General toxicity and genotoxicity studies of a new scale inhibitor for seawater desalination

Maleic acid polymer scale inhibitor is a new domestic seawater desalination scale inhibitor. This study tested the acute oral toxicity, sub-chronic toxicity and genotoxicity of this new inhibitor. The LD₅₀ obtained from the acute oral toxicity test was 6810 and 9260 mg/kg·BW for male and female rats, as well as 1/5, 1/10 and 1/20 LD₅₀ were as the dose for sub-chronic toxicity test. It showed the weight of male rats with high dose was significantly lower than the control group during the exposure period (p < 0.05), and the food consumption in the first 4 weeks was lower than the control group (p_{_week1} = 0.0261, p_{_week4} = 0.00222). The blood biochemical results showed the UREA in the medium- and high-dose groups were significantly higher than the control group (p_{_ female medium} = 0.0047, p_{_high} = 0.0037; p_{_male medium} = 0.0026, p_{_high} < 0.001), and increased as a dose dependence. Based on UREA results, the NOAEL and LOAEL were 1/20 LD₅₀ and 1/10 LD₅₀, respectively (males: 340.5 and 681 mg/kg·BW, females: 436 and 926 mg/kg·BW). Comet assay in vitro and Mammalian Erythrocyte Micronucleus Test were jointly to judge genotoxicity. This inhibitor did not cause chromosome aberrations in mouse bone marrow cells. However, the tail moment of CHO cell in all groups (p < 0.01) and the DNA% in tail in the 1/4 IC₅₀ and IC₅₀ groups were higher than the negative control (p < 0.001) in comet assay, suggesting the potential DNA damage in CHO cell. The oral LD₅₀ and the NOAEL and LOAEL obtained in this study provides a theoretical basis for further toxicity research and risk assessment.

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