Polychlorinated Biphenyl Residues Research Articles

Incorporating habitat use and life history to predict PCB residues in wild fish in an urban estuary

Owing to the heterogenous distribution of contaminated sediments in urban estuaries, contaminant residues, such as polychlorinated biphenyls (PCBs), in fish tissue can vary widely. To investigate the relationship between PCBs in fish tissue and heterogeneity of PCBs in sediment, we developed a geospatial Biota-Sediment Accumulation Factor (BSAF) model for an urban estuary. The model predicts whole fish total PCB residues at a scale of 0.1 km2 by incorporating sediment chemistry, fish home range, and habitat type. The model predicted concentrations from across the estuary ranging from 0 to 161,456 ng/g lipid. An estuary-wide (50+ km2) and a project-scale (1+ km2) field validation of the model demonstrated it produced values that were slightly skewed to low concentrations; performance improved with increased sediment data spatial coverage. We conclude this approach has potential for determining PCBs “hot spot,” estimating remediation project footprints, and evaluating potential remediation improvements to the quality of a fishery.

Health risks and sources of PCDD/Fs and PCBs residue in cultured crabs

The Chinese mitten crab (Eriocheir sinensis) holds significant importance as a popular aquaculture food source; however, there are concerns about its potential contamination with polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) from both food and aquatic environment. To assess the associated health risks and identify potential sources of contamination in crabs, a comprehensive investigation was conducted, including a total of 70 samples from the crab food web. The results demonstrated that crabs predominantly exhibited elevated concentrations of PCBs and dl-PCBs, with mean concentrations of 12 207 ± 11 962 pg g-1 and 554 ± 203 pg g-1, respectively, while PCDD/Fs concentrations were comparatively lower at 20 ± 17 pg g-1. The accumulation of PCBs in crabs significantly surpassed that of PCDD/Fs. The material balance of PCDD/Fs and PCBs in the crab food web was estimated, indicating that sediments and feeds likely constitute the two primary sources of PCDD/Fs and PCBs in crabs. The monthly intake of PCDD/Fs and PCBs through crab consumption accounted for 30% of the dietary intake, which was well below the provisional tolerable monthly intake (PTMI) limit. The weekly intake of PCDD/Fs and PCBs for adults consuming one crab (100 g) does not pose health risks and the recommended weekly intake of white crabmeat and brown crabmeat is 443 g and 21 g, respectively.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) distribution, origins, and risk evaluation in the Egyptian Mediterranean coast sediments.

A study was conducted on 31 surface sediments located in different sectors of the Egyptian Mediterranean coast. The sediments were analyzed for their pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The sediments were collected from various depths in harbors, coastal lakes, bays, and lagoons, covering the southeastern Mediterranean of the Nile Delta region. The study aimed at determining the distribution, origin, and potential ecological impact of OCP and PCB pollutants. The researchers used the SRM method of GC-MS/MS to measure the concentration of 18 PCBs and 16 OCPs residues. The study found that the total concentration of OCPs in the samples ranged from 3.091 to 20.512 ng/g, with a mean of 8.749 ±3.677 ng/g. The total concentration of PCB residues ranged from 2.926 to 20.77 ng/g, with a mean of 5.68 ±3.282 ng/g. The concentration of DDTs exceeded the effect range low (ERL) (1.00) and threshold effect level (TEL) (1.19) in several stations, but it was still below the effect range median (ERM) (7.00) and the probable effect level (PEL) (4.77). This indicates a low ecological risk. The principal component analysis (PCA) was also conducted to determine the sources of all pollutants in the sediment. The PCA showed significant correlations between the concentrations of Gama-HCH and Beta-HCH (0.741), suggesting similar sources. PRACTITIONER POINTS: OCPs and PCBs residues were analyzed in the sediment of the southeastern Mediterranean. The concentration, existence, and causes of OCPs and PCBs were investigated. OCPs and PCBs ecological risk and ecotoxicological calculation were investigated in detail. Cluster analysis, PCA, and correlation coefficient were also investigated.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in water-sediment system of southern Mediterranean: Concentration, source and ecological risk assessment

