@article { author = {Jamshidi Zanjani, Ahmad and Saeedi, Mohsen}, title = {Metals Pollution Assessment of Surface Sediment in Anzali Wetland and Their Quality Zonation}, journal = {Journal of Environmental Studies}, volume = {39}, number = {4}, pages = {157-170}, year = {2014}, publisher = {دانشگاه تهران}, issn = {1025-8620}, eissn = {2345-6922}, doi = {10.22059/jes.2014.36469}, abstract = {IntroductionHeavy metals are originated from natural or anthropogenic sources. Mining activity, fuel combustion, urbandischarge, pesticides, agricultural and industrial activities are considered as the m ain anthropogenic sources ofthe metals. Generally, more than 90% of the toxic metals load in aquatic systems is bound on solid phase of theaquatic systems such as suspended matter and sediment. Thus, assessment of heavy metals pollution in aquaticsediment is a critical issue that has been studied by many researchers. Anzali International Wetland wasregistered in Ramsar Convention in 1975 (Ramsar site #40, Wetlands International Site Reference No.: 2IR005).It is located in Guilan Province (between 48°45' and 49°42'E longitude and 36°55' to 37°32'N) and covers 192Km2 that is considered as the main freshwater coastal wetlands in southern part of the Caspian Sea. Its catchmentarea with prevalent agricultural activities is about 3610 Km2. Moreover, presence of 41 major factories such aswood and paper mill companies, food industries, metal and related industries, plastics and tires, textile andelectrical machines are samples of anthropogenic sources in the study area. In the present study forty one surfacesediment samples in January 2011 were collected from Anzali International Wetland to assess metals pollutionstate and sediment quality zonation. Moreover, metals pollution assessments in the study area were conductedusing different existing indices, multivariate analysis approach and GIS tools.Materials and MethodsThe collected samples transferred to the laboratory in sealed plastic bags under 4􀁱C. After digestion usingHNO3/HCl/H2O2 according to U.S.EPA 3050B test method, total metal (Cu, Zn, Cr, Fe, Mn, Pb, Ni, Cd)contents were determined using Atomic Absorption Spectrometry (Bulck Scientific 210VGP). Moreover,sediment quality indices such as Modified degree of Contamination (mCd), ecological Risk Index (RI), andEnrichment Factor (EF) were applied to assess metal pollution state. In addition, multivariate statistical analysiswas conducted to determine probable sources of metals in the study area and interpret data. The investigationwas conducted by Principal Component Analysis (PCA).Results and DiscussionAccording to total metals content, the higher mean concentrations of all studied metals (except for Cr) werefound compared with those of earth's crust and mean world sediments. Moreover, the minimum content of Znand Pb are also higher than earth's crust content. Based on zonation maps about metals distribution, the sampleswith the minimum metals concentration were located in central part and Siahkeshim (Protected area) of the studyarea where there is no main sources of pollution. Moreover, the higher concentration of Cu, Zn, Cr, Pb, and Cdwere determined in eastern and northwestern part of the study area. These parts are affected by river dischargesthat pass through the more populated, industrialized and higher levels of agricultural activities areas. However,no distinguished distribution pattern of Fe, Mn, and Ni were detected. Overall, it could be concluded that centraland northern parts of the wetland that are less exposed to the sources of pollution demonstrated to have higherconcentrations of Fe, Mn and Ni. Moreover, results of applied aggregative indices such as ecological RI andmodified degree of contamination (mCd) revealed higher degree of metals pollution in the eastern part. Fig. 1depicts metals pollution state based on RI and mCd. In addition, the Cluster Analysis (CA) was applied to heavy metals concentrations in Anzali Wetland toverify probable metals relationship. The CA of variables based on Pearson Coefficient identified five clusters: 1.Cu-Zn; 2. Cr-Pb; 3. Cd; 4. Fe-Ni 5. Mn. The first cluster named A including metals (Cu, Zn, Cr, Pb, and Cd) thatexhibited higher degree of enrichment may indicate