积累的状况以及潜在的健康影响，从沿水流轨迹或流动状态的代表性监测点采集了季节性的表层沉积物、土壤和植物样本。利用危害系数（HQ）作为食用大米的当地居民的指标，确定了潜在的健康风险。环境监测表明，表层沉积物中的 Pb 浓度高达 869.4mgkg(-1)干重，且在采样点之间存在差异。农田土壤中的 Pb 含量在 137.8 至 613.5mgkg(-1)干重之间，且与距污染源的距离成反比。此外，Pb 从污染源向山坡地区迁移。在污染最严重的监测站（S1、S2 和 S3），Pb 浓度超过农田土壤 Pb 最大允许浓度（300mgkg(-1))的 1.7-2 倍。土壤中的 Pb 主要与 Fe/Mn 氧化物结合态（46-56%）有关，其次是有机结合态（25-30%）。植物对 Pb 的吸收因物种而异。然而，像木薯（19.92mgPbkg(-1)干重）和姜黄（3.25mgPbkg(-1)干重）这样的根和块茎作物可以从土壤中去除 Pb，这表明在 Pb 污染的土壤中种植根作物应该避免。然而，在一个监测站（S4），作为共污染物的 Cd 使稻谷中的 Cd 含量超过了最大允许浓度，这表明如果人们食用在这个监测站种植的水稻，可能存在一些潜在的健康风险（HQ=5.34）。总体结果显示，Pb 释放到环境中带来的风险较低。
