PCB contamination in surface sediments in the coastal waters of Costa Rica

This paper describes the initial investigation of PCB concentrations in four geographical regions (three on the Pacific and one in the Caribbean) of coastal Costa Rica: Bahia Culebra, Golfo Dulce, Golfo de Nicoya, and Limón. Overall total concentrations of PCB were low in all areas except around the port of Golfito (Golfo Dulce). Overall average concentration is 2.80 ng/g dw, with a standard deviation of 2.75. The low concentration could be due to lack of contamination or the subsequent degradation in the warm climate, or the low sorptive capacity of the sediment. Further investigation is ongoing.     

PCB contamination in marine sediments from Golfo Dulce, Pacific coast of Costa Rica

Twenty-nine marine sediment samples collected from 1996 through 2002 from the Golfo Dulce embayment of Costa Rica were analyzed for PCB concentrations. The Esquinas River and Rincon Bay in the northern and western part of the gulf had relatively low overall concentrations of PCBs, with no samples having greater than 2.1 microg/g dw sediment. The Port of Golfito had the highest overall concentrations, ranging up to 15.7 microg/g dw sediment. These samples were also dominated by higher chlorinated congeners. Samples from the deeper (> 100 m) waters in the northern part of the gulf, as well as within the sediment plume from the Rio Coto Colorado had intermediate values. Within the Rio Coto Colorado sediment plume the concentrations did decrease with increasing depth and the congeners showed a shift towards less chlorinated congeners with depth. However, the deep northern basin had some of the highest PCB concentrations and the shift towards less chlorinated congeners was not apparent or significant. Whether the anoxic conditions that exist in the deep waters are capable of initiating dechlorination is still unknown. Overall, the data from Golfo Dulce show moderate PCB contamination, despite the pristine nature of the gulf and surrounding lands.     

Potential for polychlorinated biphenyl biodegradation in sediments from Indiana Harbor and Ship Canal

Polychlorinated biphenyls (PCBs) are carcinogenic, persistent, and bioaccumulative contaminants that pose risks to human and environmental health. In this study, we evaluated the PCB biodegradation of sediments from Indiana Harbor and Ship Canal (IHSC), a PCB-contaminated site (average PCB concentration = 12,570 ng/g dw). PCB congener profiles and bacterial community structure in a core sediment sample (4.57 m long) were characterized. Analysis of vertical PCB congener profile patterns in sediment and pore water strongly suggests that in situ dechlorination occurred in sediments. However, 16S rRNA genes from putative PCB-dechlorinating Chloroflexi were relatively more abundant in upper 2 m sediments, as were genes indicative of aerobic biodegradation potential (i.e. biphenyl dioxygenase (bphA)). Characterization of the bacterial community by terminal restriction fragment length polymorphism and comparison of these with sediment and pore water PCB congener profiles with the Mantel test revealed a statistical correlation (p < 0.001). Sequences classified as Acinetobacter and Acidovorax were highly abundant in deep sediments. Overall, our results suggest that PCB dechlorination has already occurred, and that IHSC sediments have the potential for further aerobic and anaerobic PCB biodegradation.     

Seasonal-spatial distributions,congener profile,and risk assessment of polychlorinated biphenyls (PCBS) in the surficial sediments from the coastal area of Bangladesh

A comprehensive congener specific assessment of polychlorinated biphenyls (PCBs) was conducted for the first time in Bangladesh. All 209 PCB congeners in the surficial coastal sediments from the coastal areas of Bangladesh were analyzed by GC-MS/MS. The total concentrations of PCBs (∑PCBs) varied from 5.27 to 92.21 and 4.61 to 105.3 ng/g dw in winter and summer, respectively, and the ranges were comparable to or higher than those recorded in the sediments from the coastal areas of India, Korea, China, and Taiwan. The seasonal difference in the levels of PCBs was not statistically significant (p > 0.05). The spatial distribution revealed that the areas with recent urbanization and industrialization (Chittagong, Cox’s Bazar and Sundarbans) were more contaminated with PCBs than the unindustrialized area (Meghna Estuary). Moderately chlorinated (4–6 Cl) homologs dominated PCB profiles. A set of congeners based on their detection frequencies and abundance were identified and categorized as potential environmental marker PCBs, which can be used for the future selective monitoring studies where there would be limitations on whole congener assessment. Ecotoxicologically, the sedimentary PCB concentrations exceeded some of the existing environmental quality standards, suggesting a potential threat to the aquatic organisms in the Bangladeshi coastal areas.     

