PCBs and PAHs in surficial sediments from aquatic environments of Mexico City and the coastal states of Sonora, Sinaloa, Oaxaca and Veracruz (Mexico (original) (raw)
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Geochimica et Cosmochimica Acta, 2012
Concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were measured in a sediment core from the tropical freshwater inner lagoon of Las Matas, near the petroleum industrial area of Minatitlán-Coatzacoalcos, in the Gulf of Mexico. A 210 Pb-derived chronology was used to reconstruct the historical PAH and PCB accumulation in the site during one century . Both geochemical and sedimentological data indicated that a major change occurred in 1947 ± 4, including a shift to coarser sediments and a significant decrease of Al, Li, Fe, organic C and total N contents. This was likely due to the changes in hydrology caused by the confinement of Las Matas Lagoon due to the construction of the Trans-Isthmus road in 1946. PAHs in these samples show relatively low concentrations (259-1176 ng g À1 ), and the congener relative abundances indicate the influence of pyrogenic (petroleum combustion) sources. Total PCB concentrations in the sediments ranged from 24 to 77 ng g À1 , and are composed by low chlorinated PCBs, with 3-and 4-CB as the prevalent species (51-65% and 29-40%, respectively). PAHs and PCBs were detected at depths corresponding to the early 1900s, when Minatitlán refinery started operations, although their time evolution appears to be influenced by different accumulation processes. The PCB background is most likely produced by the combustion of natural organic matter, and an industrial contribution can be recognized when normalizing with OC contents. We concluded that atmospheric deposition is the most significant source of PAHs and PCBs for this water body. This study also provided evidence of the alteration of the wetlands surrounding this industrial area due to urbanization; the fragmentation and alteration of Las Matas Lagoon hydrology contributes to the gradual loss of the wetlands in the zone.
Ecotoxicology, 2009
Laguna de Terminos, a wide coastal lagoon system in Campeche, Mexico, was investigated for the contamination by polychlorobiphenyls (PCBs). Distribution of these industrial chemical contaminants along with pesticide residues in the lagoon, as well as their sedimentwater partitioning and bioaccumulation by oysters and fish were assessed. Contaminant concentrations in the lagoon were compared with toxicity data for aquatic organisms and the ecotoxicological risks discussed. Current contaminant concentrations generally were several orders of magnitude below acute toxic levels for the most sensitive aquatic species and this seems compatible with the status of nature reserve and functions aimed at Laguna de Terminos. In particular, Penaeidae shrimp species that are the most valuable fisheries resources of Campeche with important populations in the Laguna are not impaired with the current low levels of these contaminants. Nevertheless, due to known environmental persistence, the surveillance of chlorinated contaminant levels in the lagoon ecosystems is recommended.
Chemosphere, 2008
Polychlorinated naphthalenes (PCNs), short-chain chlorinated paraffins (SCCPs) and polychlorinated biphenyls (PCBs) were analysed in marine sediment samples collected from the coastal area of Barcelona (Spain) and near of a submarine emissary coming from a waste water treatment plant located at the mouth of the Besò s River (Barcelona). An integrated sample treatment based on Soxhlet extraction followed by a simple clean-up with Florisil and graphitized carbon cartridge was employed. Gas chromatography coupled to ion-trap tandem mass spectrometry (GC-MS/MS) and gas chromatography-mass spectrometry in electron capture negative ionization mode, were used for PCN and SCCP determinations, respectively, while for PCB analysis gas chromatography with electron capture detection (GC-ECD) was used. The method developed provided low limits of detection (0.001-0.003 ng g À1 dry weight (dw) for PCNs, 1.8 ng g À1 for SCCPs and 0.006-0.014 ng g À1 dw for PCBs) and good run-to-run precisions (lower than RSD 8%) for the analysis of sediment samples. Concentration levels ranging from 0.17 to 3.27 ng g À1 dw for PCNs, between 0.21 and 1.17 lg g À1 dw for SCCPs, and from 2.33 to 44.00 ng g À1 (dw) for PCBs, were found in the coastal sediments, while for samples collected near to the submarine emissary higher levels (from 2.02 to 6.56 ng g À1 dw for PCNs, between 1.25 and 2.09 lg g À1 dw for SCCPs and from 22.34 to 37.74 ng g À1 dw for PCBs) were obtained. The results obtained provide new data about the occurrence of PCN and SCCP in the coastal area of Barcelona.