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were studied in the Nile Delta area of Egypt's southern Mediterranean for their environmental impacts, probable sources, and ecological risk assessment. Using the Gas Chromatography Triple Quadrupole technique, the residues of 16 OCPs and 18 PCBs were determined. The total OCPs content in the seawater and sediment samples ranged from 0.108 to 10.97 μg/L and 0.301 to 5.268 ng/g, respectively, while the PCBs residues had values between 0.808 and 1069.75 μg/L in seawater and between not detected and 575.50 ng/g in sediment samples. The findings of the risk evaluation showed that, except for endosulfan-I, OCPs caused little harm in seawater. However, PCB180, PCB153, PCB156, PCB126 and PCB138 posed a comparatively significant risk. The concentration of DDTs was higher than the effect range low and threshold effect level but remained below the effect range median and probable effect level, posing a minimal ecological concern.

Polychlorinated biphenyls residues in bivalve shellfish from Niger Delta: distribution pattern, tissue burden and food safety assessment

ABSTRACT This study investigated the distribution pattern, tissue burden, and safety of bivalve shellfish for human consumption. Edible species of bivalve shellfish harvested from Niger delta were screened for polychlorinated biphenyl (PCB) contaminants. Instrumental analysis and quantification of PCB congeners were performed using gas chromatography fitted with electron capture detector (GC-ECD). Results indicated an accumulation of PCB concentration of 0.36 ng/g, 0.89 ng/g, 0.98 ng/g, and 1.73 ng/g at Andoni, Iko Town, Ibeno, and Bonny, respectively. The PCB burden showed bloody cockle at Bonny location recorded the highest concentration of PCB congeners (2.37 ng/g), closely followed by mangrove oyster (2.13 ng/g) at Iko Town location, while Donax clam at Ibeno (0.09 ng/g) has the least PCB burden. The results obtained were lower in relation to food regulatory threshold. However, PCB tissue burden of bivalve shellfish harvested at the study locations indicated an environment impacted by anthropogenic activities that could negatively affect human health which depends on these shellfish for food.

Changes in Polychlorinated Biphenyl Residues in Milk during Lactation: Levels of Contamination, Influencing Factors, and Infant Risk Assessment.

Given the importance of breastfeeding infants, the contamination of human milk is a significant public concern. The aim of this study was to assess the contamination of human milk with dioxin-like PCBs (dl-PCBs) and non-dioxin-like PCBs (ndl-PCBs) in relation to the duration of lactation and other influencing factors, especially the frequency of the consumption of selected foods during pregnancy. Based on this, the health risk to infants was assessed and compared to the tolerable daily intake (TDI). PCB determinations were performed using gas chromatography/mass spectrometry. The ∑ndl-PCB content ranged from 0.008 to 0.897 ng/g w.w., at an average of 0.552 ng/g wet weight, which was 55% of the maximum level according to the EU guidelines for foods for infants and young children. The toxic equivalent (TEQ) was in the range of 0.033-5.67 pg-TEQ/g w.w. The content of non-ortho, mono-ortho, and ndl-PCBs in human milk decreased the longer lactation continued. Moreover, when pregnant women smoked tobacco, this correlated significantly with increases in the concentrations of PCB congeners 156, 118, and 189 in human milk. The human milk contents of PCB congeners 77, 81, 186, 118, and 189 were strongly positively correlated with the amount of fish consumed. The content of stable congeners PCB 135 and PCB 153 increased with age.

Seasonal congener survey for polychlorinated biphenyls in sediments of south-western rivers, Nigeria: Occurrence, sources, and ecotoxicological risks

