Potential genotoxicity and risk assessment of a chlorinated flame retardant, Dechlorane Plus

Dechlorane Plus (DP) is a chlorinated flame retardants that is globally ubiquitous. It is a potentially persistent organic pollutant (POPs) and an environmental toxin. However, the toxicity data is still limited and cannot provide a comprehensive environmental ecological risk assessment for DP. In this study, luminous bacteria, Vicia faba and Tetrahymena thermophila were chosen as testing organisms to investigate the acute toxicity and mutagenicity of DP. The concentration gradient of DP used in this study was chosen based on its environmental levels (experiments of luminous bacteria: 0.591, 2.95, 14.8, 73.8, 369 μg L−1; micronucleus tests: 2.4, 12, 60, 300, 1500 μg L−1; comet assay: 2.4, 12, 60, 300, 1500 μg L−1). For luminous bacteria, the relative luminosities were around 100% in treated groups, which suggested that there is no acute toxicity to luminous bacteria under the studied DP concentrations. The micronucleus test showed no significant difference between treatment and control groups, indicating no genotoxicity of DP. However the comet assay conducted with T. thermophila was relatively sensitive as there was a significant increase in DNA damage when the concentrations of DP increased from 300 to 1500 μg L−1, while the lower concentrations failed to show any treatment-related differences. Therefore, DP may pose a potential risk at concentration ⩾ 300 μg L−1. The results provide scientific information on the ecological risk assessment of DP.