The Marine Environment in the St
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FACT SHEET ON THE STATE OF THE MARINE DFO 1m1111111mr· 07013412 ENVIRONMENT OF THE ST. LAWRENCE CONTAMINATION OF BAIE DES ANGLAIS Baie des Anglais, located near Baie-Comeau, is currently Baie des Anglais sediments. In 1983, an environmental one of the most serious known cases of coastal conta impact assessment study conducted by the mination by polychlorinated biphenyls (PCBs) and Canadian Reynolds Metals Company (CRMC), polycyclic aromatic hydrocarbons (PAHs) in the prior to planned expansion of its port facilities, St. Lawrence Estuary and the Gulf of St. Lawrence. revealed the importance of the PCB contamination. Maximal PCB concentrations as high as 27.4 µg of PBCs and Furans PCB/ g of sediment were measured in sediments to be In 1982, sediment analysis of samples obtained during dredged from Anse du Moulin, whereas concentra The whelk, Buccinum maintenance dredging operations around the Cargill tions measured in surficial sediments of the Gulf of undatum. company's wharves indicated the presence of PCBs in St. Lawrence are approximately 0.01 µgig. Recently, researchers from Fisheries and Oceans Canada (DFO) and the Ministere de !'Environnement et de la Faune du Quebec (Quebec Ministry of the Environment and Wildlife) have measured levels of furans, which can be present as impurities in com mercial PCB mixtures, in Bay sediments. These are among the highest reported in Canada. PAHs It was not until 1989 that further analyses, this time done by the Ministere de !'Environnement du Quebec, now the Ministere de !'Environnement et de la Faune du Quebec (MEF), showed that QH PAHs were present in Baie des Anglais 541. 5 sediments. Liquid effluents from the .S3 CRMC were identified as the main source F48 of this PAH contamination. As with 4E PCBs, the most heavily contaminated sedi ments came from Anse du Moulin . Fisheries and Oceans Peches et Oceans ••• Canada Canada Canada BACKGROUND In general, rhe mean level of PCB contamination in rhe Bay seems co have diminished since the early PCBs 1980s, probably a consequence of the lagoon In the early 1980s, a survey conducted by rhe MEF resrauration and remedial actions taken by the indicated that the PCBs present i Baie des Anglais plant. sediments originated from oil leakages in the hydraulic system of the vertical casting facility in the PAHs CRMC aluminum smelter. Before being discharged Direct PAH discharge in the Reynolds Company's into Anse du Moulin, contaminated effluents from liquid effluents gradually diminished from 1984 co the plant were channelled through a lagoon (setrling 1989, because of the installation of dry scrubbers for basin) where a portion of rhe parricle-bound PCBs gases from the por rooms and anode preparation cen would sercle our. An analysis of sediment samples tre. It finally sropped in 1992, after a closed circuit from the lagoon revealed PCB 'concenrrations as cooling system was installed for the briquettes. In high as 9500 µgig. In 1986, hor ever, rhe lagoon addition, the aluminum and Donohue pulp and was restored, eliminating chis source of PCB paper plan ts participate in consultation efforts releases to the Bay. In addition, between 19 85 established by the Baie-Comeau ZIP committee. and 1990, the CRMC implemented various mea Activities of this committee fit inro the framework sures to eliminate rhe risk of PCB losses co the of rhe Zones of Primary Intervention program, environment. known as ZIP program, Community Involvement component of St. Lawrence Vision 2000. In 1988, following rhe rescorarion of this lagoon, the Department of Fisheries and Oceans (D FO), within the framework of an ecoroxicology moni toring program for fish habitats, identified two sites heavily contaminated with PCBs which were BAIE DES ANGLAIS contamination sources for the Baie des Anglais. Anse du Moulin, which in part received rhe residual Baie des Anglais is situated near Baie-Comeau contaminated effluents from rhe smelrer, repre on the north shore of rhe Lower St. Lawrence sented the main contamination source for the Bay. The secondary source, located off rhe wharves of Estuary (Figure 1), approximately 350 kilome the Reynolds plant, consisted of the disposal sire tres norrheast of Quebec Ciry. This small Bay is for the cove's dredge sediments. bounded by Sr. Gilles Point co the southwest and by St. Pancrace Point to the northeast. The Map of 2 Ba1e des Angla1s Bay covers a coral area of about 11 km , most of 1 which (10 km ) is over 40 metres deep, with a maximum depth of l 00 metres. Anse du 2 Moulin, with an area of roughly 0.09 km , lies on rhe west side of Baie des Anglais. Most of the cove is less than 7 metres deep, except for the area around the port facilities, where a depth of about 10 metres is maintained through dredging. Riviere aux Anglais empties into the Bay 500 metres north of Anse du Baie des Anglais Moulin. Saint-Gilles Point ~ · - • 1 ""' '---' FIGURE 1 Map of Baie des An glais, showing Anse du Moulin, Saint Pancrace Point, Saint-G illes Point and 1he location of the three main industrial plants : CRMC 1Canachan Reynolds Metals Co . Ltd), Donohue (Donohue QUNO lnr paper mill) and Cargill (Cargill Ltd grain comp,m y). II PC Bs Polychlorinated biphenyls (PCBs) are synthetic chemical PCB congeners. In North America, they are identified by the compounds consisting of two phenyl nuclei with varying num trade name Arodor. On July 1, 1980, the use of PCBs was pro bers and arrangements of chlorine and hydrogen atoms. Some hibited in the manufacture of products in Canada. The use of 209 PCB molecules exist, called congeners, which are subdivided these compounds is restricted to existing hermetically sealed into 10 homolog groups, each composed of congeners with one electric and hydraulic systems. to ten chlorine atoms. PCBs possess excellent thermal and chemical stability and are resistant to both oxidation and PCBs are very persistent in the environment and some of them reduction; they also possess good dielectric (insulating) proper are virtually non-biodegradable. In the aquatic environment, ties, are virtually insoluble in water, are non-flammable and these substances tend to bind to suspended particles. have a strong affinity for lipids (fat soluble). Due to these Depending on ambient hydrodynamic conditions, the sus properties, they have been widely used, since about 1930, as pended particles may be deposited on the seabed, and accu hydraulic fluids, coolants (heat exchange systems) and dielec mulate in the sediments. PCBs, which have varying toxicities, tric fluids (electrical transformers and capacitors), as well as in depending on the number and position of their constituent the manufacture of many everyday products such as rubbers, chlorine atoms, can accumulate in fatty tissues of marine lubricants, synthetic resins, plastics, paints, glues, waxes, tex organisms. Some of the compounds can impair the organisms' tiles, inks, road dust control agents and insecticide spray sol immune system, their growth and reproduction, or cause various vents. Commercial PCB products consist of a mixture of many cancers. PAHs The family of polycyclic aromatic hydrocarbons (PAHs) con quantities of PAH to the aquatic environment through tains some 100 molecules which are differentiated by the atmospheric fallout. Some PAHs, particularly those with a number and positions of their aromatic rings. Natural sources high molecular weight, are almost insolvable in water and of PAHs consist mainly of forest and grass fires, and volcanic tend to bind to the surface of suspended particles, eventually activity. In highly industrialized areas, human activities gen accumulating in sediments, which represent the main sink of erate the largest quantities of these substances. Petroleum PAHs in water bodies. A number of PAHs have muragenic spills and industrial and municipal discharges result in direct properties, and bmzo(a)pyrene has been identified as being a inputs of PAHs to the aquatic environment. Incomplete fo s potential carcinogen. Some PAHs concentrate in invertebrate sil fuel combustion in the residential hearing and transporta tissues and can thus be transferred up the food chain. tion sectors, waste incineration, reduction smelting of alumi Although PAHs do not accumulate in vertebrate tissues, na to produce aluminum by the Soderberg process, and cat· enzymes can break these compounds down, releasing degra alytic cracking of crude petroleum all release substantial dation products which may be toxic. DIOXINS AND FURANS Dioxins and furans are two families of compounds with very The Donohue paper mill, which releases its effluents into similar chemical compositions. These chlorinated compounds Baie des Anglais, does not employ this industrial process. are thermally stable, resistant to biodegradation, nearly insoluble Commercial PCB mixtures also represent a potential source in water, but are fat soluble; they also have a strong affinity to of dioxins and furans as impurities. Furthermore, when com sediments. There are 75 dioxin congeners and 135 furan con mercial PCB mixtures containing furans as impurities are geners which normally occur together in the environment as used as a coolant, heat exposure can lead to the formation of complex mixtures. Forest fires and volcanoes are the two natural furan concentrations hundreds of rimes higher than the sources of dioxins and furans. The most important sources, original fluid. Dioxins and furans can be highly toxic; labo however, are anthropogenic ones : chemicals for wood ratory rests have shown that some of these substances can preservation (pemachlorophenol), municipal and industrial cause congenital malformations and cancers, as well as impair waste incinerators, commercial chemical manufacturing reproduction and immune system functioning. plants, and pulp and paper mills which use a chlorine bleaching process. II THE MAIN CONTAMINANTS OF BAIE DES ANCLAIS In addition to PCBs and PAHs, other potential However, an important difference between sedi contaminants such as metals (lead, cadmium, cop ment granulometry or carbon content of compared per, zinc and mercury), dioxins and furans have sectors would also explain the large differences been analysed in surficial sediments and marine observed.