Kıyısal Deniz Ortamında Pasif Örnekleyiciler, Sedimentler Ve Midyeler İle Organik Kirletici Dinamikleri

Abstract

Kalıcı organic kirleticiler (KOK) ve poli aramatik hidrokarbonlar (PAH) bir çok kaynaktan sisteme girmektedir. Doğada parçalanmayan dayanıklı yapıları ve canlıların bünyesinde birikip istenmeyen etkiler göstermeleri (kanserojenik, mutojenik vb..) bu kimyasalları izlemek ve haklarında bilgi edinmek gerekliliğini doğurmuştur. Kıyı ekosistemleri nüfusun ve sanayinin yoğun olduğu ve buna paralel olarak da gemi taşımacılığının önemli rol oynadığı ortamlar haline gelmektedir. Bu noktalarda kirleticilerin etkilerinin ve değişik medyalarda(sediman, biyota, pasif örnekleyici, su vb) dağılımlarının incelenmesi, bu kirleticilerin kontrolü bakımından önem taşımaktadır. Bu amaçla canlıları taklit eden yapısıyla pasif örnekleme sistemleri ve midyeler gibi suyu filtre ederek beslenen organizmalar sıklıkla kullanılmaktadır. Bu çalışma kapsamında Istanbul Boğazındaki kalıcı organik kirleticiler ve poliaromatik hidrokarbonlar kirliliğinin çeşitli medyalardaki(midye, sediman, pasif örnekleyici ve su) miktarı, kaynakları ve birbirleri ile olan ilişkisi incelenmiştir. Yapılan çalışma iki aşamada gerçekleşmiştir. Birinci aşamada, İstanbul Boğazından toplanan midye ve sedimanlarda Poliklorlu Bifeniller (PKB), Dioksin/Furan (PCDD/F) ve Organoklorlu Pestisitlerin (OKP) analizleri yapılmıştır ve olası kaynakları araştırılmıştır. İkinci aşamada, Pasif örnekleme sistemleri ve transplante midyeler seçilen örnekleme noktalarına yerleştirilmiştir. Sediman ile birlikte toplanan pasif örnekleyicilerde, PAH, PKB ve OKP analizleri yapılmıştır.Yarı geçirgen membran örnekleyici ve sediman verileri kullanılarak kirletilcilerin su konsantrasyonları hesap edilmiştir. Toplam olarak 16 tane PAH, 18 tane PKB, 6 tane PCDD, 10 tane PCDF ve 28 tane OCP İstanbul Boğazı ve Marmara denizinden toplanan sediman, midye, SPMD ve BR sorbente analiz edilmiştir.

The research was conducted in two phases. In the first phase: sampling 2007, the detailed distribution and source of polychlorinated biphenyl (PCB), polychlorinated dibenzo-p-dioxin/furan (PCDD/F) and organochlorine pesticides (OCP) in the Istanbul Strait were determined by sampling sediments and mussels (Mytilus galloprovincialis) along the Strait area. Sediment and mussel samples were analyzed for six indicator PCB, 12 dioxin-like PCB (dl-PCB) and 17 polychlorinated dibenzo-p-dioxin/furan (PCDD/F) congeners. Samples contained different concentrations of PCB and among these, congeners 153, 75, 105 and 118 in sediments and congeners 153, 138 and 118 in mussels were most abundant. The concentration levels of total PCB and PCDD/Fs in sediments ranged from 17.9 to 539,746 pg g-1 dw and 2.04 to 60.5 pg g-1 dw, respectively. The total WHO-TEQ values ranged between 0.01 and 17.8 pg g-1 dw in sediments and 0.98-1.01 pg g-1 ww in mussels. None of the sediment and mussel samples analyzed exceeded the limits suggested in the sediment quality guideline and safe values set by the European Community for seafood intended for human consumption respectively. The total concentrations of OCP were found in the range of 40-13852 pg g-1 dw for sediments and 5195-12322 pg g-1 ww for mussels. The levels of OCP in both sediments and mussels were dominated by DDTs and HCHs; β-HCH, 4,4'-DDD, and 4,4'-DDE were the major pollutants. The degree of sediment pesticide contamination was more severe in the inner part of the strait. OCP concentrations in sediments and mussels were compared with the sediment guideline values and legal limits for human health respectively. The results showed that OC pesticide contamination in the strait might not pose a serious threat to the health of the marine inhabitants at most of the stations. In the second phase: sampling 2009, passive sampling systems were used together with transplant and local mussel samples. The results were compared to find out transplant mussel, semipermeable membrane devices (SPMD) and Butyl rubber (BR) sorbent performance. Water concentrations of polycyclic aromatic hydrocarbons (PAH), PCB and OCP were estimated from SPMD and from sediment pollutant concentrations. SPMD were deployed in the Istanbul Strait and Marmara Sea and retrieved after 7 and 21 days. Performance reference compounds (PRC) were used to determine the site-specific sampling rates of the compounds. Water concentrations (Cw) of the analyzed compounds estimated by using two different calculation methods for SPMD were found similar. Cw of total PAH estimated from SPMD (Cw-spmd) were found between 13-79 ng L-1 and between 7.0-68 ng L-1 for 7 and 21 days of deployments respectively. Water concentrations of PCB using sediment data was found as between 0.001 and 11.0 ng L-1. The highest value of Cw-spmd for two deployments were 2.8 ng L-1 for OCP. Cw estimated from sediment concentrations were generally higher than those estimated from SPMD. Sampling results from BR sorbent are similar with SPMD. In general, BR sorbent has much better sampling capacity for PCB, OCP and HMW PAH. Transplanted mussel data show similar trend with the passive samplers. Depurations of the pollutants are visible in clean sites. On the other hand, mussels are more sensitive to temperature, salinity and seasonal changes. Obtain data from this study provided relevant information for future risk assessment and passive sampling studies.