Trace metals in coastal sediments from Costa Rica

Marine sediment samples from four coastal ecosystems in Costa Rica were taken between the years 2000-2002 and their iron, lead, copper and zinc concentrations were determined by the atomic absorption technique with flame or graphite furnace. In the Pacific coast, Culebra Bay (Papagayo Gulf), Gulf of Nicoya, and Golfito Bay (Dulce Gulf), were selected as representative sites, and Moín Bay, at the Caribbean coast. Mean metal concentrations for all ecosystems followed the same pattern: Fe > Zn > Cu > Pb. No temporal pattern was found for any metal. Iron and copper mean concentrations were higher in Golfito Bay (5.8% and 87 microg/g, respectively) and lower in Moín Bay (3.4% and 52 microg/g, respectively). Zinc mean concentration was also higher in Golfito Bay (96 microg/g), but lower in Culebra Bay (66 microg/g). Lead mean concentration was higher in Moín Bay (6.4 microg/g) and lower in Culebra Bay (3.0 microg/g). Lead highest concentrations occurred in the Caribbean and in Golfito Bay, and for the rest of the elements the maximum values were found in Golfito Bay. On the basis of data obtained in this work, Culebra Bay was considered a relatively unpolluted location; Golfito Bay was more contaminated, and Moín Bay and the Gulf of Nicoya showed an intermediate condition.     

Oil pollution status expressed as the fraction of dissolved and dispersed petroleum hydrocarbons

Four coastal ecosystems with contrasting characteristics were sampled in Costa Rica (2000-2002). Oil pollution status, expressed as the fraction of dissolved/dispersed petroleum hydrocarbons related to chrysene equivalents, was determined by the molecular fluorescence analytical technique. A total of 130 water samples were taken, from the Caribbean (Moín Bay), and from the Pacific (Bahía Culebra, Gulf of Nicoya and Dulce Gulf). On one occasion, seven samples along the Puntarenas estuary were also analysed. In Moín the mean and standard deviation were 0.10 microg x L(-1) +/- 0.18 micro x L(-1), ranging from non detectable (nd) to 0.65 microg x L(-1). For the Pacific ecosystems the total range was from nd to 0.37 microg x L(-1). In Bahia Culebra no fluorescence signals were obtained. In the Gulf of Nicoya the mean and standard deviation were 0.04 microg x L(-1) +/- 0.09 microg x L(-1), from nd to 0.33 microg x L(-1). Values in Dulce Gulf were 0.05 microg x L(-1) +/- 0.11 microg x L(-1), from nd to 0.37 microg x L(-1). Along the Puntarenas estuary the range was 0.17 to 5.91 microg x L(-1), with a mean of 1.21 microg x L(-1) and a standard deviation of +/- 2.10 microg x L(-1). The four coastal ecosystems had concentrations below the 10 microg x L(-1) limit for polluted oceanic areas. The Puntarenas estuary reflects the influence of antropogenic activities from and around the City of Puntarenas. These levels are considered low for inshore waters.     

Bacteriological study of bivalves from the Gulf of Nicoya, Costa Rica. I. Condition of the mollusk recently collected]

During the first six months of 1970 we collected 16 lots of the bivalve Anadara tuberculosa from two areas within the Gulf of Nicoya, Costa Rica. These were examined bacteriologically and the coliform levels found in all of them were such that they had to be graded as not satisfactory for human consumption, according to generally accepted norms. The source of these coliforms is attributed to the sewage discharge of the city of Puntarenas into its estuary.     

