Fig. 4. Toxicity evaluation of BPS in multiple generations of continuous exposure to C. elegans. A: Comparison of head thrashes of the exposed C. elegans; B: comparison of body bends of the exposed C. elegans; C: comparison of the body length of the exposed C. elegans; D: comparison of the brood size of the exposed C. elegans. Data (mean ± SEM) are expressed as the percentage value compared to the control group. The asterisks indicate significant differences between the exposure group and control group. *p < 0.05, **p < 0.01.