Water Science and Technology, 2017
In this research, the levels of polychlorinated biphenyls (PCBs) were investigated in the marine sediments of Asaluyeh harbor, in the Persian Gulf. The samples were taken from industrial, semi-industrial and urban regions. The mean concentration levels of total (Σ) 18 detected PCBs were 514.32, 144.67 and 31.6 pg/g dw for the industrial, semi-industrial and urban sampling stations, respectively. Based on a multivariate statistical analysis, it was found that high contamination levels of PCBs in sediments collected along the Persian Gulf were associated with releases from local industries. Total organic carbon (TOC) content was significantly and positively correlated with the concentrations of PCB congeners. World Health Organization toxic equivalents (TEQs) for PCBs ranged from 0.04 to 2.66 pg TEQ/g dry weight (dw) in the coastal sediments. The TEQ values in this study were higher than many reported worldwide in the literature for sediments. This suggests that there are high levels ...
Regional Studies in Marine Science, 2020
Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in sediment cores of the microtidal coastline of Lagos lagoon were investigated for the occurrence, sources and depositional contamination history. Sediment core samples were collected using the Wildco @ hand corer (50 cm) SS kit and extracted using a 40 mL mixture of hexane and acetone (1:1), and cleaned-up using 10 mm ID chromatographic column before the concentration of aliquots. In this investigation, 16 US EPA priority PAHs and PCB congeners were analysed in aliquots of sediment cores using Agilent 7820A gas chromatograph coupled to a 5975C inert mass spectrometer (with triple-axis detector) with an electron-impact source. PAHs and PCBs were detected at varying concentrations across the 50 cm depth of each sediment core. The total PAH concentrations ranged from 1.43-5.90 mg/kg, and were more widely distributed than the total PCBs. The total PCB concentrations ranged from BDL-6.41 mg/kg. The PAH diagnostic ratios used identified the sources of the PAHs as pyrogenic rather than petrogenic. About 52% of the samples had concentrations above the ERM limit for total PCBs, suggesting that adverse effects on biota may occur in the long term. In general, the PAHs and PCBs concentrations detected in sediment cores of the Lagos lagoonal system may pose a considerable ecotoxicological risk to estuarine organisms.
Polychlorinated biphenyls in sediments of the Venice Lagoon
Chemosphere, 2001
Twenty-four surficial sediment samples, representing different environments within the Venice Lagoon, were analyzed for polychlorinated biphenyls (PCBs) in order to assess degrees of pollution, sources, areal distribution, and potential risk for the environment. Concentrations in surficial sediments range from 2 to more than 2049 μg kg−1 dw. The maximum is probably due to the discharge of industrial wastes into the Brentella Canal, within the first Industrial Area. Lagoon samples are 11–205 times less contaminated, being influenced by pollutants stored in the canals only occasionally. Congener profiles distinguish PCBs in two main categories. The baseline pollution is probably due to a variety of sources within the lagoon system, whereas less chlorinated PCBs were discharged into the Brentella Canal. Our estimates suggest that, due to high concentrations, toxic equivalents (TEQs) of PCBs are comparable to those relative to PCDD/Fs for the least contaminated samples, whereas they are lower in case of heavy PCDD/F contamination.