Distribution,Sources Identification,and Ecological Risk of PAHs and PCBs in Coastal Surface Sediments from the Northern Persian Gulf

Hormozgan Province plays a vital role in fishery, petroleum, and industrial activities in southern Iran. However, no comprehensive studies on organic pollution have been performed. PCBs and PAHs were analyzed in surface sediments from areas receiving industrial (nine sites), river (one site), and urban (two sites) effluents. The sediment samples were collected in March and September 2010 (in dry and wet seasons) at the highest tidal time. The overall pollution level of PCBs ranged from 2.5 ± 0.8 to 462.0 ± 206.7 ng/g dry weight. CB153 congener dominated in most of the sediment samples. Congener profiles of PCBs showed close similarity with formulations of commercial products such as Aroclor 1260 and 1254 g. A wide range of 55.3 to 1231.6 ng/g dry weight was detected for ∑PAHs. Results of PCA and PCA-MLR tests confirmed both petrogenic and pyrogenic origins for PAH pollution. The higher means of ∑PAHs and ∑PCBs in industrial and urban wastewaters were found near the shore, evidencing the role of these wastewaters in the PAH and PCB contamination in Hormozgan sediment. The concentrations of PAHs and PCBs in detected hotspots exceed the U.S. NOAA sediment quality guidelines.     

Molecular assessment of the potential for in situ bioremediation of PCBs from aquatic sediments

Polychlorinated biphenyls (PCBs) are a family of xenobiotic compounds that are ubiquitous and oftentimes persistent environmental pollutants. As such, PCBs are a common target of sediment remediation efforts. Microbial degradation of sediment pollutants such as PCBs offers an environmentally sound and economically favorable alternative to conventional means of remediation such as dredging. This project describes the development of a PCR-based assay to determine the potential for PCB bioremediation by the resident microbial consortium in contaminated sediments. Using PCR and RT-PCR of DNA and RNA, respectively, extracted from aquatic sediments collected from the western basin of Lake Erie and one of its tributaries, we were able to amplify the bphA1 gene that encodes the large subunit of biphenyl dioxygenase. Since other studies have determined that the BphA1 gene product dictates PCB congener specificity, this assay may prove to be a useful screen for endemic catabolic activities for PCB mixtures in aquatic sediments.     

PCBs in Passaic River Sediments: Some Analytical Considerations

Analytical results for Aroclor may contain a great deal of uncertainty if the relative ratios of certain PCB congeners are substantially altered following differential environmental degradation. Selective degradation of PCB congeners has been shown to occur in biological tissues, and recent studies have shown that Aroclor analyses may significantly underestimate PCB concentrations in fish. The purpose of this study is to assess whether a similar phenomenon can occur with PCB-impacted sediments. Five hundred and thirty-seven sediment samples from the Passaic River were analyzed for Aroclors and selected non-ortho (PCB #77, 126, and 169) and mono-ortho (PCB #105, 114, 118, 123, 156, 157, 167, and 189) coplanar PCB congeners. Aroclors 1248 and 1254 were detected in 67 and 53% of the samples, respectively; 54 samples (approximately 10%) did not contain detectable levels of any Aroclors. In these 54 samples, the sum of the detected PCB congener concentrations was significantly greater, on average, than the Aroclor limit of detection by approximately threefold. In individual samples the sum of the PCB congeners exceeded the Aroclor limit of detection by up to 36-fold. In those samples in which Aroclors were detected, the summed PCB congener concentrations exceeded the Aroclor 1248 and 1254 concentrations, on average, by 41 and 33%, respectively. Given the fact that only a fraction of the 209 PCB congeners were quan-titated, these findings indicate that Arocolor data may significantly underestimate total PCB concentrations in Passaic River sediments. Total PCB data obtained from total homologue analysis indicated that Aroclor results underestimated total PCB mass by up to 43-fold. These findings suggest that caution is required when comparing Aroclor sediment data from the Passaic River to total PCB sediment criteria.     