In this work, sediment samples from major rivers within southwestern Nigeria were collected to study the seasonal distribution, transport, and ecological risk assessment of polychlorinated biphenyls (PCB) using gas chromatography coupled with an electron capture detector (GC–ECD). The ΣPCB concentrations ranged from 9.86–77.56 μg/kg and 11.88–80.76 μg/kg in dry and wet seasons respectively. The most predominant PCBs congener in all the sediments was 2,2’,4,5,5’-PeCB(#101) with mean concentrations of 4.35 ± 2.96 and 6.10±3.38μg/kg across all locations in dry and wet seasons respectively. Relevant guidelines including sediments quality guidelines (SQGs) mean effect range-median quotient (m-ERM-Q), and toxic equivalent factor (TEF) were used for risk assessment and to evaluate the ecological risks of PCBs across the rivers. The toxic equivalent quantity (TEQ) ranged from 0.044–0.807 μg-TEQ/kg and 0.055–0.825 μg-TEQ/kg for the dry and wet seasons respectively. The non-ortho PCBs congeners constituted ≥ 99.8% of the ∑TEQ values. The seven indicators PBCs for evaluating non-dioxin-like PCBs ranged from 3.70–32.69 μg/kg across the seasons and accounted for 33.4%, 39.8%, 36.8%, 37.9%, 41.4%, and 40.4% of the ∑PCBs at Asejire, Odo Ona, Ogbese, Ogun, Ikorodu rivers and Third Mainland Bridge Ocean respectively. In two out of six rivers, the ∑PCBs exceeded the Canadian SQG threshold effect level of 21.5 and 34.1μg/kg for fresh and marine sediments respectively. The results of the study call for a concerted effort toward holistic monitoring of PCB residues in rivers in Nigeria to ensure ecological integrity and the protection of human health.

Assessment of Polychlorinated Biphenyls and Their Hydroxylated Metabolites in Postmortem Human Brain Samples: Age and Brain Region Differences.

Exposure to polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (OH-PCBs) has been implicated in neurodevelopmental disorders. However, the distribution of PCBs and OH-PCBs in the human brain has not been characterized. This study investigated the age-, sex-, and brain region-specific distribution of all 209 PCBs using gaschromatography–tandem mass spectrometry (GC–MS/MS) in neonatal (N = 7) and adult (N = 7) postmortem brain samples. OH-PCB analyses were performed by GC–MS/MS (as methylated derivatives) and, in a subset of samples, by nontarget liquid chromatography high-resolution mass spectrometry (Nt-LCMS). Fourteen higher chlorinated PCB congeners were observed with a detection frequency >50%. Six lower chlorinated PCBs were detected with a detection frequency >10%. Higher chlorinated PCBs were observed with higher levels in samples from adult versus younger donors. PCB congener profiles from adult donors showed more similarities across brain regions and donors than younger donors. We also assess the potential neurotoxicity of the PCB residues in the human brain with neurotoxic equivalency (NEQ) approaches. The median ΣNEQs, calculated for the PCB homologues, were 40-fold higher in older versus younger donors. Importantly, lower chlorinated PCBs made considerable contributions to the neurotoxic potential of PCB residues in some donors. OH-PCBs were identified for the first time in a small number of human brain samples by GC–MS/MS and Nt-LCMS analyses, and all contained four or fewer chlorine.

Polychlorinated biphenyls (PCBs) in soils from typical paddy fields of China: Occurrence, influencing factors and human health risks

The contamination of paddy soils is of great concern since it links to human health via food supply. Limited knowledge is available on PCB residue characteristics and the associated health risks in paddy soils under various environmental conditions. In this study, a soil sampling campaign was conducted in three typical paddy fields, i.e., Sanjiang Plain (SP), Taihu Plain (TP) and Hani Terrace (HT), crossing a transect of 4000 km in China. The concentrations of 29 quantified PCBs varied from 58.6 to 1930 pg/g in paddy soils, with samples at TP showing the highest burden. Tri-CBs were the major homologue group at SP and HT, whereas hexa-CBs at TP. Altitude, temperature, soil organic matter content and soil conductivity well explained the variations in PCB concentrations among sites. The homologue profiles of soil PCBs followed the fractionation theory. In addition, soil conductivity was found to be negatively correlated to low-chlorinated PCBs and positively to high-chlorinated congeners. Furthermore, the toxicities of soil PCBs and the exposure risks through rice intake were estimated. Higher toxicity equivalent quantities and hazard indexes were found at SP than TP and HT, with over one third of the samples displaying health risks. The results of this work highlight the necessity to better understand the occurrence characteristics and the associated health risks of PCBs in soils of rice-growing regions.

Residues of endocrine-disrupting PCBs in drinking water - influence of water and wastewater treatment in Szczecin (Poland)

ABSTRACT Drinking water is subjected to several stages of treatment, but it can still retain residues of endocrine-disrupting compounds. These include polychlorinated biphenyls (PCBs). The aim of this study was to assess the efficiency of water and wastewater treatment processes on reducing residues of endocrine-disrupting PCB congeners in drinking water and treated wastewater. The analyses were performed with liquid–liquid extraction and gas chromatography coupled with mass spectrometry. PCB congener residues were found in 18% of the drinking water samples. The water treatment process reduced the content of these compounds within a wide range of 4% to 100%. Estimates of consumer exposure to these compounds from drinking water consumption accounted for as much as 30% of the tolerable weekly intake (TWI). The wastewater treatment process reduced the concentration of PCB congeners by 38–98%, with trace contents in the treated wastewater (from 0.02 · 10–6 to 6.21 · 10–6 mg/l).

