Morpho-chemical characterization and source apportionment of potentially toxic metal(oid)s from school dust of second largest populous city of Pakistan


Rehman A., Liu G., Yousaf B. , Ahmed R., Rashid M. S. , Irshad S., ...More

Environmental Research, vol.196, 2021 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 196
  • Publication Date: 2021
  • Doi Number: 10.1016/j.envres.2020.110427
  • Title of Journal : Environmental Research
  • Keywords: Geo-accumulation index, Ecological risk assessment, metal(oid)s speciation, Multivariate statistical analysis, School indoor pollution, NATURALLY VENTILATED SCHOOLS, HEALTH-RISK ASSESSMENT, AMBIENT AIR-POLLUTION, PARTICULATE MATTER, HEAVY-METALS, ROAD DUST, TRACE-ELEMENTS, SURFACE SOILS, PM10, BIOACCESSIBILITY

Abstract

© 2020 Elsevier Inc.Interior settled dust is one of the greatest threats of potentially toxic metal(oid)s (PTMs) exposure to the children, especially in the school environment. Therefore, it is more worthy of having in-depth knowledge of compositional characteristics of school dust. Forty schools were selected of Lahore city for dust sampling. The school dust was analyzed to determine the PTMs (As, Cd, Cr, Cu, Ge, Mo, Ni, Pb, Sb, Sn, Sr, V, and Zn) concentrations using ICP-MS. The morphological characteristics, PTMs speciation, and mineralogy of school dust were examined using SEM with EDS, XPS, and XRD, respectively. Moreover, the geo-accumulation index (Igeo), potential ecological risk index (PERI), and multivariate statistical analysis were employed to assess the pollution levels, ecological risk, and source identification of PTMs, respectively. The Igeo indicated a heavily-extreme pollution level of Cd (Igeo = 4.92), moderate-heavy pollution of Zn (Igeo = 3.22), and Pb (Igeo = 2.78), and slight-moderate pollution of Cr (Igeo = 1.62), and Cu (Igeo = 1.53). The ecological risk has been found extremely high for Cd and moderately high for Pb and As, while potential ecological risk found extremely high posed by cumulatively all selected PTMs. Multivariate statistical analysis showed that sources of PTMs comprise of natural processes as well as several anthropogenic processes like vehicular emissions, agricultural and industrial activities. The SEM, XRD, and XPS analyses demonstrated the presence of airborne particles and PTMs containing minerals with several toxic chemical species in school dust. This study can help to develop strategies to reduce school indoor pollution and hence to establish an eco-friendly learning environment for children.