3.1.4. Journal Analysis

The 2637 publications were retrieved from 399 journals. Among them, most journals (384, 96.2%) published fewer than 20 articles about MPs. Table 3 shows the top 15 most productive journals in which more than 65% of publications related to MPs were published during the period 2004-2019. These journals were classified in six categories, and all placed in higher quartiles in category (Q1/Q2) according the 2018 JCR report. Ten of the journals were grouped in the *Environmental Sciences* category and three were grouped in the *Marine and Freshwater Biology* category, which indicated that MPs in the aquatic environment was the research hotspot. *Mar Pollut Bull* published the most articles (536) and had the highest STC and NSC, but its NSCR was lower than that of the other 14 journals. *Environ Pollut*, with 327 articles, ranked second. *Water Res* ranked eighth for TNP, but had the highest IF (7.913) among the ten *Environmental Sciences* journals. *Sci Rep-UK* and *Plos One*, were grouped in the *Multidisciplinary Sciences* category, and *Trac-Trend Anal Chem* and *Analmethods-UK* were grouped in the *Chemistry, Analytical* category. Articles in *Environ Toxicol Chem* and *Ecotox Environ Safe*, which were classified in the *Toxicology* category, focused on the ecotoxicological effects of MPs.

**Table 3.** The top 15 productive journals that published articles about the MPs issue.