Presence of the dinoflagellates Ceratium dens, C. fusus and C. furca (Gonyaulacales: Ceratiaceae) in Golfo de Nicoya, Costa Rica

Harmful Algae Blooms (HAB) are a frequent phenomenon in the Gulf of Nicoya, Costa Rica, as in other parts of the world. The morphology and physiology of these microalgae are important because HAB species have adaptive characteristics. The production of high concentrations of paralytic toxins by Ceratium dinoflagellates has only been documented at the experimental level. However, this genus has been associated with the mortality of aquatic organisms, including oyster and shrimp larva, and fish, and with decreased water quality. Recently, fishermen reported massive mortality of encaged fish near Tortuga Island (Gulf of Nicoya). Samples were taken from an algal bloom that had produced an orange coloration and had a strong foul-smelling odor. Ultrastructural details were examined with scanning electron microscopy. The dinoflagellates Ceratium dens, C. furca and C. fusus were found in samples taken at the surface. The cell count revealed four million cells of this genus per liter. The morphological variability of these species is high; therefore electron microscopy is an useful tool in the ultrastructural study of these organisms. This is the first time that three Ceratium species are reported concurrently producing harmful blooms in Costa Rica.     

Behaviour of selected PCBs,PAHs and γ-HCH in the Scheldt estuary,S.W. Netherlands

The behaviour of some organic micropollutants in the abiotic compartments water, particulate matter and bottom sediments of the Scheldt estuary, S.W. Netherlands, was studied between 1986 and 1989. Special attention was given to two individual PolyChlorinated Biphenyl congeners (PCB 52 and PCB 153), two Polycyclic Aromatic Hydrocarbons (PAHs) fluoranthene and benzo(a)pyrene and γ-HCH. Dissolved PCBs and γ-HCH behave conservatively during estuarine mixing. The concentration of γ-HCH in the fresh-water is extremely high in spring compared to the other seasons. Dissolved fluoranthene does not behave conservatively. The concentration of dissolved fluoranthene in the freshwater endmember shows a seasonal dependence with highest concentrations in winter and lowest in summer. Benzo(a)pyrene could hardly be detected in the dissolved phase with the methods used. PCBs and PAHs in particulate matter and sediments behave essentially conservatively as a result of the mixing of riverine particulates with high, and marine particulates with low organic micropollutant contents. Particulate fluoranthene is removed at low salinities under (nearly) anoxic conditions probably by microbial degradation. The rivers Scheldt and Rupel appear to be the major sources for the compounds studied. However, in particular the organic micropollutant contents of the sediments indicate that important emissions along the estuary were or are still present. Measurements of individual PCBs and PAHs in the <63 μm fraction of a dated sediment core from a salt marsh in the eastern part of the Scheldt estuary show that the recent input of PCBs and PAHs into the estuaryis probably 2–3 times lower than the maximum input in the mid-1960s. The PCB profile shows postdepositional congener-selective mobilization caused by advective transport. The PAH assemblage is remarkably uniform in the sediment core. The PAH ratios indicate that combustion of coal is the main source of PAHs in the Scheldt estuary.     

On Branchiostoma californiense (Cephalochordata) from the Gulf of Nicoya estuary, Costa Rica

The cephalochordates are represented by the lancelets, of which species of the genus Branchiostoma are the best known. In recent years, these organisms have been the center of activity of studies focusing on the phylogenetic relationships of the chordates. In 1980, a survey of the benthos at 48 stations in the Gulf of Nicoya estuary, Pacific coast of Costa Rica, yielded 265 specimens of the lancelet Branchiostoma californiense. A total of 48 specimens was also collected at an intertidal flat in the mid upper estuary. Of the 48 subtidal stations, only eight had B. californiense, and these sites all had a sand fraction above 72%. The remaining stations ranged in their sand content from as low as 1% to as high as 92%, with an average of 25.9%, with 29 stations having a sand content lower than 72%. Lower salinities and muddy sediments may limit the distribution of the lancelet further upstream. This information is useful when changes over decades in the ecology of the estuary need to be evaluated against the background of local, regional, and global dynamics.     

