Identification and quantification of the combined phytotoxicity of one element with various valences: Cr(III) and Cr(VI) for barley root elongation as an example

Linheng Chen; Weixi Liu; Yang Wu; Jumei Li; Yibing Ma

doi:10.1016/j.jhazmat.2022.128430

Identification and quantification of the combined phytotoxicity of one element with various valences: Cr(III) and Cr(VI) for barley root elongation as an example

J Hazard Mater. 2022 May 15:430:128430. doi: 10.1016/j.jhazmat.2022.128430. Epub 2022 Feb 4.

Authors

Linheng Chen¹, Weixi Liu¹, Yang Wu², Jumei Li³, Yibing Ma¹

Affiliations

¹ Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality, Macao Environmental Research Institute, Macau University of Science and Technology, Macao 999078, China; National Observation and Research Station of Coastal Ecological Environments in Macao, Macau University of Science and Technology, Macao 999078, China.
² Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality, Macao Environmental Research Institute, Macau University of Science and Technology, Macao 999078, China; National Observation and Research Station of Coastal Ecological Environments in Macao, Macau University of Science and Technology, Macao 999078, China. Electronic address: yawu@must.edu.mo.
³ Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: lijumei@caas.cn.

PMID: 35149490
DOI: 10.1016/j.jhazmat.2022.128430

Abstract

There is uncertainty in quantifying the toxic effects of total chromium (Cr) in the environment by modeling the toxicity of individual Cr(III) or Cr(VI). In the present study, the effects of Cr(III) and Cr(VI) on barley root elongation were investigated in a hydroponic system where Cr(III) and Cr(VI) combination dose-response experiments under monotoxicity concentration, single-dose addition, and fixed concentration ratios were designed to identify and quantify their combined phytotoxicity of one element with various valences. The results show that the calculated mixed toxicity unit values for 50% inhibition (TU_mix50) ranged from 1.06 to 1.45, indicating the weak antagonism effects of Cr(III) and Cr(VI) on barley root toxicity. Also, the single-dose group experiment has proved that the EC₅₀ of Cr(VI) was increased from 71.2 μM to 119.9 μM with Cr(III) addition, which suggested that Cr(III) has antagonism on the toxicity of Cr(VI). While EC₅₀ of Cr(III) was not affected by Cr(VI) addition. After introducing the expansion coefficient of Cr(III) on Cr(VI) toxicity, both the extended concentration addition model (e-CA) based on the log-logistic and Weibull equations and the extended independent action model (e-IA) could more accurately predict the barley root elongation under Cr(III) and Cr(VI) interaction. The e-CA model based on the Weibull equation had almost the best correlation coefficient (R²) and lowest root mean square error (RMSE) between the measured and predicted values. Finally, the combined toxicity and antagonism of the same element with co-existing different valences simultaneously were successfully and firstly identified and quantified in the present study.

Keywords: Concentration addition model; Hexavalent chromium; Independent action model; Trivalent chromium.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chromium / toxicity
Hordeum*
Hydroponics

Substances

Chromium
chromium hexavalent ion