*2.1. Data Sources*

The Web of Science Core Collection (WoSCC), which generates standardized and high-quality academic publication information, is used extensively for the bibliometric examination of the evolution of scientific issues [18,26,27]. On March 12, 2020, all original data were extracted from the online version of the WoSCC database (indexes: Science Citation Index-Expanded and Conference Proceeding Citation Index), using the TOPIC "microplastic\* or (micro near/1 plastic\*)" for the years 2004 to 2019. ESI highly cited individuals along with the number of their MPs-related publications and ESI highly cited papers were collected by the same TOPIC from Clarivate Analytics on the same day.
