The PubMed database was used to study the combination of keywords. The search terms for the data were set as "nanotechnology toxicity [Title/Abstract]". The data for articles from 2015 to 2020 was exported. The 2015 database included 621 articles, 2016 -621 articles, 2017 -693 articles, 2018 -703 articles, 2019 -743 articles, and 2020 -793 articles. Cluster analysis was carried out to determine the dynamics of keywords for each database: type of analysisco-occurrence, unite of analysisall keywords. Minimum numbers of keyword occurrences were selected so that the final number of keywords included in the analysis did not exceed 100. For analysis of co-occurrence of keywords firstly used in 2020, to identify future trends, we analyzed the database of articles for 2020 with minimum numbers of occurrences of a keyword = 2. The number of keywords included in this graph was 674.