JoséL. Sericano

Trace organic contamination in the Americas: An overview of the US National Status & Trends and the International ‘Mussel Watch’ programmes

Abstract The National Status & Trends (NS&T, 1986–1993) and the International Mussel Watch (IMW, 1991–1992) programmes provide a good coverage of a broad range of environmental conditions along the North, Central and South American coasts. Total concentrations of DDTs, chlordane-related compounds, PCBs and PAHs present fairly homogeneous distributions along the northern Gulf of Mexico coast, with very few sites showing extremely high or low concentrations. In contrast, a larger variability in the geographical distribution of some of these organic contaminants was observed for IMW sites. For example, high concentrations of DDT and its metabolites, DDD and DDE, were generally found in tropical and subtropical areas as compared to more temperate zones of South America. ‘Industrial’ contaminants, such as PCBs and PAHs, have similar distributions with the highest concentrations encountered generally along the southern South Atlantic coast. An overall comparison of the concentrations of these organic contaminants measured at NS&T and IMW sites indicates that contamination is significantly higher along the northern coast of the Gulf of Mexico.

NOAA's status and trends mussel watch program: Chlorinated pesticides and PCBs in oysters (Crassostrea virginica) and sediments from the Gulf of Mexico, 1986–1987

Abstract Chlorinated pesticides and PCBs were analyzed in more than 590 oyster and sediment samples collected during 1986 and 1987, the first 2 years of the NOAAs Status and Trends Mussel Watch Program established to monitor the current status and temporal trends of these contaminants in the Gulf of Mexico. Chlorinated hydrocarbons in oysters and sediments presented similar distribution patterns; however, their concentrations in oysters were several times higher than the concentration detected in the surrounding sediments. Alpha-chlordane, trans -nonachlor and dieldrin were the most abundant non-DDT pesticides in both types of sample. The major fraction of DDT related compounds measured in oysters and sediments was DDD. Based on average PCB concentrations, penta-, hexa-, and tetrachlorobiphenyls were preferentially accumulated by oysters as compared to the average sediment composition. Although this study was designed to avoid known point-sources of contaminant inputs, the measured concentrations were, in general, within the range of concentrations previously reported for the Gulf of Mexico. After the first 2 years of this program, the geographical distribution of chlorinated hydrocarbons in oysters and sediments is well defined. In contrast, the temporal trends at the different sites are not clear. Continued sampling will allow the identification of long-term trends in concentrations of chlorinated hydrocarbons in the Gulf of Mexico.

NOAA's ‘Mussel Watch’ project: Current use organic compounds in bivalves

Abstract The National Oceanic and Atmospheric Administration (NOAA) established the National Status and Trends (NS&T) Mussel Watch Project in 1985 to assess the current status and the long term trends for selected contaminants in US coastal waters. Starting in 1994 bivalves have been analyzed for compounds not reported in previous years. Dicofol, alachlor, trifluralin and atrazine were detected in 5% of the samples and analyses were not continued. On the other hand, the concentrations of 1,2,4,5-tetrachloro-benzene, 1,2,3,4-tetrachlorobenzene, pentachlorobenzene, pentachloroanisole, endosulfan and chlorpyrifos were measurable in bivalves collected from 1994 to 1997. The distribution of concentrations for these analytes were different from each other and from the pesticides, polycyclic aromatic hydrocarbons and polychlorinated biphenyls historically measured in the NS&T project. The concentrations of these analytes are comparatively low and some were not detected at a majority of sites sampled. However, continued monitoring will provide information on the temporal trends of these environmental contaminants and therefore should be continued.

Polybrominated diphenyl ether flame retardants in lichens and mosses from King George Island, maritime Antarctica

Lichens and mosses are considered good indicators of atmospheric pollution as they absorb contaminants directly from the air. Polybrominated diphenyl ethers (PBDEs) are man-made chemicals used as flame retardants in materials such as plastics, textiles, electronic circuitry and furnishing foam. Few studies have investigated PBDEs in the southern hemisphere including Antarctica. This paper presents the first evaluation of PBDEs in lichens (Usnea antarctica and Usnea aurantiaco-atra) and mosses (Sanionia uncinata) collected at King George Island, maritime Antarctica. PBDEs were detected at low levels in all lichen and moss samples. On average, the levels of PBDEs in mosses (818 pg g(-1) dry weight; 101 ng g(-1) lipid) were significantly higher than in lichens (168 pg g(-1) dry weight; 9.11 ng g(-1) lipid). This difference is most likely due to the differing mechanisms of PBDEs uptake from the atmosphere which are controlled by a number of chemical, environmental and plant variables. Contaminant concentrations were not statistically different at sites close to and distant from human facilities. Long-range atmospheric transport is believed to be the primary source of PBDEs to King George Island. The pattern of congeners in plants resembles those found in commercial mixtures of Penta-BDE. In addition, the presence of BDE-183 in lichens and mosses suggests that other technical formulations (e.g., Octa-BDE and Deca-BDE) have reached Antarctica. Further studies are needed to better understand the role of Antarctic vegetation as a sink for anthropogenic organic pollutants.

Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean.

