TY - JOUR
T1 - Distribution coefficients (K d) of stable iodine in estuarine and coastal regions, Japan, and their relationship to salinity and organic carbon in sediments
AU - Takata, Hyoe
AU - Zheng, Jian
AU - Tagami, Keiko
AU - Aono, Tatsuo
AU - Fujita, Kazuhiro
AU - Yamasaki, Shin Ichi
AU - Tsuchiya, Noriyoshi
AU - Uchida, Shigeo
PY - 2013/5/1
Y1 - 2013/5/1
N2 - The sediment-water distribution coefficient, K d, is one of the most important parameters in radionuclide assessment models. In this study, we determined K ds of stable iodine (I) in estuarine and coastal regions. We studied 16 estuarine and coastal regions of Japan and obtained I data on water and sediments. Data on salinity, pH, dissolved organic carbon and dissolved oxygen in water, and organic carbon (OC) in sediments were also obtained as estuarine variables. Determined K ds of I in the Sagami River estuary decreased along the salinity gradient (salinity range, 0.1-33.8), indicating that salinity is one of the important factors controlling the K d values; however, when the K d values were compared among all the estuaries, the difference between minimum and maximum K d values varied by about two orders of magnitude in a narrow salinity range of 30.0-34.4. A significant correlation between K d value and OC content in sediments was observed in all the stations with a salinity of ≥30 except for stations in the Ishikari and Onga River estuaries. The exceptions are probably due to different sources of the sediments, which are explained by the results of relatively low I/OC ratios in sediments in those two estuaries, compared to the other estuaries. Thus, OC in sediments as well as salinity may be responsible for the variation of K ds of I in the estuarine and coastal regions.
AB - The sediment-water distribution coefficient, K d, is one of the most important parameters in radionuclide assessment models. In this study, we determined K ds of stable iodine (I) in estuarine and coastal regions. We studied 16 estuarine and coastal regions of Japan and obtained I data on water and sediments. Data on salinity, pH, dissolved organic carbon and dissolved oxygen in water, and organic carbon (OC) in sediments were also obtained as estuarine variables. Determined K ds of I in the Sagami River estuary decreased along the salinity gradient (salinity range, 0.1-33.8), indicating that salinity is one of the important factors controlling the K d values; however, when the K d values were compared among all the estuaries, the difference between minimum and maximum K d values varied by about two orders of magnitude in a narrow salinity range of 30.0-34.4. A significant correlation between K d value and OC content in sediments was observed in all the stations with a salinity of ≥30 except for stations in the Ishikari and Onga River estuaries. The exceptions are probably due to different sources of the sediments, which are explained by the results of relatively low I/OC ratios in sediments in those two estuaries, compared to the other estuaries. Thus, OC in sediments as well as salinity may be responsible for the variation of K ds of I in the estuarine and coastal regions.
KW - Estuarine and coastal regions
KW - Organic carbon in sediments
KW - Salinity
KW - Stable iodine as an analog to radioactive iodine
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U2 - 10.1007/s10661-012-2816-5
DO - 10.1007/s10661-012-2816-5
M3 - Article
C2 - 22923376
AN - SCOPUS:84878356786
VL - 185
SP - 3645
EP - 3658
JO - Environmental Monitoring and Assessment
JF - Environmental Monitoring and Assessment
SN - 0167-6369
IS - 5
ER -