PCBs, PBDEs and pesticidesreleased to the Arctic Ocean by theRussian Rivers Ob and YeniseiJ O L Y N N C A R R O L L , *, †V L A D I M I R S A V I N O V ,†T A T I A N A S A V I N O V A ,†S A L V E D A H L E ,†R O B E R T M C C R E A ,‡A N DD E R E K C . G . M U I R‡Akvaplan-niva, Polar Environmental Center,9296 Tromsø, Norway, and National Water Research Institute,Environment Canada, Burlington ON, Canada L7R 4A6Received July 7, 2007. Revised manuscript received October12, 2007. Accepted October 22, 2007.TheObandYeniseiRiverscontribute37%ofriverinefreshwaterinputs to the Arctic Basin and thus represent an importantpathway for the land-Arctic ocean exchange of contaminants.Sampling was carried out in the Yenisei (2003) and Ob (2005)RiverestuariesandKaraSeatoaddressthegenerallackofreliabledissolved contaminant f l ux data for these major rivers.Contaminant analyses were performed by high resolution massspectrometry on sample extracts taken from f i ltered largevolume water samples (50–100 L) and concentrated in situ ontoXAD-2 resin columns. Hexachlorocyclohexanes (HCHs), thepolychlorinatedbiphenyl(PCB)mixturesSovolandtrichlorodiphenyl,dichlorodiphenyltrichloroethane (DDT), as well as “penta”brominated technical mixtures of polybrominated diphenyl ethers(PBDEs) are important contributors to persistent organohalogencontamination for these waterways. Dissolved f l uxes to theKara Sea were estimated at ΣHCH 246 kg/yr, ΣPCB 63 kg/yr,ΣDDT 16 kg/yr, hexachlorobenzene 8 kg/yr, R-endosulfan 8 kg/yr, dieldrin 5 kg/yr, ΣPBDE 4 kg/yr, and chlordanes 4 kg/yr.Contaminantf l uxesfromtheseriversaresimilartothosereportedfor major Canadian rivers, conf i rming expectations that the Oband Yenisei are also major point sources for the Arctic basin.IntroductionThe catchment area of the Russian Rivers Ob and Yeniseirank fourth and sixth among world rivers with a combineddrainage area of 5.57 × 10 6 km 2 (1). Together these riverssupply more than 1 × 10 3 km 3 /yr of freshwater to the ArcticOcean (1) or about 37% of the total annual runoff from allmajor Arctic rivers. As such, they serve as an importantpathway for land-Arctic ocean input of contaminants (2).Atmosphericdeposition,e.g.airmassesfromEasternEurope,Kazakhstan,andCentralAsiacontributetothecontaminationof these river catchments (3–5). Also, numerous industries,located within these river basins, such as, mining, machine-building,oil-processing,andagriculturerepresentpotentialpollution sources to these waters.RivercontaminantlevelsweremonitoredthroughFormerSoviet Union and Russian government-sponsored environ-mental programs until the mid-1990s (6). Since then,monitoring programs have been severely curtailed, leadingto a critical lack of f i eld data with which to assess rivercontaminant loads and f l uxes to the Kara Sea. Informationfrom the current time period is particularly important giventhe expectation of increasing river discharges in response toglobal warming (7).The compounds investigated include polychlorinatedbiphenyls (PCBs), hexachlorocyclohexanes (HCHs), hexachlo-robenzene (HCB), dichlorodiphenyltrichloroethane (DDT)and its metabolites, chlordanes (CHLs), mirex, endosulfan,aldrin,dieldrin,methoxychlor,andpolybrominateddiphenylethers (PBDEs).In the Former Soviet Union, the production and use ofmany hazardous substances was banned in the late1980s–1990s. Historical information on Russia’s productionand usage levels for persistent organic pollutants andpesticides are only selectively available. However, somecompoundscontinuetobeintroducedintotheenvironmentfor authorized selective use (e.g., pesticide applications fordisease vector control).HCH and DDT were the most widely used pesticides inthe former Soviet Union. From 1950 to 1990, technical HCH(R-HCH (55–80%), γ-HCH (8–15%), ?-HCH (5–14%)) (8) andlindane (90% γ-HCH) were used mainly for agriculturalpurposes (1.96 × 10 6 and 40 × 10 3 tonnes, respectively) (9).DDTproductionoccurredfrom1946to1970;however,usagetocontrolinsectpopulationscontinueduntiltheearly1990s,particularly in the Ob, Nadym, Pur, and Taz River basins(10, 11). In total, DDT usage by the former Soviet Union(1946–1990) is estimated at 250–520 × 10 3 tonnes (11). HCBusage (610 tonnes in total) was also widespread until 1986(12). HCB is still entering the environment as a byproductof the production of several pesticides and chlorinatedcompounds, particularly lower chlorinated benzenes. It isalsoemittedtotheatmospherebywasteincinerationfacilitiesand metallurgical industries (13). Chlordane, althoughprohibited in the Russian Federation (14, 15), is still beingused in China (16) and therefore may be transferred to theArctic through long-range atmospheric transport. Dieldrin,and the highly toxic insecticide, endosulfan, were also usedin Russia to control insect outbreaks (16, 17).PBDEs are structurally similar to well-known persistentorganic pollutants, such as PCBs, with similar bioaccumu-lation potential and air–water partitioning (18). Produced atthreedifferentdegreesofbromination,i.e.,deca-,octa-,andpenta-BDEs, these compounds are released into the envi-ronment at industrial manufacturing sites and leach fromsewagesludgeandcommonhouseholdproducts(19,20).In1999, the global market demand for deca-, octa, and penta-BDEs was 55 × 10 3 , 4 × 10 3 , and 8 × 10 3 tonnes, respectively(21). In 2004, production of penta- and octa-BDE technicalmixtureswashalted(22),butlargequantitiesremaininend-use products. Although not produced in Russia, PBDEs areimported from the U.S., Israel, Belgium, Ukraine, India, andother countries. In 2004, 21 tonnes of penta-BDEs and 74 kgofocta-BDEswereimportedfromthesecountries(23).PBDEshave been found in Arctic marine food webs (19, 24); theirlevels in Arctic seawater have not been previously reported.The f i rst usage of PCBs in the former Soviet Union wasthe technical PCB mixture, Sovol, synthesized in 1934 (25).Beginning in 1939, Sovol and various mixtures of Sovol andtrichlorobenzeneswasdistributedunderthecommonnameSovtol (26). The manufacture of trichlorodiphenyl (TCD)began in 1968 (25, 26). These compounds were banned bythe former Soviet Union in 1990. Until that time, total* Corresponding author phone: +47 77 75 03 14; fax: +47 77 7503 01; e-mail: jc@akvaplan.niva.no.† Polar Environmental Center.‡ Environment Canada.Environ. Sci. Technol. 2008, 42, 69–7410.1021/es071673l CCC: $40.75 ? 2008 American Chemical Society VOL. 42, NO. 1, 2008 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 69Published on Web 11/23/2007
