Department of Environmental Science, Tezpur University, Napaam, Tezpur, Assam, 784028, India.
Environ Monit Assess. 2020 Oct 31;192(11):741. doi: 10.1007/s10661-020-08684-6.
This study reports concentrations of trace metals and the associated health risks in settled dust of different microenvironments of a university in Northeast India. Settled dust samples were collected from the most accessible indoor locations by the students of Tezpur University, a rural-residential university of mid Brahmaputra Valley of Assam. Collected samples were digested in an aqua regia-assisted microwave digestion system and analyzed for iron (Fe), nickel (Ni), zinc (Zn), cadmium (Cd), and lead (Pb) using atomic absorption spectroscopy (AAS). The highest concentration was obtained for Fe with a mean value of 1353.51 ± 123 mg/kg. Cadmium showed the lowest concentration with a mean value of 0.75 ± 0.57 mg/kg. Cadmium was the highly enriched element followed by Pb, Zn, and Ni. The metals mostly fall in the "extremely high enrichment" category. The study revealed that infiltrated soil or street dust, eroding wall paints, and automotive sources were the main contributing sources of the metals. The calculated Hazard Index (HI) value, 0.39, was lower than the acceptable HI value of 1 indicating no significant non-cancer risk to the students from exposure to these heavy metals at present. The study also found no carcinogenic risk on exposure to the metals present in the indoor dust samples.
本研究报告了印度东北部一所大学不同微环境中沉降尘中痕量金属的浓度及其相关健康风险。收集的沉降尘样本是由 Assam 地区布拉马普特拉河谷中部的农村住宅式 Tezpur 大学的学生从最容易进入的室内地点采集的。采集的样本在王水辅助微波消解系统中进行消解，并使用原子吸收光谱法（AAS）分析铁（Fe）、镍（Ni）、锌（Zn）、镉（Cd）和铅（Pb）的含量。浓度最高的是 Fe，平均值为 1353.51 ± 123 mg/kg。Cd 的浓度最低，平均值为 0.75 ± 0.57 mg/kg。Cd 是高度富集的元素，其次是 Pb、Zn 和 Ni。这些金属大多属于“极高富集”类别。研究表明，渗透土壤或街道灰尘、侵蚀的墙壁涂料和汽车来源是这些金属的主要来源。计算得出的危害指数（HI）值为 0.39，低于可接受的 HI 值 1，表明目前学生接触这些重金属不会产生显著的非癌症风险。该研究还发现，室内灰尘样本中存在的金属没有致癌风险。
