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Organochlorine Residues in Sediment Cores of a Midwestern Reservoir
Author(s) -
Ricci Edward D.,
Hubert Wayne A.,
Richard John J.
Publication year - 1983
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1983.00472425001200030022x
Subject(s) - dieldrin , sediment , environmental chemistry , chemistry , contamination , transect , deposition (geology) , zoology , pesticide , geology , ecology , biology , oceanography , paleontology
Organochlorine residues detected in sediment core samples collected from Rock Reservoir, Iowa, in early 1981 were < 5 µ g/kg dry weight for dieldrin (1,2,3,4,10,10‐hexachloro‐ exo ‐6,7‐epoxyl,4,4a,5,6,7,8,8a‐octahydro‐1,4‐ endo, exo ‐5,8‐dimethanophthalene), p,p′ ‐DDE (1,1‐dichloro‐2,2‐bis( p ‐chlorophenyl) ethylene), p,p′ ‐DDD (1,1‐dichloro‐2,2‐bis( p ‐chlorophenyl)ethane), and < 16 µ g/kg for PCB's (polychlorinated biphenyls). The mean concentration of PCB residues (13 µ g/kg) was higher than that of the three insecticides (dieldrin, 2.9 µ g/kg; DDE and DDD, 2.4 µ g/kg each). Concentrations of organochlorine contaminants in sediments were higher at the upper and lower ends of the reservoir than at midreservoir locations. Deposition of organochlorine residues did not correlate well with either clay or organic composition of the sediment. A mechanism not related to clay‐organic sediment appears to be influencing accumulation of organochlorines in the upper end of the reservoir. In the river channel, dieldrin levels were higher than at loations on either side of the channel, while no variation due to transect location was noted for DDE, DDD or PCB's. Dieldrin concentrations were highest in surficial sediments, whereas those of PCB's, DDE, and DDD were highest near the bottom of core samples. An estimated 53 kg of PCB's, 17 kg of dieldrin, 14 kg of DDD, and 9.3 kg of DDE were present in the top 7.5 cm of sediment over Red Rock Reservoir's 3600 ha.