How BPA-free alternative fluorene-9-bisphenol affects the freshwater ecosystems: acute toxicity, immunology and biochemical responses of mussels?

After the classification of bisphenol A as a worrisome endocrine disruptor due to its effects on the male and female reproductive systems, the plastic industry began to search for alternative substance production. One of these substances, Fluorene-9-bisphenol (BHPF), started to be used in plastic products following its production and took its place in materials described as BPA-free. However, this rapid development in the industrial field did not fully explain the effects of this alternatively produced substance on organisms. Various model organism studies conducted with BHPF have shown that BHPF may also be a possible endocrine disruptor compound. Therefore, this study aimed to investigate its toxic effects on freshwater mussels ( Unio terminalis ) used as a model organism in aquatic biological monitoring studies. After the 96-hour mean lethal concentration value of BHPF was determined as 0.84 mg/L (0.42-1.57 mg/L, 95% confidence interval), mussels (n=150) were exposed to sublethal BHPF concentrations (8.5 μg/L, 85 μg/L and 170 μg/L) for 2 and 7 days. According to the results of total hemocyte cell counts, exposure to BHPF caused a significant decrease in cell numbers ( p