Ecological and Health Risks Attributed to Rare Earth Elements in Coal Fly Ash

Latinka Slavković-Beškoski; Ljubiša Ignjatović; Mirjana Ćujić; Jelena Vesković; Katarina Trivunac; Jelena Stojaković; Aleksandra Perić-Grujić; Antonije Onjia

doi:10.3390/toxics12010071

Ecological and Health Risks Attributed to Rare Earth Elements in Coal Fly Ash

Toxics. 2024 Jan 15;12(1):71. doi: 10.3390/toxics12010071.

Authors

Latinka Slavković-Beškoski¹, Ljubiša Ignjatović², Mirjana Ćujić³, Jelena Vesković⁴, Katarina Trivunac⁴, Jelena Stojaković⁵, Aleksandra Perić-Grujić⁴, Antonije Onjia⁴

Affiliations

¹ Anahem Laboratory, Mocartova 10, 11160 Belgrade, Serbia.
² Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia.
³ Vinča Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11351 Vinča, Serbia.
⁴ Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia.
⁵ Innovation Center of the Faculty of Technology and Metallurgy, Karnegijeva 4, 11120 Belgrade, Serbia.

Abstract

The occurrence and distribution of yttrium and rare earth elements (REYs), along with major elements and heavy metal(loid)s (HMs) in coal fly ash (CFA) from five coal-fired power plants (CFPPs), were analyzed, and the REY-associated ecological and health risks were assessed. The individual REYs in CFA were abundant in the following order: Ce > La > Nd > Y > Pr > Gd > Sm > Dy > Er > Yb > Eu > Ho > Tb > Tm > Lu. The total REY content ranged from 135 to 362 mg/kg, averaging 302 mg/kg. The mean light-to-heavy REY ratio was 4.1, indicating prevalent light REY enrichment in CFA. Significantly positive correlations between the REYs suggested that they coexist and share similar origins in CFA. REYs were estimated to pose low to moderate ecological risks, with risk index (RI) values ranging from 66 to 245. The hazard index (HI) and target cancer risk (TCR) of REYs from CFA, estimated to be higher for children (HIc = 0.15, TCRc = 8.4 × 10^-16) than for adults (HIa = 0.017, TCRa = 3.6 × 10^-16), were well below the safety limits (HI = 1, TCR = 1.0 × 10^-6). However, the danger to human health posed by HMs in the same CFA samples (HIc = 5.74, TCRc = 2.6 × 10^-4, TCRa = 1.1 × 10^-4) exceeded the safe thresholds (excl. HIa = 0.63). The mean RI and HI attributed to REYs in CFA were 14% and 2.6%, respectively, of the total risks that include HMs.

Keywords: ICP-MS; Monte Carlo; REEs; REYs; cancer risk; hazard quotient; heavy metal(loid)s; multivariate analysis; power plant; risk index.

Grants and funding

This research was supported by the Science Fund of the Republic of Serbia (grant no. 7743343 SIW4SE—Serbian Industrial Waste towards Sustainable Environment: Resource of Strategic Elements and Removal Agent for Pollutants).