Natural resources engineering
Tarbiat Modares University
Department of Environment
Department of Environment
Tarbiat Modares University
Tarbiat Modares University
Human biomonitoring is a reliable method for evaluating human exposure to specific contaminants. Although blood is an ideal matrix for monitoring purposes, it is regarded as an invasive matrix. Therefore, current developments in the field of human biomonitoring are based on introducing new methods that use non-invasive matrices, such as hair. In this study, we examined the efficiencies of several extraction methods for the analysis of hexabromocyclododecane (HBCD) and tetrabromobisphenol-A (TBBPA) in human hair. The selected pretreatment method was validated through a general QA/QC process that included spiking experiments, and then, the method was used for the determination of HBCD and TBBPA concentrations in scalp hair samples collected from individuals in Korea (n ¼ 24) and Iran (n ¼ 15). The HBCD and TBBPA concentrations in the collected hair samples ranged from ND to 3.24 ng g1 and ND to 16.04 ng g1, respectively. Significantly higher concentrations of TBBPA were found in hair samples from Korea than those in hair samples from Iran (p < 0.05), which is expected to be the result of the large market and higher exposure of TBBPA in Korea. HBCD was not detected in hair samples from Iran. According to our knowledge this is the first study demonstrating the presence of TBBPA in human hair with nonspecific exposure. Lastly, we investigated the important factors that influence the interpretation of the contributions of endogenous and exogenous contaminations in hair. Based on the information, the HBCD and TBBPA in the collected hair samples were most likely from endogenous exposure. Therefore,
Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus (P) nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler (LCM) combining with the Soil Water Assessment Tool (SWAT) model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.
در این مطالعه میزان جیوه در موی و شیر ماردان مورد مطالعه قرار گرفت و یک ارتباط معنا داری بین غظلت جیوه و تعداد دندانهای پر شده یافت شد
در جهان آلودگیهای زیادی مانند فلزات سنگین و ترکیبات آلی پایدار در داخل محیطزیست رها می و غیره میباشند. )OCP( آفتکشهای آلیکلره ،)PCB( شوند. ترکیبات آلی پایدار شامل پلیکلرهبیفنیل این ترکیبات به دلیل پایداری و چربیدوست بودن، تمایل به تجمع در زنجیره غذایی را دارند. اگرچه همه مهرهداران نسبت به اثرات ترکیبات آلی کلردار حساس هستند اما پرندگان به خاطر حساس بودن به تغییرات زیستمحیطی و قرارگرفته در بالای زنجیره غذایی برای مطالعات بزرگنمایی زیستی بسیار مناسب هستند. در زمستان سال 8838 از سواحل دریای )Phalacrocorax carbo( ازاینرو، گونه باکلان بزرگ خزر در استان مازندران که تحت کشاورزی و استفاده شدید از آفتکشها میباشد جمعآوری و میزان آلودگی PCBs آنالیز شد .میزان )GC( بافت ماهیچه با استفاده از دستگاه کروماتوگرافی گازی OCPs و PCB PCB883 ،PCB883 ،PCB سه ایزومر 858 ،PCB بود. در میان ایزومرهای ng/g wet wt در باکلان 39 بالاترین غلظت را در بین ایزومرها دارد و 55 درصد از مجموع 5 ایزومر را شامل میشود. بالاترین غلظت 44 نانوگرم بر ( DDTs )44 ng/g wet wt( در میان آفتکشهای آلی کلره اندازهگیری شده مربوط به 2( میباشد که به ترتیب حدود 49 و ng/g wet wt( گرم وزن تر( و پایینترین غلظت مربوط به هپتاکلر 2 درصد از کل آفتکشهای آلی کلره را دارا میباشند. با توجه به ترکیبات آلی کلره یافت شده در گونه باکلان و با توجه به مصرف خوراکی آن، میبایست استراتژیهای نوین کنترل آفت مبنی بر حذف کاربرد نابخردانه آفتکش بهکارگرفتهشود بهطوریکه امروزه این رهیافت در بیشتر مباحث توسعه پایدار کشاورزی مطرح میشود
Persistent organic pollutants (POPs), including the organochlorine pesticides (OCPs), such as di- chlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α, β and γ-hexa- chlorocyclohexane (HCH) isomers, and the polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180), were determined in hair samples collected from 41 Iranian wild cats belonging to 8 different species. This is the first report on the presence of selected POPs in feline hair from museum collections and it is an indication of the concentrations of OCPs and PCBs in Iran from 2000 to 2010. Median concentrations of HCHs, DDTs, PCBs, and HCB were 108, 99, 70 and 38 ng/g hair, respectively. p,p\\\'-DDE and β-HCH were the most abundant OCPs (detected in 91% and 74%, respectively, of the analyzed samples), while CB 180 and CB 138 were the predominant PCB congeners, found respectively in 49% and 61% of the samples. Significant differences (p < 0.05) in the median concentrations of DDTs were found among species grouped according to both their feeding habits and territory range. Levels of DDTs and PCBs were generally higher in the omnivorous species compared with the carnivorous ones, likely due to both their dietary habits and habitat in the proximity of human settlements.