Distribution of polychlorinated biphenyls (PCBs), lead,and cadmium in Manko Tidal Flat,Okinawa

Concentrations of polychlorinated biphenyls (PCBs), Pb, and Cd in sediment samples from the Manko Tidal Flat, an important area for migratory birds in Okinawa, were analyzed. High concentrations of PCBs were detected in the sediment samples from sites under a bridge at the end of the Manko Flat, whereas Pb and Cd concentrations did not indicate specific pollution. The spatial distribution and homologue proportion of PCBs indicated that these PCBs are probably attributed to the residue of paints used on the bridge in the 1970s. PCBs were detected in tilapias from sites in the Manko Flat and in a river connecting to the flat without head constructions. PCBs were also detected in small invertebrates, tanaids, in the flat. The distribution of PCB concentrations in the fauna was parallel to that in the sediments. The average PCB homologue proportions in tilapias and tanaids were similar to those in sediments.     

Isolation of Vibrio cholerae no-01 in the Gulf of Nicoya, Costa Rica]

In a bacteriological study on samples of bivalves, mud and surface waters from the Gulf of Nicoya, Costa Rica, 18 strains of non-01 Vibrio cholerae and 50 of V. mimicus were isolated. The samples were enriched in alkaline peptone water, and streaked on MacConkey and inositol-brilliant green bile agars. Biochemical and serological tests were used for their identification. Both species were isolated from all sampling sites (Lepanto, Jicaral and Puntarenas) with either of the two agar media, even though these were not specific for vibrios.     

Reductive dechlorination of low concentration polychlorinated biphenyls as affected by a rhamnolipid biosurfactant

We investigated whether the threshold concentration for polychlorinated biphenyl (PCB) dechlorination may be lower in biosurfactant-amended sediments compared with biosurfactant-free samples. At PCB concentrations of 40, 60, and 120 ppm, the surfactant amendment enhanced the PCB dechlorination rate at all concentrations and the rate was also faster at higher concentrations. On a congener group basis, dechlorination proceeded largely with group A (congeners with low threshold) in both surfactant-free and -amended sediments, accumulating mainly group C (residual products of dechlorination) congeners, and surfactant enhanced the dechlorination rate of group A congeners. Since the PCB threshold concentration for the inoculum in the experiment was lower than 40 ppm, we carried out another experiment using sediments with lower PCB concentrations, 10, 20, and 30 ppm. Sediments with 100 ppm were also performed to measure dechlorination at a PCB saturation concentration. Comparison between the plateaus exhibited that the extent of dechlorination below 40 ppm PCBs was much lower than that at a saturation concentration of 100 ppm. There was no significant difference in the extent of dechlorination between surfactant-free and -amended sediments. Moreover, surfactant did not change the congener specificity or broaden the congener spectrum for dechlorination at PCB concentrations below 40 ppm. Taken together, it seems that at a given PCB concentration, dechlorination characteristics of dechlorinating populations may be determined by not only the congener specificity of the microorganisms but also the affinity of dechlorinating enzyme(s) to individual PCB congeners.     