Environmental Monitoring and Assessment, 2011
Seventeen parent polycyclic aromatic hydrocarbons (PAHs) and 38 congeners of polychlorinated biphenyls were measured at five different sediment depths (between the surface and ~300 cm below the seafloor) at 160 sites in Naples harbour. Total PAH (ΣPAH) and PCB (ΣPCB) concentrations ranged between 0.012–21.73 − nd 0.001–0.222 mg kg − 1, respectively. For PAHs, an evident and progressive decrease in concentration with depth documents the effects of a more intense anthropic impact of this group of pollutants in the recent period. A selected number of PAH isomer pairs (phenanthrene/anthracene, fluoranthene/pyrene and benzo(a)anthracene/crysene) were used to distinguish between contaminants of pyrolitic and petrogenic origin. More than 90% of PAHs present at the different depths of the studied sediments indicate pyrolitic industrial origins. On the other hand, relatively high concentrations of three- and four-ring PAHs suggest a limited contribution of vehicular emissions to the contamination of sediments. An unexpected and systematic increase of ΣPCB concentration, exceeding values approved by international regulations, was found in the studied sediments, testifying to the uncontrolled discharge to the studied area from industrial and commercial activity on nearby land. Ecotoxicological risk levels calculated for PAHs suggests a relatively elevated level of toxicity in surface sediments decreasing with depth and very low toxicity values associated to PCB toxicity.
Archives of Environmental Contamination and Toxicology, 2006
The concentrations of polychlorinated biphenyls (PCBs) were measured in surficial sediments receiving industrial and municipal effluents in Kuwait. The ΣPCB concentrations varied by two orders of magnitude ranging from 0.4 to 84 μg kg−1 dw. The homologue distribution in the study favored the more chlorinated congeners and generally followed the order: penta-PCBs > hexa-PCBs > tetra-PCBs ≈ hepta-PCBs, with the dominant congeners being 138, 101, 110, 180, 153, 132, 149, and 118. The spatial distribution revealed significant intersite difference in concentration, with high levels encountered close to a harbor and several wastewater outlets suggesting that point source input is the primary delivery mechanism of PCBs to the sediment. This study suggests that atmospheric deposition of PCBs may not be a significant delivery mechanism to sediments in Kuwait possibly due to low annual precipitation and high annual temperatures that are experienced in the Arabian Gulf. The implication of this observation is that PCBs in air are likely to remain in the gas phase long enough to be subject to long-range atmospheric transport to other regions.
Polychlorinated biphenyls in two salt marsh sediments of the Venice Lagoon
Environmental Monitoring and Assessment, 2011
Polychlorinated biphenyls (PCBs) were measured in two dated salt marsh cores of the Venice Lagoon to assess their input chronology and to evaluate the importance of atmospheric deposition as a source. Sampling sites were chosen in order to evidence the differences between areas located leeward and windward with respect to inputs originating in both the city of Venice and the industrial area. Concentrations of PCB indicators (0.13-15.6 ng g −1 ) increased gradually from the 1930s, reached maxima from the 1950s to the late 1970s, and then decreased. PCB loadings to marshes are driven by both the atmospheric depo-sition and the resuspension of subtidal sediments, this latter being more important for heavier congeners. The downwind marsh recorded higher fluxes (0.06-9.72 ng cm −2 year −1 ) than the upwind one (0.01-0.53 ng cm −2 year −1 ). Recent fluxes are rather consistent with bulk deposition measurements. A higher contribution of CB-101 and CB-118 was detected in the intermediate layers of the downwind site, suggesting a different PCB source for the corresponding time interval. In the other marsh, PCBs showed a rather constant composition at all levels (mostly CB-153, CB-138 and CB-180), accounting for a regional influence. Deep layers showed an enrichment of higher chlorinated congeners at both sites, whereas recent samples conserve the patterns typical of surficial and subsurficial subtidal sediments. The scientific approach adopted in this research can be considered as a sort of methodological procedure for the determination of fluxes and pathways of PCBs through the study of marsh cores.