Vertical profiles of legacy organochlorine pesticides in sediment cores from lake Nakaumi, Japan

• Published in: Chemosphere (Oxford) 2022-03, Vol.290, p.133254-133254, Article 133254
• Main Authors: Eun, Heesoo, Kim, Yun Seok, Sakamoto, Toshihiro, Miecznikowska, Agata, Falandysz, Jerzy, Masunaga, Shigeki, Kunii, Hidenobu
• Format: Article
• Language: English
• Subjects: Brackish; China; Environmental Monitoring; Geologic Sediments; Hydrocarbons, Chlorinated - analysis; Japan; Lakes; Land reclamation project; Pesticides - analysis; Pesticides usage; Water Pollutants, Chemical - analysis
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2021.133254

Two sediment core samples from the brackish Lake Nakaumi in Japan were analyzed to determine the historical profiles of organochlorine pesticides (OCPs). It was observed that from the 1940s to 2005, the vertical distribution of OCPs in sediment cores reflected the temporal trend of pesticide usage in Japan. Dichlorodiphenyltrichloroethane (DDT) and its metabolites were predominant, with concentrations of 0.008–8.27 ng g−1 dry weight, and their contribution to ΣOCPs was over 58%. The results also confirmed that the DDTs in the sediment cores originated from past input. Further, even though hexachlorocyclohexanes were the most used OCP in Japan, their residual concentrations were lower than those of DDTs and chlordane related compounds (CHLs). The concentrations of CHLs were 0.163–1.539 ng g−1 dry weight, whereas hexachlorobenzene (HCB), drins, heptachlor, and mirex showed very low concentrations. Interestingly, although HCB was never registered as a pesticide in Japan, it was detected in both core samples. This HCB contamination might be attributed to pentachlorophenol. Additionally, the hierarchical cluster analysis results corresponding to both sediment cores could be classified under four groups based on a similarity of over 50%. The results also showed that the OCP burden in Lake Nakaumi for the past 60 years was 130 kg and 1153 kg at Honjo and at the center of Lake Nakaumi, respectively. Overall, the results of this study indicate that the distribution of OCPs in Lake Nakaumi reflects the trend of pesticide usage in Japan. [Display omitted] •Two sediment cores were assessed for OCPs in the brackish Lake Nakaumi, Japan.•The vertical distribution of OCPs reflects historical pesticide usage in Japan.•210Pb and 137Cs dating suggest highest DDT concentration appeared during 1960–1965.•Although used the most, HCHs had lower residual concentrations than DDTs and CHLs.•There was no legacy OCP input by the landfill agricultural land expansion project.