This study analyzes the chemical composition (water-soluble ions and trace elements) of the total suspended particles (TSP) and particulate matter less than 10 and 2.5 mm (PM10 and PM2.5) in the Sistan basin, southeast Iran during the dusty and windy period June – October 2014. Extreme TSP, PM10 and PM2.5 concentrations, means of 1624.8, 433.4 and 320.8 mgm3, respectively, were recorded in the Zabol sampling site, while the examined water-soluble ions and trace metals constitute small fractions (4.1%–17.7%) of the particulate masses. Intense winds on the dust-storm days result in weathering of soil crust and deflation of evaporate minerals from the dried Hamoun lake beds in the Sistan basin. The soil samples are rich in Ca2+, SO4 2 , Na+ and Cl revealing the existence of non-sea salts, as well as in Al, Fe and Mg, while the similarity in the chemical composition between soil and airborne samples indicates that the dust events over Sistan are local in origin. In contrast, low concentrations of secondary ions (i.e., nitrate) and heavy metals (i.e., Pb, Cr, Ni, Cu) indicate less anthropogenic and industrial emissions. Enrichment Factor analysis for TSP, PM10 and PM2.5 reveals that the anthropogenic sources contribute a substantial amount in the heavy metals rather than soil crust, while Al, Fe, Sn, Mg are mostly of crustal origin. The results provide essential knowledge in atmospheric chemistry over Sistan and in establishing mitigation strategies for air pollution control.
Identifying the sources of aeolian dust is a crucial step in mitigating the associated hazards. We apply a Generalized Likelihood Uncertainty Estimation (GLUE) model to constrain the uncertainties associated with sediment fngerprinting of atmospheric dust in the Sistan region on the Iran-Afghanistan border, one of the world’s dustiest places. 57 dust samples were collected from the rooftop of the Zabol Department of Environmental Protection during a summer dusty period from June to October 2014, in addition to 31 surface soil samples collected from potential sources nearby, including cultivated land (n = 8), uncultivated rangeland (n = 7), and two dry lakes: Hamoun Puzak (n = 10) and Hamoun Saberi (n = 6). Dust and soil samples were analyzed for 24 tracers including 16 geochemical elements and 8 water-soluble ions. Five optimum composite fngerprints (Fe, Sr, Mn, Cr and Pb) were selected for discriminating sources by a two-stage statistical process involving a Kruskal-Wallis test and stepwise discriminant function analysis (DFA). Uncertainty ranges for source contributions of dust determined by the GLUE model showed that the dry lake Hamoun Puzak is the dominant source for all dust samples from Zabol and cultivated land is a secondary source. We found marked spatial variance in the importance of regional dry lake beds as dust sources, and temporal persistence in dust emissions from Hamoun Puzak, despite very large areas of adjacent lake beds drying during the study period. Aeolian sediment fngerprinting studies can beneft considerably from the constraints provided by modelling frameworks, such as GLUE, for quantifying the uncertainty in dust provenance data