140 years-long sedimentary records of PAHs and CN stable isotopes from Ninomiya River, Japan

Rodrigo Mundo; Hisanori Iwai; Shinya Ochiai; Tetsuya Matsunaka; Noriko Hasebe; Seiya Nagao

doi:10.1016/j.marpolbul.2023.114943

140 years-long sedimentary records of PAHs and CN stable isotopes from Ninomiya River, Japan

Mar Pollut Bull. 2023 Jul:192:114943. doi: 10.1016/j.marpolbul.2023.114943. Epub 2023 May 8.

Authors

Rodrigo Mundo¹, Hisanori Iwai², Shinya Ochiai³, Tetsuya Matsunaka⁴, Noriko Hasebe⁵, Seiya Nagao⁶

Affiliations

¹ Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan.
² Sustainable Energy & Environmental Society Open Innovation Research Organization, Waseda University, Shinjuku, Tokyo 169-8555, Japan. Electronic address: h.iwai@aoni.waseda.jp.
³ Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Nomi, Ishikawa 923-1224, Japan. Electronic address: sochiai@se.kanazawa-u.ac.jp.
⁴ Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Nomi, Ishikawa 923-1224, Japan. Electronic address: matsunaka@se.kanazawa-u.ac.jp.
⁵ Institute of Nature and Environmental Technology, Kanazawa University, Ishikawa 920-1192, Japan. Electronic address: hasebe@staff.kanazawa-u.ac.jp.
⁶ Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Nomi, Ishikawa 923-1224, Japan. Electronic address: seiya-nagao@se.kanazawa-u.ac.jp.

PMID: 37163791
DOI: 10.1016/j.marpolbul.2023.114943

Abstract

Anthropogenic activities' impacts over 140 years were studied at West Nanao Bay using a variety of geochemical techniques on sedimentary records. The bay is influenced by the Ninomiya River which is fed by a small watershed at which Tatzuruhama Town is located. Sedimentation rate was calculated using ²¹⁰Pb-excess and ¹³⁷Cs activities. C/N decreased after 1975, indicating a decrease in lignin-rich organic matter. From δ¹³C, δ¹⁵N and biogenic silica it was indicated that the population increased sewage-discharges until the construction of waste-water treatment plant in 1986. Several recorded changes in the landuse matched with the variation of the particle size. Total PAHs concentration was 1.17-62.78 μg g^-1, being highest during Japan's fastest economic growth period (1946-1975). Using diagnostic ratios and PCA analysis, PAHs' sources were identified as pyrogenic for all depths, varying from coal combustion (90.7 %) before 1946 to a mixture of biomass and vehicle combustion after 1961.

Keywords: Carbon and nitrogen stable isotopes; Coastal areas; Environmental organic pollutants; Polycyclic aromatic hydrocarbons; δ(13)C; δ(15)N.

MeSH terms

China
Environmental Monitoring
Geologic Sediments / analysis
Isotopes / analysis
Japan
Polycyclic Aromatic Hydrocarbons* / analysis
Rivers
Water Pollutants, Chemical* / analysis

Substances

Isotopes
Polycyclic Aromatic Hydrocarbons
Water Pollutants, Chemical