Health risk assessment of potentially toxic elements in Maros karst groundwater: a Monte Carlo simulation approach

This study investigated potentially toxic elements (PTEs) pollution in groundwater across the Maros karst area. The groundwater quality was evaluated using three indexing methods, the heavy metal pollution index (HPI), the heavy metal evaluation index (HMEI) and the contamination index (Cd). The levels of PTEs were calculated to determine the noncancer and cancer risks to the residents through ingestion and dermal adsorption. To obtain high-level accuracy in cancer risk estimation, a Monte Carlo simulation model and sensitivity analysis were performed. The mean values of PTEs in rainy and summer season were followed the order of Cr > Pb > Zn > Cu and Cr > Zn > Pb > Cu, respectively. The high level of Pb and Cr were exceeded the permissible limit of the World Health Organization (WHO) and Indonesian Standards. However, TDS, pH, EC and temperature were still in accordance with WHO guidelines. The geostatistical interpolation of HPI, HMEI and Cd revealed that the groundwater quality around Maros karst is low, particularly in Tukamasea and Leang-Leang village. Hazard index values were lower than one, implying no possibility of noncancer risk. The Monte Carlo simulation results with 95% confidence demonstrated children and adults are at risk for developing cancer due to PTE exposure.

本研究针对马罗斯喀斯特（Maros karst）地区地下水中的潜在有毒元素（PTEs）污染状况开展了系统调查。本次研究采用重金属污染指数（HPI）、重金属评价指数（HMEI）与污染指数（Cd）三种评价方法，对该区域地下水水质进行了综合评估。通过摄入与皮肤接触吸附两条暴露途径，计算了潜在有毒元素的暴露水平，以明确当地居民所面临的非致癌与致癌健康风险。为提升致癌风险评估的精准度，本研究引入蒙特卡洛模拟（Monte Carlo simulation）模型开展量化分析，并同步进行了敏感性检验。
雨季与夏季的潜在有毒元素平均浓度排序分别为Cr > Pb > Zn > Cu与Cr > Zn > Pb > Cu。研究发现，铅（Pb）与铬（Cr）的高浓度值超出了世界卫生组织（WHO）及印度尼西亚国家标准规定的限值。
但总溶解固体（TDS）、pH值、电导率（EC）及水温均符合WHO的水质指导标准。
针对重金属污染指数、重金属评价指数与污染指数的地质统计学插值分析结果显示，马罗斯喀斯特周边区域的地下水水质整体处于较低水平，尤其在图卡马塞阿（Tukamasea）村与梁梁（Leang-Leang）村一带污染更为显著。
危害指数值均小于1，表明当地居民暂无非致癌健康风险。基于95%置信水平的蒙特卡洛模拟结果表明，儿童与成人均存在因潜在有毒元素暴露而罹患癌症的健康风险。