Are BPA-free plastics safe for aquatic life? - Fluorene-9-bisphenol induced thyroid-disrupting effects and histopathological alterations in adult zebrafish (Danio rerio)

Fluorene-9-bisphenol (BPFL) is used as an alternative compound for bisphenol A, an endocrine disruptor compound which is present in various materials including plastic bottles and packaging. Although it is used extensively in products that are labelled BPA-free, its effect on wildlife and humans have not been fully studied. Therefore, this study aimed to investigate the effects of BPFL in adult zebrafish. In the preliminary experiments of the study, the median lethal concentration value (LC50) of BPFL was 0.25 mg/L (95 % confidence interval 0.15–0.41) for 96 h. Following exposure to three different sublethal concentrations of BPFL after 96 h and 15 days, T4 hormone levels, expression levels of genes involved in thyroid metabolism and histopathological alterations were assessed. T4 hormone levels were found to be significantly higher in females at the lowest BPFL concentration following 96 h exposure (P