Bayona Termens, Josep María

Díez, Sergi

English

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EFFECTIVENESS OF THE RETAIL BAN ON TBT BASED ANTIFOULING PAINTS IN THE WESTERN MEDITERRANEAN HARBORSSergi Díez1 and Josep M. Bayona2Environmental Chemistry Department, IIQAB-CSIC, Barcelona, Spain1sdsqam@iiqab.csic.es, 2jbtqam@iiqab.csic.esIntroductionEnvironmental aspects of harbours are an important issue of their management sincethey are recipients of toxic chemical inputs from a wide variety of pollution sources andcan affect marine coastal ecosystems by sediment dredging, seawater diffusion oradvective sediment transport.  Organotins (OTs) have been widely used during the lastdecades as biocides, polymer stabilisers, wood preservatives, and catalysts in anumber of industrial processes1-3. Nevertheless, their main source in the marineecosystem is related to their use as antifouling paint biocides. Therefore, OTs aretransferred from wastewaters to sewage sludges produced in wastewater treatmentplants (WTP) due to partial degradation of OTs4. Therefore, in urban coastal areaswhere raw sewage is disposed to only physical treatment, OT sources coming fromsewage disposal could be not negligible. The high ecotoxicological risk of thesecontaminants on marine ecosystems is widely documented (i.e. imposex, oystermalformation, mussel larvae mortality) at very low concentration levels (few ng L-1)5-7.These negative effects on the aquatic environment were discovered in the ArcachonBay (France) in the early 1980s8. As a consequence, the French authorities banned theuse of antifouling paints containing tributyltin (TBT) on boats less than 25 m long in1982. Similar regulations on the usage of TBT in paints came into effect few years laterin other countries. As a consequence, TBT and triphenyltin (TPhT), which is also usedas biocide in antifouling paints, have been included in the US EPA EnvironmentalEndocrine Disrupters and in the European Union Priority Pollutant Lists (EU, Directive76/464). Moreover, their global ban is under scrutiny in the forthcoming years (UNEP,POPS/INC/CEG, 1999). Preprints of Extended Abstracts                                                             Vol. 42 No. 2346CHEMISTRY OF EPA CONTAMINANT CANDIDATE LIST COMPOUNDS:DEGRADATION MECHANISMS AND PRODUCTSOrganized byM.L. MagnusonSymposia Papers Presented Before the Division of Environmental ChemistryAmerican Chemical SocietyBoston, MA       August 18-22, 2002The aim of this work is to provide recent data (e.g. 1995 to present) on the occurrenceof TBT and TPhT, and their degradation products in the Western Mediterranean Sea.Surface sediments were analysed from harbours, marinas and sewage disposal sites(domestic and industrial) of the North-western Mediterranean Spanish coast tocompare with previous data corresponding to late 1980s9 in order to evaluate theeffectiveness of the European Community regulations.Area of StudyThere are two study areas precisely distinguished; one corresponds to Northeast of theSpanish Mediterranean coast, the Catalan Sea, including four harbours: Masnou,Barcelona, Tarragona and Sant Carles. The other corresponds to the Southeast ofSpain, namely the Alboran Sea, including eight harbours, located in Almería,Aguadulce, Almerimar, Marbella, Estepona, Banús, Duquesa and Sotogrande.Furthermore, three sewage disposal areas of different effluent characteristics (type oftreatment and composition) were investigated corresponding to municipal (i.e.Barcelona and Almería) and industrial (Tarragona) WTP plants.Sampling and StrategySurface sediment (0-5 cm) was collected from a vessel by using a small van Veen grab.Then, they were placed in aluminium foil plates, transferred to polyethylene bags andkept in a portable refrigerated freezer. To ensure that only the most recent sedimentwas sampled, only the top 2 cm of sediment was collected. After sampling, sedimentsamples were transported to the laboratory in refrigerated boxes and frozen at –20 ºCuntil analysis.Sample preparation, extraction procedure and derivatizationFreeze-dried and sieved sediments (ca. 2 g; 120 mm mesh) were weighed andtransferred to a glass centrifuge tube with a Teflon-lined cap previously wrapped withaluminium foil. Tripropyltin (TPrTCl) and tricyclohexyltin (TCyTCl) chlorides were addedas recovery spike (surrogates) to the sample at a spiking level of 200 ng each. Detailson the extraction process accomplished by sonication with toluene/HOAc (10:4) for 5min and derivatization with Grignard reagent are described elsewhere [10]. Finally,evaporation down to 1 mL was carried out under a gentle stream of nitrogen. About 600ng of TeBT was added to the sample as an internal standard prior to the GC-FPDdetermination. Results and DiscussionOrganotin accumulation in sedimentsThe Catalan SeaOrganotin concentrations in sediments from this area varied widely depending on thelocation. Results for the 1995 sampling survey are shown in Fig. 1. Butyltins werepredominant in the whole area