Seasonal Distributions, and Risk Assessment of Polychlorinated Biphenyls (PCBs) in the Surficial Sediments from the Turag River, Dhaka, Bangladesh

Polychlorinated biphenyls (PCBs) assessment in sediments of Turag River, Dhaka, Bangladesh has been conducted for the first time. This River provides critical ecological services to agriculture, industry, and transportation. However, the Turag River is one of the most industrially polluted rivers surrounding Dhaka in Bangladesh. In this study, six PCB congeners namely PCB 10, PCB 28, PCB 52, PCB 138, PCB 153, and PCB 180, were analyzed in surface sediments by GC-ECD at 9 sampling sites. Pre-monsoon and post-monsoon season sampling were collected in this study. The total concentrations of PCBs varied from 344.49 to 0.22 ng/g dw and 10.6 to 1.68 ng/g dw in pre-monsoon and post-monsoon, respectively. The paramount contributor congener to the total PCBs was PCB 180 and was found at all sites. The ecological risk assessment indicated a high potential risk in pre-monsoon (Eri = 277.32) and low potential risk in post-monsoon (Eri = 25.69). Sediment quality guideline quotients (SQGQs) showed that PCBs in pre-monsoon would cause no or moderate biological effects on organisms at most sampling sites except in surface sediments of site S5 (high biological effects), while no adverse ecotoxicological effect was observed in post-monsoon. Considering both probable effect level (PEL) and threshold effect level (TEL), the new sediment quality guideline quotient (NSQGQ) showed that in post-monsoon PCBs contamination would cause moderate biological effects, while in pre-monsoon the findings remained consistent with the findings of SQGQ. This study gave a quick look at the PCB contamination scenario in the Turag River sediments and also allowed for a comparison between the investigated River and other rivers worldwide.

Comparative trace element trends in Posidonia oceanica and its sediments along the Turkish-Mediterranean coast

Concentrations of eight trace elements (V, Cr, Ni, Cu, Zn, As, Cd, and Pb) were investigated in Posidonia oceanica blades and in the sediments sampled from 23 stations along the Turkish-Mediterranean Sea coast. Trace element (TE) concentration in both sediment and P. oceanica showed a statistically significant distribution among sampling stations. Most of the TE concentration in samples varied remarkably among stations without a consistent trend. Concentrations of Zn, Cd, Cu, and Pb in sediment of all of the sampling stations were determined as non-polluted based on the comparison with the sediment quality guideline index. More than quarter of the sampling stations were found as moderately or heavily polluted for Cr, Ni, and As. The mean TE concentrations found in the sediment sample in the present study were similar to the concentrations reported from the different parts of the eastern Mediterranean Sea. TE concentrations in P. oceanica were generally lower compared to the concentrations in the sediment except for Cd, Zn, and Cu. While positive correlation was found for Ni concentrations between sediment and P. oceanica samples, negative correlation was detected for V, Cr, Zn, Cu, As, and Cd concentrations between sediment and P. oceanica. The highest bioaccumulation factor in P. oceanica was calculated for Cd. The study area of the present study, especially the western sites (provinces of Antalya and Muğla) hosts millions of tourists annually and under the influence of intensive human activities in summer. Thus, coastal waters are heavily exposed to TEs and significantly positive correlations were detected between the anthropogenic TE pollutants (As, Cd, Cu, Zn, Pb, and V) and natural sourced TE (Ni and Cr).

Analisis Kandungan Timbal (Pb) pada Udang Putih (Penaeus merguiensis) sebagai Kontribusi Perhitungan Ocean Health Index (OHI)