Non detection of enterovirus in the bivalve Anadara tuberculosa (Bivalvia:Arcidae) caused by chemical contamination in the Pacific of Costa Rica

Anadara tuberculosa is one of the most abundant mollusks of commercial importance in Costa Rica. Its habitat water is a potential source of fecal and chemical contamination to humans. We wanted to asses enterovirus, mainly poliovirus and hepatitis A virus and chemicals such as sulphates and nitrates in meat and body fluids. Thirteen samples were taken from four sites in Nicoya Gulf, three sites in the Sierpe-Térraba mangrove (Pacific of Costa Rica) and from five fish markets in San José, the capital of Costa Rica. Samples were tested for 1) fecal coliforms (Most Probable Number/100 ml), 2) isolation of enterovirus in cell culture (Hep-2, FrhK-4), 3) cell cytotoxicity in Vero cells and 4) the ability to inactivate 10 ID50% of poliovirus in cell culture. The Most Probable Number/100 ml in surrounding water was higher than the accepted standard for recreational waters, although the number of fecal coliforms in meats and body fluids was lower than in the external water. No cytopathogenic agents were isolated, but we found nitrate and sulphate concentrations that exceeded maxima for human consumption and recreation. The intrinsic cytotoxicity of the samples was at a 1/8 dilution, but some samples were cytotoxic at dilutions of 1/128. Body fluids were more cytotoxic than meats, but a positive correlation between cytotoxicity and chemical contamination was not determined: apparently other pollutants not identified in this study were responsible. Fluid and meat capacity to inactivate 10 ID50% of poliovirus in cell culture was demonstrated. Samples that were toxic for cell cultures also showed a higher percentage of poliovirus inactivation. Monitoring chemical pollution in these waters is highly recommended.     

Distribution and Toxicity Risks of PCBs in the Tidal Flat Ecosystem Near the 37th PCBs Sealed Site on the Coast of Zhejiang Province,China

This study investigated the dioxin-like (DL) PCB concentration and congener distributions in water, sediment, and Boleophthalmus pectinirostris samples collected from a beach near the 37th PCBs sealed site (the hazardous waste storage site was sealed by Zhejiang Province Environmental Monitoring Center) of Zhejiang Province, China, so as to evaluate the harmful effects of PCBs waste sealed sites on the surrounding environment. The results showed that DL-PCBs were in all samples. For all samples, the detection ratio of the mono-ortho congener PCB118 and the non-ortho congener PCB81 reached 100%, and both of their contents correlated well with the total DL-PCBs contents. Levels of low-chloride congeners were higher in environmental samples, while the enrichment of the high-chloride congeners was higher in fish. The content of PCBs in B. pectinirostris was highly related to the sediment environment, thus B. pectinirostris could well indicate environmental PCBs pollution. Considering both of the PCBs content and toxic analysis, even after 4 years of being excavated and cleaned, water, sediment, and fish samples were still at a certain degree of toxicity risks. Some areas were revealed to have a high toxicity risk, suggesting this PCBs sealed site still posed toxicity risks to the surrounding tidal flat ecosystem and might potentially endanger animals and human health.     

Site-specific microbial communities in three PCB-impacted sediments are associated with different in situ dechlorinating activities

Competitive PCR and denaturing HPLC analyses together with an assay detecting potential polychlorinated biphenyl (PCB) dechlorinating activities were combined with physical-chemical site characterizations to identify factors affecting the reductive dechlorination of PCBs in the three historically impacted sediments: Grasse and Buffalo Rivers, NY and Anacostia River, DC. In Grasse River sediment an in situ enriched population of Dehalococcoides phylotypes was abundant in high numbers together with a relatively high dechlorination activity and a high concentration of congeners containing unflanked chlorine substitutions. In contrast microbial communities in Anacostia and Buffalo Rivers sediments consisted of similar total numbers of putative dechlorinating bacteria, but the populations consisted of more diverse putative dechlorinating phylotypes and were associated with lower dechlorination activities and higher concentrations of flanked congeners. Differences observed in the PCB dechlorination activity were not influenced by the chemical PCB availability in spiked sediment or physical sediment characteristics, but were consistent with the concentration of PCBs and total organic carbon in the native sediment. Application of molecular methods for selective detection of indigenous microbial dechlorinating communities combined with assessment of the dechlorinating activity and analysis of the in situ congener profiles provided a comprehensive approach for characterization and identification of sites that are amenable to bioremediation, which is essential for the development of in situ treatment strategies.