Live in same region, respond differently: Canine and human response to pollutants in placental accumulation

Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) are endocrine-disrupting chemicals (EDCs). Their presence in the environment is particularly concerning in cases of fetal exposure, which is the most vulnerable period of life for both human and animals who share the same environment. Placenta, as a sample collected using noninvasive methods to screen EDCs, is a good indicator for potential fetal exposure. Although recent studies indicate that companion animal may correspond to human exposure, species-specific anatomo-morphological and metabolic differences are controversial. In this study, placenta samples of 60 women and 25 dogs living and giving birth within the same region were evaluated for the presence of PCB, OCP, PBDE, and PAH residues; where, socio-demographic factors were also assessed to identify the possible sources. Gas chromatography-mass spectrometry method was validated for the matrix, and among 45 screened and targeted pollutants, only 18 were found in human placentas. While the most frequently detected pollutants were DDTs, followed by PAHs and PCBs in decreasing order, the pollutants with the highest concentrations were PAHs, followed by PCBs and DDTs. Only five of the target contaminants were detected in the dog placentas. These results indicate that; as dogs have different bioaccumulation capacities and higher excretion rates than humans, the life-long effects of exposure to endocrine compound and possible consequences related to adverse health outcomes are expected to vary and concentrations cannot be directly correlated.

Interlaboratory Comparison of Three Sediment Bioaccumulation Tests

Standard bioaccumulation tests are commonly conducted using Macoma nasuta (clam), and Alitta virens (polychaete) for marine tests, and Lumbriculus variegatus (an oligochaete) for freshwater tests. Because the interlaboratory variability associated with these tests is unknown, four experienced laboratories conducted standard 28‐day bioaccumulation tests with the above species using sediments contaminated with polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Chemical analysis of tissue samples was performed by a single laboratory. The intralaboratory variance among replicates was relatively low for PCB tissue concentrations, with coefficients of variation (CVs) ranging from 9% to 28% for all laboratories and species, with the exception of one laboratory reporting higher variability for L. variegatus (CV = 51%). Intralaboratory variance for PCB tissue concentrations was higher than interlaboratory variance for A. virens and L. variegatus, and the magnitude of difference (MOD) for laboratory means ranged from 1.4 to 2.0 across species. Intralaboratory variability was also low for lipid content, and lipid normalization of PCB and PAH body residues generally had little impact on variability. In addition to variability across bioassay laboratories, analytical variability was evaluated by different laboratories measuring the concentration of PCBs and total lipids in a subsample of tissue homogenate of sediment‐exposed test organisms. Variability associated with tissue analysis was higher than bioassay laboratory variability only in tests with L. variegatus. Statistical differences between samples may be observed due to the low intralaboratory variability; however, the biological significance of these differences may be limited because the MOD is low. Considering the MOD when comparing bioaccumulation across treatments accounts for uncertainty related to inherent variability of the test in the interpretation of statistically significant results. Environ Toxicol Chem 2022;41:1260–1275. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Magnetic solid phase extraction based on Fe3O4@SiO2@CTS nano adsorbent for the sensitive detection of trace polychlorinated biphenyls in environmental water samples

In this study, a magnetic composite material was developed by bonding the modified natural polysaccharide chitosan (CTS) with SiO2 on the surface of magnetic Fe3O4 nanoparticles to detect polychlorinated biphenyls (PCBs). The structural, porosity, and magnetic properties of Fe3O4@SiO2@CTS were characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, nitrogen sorption, and vibrating sample magnetometry. Various experimental parameters affecting the extraction capacity were investigated, including extraction time, desorption time, desorption solvent, solution pH value, and salt ion concentration. Results showed that Fe3O4@SiO2@CTS exhibited excellent selectivity, easy separation by magnet, and reusability (at least 10 cycles). Under optimized experimental condition, this magnetic solid phase extraction material was applied to detect three PCBs with low limits of detection of 0.02–0.15 μg·L−1. The linear correlation coefficient was higher than 0.998, while the recoveries ranged between 90.34% and 106.99% with the relative standard deviation less than 11.31%. The practical application of Fe3O4@SiO2@CTS was verified through quantitative analysis of PCB residues in environmental water, supporting its promising role in simple, convenient, and low-cost detection of PCBs in real environmental samples.