Penelitian ini bertujuan untuk mengetahui kualitas perairan Sungsang Kabupaten Banyuasin Provinsi Sumatera Selatan berdasarkan beberapa parameter kualitas air dan mengetahui tingkat akumulasi logam berat timbal (Pb) dalam jaringan udang putih (Penaeus merguiensis) terhadap lingkungan abiotik (air dan sedimen) berdasarkan nilai Bioconcentration Factor (BCF). Penelitian ini diharapkan dapat memberikan kontribusi terhadap perhitungan Ocean Health Index (OHI) sebagai indikator penting untuk penilaian kesehatan laut secara berkelanjutan yang mampu dijadikan sebagai basis data dalam membuat kebijakan kelautan. Berdasarkan hasil penelitian diperoleh hasil kandungan logam berat Pb pada air dan sedimen di perairan Sungsang belum melebihi baku mutu yang ditetapkan berdasarkan Peraturan Gubernur Sumsel No. 16 Tahun 2005 dan berdasarkan standar sediment quality guideline values for metals and associated levels of concern to be used in doing assessment of sediment quality tahun 2003 dan menurut IACD/CEDA (International Association of Draging Companies/Central Dreging Association) tahun 1997. Konsentrasi logam timbal yang terkandung pada udang putih yang dihasilkan dari tiga lokasi telah melebihi batas yang ditetapkan oleh Kepala BPOM RI No HK.00.06.1.52.4011 tahun 2009. Berdasarkan nilai Bioconcentration Factor (BCF), penyerapan Pb dalam jaringan udang putih (Penaeus merguiensis) terhadap lingkungan abiotiknya pada ketiga lokasi penelitian di perairan Sungsang Kabupaten Banyuasin Provinsi Sumatera Selatan menunjukkan tingkat akumulatif rendah.

Elevated trace elements in Posidonia oceanica and Cymodocea nodosa at six Mediterranean volcanic seeps

Seagrasses form important habitats around shallow marine CO2 seeps, providing opportunities to assess trace element (TE) accumulation along gradients in seawater pH. Here we assessed Cd, Cu, Hg, Ni, Pb and Zn levels in sediment and seagrasses at six CO2 seeps and reference sites off Italy and Greece. Some seep sediments had much higher concentrations of TEs, the extreme example being Cd at 43-fold above reference levels. Sediment Quality Guideline (SQG) scores indicated that three seeps had sediment TEs levels likely to have “Adverse impacts” on marine biota; namely Vulcano (for Hg), Ischia (for Cu) and Paleochori (for Cd and Ni). SQG indicated seep sediments of Italian seeps were adversely affected by Cu and Hg, whereas Greek CO2 seeps were affected by Cd and Ni. An increase in sediment TEs levels positively corelated with higher levels of TEs in seagrass roots of Posidonia oceanica (Zn and Ni) and Cymodocea nodosa (Zn). Differences in the bioavailability and possible toxicity of TEs helps explain why seagrasses were abundant at some CO2 seeps but not others.

Geochemical Assessment of Trace Metal Distribution and Contamination in the Surface Sediments of the Coast of Okinawa Island, Japan

In this study, sediment samples were collected from the Awase tidal, the Minamigusuku, and Nakagusuku areas located in the Okinawa Island. The collected samples were analyzed using X-ray fluorescence to determine their geochemical compositions and distribution, and to assess the sediment quality in the study areas. Contamination factor (CF), geoaccumulation index (Igeo), and the United State Environmental Protection Agency Sediment Quality Guideline (US EPA SQG) were used to assess the sediment quality. The results show that the highest average concentrations of As (11mg/kg), Pb (8 mg/kg), Zn (19 mg/kg), Cu (6 mg/kg), and Cr (14mg/kg) occurred in the Minamigusuku area. The CF and Igeo values, and the US EPA SQG indicate that among the selected trace metals only As displays significant values in the study areas. The CF values of As in the Minamigusuku area show moderate enrichment, and in this same area, the Igeo values of As present significant values, ranging from moderate to considerable contaminations, implying a possible effect on the biota in this location. Compared to the US EPA SQG, the Awase tidal flat and Nakagusuku areas are moderately polluted, whereas Minamigusuku is heavily polluted, suggesting that As may possible impact the biota in these areas. Consequently, for a better sustainable development of the coast of Okinawa Island , a regular monitoring and assessment of study areas, particularly the Minamigusuku area, is necessary to determine over time the concentration of As.