of study and the higher levels were found in theBarcelona commercial harbour. Maximum levels for TBT (18700 ng g-1), DBT (6860 ngg-1) and MBT (1675 ng g-1) were found Barcelona harbour. Concentrations of di- andtriphenyltin were one or two orders of magnitude lower than butyltins but comparablePreprints of Extended Abstracts                                                             Vol. 42 No. 2347for MPhT. The highest phenyltin values were also detected in the Barcelona harbour.As expected, in the Masnou marina, where pleasure boats are predominant, OTconcentrations are lower than in the Barcelona commercial harbour. In MSN stations,butyltin concentrations average  204 ng MBT g-1, 530 ng DBT g-1 and 920 ng TBT g-1. Inthis area of study, the contamination for phenyltin is not relevant (average of 140 ng g-1for all phenyltin species).  Butyltin derivatives in Sant Carles harbour were higher thanexpected according to the harbour characteristics. Station SC1 is the most polluted,located in the marina with longer water residence time than sampling stations locatedcloser to the harbour entrance. In any case, average values for butyltins aremoderately high (200 ng MBT g-1, 600 ng DBT g-1 and 1600 ng TBT g-1). On the otherhand, the station SC3 shows higher values for a fishing wharf (MBT: 202 ng g-1, DBT:955 ng g-1 and TBT: 1110 ng g-1). Those results lead us to consider that fishing boatsare using TBT-based antifouling paints. The Alboran SeaIn the Alboran Sea, OT concentrations in sediments were determined for the first time.Nine harbours and twelve sites were selected in this study. Results are shown in Fig. 1.Almería harbour is the only commercial harbour where OTs were measured. It showsthe highest values for butyltins among the harbours located into the southern basin,with maximum levels reaching 785 ng g-1 for MBT, 540 ng g-1 for DBT, and 2135 ng g-1for TBT. Moreover, a remarkable difference in the concentration levels between thisharbour and the Barcelona harbour is noticeable, attributable to the enormous contrastof traffic volume (4 106 t versus 28.5 106 t, respectively) and passenger traffic (i.e.Barcelona doubles Almería).  All the rest of marinas from the southern Spanish coastanalysed show values that average 975 ng g-1 of TBT, except Sotogrande that has ahigher value over the average reaching around 3868 ng g-1 of TBT. Those values arereasonable because Sotogrande marina has a large number of moorings and alsomaximum length permitted for the boats. Sewage disposal sitesOrganotin values obtained from the different sewage disposal areas are also shown inFig. 1. In Barcelona (BS), phenyltins are in the average of 25 ng g-1 with maximumlevels for butyltins of 120 ng g-1. In any case OT concentrations in Barcelona region arelower in comparison to the Almería sewage disposal site (ASO) analysed, reachingvalues of 600 ng g-1 for MBT, 80 ng g-1 for DBT and 270 ng g-1 for TBT. Thosedifferences could be accounted for by wastewater treatment and the population servedby each treatment plant. In our study, the WTP of Barcelona, which serves ca. 1.5millions of inhabitants and its composition is 80% domestic, owns a physical-chemicaltreatment using basic conditions which could lead to an OT hydrolysis. On the otherhand, the population of Almería is around 4.5 105 inhabitants but its municipal WTPhas only primary treatment without alkaline flocculation conditions leading to a higheraccumulation of OTs in sediments since their removal efficiency is presumably lowerthan in the Barcelona treatment plant. Preprints of Extended Abstracts                                                             Vol. 42 No. 2348In Barcelona and Almería sewage sludges, phenyltins are found at negligible levelsdue to the lack of domestic applications of these compounds. These results contrastwith the OT composition in an industrial sewage disposal area located in the Tarragonacommercial harbour. In this case, butyltin concentrations are similar to those of theBarcelona sewage disposal but phenyltins were identified at low concentrations, exceptfor the station TRQ where values reached the 300 ng g-1 of MPhT, attributable tospecific manufacturing activities undertaken at this chemical plant. Then, the dischargeof OTs related to the disposal of urban and industrial sewage sludge into the coastalenvironment should not be neglected. In this concern, OTs could be bioavailable bydesorption, resuspension or diffusion from sewage sludge into the water columntriggering a variety of ecotoxicological effects.Historical TrendsOrganotin concentration for the 1988 and 1995 surveys are shown in Fig. 2. In theBarcelona harbour, the comparison with the data obtained in 1988 shows that OTlevels in all stations in 1995 are even higher than those reported previously [9]. Sincethe first sampling, Barcelona has become a relevant commercial port in theMediterranean Sea and nowadays, most of the docks are used for cargo boats or forinternational passenger ferries. Therefore, the