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

Anthropogenic activities have led to widespread contamination with mercury (Hg), a potent neurotoxin that bioaccumulates through food webs. Recent models estimated that, presently, 200 to 600 t of Hg is sequestered annually in deep-sea sediments, approximately doubling since industrialization. However, most studies did not extend to the hadal zone (6,000- to 11,000-m depth), the deepest ocean realm. Here, we report on measurements of Hg and related parameters in sediment cores from four trench regions (1,560 to 10,840 m), showing that the world’s deepest ocean realm is accumulating Hg at remarkably high rates (depth-integrated minimum–maximum: 24 to 220 μg ⋅ m−2 ⋅ y−1) greater than the global deep-sea average by a factor of up to 400, with most Hg in these trenches being derived from the surface ocean. Furthermore, vertical profiles of Hg concentrations in trench cores show notable increasing trends from pre-1900 [average 51 ± 14 (1σ) ng ⋅ g−1] to post-1950 (81 ± 32 ng ⋅ g−1). This increase cannot be explained by changes in the delivery rate of organic carbon alone but also need increasing Hg delivery from anthropogenic sources. This evidence, along with recent findings on the high abundance of methylmercury in hadal biota [R. Sun et al., Nat. Commun. 11, 3389 (2020); J. D. Blum et al., Proc. Natl. Acad. Sci. U. S. A. 117, 29292–29298 (2020)], leads us to propose that hadal trenches are a large marine sink for Hg and may play an important role in the regulation of the global biogeochemical cycle of Hg.

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Polybrominated diphenyl ethers, polychlorinated biphenyls and organochlorine pesticides in sediment cores from the Western Scheldt river (Belgium): analytical aspects and depth profiles

Environment International ◽

10.1016/j.envint.2004.08.009 ◽

2005 ◽

Vol 31 (3) ◽

pp. 367-375 ◽

Cited By ~ 127

Author(s):

A. Covaci ◽

A. Gheorghe ◽

S. Voorspoels ◽

J. Maervoet ◽

E. Steen Redeker ◽

...

Keyword(s):

Polychlorinated Biphenyls ◽

Organochlorine Pesticides ◽

Polybrominated Diphenyl Ethers ◽

Sediment Cores ◽

Depth Profiles ◽

Diphenyl Ethers ◽

Scheldt River

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Residual Level, Profile and Potential Ecological Risk of Organochlorine Pesticides in Subsurface Sediments from Lakeshore Backfill Site and Lakebed of an Abandoned Oxidation Pond After Desilting for 15 Years

10.21203/rs.3.rs-510071/v1 ◽

2021 ◽

Author(s):

Ya-Fen Wang ◽

Tao Liu ◽

JinCan Tang ◽

ZhiWei Xiong ◽

LiangChu Song ◽

...

Keyword(s):

Organochlorine Pesticides ◽

Sediment Cores ◽

Acid Methyl Ester ◽

Principal Component ◽

Potential Ecological Risk ◽

Mean Value ◽

Oxidation Pond ◽

Subsurface Sediments ◽

Deep Layers ◽

Agricultural Input

Abstract The occurrence and distribution of 19 organochlorine pesticides (OCPs), together with microbial ester-linked fatty acid methyl ester (EL-FAME) profiles were investigated in sediments from an abandoned oxidation pond of Ya-Er lake, China, which had been heavily polluted by hexachlorocyclohexanes (HCHs) and chlorobenzenes in 1980s. Subsurface sediment samples were taken from five sediment cores along the transect running from lakeshore to lakebed. The concentration of total OCPs ranged from 29.8 to 941.8 ng g-1 dw, with a mean value of 193.3 ng g-1 dw. Hexachlorobenzene (HCB), HCHs and dichlorodiphenyl-trichloroethanes (DDTs) were the three dominant OCP classes, accounting for 26.5%-97.4%, 1.8%-51.5%, and 0.4%-15.5% of the total, respectively. Hot spots of HCB, HCHs and DDTs were detected in 0.9-2.7 m deep layers of the lakeshore, where was one of the dredged sediment backfill sites for in-situ remediation of the oxidation pond in 2002-2004. High potential risks of HCHs and HCB were still indicated. Historical industrial input (27.2%), recent agricultural input (14.7%), and persistent residuals (14.3%) were the three major identified sources of OCPs, using Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR). Redundancy analysis of microbial EL-FAME profiles and nine dominant OCPs revealed that the spatial variation in microbial community structure was significantly corresponded with the OCP composition. This is the first study highlighted the concern on historical industrial inputs of OCPs in subsurface sediments of the lakeshore disposal zone. The findings could help to distinguish the artificial backfill sediments from natural polluted sediments for optimization of further desilting plans.

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Vertical Profiles and Assessment of Trace Metals in Sediment Cores From Outer Sea of Lake Shihwa, Korea

Journal of the Korean Society for Marine Environment & Energy ◽

10.7846/jkosmee.2013.16.2.71 ◽

2013 ◽

Vol 16 (2) ◽

pp. 71-81 ◽

Cited By ~ 3

Author(s):

Kongtae Ra ◽

Joung-Keun Kim ◽

Eun-Soo Kim ◽

Kyung-Tae Kim ◽

Jung-Moo Lee ◽

...

Keyword(s):

Trace Metals ◽

Sediment Cores ◽

Vertical Profiles ◽

Lake Shihwa

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Temporal evolution of urban wet weather pollution: analysis of PCB and PAH in sediment cores from Lake Bourget, France

Water Science & Technology ◽

10.2166/wst.2008.273 ◽

2008 ◽

Vol 57 (10) ◽

pp. 1503-1510 ◽

Cited By ~ 14

Author(s):

S. Jung ◽

G. Chebbo ◽

C. Lorgeoux ◽

B. Tassin ◽

F. Arnaud ◽

...

Keyword(s):

Surface Sediments ◽

Sediment Cores ◽

Stormwater Runoff ◽

Control Measures ◽

Local Source ◽

Vertical Profiles ◽

Urban Stormwater ◽

Polycyclic Aromatic ◽

Urban Stormwater Runoff ◽

Lake Bourget

In order to evaluate the historical impact of urban stormwater runoff on a lacustrine environment, eight sediment cores were collected in October 2006 in Lake Bourget (Savoie, France). Sediment samples were analysed for polycyclic aromatic hydrocarbons (PAH) and polychlorobyphenyls (PCB) in order to correlate the vertical profiles of contamination and the evolution of the urbanisation on the watershed for the last 100 years. Overall, we observe that vertical profiles of PCB and PAH concentrations in Lake Bourget are showing a downward trend, probably resulting from the pollution control measures. Concentrations of PCB and PAH measured in surface sediments are approximately 5–10 fold less than maximal concentrations found in the cores. Maximal PAH concentrations were found at the bottom of the cores (∼40 cm) which approximately correspond to the beginning of the 20th century. Maximal PCB concentrations measured in cores L5 and L6 are respectively 850 and 790 μg/g dw (dryweight). The peak of PCB corresponds to the maximum of PCB production and consumption in the 1970s. In surface sediments total PCB concentrations range between 47 and 79 μg/kg dw. Those concentrations are particularly high compared to other values measured in lake sediments and highlight the problem of a local source of PCB contamination in the watershed. General trends were observed, yet the part of urban stormwater runoff in the total contamination could not be determined.

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