Effects of Polychlorinated Biphenyls on Animal Reproductive Systems and Epigenetic Modifications.

Polychlorinated biphenyls (PCBs) are a group of highly toxic endocrine-disrupting chemicals comprising 209 homologs. PCBs are extensively found in the environment and can induce typical estrogenic and profound, long-lasting effects on animals. In this article, the introduction of PCB residues into the environment and the pathways of PCB enrichment in animals are described. PCBs are widely deposited and eventually accumulate in human tissues and body fluids through biomagnification. PCBs can significantly decrease animal fertility and interfere with endocrine processes, leading to the development of various diseases and even cancer. The effects of PCBs on the reproductive systems of animals can also be passed to their offspring, indicating that PCBs may affect the epigenetic modification process. There is currently no treatment to effectively inhibit the toxicity of PCBs in organisms; therefore, the severity of PCB toxicity needs to be widely recognized.

Monitoring of Organochlorine Pesticide and Polychlorinated Biphenyl Residues in Common Swifts (Apus apus) in the Region of Hannover, Lower Saxony, Germany.

The use of pesticides is associated with the decline of several avian species. In this study, we monitored the organochlorine contaminants in common swifts (Apus apus) in the years 2016 to 2018. These long-distance migrants breed in Europe and winter in Africa. Their only feeding source is aerial plankton. Pooled organ samples of 42 adult and 40 juvenile swifts were tested with the multi-residue method by gas chromatography-mass spectrometry (GC-TOF/MS). Predominantly, 4,4′-DDE, dieldrin, hexachlorobenzene (HCB), lindane and polychlorinated biphenyls (PCBs) were found in most of these common swifts. Only 4,4′-DDE (adult: 83 ± 70 μg/kg, juvenile: 17 ± 39 μg/kg) and dieldrin (adult: 2 ± 3 μg/kg, juvenile: 0.3 ± 1 μg/kg) concentrations were significantly different between adult and juvenile birds. All detected concentrations in our study were far lower than the previously recorded pesticide concentrations of common swifts in Italy and those which are known to cause toxicity and death in birds.

Recent Status of Global Polychlorinated Biphenyls Contamination

Organic pollutants are continuously disrupting the equilibrium of nature. Polychlorinated Biphenyls are a member of the broad family of man-made organic chemicals well-known as chlorinated hydrocarbons. Due to their chemical stability, high boiling point and electrical insulating properties, non-flammability, Polychlorinated Biphenyls are used in various commercial as well as industrial applications. Polychlorinated Biphenyls residues remain in the ecosystem and bioaccumulate in various organisms due to their persistent nature and resistance against natural breakdown agents. This leads to the enlisting of approximately 209 chlorinated congeners in the list of persistent organic pollutants (POPs) under the Stockholm Convention. Their residues have been detected in various environmental components even though their production has been banned for more than a decade. High residues of Polychlorinated Biphenyls in water bodies, aquatic faunas, soils and sediments, air, and biota samples have been reported. Therefore, the current review aims at depicting the source and dynamics of Polychlorinated Biphenyls in the environment as well as the exploitation of various detection tools for the analysis of Polychlorinated Biphenyls. Besides, it provides a critical description of worldwide contamination scenarios of Polychlorinated Biphenyls and the need for further advancement in the detection and extensive identification.