High molecular weight hydrocarbons in Gulf of Mexico continental slope sediments

Sediments on the Gulf of Mexico continental slope contain a mixture of terrigenous, petroleum and planktonic hydrocarbons. The relative amount of these three inputs varies as a function of location, water depth, and time of sampling. The hydrocarbon concentrations measured are generally lower than those previously reported for shelf and coastal Gulf of Mexico sediments. The influence of land-derived material decreases from the central to the western to the eastern Gulf of Mexico. Petroleum inputs are measurable at all sites sampled. Natural seepage was considered to be a significant source of hydrocarbons to slope sediments. Hydrocarbon concentrations vary by 1–2 orders of magnitude along a given isobath due to changes in sediment texture and hydrocarbon inputs. Variability along an isobath is as great if not greater than that seen over a depth range of 300–3000 m along a single transect. In general, the highest aliphatic hydrocarbon concentrations are associated with the more clayish/organic-rich sediments. Aromatic hydrocarbons are below gas chromatographic detection limits at all sites (<5 ppb), but their presence is inferred from spectrofluorescence analyses, confirming the presence of petroleum-related hydrocarbons at all sites.

Risk ranking of multiple-POPs in detritivorous fish from the Río de la Plata

To evaluate the bioaccumulation and the risk associated to consumption of lipid-rich detritivorous fish, a comprehensive set of organic pollutants (n=213) including polychlorinated biphenyls (PCBs), dioxin like PCBs (dlPCBs), chlorinated pesticides (CHLPs), chlorobenzenes (CBzs), polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo dioxins and furans (PCDD/F), resolved (ALI) and unresolved aliphatic hydrocarbons (UCM) and linear alkyl benzenes (LABs) were analyzed in Sábalo fish (Prochilodus lineatus) collected in the polluted Metropolitan Buenos Aires coast and in migrating specimens. Fatty fish muscles (lipids: 74±9.3% dry weight) contained homogeneous (24-51% variability) and very high-concentrations of organic pollutants ranging from 60 to 1,300 μg g(-1) fresh weight (fw) ALI+UCM; 10-40 μg g(-1) fw LABs and PCBs; 0.1-1 μg g(-1) fw dlPCBs, DDTs, chlordanes, CBzs and PBDEs; 0.01-0.1 μg g(-1) fw mirex, endosulfans, aldrin, dieldrin, endrin and 0.07-0.2 ng g(-1) PCDD/F. Total toxicity equivalents (TEQs) ranged from 60 to 395 pg g(-1) fw (34±17 and 213±124 pg g(-1) TEQs for PCDD/F and dlPCBs respectively). These are among the highest concentrations reported for fish and point out the remarkable ability of Sábalo to feed on anthropogenic organic-enriched particles and tolerate a high pollutant load. Contaminant signatures show partial alteration with still abundant lower molecular weight components indicating that fish feeds directly in the outfalls. Consumption limits based on reference doses ranged from 0.1 (PCBs) to >1,2000 g d(-1) (endosulfan) allowing a comprehensive risk-based ranking of contaminants in this long-range migrating, detritivorous fish.

National status and trends mussel watch program: Chlordane-related compounds in Gulf of Mexico oysters, 1986–1990

The National Oceanic and Atmospheric Administrations National Status and Trends (NS&T) Program has been monitoring the chemical contamination in bivalve tissues from the US coastal waters since 1986. alpha-Chlordane, trans-nonachlor, heptachlor and heptachlor epoxide, components of technical chlordane, are among the chlorinated pesticides measured. The geographical distribution of these chlordane compounds in oyster samples from the US Gulf of Mexico is well-established. For example, highest residue levels, predominantly alpha-chlordane and trans-nonachlor, were encountered in samples collected near highly populated areas in contrast with the concentrations measured in predominantly agricultural areas. Data collected during 5 years of bivalve sampling are used to evaluate temporal trends in residue concentrations at most NS&T sites. Minor decreases can be observed in the concentrations of alpha-chlordane and trans-nonachlor. Heptachlor and its epoxide concentrations, in contrast, have been increasing since 1987.

Toxaphene, PCB, DDT, and chlordane analyses of beluga whale blubber

Beluga whales bioaccumulate organochlorines from their environment. Blubber samples of Beluga Whales from Alaskas north coast contain organochlorines, including Toxaphene (polychlorinated camphenes) PCBs, DDTs and chlordane. Toxaphene was the organochlorine pesticide found in the highest concentration in all samples with the exception of the 6 year old male where PCBs were highest. The source of these organochlorines is likely global distillation from lower latitudes. Males had higher concentrations than females and the oldest male had higher concentration than the younger male. Females exhibit a decrease in concentrations with age. The fetus had about 10% higher concentrations for all organochlorines compared to the mother. Transplacental transfer of organochlorines and lactation lower the contaminant concentration in females. Older females have lower contaminate concentrations likely due to continual reproductive success. Consumption of older males will expose humans to higher levels of organochlorines.

Isolation of planar polychlorinated biphenyls by carbon column chromatography

Abstract A simple, sensitive, precise and specific method for the isolation of planar PCB congeners having four, five and six chlorines in environmental samples is presented. On average, recoveries of 3,3′,4,4′; 3,4,4′,5; 3,3′,4,4′5 and 3,3′,4,4′,5,5′ (IUPAC No 77, 81, 126 and 169) planar PCB congeners from spiked Aroclor mixtures were 94±7.2, 82±5.4, 93±3.9 and 96±2.5%, respectively; while recoveries from spiked dolphin blubber samples were 87±4.0, 70±2.3, 91±2.8 and 97±2.3%. As compared to previously published methods, this methodology saves both time and materials, i.e. solvents, and eliminate the use of benzene, a highly carcinogenic solvent, which requires extreme care in handling by the analyst.