that they were originated from anthropogenic sources.However, it seems that Cd might be derived from different anthropogenic sources. The second cluster named Bwas made by Fe and Ni. It may be concluded that Ni and Fe are originated from same sources, while Mn incluster C has separate sources.Results of multivariate statistical analysis demonstrated three main principal components with theireigenvalues greater than 0.8. The cumulative variance of the components was about 81% of total variance. Thehigh positive loadings for Cu, Zn, Cr, and Pb, and moderate positive loadings of Fe, Ni, and Cd were extracted inthe first component with 46% of total variance. The loadingslevel of these two groups was not the same, so it could beconcluded that Fe, Ni, and Cd may be originated from thedifferent sources. In general, high loading values of Cu, Zn, Cr,and Pb in the first component may imply the anthropogenicsources of these metals. The positive loadings of Fe, Ni, and Mnwere found in second component with 24% of total variance.This fact may indicate natural sources of theses metals. Cd isdominant element in the third component with 11% of totalvariance. Results of PCA are depicted in Fig. 2.According to the results of PCA, it can be concluded that thefirst and the third factors are originated from anthropogenicsource like agricultural and industrial activities, and discharge ofurban wastewater and leaching from prevalent dumping waste inopen space that is considered as the main waste disposalmethods in the north of Iran.ConclusionIn the present study, metals concentrations in surface sediments of Anzali Wetland were determined. Manyprevalent and useful indices such as mCd, ecological RI, and EF were applied to assess metals pollution state inthe collected samples. Moreover, based on the results of applied indices and total metals content, sedimentquality zoning were performed using GIS software. Overall, it could be concluded that aggregative indices suchas mCd and RI could assess metals pollution state in surface sediments of the study area in an acceptable manner.According to the obtained results, eastern parts of the Anzali Wetland were more polluted than the other parts ofthe area. Moreover, concentration of all studied metals except Cr was higher than those in the earthcrust.Application of multivariate statistical analysis also revealed that Cu, Zn, Cr, Pb, and Cd may be originatedfrom anthropogenic sources and metals like Fe, Mn, and Ni might be derived from natural sources in the studyarea.}, keywords = {Anzali wetland,ecological risk,GIS,Heavy metals,multivariate statistical analysis}, title_fa = {ارزیابی آلودگی و پهنه‌‌‌بندی کیفی رسوبات سطحی تالاب انزلی بر اساس نتایج شاخص‌های سنجش آلودگی فلزات سنگین}, abstract_fa = {فلزات سنگین از جمله آلاینده‌‌هایی محسوب می‌‌شوند که از طریق منابع متعدد انسان‌ساخت یا طبیعی به صورت مستقیم یا غیرمستقیم وارد پیکره‌‌های آبی می‌‌‌شوند. تالاب انزلی یکی از اکوسیستم‌های بسیار حائز اهمیت در ایران است که به علت برنامه‌‌های توسعۀ صنعتی و کشاورزی از منابع آلایندۀ متعددی تأثیر می‌پذیرد. در تحقیق حاضر رسوبات 41 ایستگاه نمونه‌‌بردرای در تالاب انزلی مطالعه و غلظت فلزات مس، روی، کروم، آهن، منگنز، سرب، نیکل و کادمیوم در رسوبات این نمونه‌‌ها آنالیز و بررسی شد. همچنین، شاخص‌های سنجش آلودگی فلزات (شاخص غنی‌‌‌سازی، درجۀ آلودگی اصلاح‌شده و ریسک اکولوژیک) همراه آنالیزهای آماری چند‌متغیره (PCA و CA) برای سنجش وضعیت آلودگی فلزات سنگین در رسوبات تالاب انزلی استفاده شد که نتایج بیانگر آلودگی بیشتر مناطق شرقی و رودخانه‌‌های پیربازار، پسیخان و شیجان (ایستگاه‌های 1، 3 و 4) در مقایسه با سایر مناطق بود. بر اساس نتایج به‌دست‌آمده از شاخص غنی‌‌سازی، غنی‌شدگی رسوبات به فلزات کادمیوم، سرب و کروم مشهود بود. علاوه بر موارد بالا، نتایج شاخص‌های ریسک اکولوژیک و درجۀ آلودگی اصلاح‌شده بیانگر وضعیت آلودگی متوسط و ریسک اکولوژیکی بالایی در مناطق شرقی و جنوب شرقی تالاب انزلی بود. نتایج آنالیزهای آماری چندمتغیره تأثیر زیاد منابع انسان‌ساخت در مقادیر فلزات مس، روی، کروم، سرب و نیکل را تأیید کرد. همچنین، فلزات آهن، منگنز و تا حدی نیکل نیز احتمالاً از منابع طبیعی در منطقۀ مورد مطالعه سرچشمه می‌گیرند. }, keywords_fa = {آنالیز آماری چندمتغیره,تالاب انزلی,ریسک اکولوژیک,فلزات سنگین,GIS}, url = {https://jes.ut.ac.ir/article_36469.html}, eprint = {https://jes.ut.ac.ir/article_36469_3a861b3504640e65820ca1c71b862861.pdf} }