Strategies for mitigation of polychlorinated biphenyls (PCBs): A review

Polychlorinated Biphenyls or PCBs belong to a broad family of chlorinated hydrocarbons and find use across industrial and commercial applications including hydraulic and electrical equipments, plastics, paints, rubber products, dyes, pigments and carbonless copy paper etc. PCB residues persist in the ecosystem and bioaccumulate in food chain due to their persistent nature and resistance against natural breakdown agents. Global case studies suggest widespread contamination of the toxicant. So it becomes the need of an hour to remove polychlorinated biphenyls entirely from the environment. Stepwise, physical, chemical and ecological remediation strategies have been applied but some lacuna in efficient mitigation was felt by various researchers in each of the methods. Therefore, combination of multiple technologies have been suggested. The current review provides the detailed descriptions on the different physical and chemical methods used for removal of PCBs including incineration, natural attenuation, supercritical water oxidation, ultrasonic radiation, bimetallic systems, nZVI, etc as well as the combination of multi techniques that have been used till date e.g. nZVI with metal combo and bimetallic metal combination etc. It also depicts the future prospects and acceptability of these methods for removal of the polychlorinated biphenyls from the ecosystem to help us achieve a green sustainable world.

Edible clay inclusion in the diet of oysters can reduce tissue residues of polychlorinated biphenyls.

Polychlorinated biphenyls (PCBs) are lipophilic and persistent environmental pollutants that are readily absorbed and accumulated in high concentrations in fatty tissues of humans and animals. Invertebrate animals, such as oysters, are vulnerable and sensitive to PCB contamination. Previously, our in vitro isothermal studies have shown that acid processed montmorillonites (APM) can effectively bind PCBs and Aroclors. Therefore, in a novel application of this work, a dietary strategy for shellfish was developed using APM, and its parent clay to reduce exposures to PCBs in oysters. PCB residues in oysters with clay treatment at different dietary inclusion rates and durations were measured and compared to a washout treatment. The efficacy and safety of this strategy were supported by a significant reduction of PCB residues with the inclusion of a low level of APM (0.05%) during a 4-day treatment. Moreover, this sorbent strategy reduced PCB residues in oysters in a dose- and time-dependent manner. Based on our results, it is possible that clay-based sorbents such as APM, can be included in the diet to significantly reduce exposures to PCBs.

Contamination status and temporal trends of persistent toxic substances in sediment cores from coastal areas of central Vietnam

Residue concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were measured in sediment core samples from two estuary areas of central Vietnam to elucidate recent status and temporal trends of pollution based on the depth profiles. Concentrations of PCBs, PBDEs, and endosulfan compounds were generally higher than those of the remaining OCPs. Peak concentrations of OCPs were found in the sediment layers corresponding to the late 1950s to the early 1980s, implying the intensive application of these insecticides in Vietnam during such periods. Although the highest PCB concentrations were measured in sediment layers dated in the 1970s, increasing PCB residues observed in the shallower layers may be related to the strong industrialization and urbanization in Vietnam. BDE-209 exhibited increasing concentrations and proportions to total PBDEs towards shallower depths, suggesting substantial use and on-going releases of deca-BDE products in recent years.

Distribution of Organochlorine Pesticide and Polychlorinated Biphenyl Residues in Lake Sediment Cores from the Plitvice Lakes National Park (Croatia)

The occurrence and distribution of 11 organochlorine pesticides (OCPs) and their degradation products as well as of 17 polychlorinated biphenyl congeners (PCBs) were investigated for the first time in sediments of three (Lake Prošće, Lake Kozjak, Lake Kaluđerovac) out of 16 cascading karst lakes within the protected area of the Plitvice Lakes National Park in central Croatia. The 15-cm-long sediment cores were divided for analysis into three 5-cm-long segments. The abundance and levels of sediment-associated OCPs and PCBs were evaluated with respect to sampling location and sediment depth, presumed age of deposition, and organic carbon content. The burden of sediments with OCPs and PCBs decreased downstream with the highest mass fractions measured in the uppermost Lake Prošće (total OCPs 2.72-5.86μgkg-1d.m., total PCBs 0.37-1.78µgkg-1d.m.) and the lowest in Lake Kaluđerovac (total OCPs 0.30-0.58μgkg-1d.m., total PCBs 0.07-0.12µgkg-1d.m.). The predominant organochlorine pollutants were DDT-type compounds (total DDX, w = 0.30-5.72µgkg-1d.m.) with p,p'-DDE and p,p'-DDD accounting for up to 100% and 50%, respectively, of the total DDX. The findings indicated an old input of p,p'-DDT that largely converted to its degradation products. The OCP and PCB mass fractions in the Plitvice lake sediments were at trace levels characteristic for preserved pristine natural environments with no or limited anthropogenic impact wherein long-range atmospheric transport is considered as their main source.