Production of bisphenol A (BPA) analogues such as bisphenol F (BPF) and bisphenol AF (BPAF) has recently increased, due to clear evidence of adverse effects of BPA on humans and wildlife. Bisphenols (BPs) have already been released into aquatic environment without previous available information about potential adverse effects of BPs and their potential risk to aquatic ecosystems. In this study, lethal and sublethal effects of BPF and BPAF to bacteria, algae, crustacea and fish embryos were investigated and the results were compared to the adverse effects obtained for BPA. We found that BPAF was the most toxic compound to Daphnia magna, Danio rerio and Desmodesmus subspicatus; the lowest 72 h EC50 (median effective concentration) and 21 d NOEC (no observed effect concentration) values were determined at 2.2 mg/L regarding zebrafish hatching success and 0.23 mg/L of BPAF obtained for growth and reproduction of water fleas, respectively. In most cases, BPA was more toxic to D. magna, D. rerio and D. subspicatus in comparison to BPF, but pigmentation of zebrafish embryos after 48 h of exposure and reproduction of water fleas after 21-day D. magna reproductive test exposure to BPF were much more impaired. Risk quotients (measured environmental concentration/21 d NOEC) showed that BPA, BPF and BPAF are recently not chronically hazardous to the survival, reproduction and growth of water fleas in surface waters. On the other hand, we importantly show that currently present BPAF concentrations in surface waters could cause a potential ecological risk to aquatic organisms. In the near future, higher concentrations of BPF and BPAF in surface waters are anticipated and for this reason further testing using test systems with various aquatic species and endpoints are needed to provide additional information about toxic impacts of BPF and BPAF on aquatic biota.

We analyzed the acute toxicity of the 48% glyphosate (GLY)-based Credit®, the 57.71% dicamba (DIC)-based Kamba®, and the 83.5% 2,4-dichlorophenoxyacetic acid (2,4-D)-based Weedar® Full, alone and as mixtures on the fish Cnesterodon decemmaculatus. Mortality revealed the LC50 96h values of 91.73 mg L−1 (range: 86.80–98.00 mg L−1), 1401.57 mg L−1 (range: 1243.78–1527.35) and 678.04 mg L−1 (range: 639.35–718.04 mg L−1) for GLY, DIC and 2,4-D, respectively. Mean values for the toxic unit (TU) that induced 50% mortality (TU50 96h) of fish exposed to equitoxic mixtures were 1.67 (range: 1.65–1.69) for Credit® and Kamba® and 1.28 (range: 1.20–1.36) for Credit® and Weedar® Full suggesting that both mixtures are antagonic. Non-equitoxic combinations demonstrated an antagonistic interaction of herbicides Credit® and Kamba®, whereas a synergistic effect was observed for Credit® and Weedar® Full formulations. GLY and DIC as a mixture demonstrated lower toxicity on non-target species compared to GLY and 2,4-D in combination, at least for C. decemmaculatus, leading to the conclusion that the former combination could be strongly recommended in further agricultural practices.

Dicamba (DIC) and 2,4-dichlorophenoxyacetic acid (2,4-D) are two of the most applied auxinic herbicides worldwide, both individually and as part of a mixture. However, the toxicity and interactions achieved when applied as a mixture have not yet been characterised. The equitoxic and non-equitoxic acute toxicity exerted by binary mixtures of Banvel® (57.71% DIC) and DMA® (58.4% 2,4-D) on the Neotropical fish Cnesterodon decemmaculatus were evaluated. Results revealed mean values of 1.02 (range, 0.96–1.08) for the toxic unit (TU) that induced 50% mortality (TU50 96 h) to the fish exposed to binary equitoxic mixtures of the commercial formulations Banvel®–DMA®. These results suggest that the mixture is nearly concentration additive. Furthermore, results demonstrated the occurrence of synergistic interaction when non-equitoxic combinations of Banvel®-or DMA®-formulated herbicides were assayed. In this context and regardless of their concentrations, either Banvel®- or DMA®-induced toxicity were synergised by the presence of the counterpart within mixtures. The present study represents the first evidence of the lethality exerted by mixtures of two auxinic herbicides—namely, DIC and 2,4-D—reported to date for fish and other biotic matrices. When C. decemmaculatus is used as the target organism, a synergistic pattern is observed following exposure to a mixture of both herbicides.