**3. Results**

## *3.1. Study Selection*

The flow diagram in Figure 1 displays the results of the literature search and study selection process. A total of 6254 studies were initially identified. After duplicate removal, 4915 studies remained for titles and abstracts screening. Thirteen studies were excluded for the following reasons: in vitro studies (n = 8) [9,19,24–29], no assessment outcomes of interest (n = 1) [30], microbiota of mussel hemolymph (n = 1) [31], review (n = 1) [32], Chinese language (n = 1) [33], TiO2 and bisphenol A co-exposure (n = 1) [34]. Eighteen studies [8,35–51] were identified for inclusion in the systematic review.

**Figure 1.** Preferred reporting items for systematic reviews and meta-analyses (PRISMA) flow diagram.
