Department of Civil and Environmental Engineering, Green Environment and Energy Lab., National Laboratory Astana, Nazarbayev University, 53 Kabanbay Batyr Ave., Nur-Sultan 010000, Kazakhstan.
Department of Mathematics and Computer Science, Illinois Wesleyan University, Bloomington, IL 61702, USA.
Sci Total Environ. 2021 Jan 1;750:141535. doi: 10.1016/j.scitotenv.2020.141535. Epub 2020 Aug 5.
Kazakhstan's growing economy has been posing a threat to the natural environment in the country. The study aimed to investigate the status of soil contamination by five heavy metals (Pb, Cd, Cu, Zn, and Cr) in Kazakhstan during 2010-2018 as well as its impact on the population. Data for the analysis were collected from the governmental monitoring agency, which has reported the concentrations of five heavy metals in the Kazakhstan soil each year. Preliminary screening suggested the four most contaminated cities (Balkhash, Ust-Kamenogorsk, Ridder, and Shymkent). Mean soil concentrations in these cities varied between 251 and 442 mg/kg for Pb, 5-9 mg/kg for Cd, 8-138 mg/kg for Cu, 87-178 mg/kg for Zn, and 2-5 mg/kg for Cr. Analysis of geo-accumulation index pointed out the possible anthropogenic origin of the contamination by Pb and Cd in these cities (mean I was 3.81 for Pb and 3.45 for Cd). Further probabilistic risk assessment for these cities demonstrated that mean hazard indices for children fluctuated between 1 and 2 in two cities (Shymkent and Balkhash), whereas cancer risks for both age groups stayed in the range of 1 × 10 and 5 × 10, indicating that soil remediation is urgently required for the health of the citizens and environments. Both ~60-90% of adults and ~30-60% of children cases exceeded the threshold of carcinogenic assessment (1 × 10), suggesting that a large portion of the population in these cities could be affected by heavy metals in soil. The study provides background understanding for decision making on remediation actions and environmental policy and hazardous waste management in Kazakhstan.
哈萨克斯坦不断增长的经济对其国内的自然环境造成了威胁。本研究旨在调查 2010 年至 2018 年期间哈萨克斯坦境内五种重金属（铅、镉、铜、锌和铬）污染土壤的状况及其对人口的影响。分析所使用的数据来自政府监测机构，该机构每年都会报告哈萨克斯坦土壤中五种重金属的浓度。初步筛选表明，有四个污染最严重的城市（巴尔喀什、乌斯季卡缅诺戈尔斯克、里德和希姆肯特）。这些城市的土壤中铅的平均浓度在 251 至 442mg/kg 之间，镉的浓度为 5-9mg/kg，铜的浓度为 8-138mg/kg，锌的浓度为 87-178mg/kg，铬的浓度为 2-5mg/kg。基于地积累指数的分析表明，这些城市的铅和镉污染可能具有人为来源（铅的平均 I 值为 3.81，镉的平均 I 值为 3.45）。对这些城市的进一步概率风险评估表明，儿童的平均危害指数在两个城市（希姆肯特和巴尔喀什）之间波动在 1 到 2 之间，而两个年龄段的癌症风险都在 1×10 和 5×10 之间，这表明为了公民和环境的健康，急需对土壤进行修复。约 60-90%的成年人和约 30-60%的儿童病例超过了致癌评估的阈值（1×10），这表明这些城市的大部分人口可能受到土壤中重金属的影响。该研究为哈萨克斯坦的修复行动、环境政策和危险废物管理决策提供了背景理解。