growth in boat traffic observed duringthe last ten years is the reason for the increase of TBT concentration inside theBarcelona harbour. As a brief example, in 1988, 60 ng g-1 of TBT were found in BCN3increasing to 5410 ng g-1; and 975 ng g-1 in BCN1 are now close to 19000 ng g-1. As weknow all those freighters and ferries are longer than 25 m, so restrictions on TBT-basedanti-fouling paints do not affect them. Moreover, the great maritime traffic of shipscoming from convenience flag countries where no legislation might be another reason.In the Masnou marina, a decrease of the levels reported in 1988 [9] was found. In allthe stations, OT concentrations declined, in more of the cases, even more than half ofthe value obtained in the previous sampling. Consequently, the Masnou marina seemsto show an effective fulfilment of the TBT regulation. However, in order to estimate thetheoretical concentrations assuming reported degradation rate kinetics, actualsediments are exceeding the expected levels. In Sant Carles marina (SC1), sediment concentrations of OTs were higher thanprevious data. Consequently, in contrast to Masnou, butyltin values increasedenormously from 1988 to 1995 (MBT from 7 to 448 ng g-1, DBT from 24 to 1327 ng g-1and TBT from 12 to 5226 ng g-1). In Sant Carles fishing wharf (SC3) we do not haveprevious data to compare, but high levels found on it in 1995 also indicate therequirement to implement a monitoring program to control an ecological area of itsimportance. Finally, in the Barcelona sewage outfall, the sediment analysisaccomplished in the late 1980s compared with actual values show no large differences,in both cases values are close to 30 ng g-1 in the OT analysed.Preprints of Extended Abstracts                                                             Vol. 42 No. 23491543318722010002000300040005000600070008000BCN1BCN3BCDSMSN2SC 1SC 3MB2EST1SOTBA1 DQ AGUAMMALPBS1TRPTRQASOng/gMBT DBT TBTMPhT DPhT TPhTFigure 1. Organotin concentrations (ng g-1 dry wt) in all the marinas sediments of thenorthern (BCN: Barcelona, MSN: Masnou, SC: Sant Carles) and southernMediterranean Spanish coast (MB:Marbella, EST: Estepona, SOT: Sotogrande, BA:Banús, DQ: Duquesa, AGU: Aguadulce, AMM: Almerimar,  ALP: Almería commercialport) and in the sewage outfall in Barcelona (BS), Tarragona (TRP, TRQ) and Almeria(ASO) collected in the 1995-2000 sampling campaigns.Preprints of Extended Abstracts                                                             Vol. 42 No. 2350References1. Maguire R.J. Review: Environmental aspects of tributyltin (1987) AppliedOrganometallic Chemistry, 1, 475-498.2. Evans C.J. and Karpel S. Organotins Compounds in Modern Technology; Elsevier,Amterdam, 1985.3. Blunden, S.J., Cusack, P.A., Hill, R. The industrial uses of Tin Chemicals, ed.H.J.M. Bowen. Environmental Chemistry, Royal Society of Chemistry, London, pp.346-350, 1985.4. Fent K. (1996) Organotin compounds in municipal wastewater and sewage sludge:contamination, fate in treatment process and ecoxitological consequences, TheScience of the Total Environment 185(1-3), 151-159.5. Smith P.J. (1996) Selective decline in Imposex levels in the dogwhelk Lepsiellascobina following a ban on the use of TBT antifoulants in New Zealand.  MarinePollution Bulletin,  32(4), 362-365.6. Bryan G.W. and Gibbs P.E. in Metal Ecotoxicology Concepts and Applications,eds. M.C. Newman and A.W. McIntosh, Lewis Publishers, pp.323-361, 1991.7. Solé M., Morcillo Y. and Porte C. (1998) Imposex in the commercial snail Bolinusbrandaris in the northwestern Mediterranean. Environmental Pollution 99(2),241-246.8. Alzieu C., Sanjuan J., Deltreil J.P. and Borel M. (1986) Tin contamination inArcachon Bay:  effects on oyster shell anomalies. Marine Pollution Bulletin 17(11),Preprints of Extended Abstracts                                                             Vol. 42 No. 2351 MSN (Masnou)marina02000400060008000100001200014000MBT DBT TBT MPhT DPhT TPhTng/g1988 1995 BCN (Barcelona)commercial020004000600080001000012000MBT DBT TBT MPhT DPhT TPhT18722ng/g1988 1995 SC (Sant Carles)marina0500100015002000MBT DBT TBT MPhT DPhT TPhT5226ng/g1988 1995494-498.9. Tolosa I., Merlini L., de Bertrand N., Bayona J.M. and Albaigés J. (1992)Occurrence and fate of tributyl- and triphenyltin compounds in westernMediterranean coastal enclosures Journal of Environmental Toxicology andChemistry 11(2), 145-155.10. Díez, S., Ábalos, M. and Bayona, J.M. (2002). Organotin Contamination inSediments from the Western Mediterranean Enclosures Following 10 Years ofTBT Regulation. Water Research, 36, 905-918.Preprints of Extended Abstracts                                                             Vol. 42 No. 2352

Effectiveness of the retail ban on TBT based antifouling paints in the western Mediterranean harbors

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Effectiveness of the retail ban on TBT based antifouling paints in the western Mediterranean harbors

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