dl-PCBs Concentrations Research Articles

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.

Occurrence, sources and risk assessment of 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in sediments from the Soummam River protected area, Algeria: A potential threat to the Mediterranean Sea

The levels, the sources and the potential risks associated with twelve dioxin-like PCBs were investigated in the sediments of the Soummam River in northeastern Algeria. Total dl-PCBs concentrations ranged from 3.64 ng/g to 9.38 ng/g with PCB 118 and PCB 105 being the predominant congeners. Principal component analysis suggested that commercial mixtures and municipal waste incineration could be responsible for the presence of PCBs in the region. TEQ values ranged from 12.93 pg/g to 60.98 pg/g indicating adverse effects on aquatic organisms. Moreover, cancer risk assessed via Total Lifetime Cancer Risk (TLCR) suggested that for all the stations, the risk was low but not negligible. Additionally, the non-cancer risk was significant at half of the stations for children but negligible for adults at all the stations. Consequently, measures must be taken by local authorities to protect the environment and the human health.

Using food waste to cultivate safe, good-quality Sabah (giant hybrid) grouper: Dioxins and dioxin-like polychlorinated biphenyls

Dioxins and dioxin-like polychlorinated biphenyls (dl-PCBs) in fish fillet counteract the health benefits of fish products. In this study, food waste was used as a protein alternative to replacing fishmeal commonly used in the commercial fish feed, aiming to cultivate Sabah grouper with acceptable levels of dioxins and dl-PCBs. The concentrations of dioxins and dl-PCBs, as well as the fish growth performance, were compared between the fish groups fed with food waste-based feed (FWBF) and commercial feed (Nanyu®, control). The results showed that the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) (1.22 pg/g dry weight (d.w.)) and non-ortho-dl-PCBs (13.0 pg/g d.w.) were significantly lower (p < 0.05) in the FWBF than in the control feed (commercial feed) (PCDDs: 2.35 pg/g d.w.; non-ortho-dl-PCBs: 27.2 pg/g d.w.). The growth performance of the fish group fed with the FWBF was comparable to that fed with the control feed. There were no significant differences between the WHO2005-TEQ values of different fish fillets (1.00, 1.11, and 1.10 pg WHO2005-TEQ/g d.w. for FWBF group, control feed group, and local market fish, respectively). Based on the guidelines provided by European Food Safety Authority (ESFA) and U.S. Environmental Protection Agency (USEPA), the fish fed with the FWBF were safe for human consumption (hazard index values: 0.284–0.522; cancer risk range: 2.59–2.97 × 10−5). The findings of this study suggest that food waste could serve as an alternative protein source for cultivating Sabah grouper with acceptable levels of dioxins and dl-PCBs.

Determination of PCDD/F and DL-PCB pollution levels, source appointment and risk assessment of surface sediments in dam lakes in Istanbul, Türkiye.

The current situation of the water resources of Istanbul, which is one of the important metropolises of Europe, should be known and constantly monitored by the reasons of the rapid increase in the city population, the acceleration of production-related industrial activities, the expansion of the city with construction activities, and the decrease in precipitation. The purpose of this study was to reveal the situations of surface sediments collected from Istanbul water reservoirs in terms of PCDD/Fs and DL-PCBs, to identify possible sources, and to conduct their ecological risk assessment. Total PCDD/Fs and DL-PCBs concentrations varied between 28.13 and 457.4pg/g (average 136.8pg/g) and 12.19-340.1pg/g (average 72.09pg/g). The corresponding TEQ values of PCDD/Fs and DL-PCBs were between 0.53 and 5.37pg TEQ/g (average 2.23pg TEQ/g) and 0.02-0.44pg TEQ/g (average 0.12pg TEQ/g), respectively. Octachlorodibenzo-p-dioxin (OCDD) is the dominant congener by constituting about 75% of the total PCDD/Fs on average, while congener distributions of DL-PCBs showed the dominance of PCB-118 and PCB-105. The sediments taken from Kazandere dam have the lowest pollution levels for both PCDD/Fs and DL-PCBs. The highest PCDD/F and DL-PCB amounts were measured in sediments of Alibey and Elmalı dams (closest to highly populated settlements of Istanbul), which are most affected by the air pollution caused by the traffic, commercial/industrial combustion (like waste incineration facility) and combustion for residential heating. Almost all the sediments have total dioxin-like toxicity levels higher than the safe threshold level (with two exceptions) of 0.85pg TEQ/g dw, proposed for ecological risk. Health risk assessment shows that levels of dioxin-like compounds would result in a total intake of 0.33pg TEQ/kg bw/day even in the worst-case scenario, not exceeding the tolerable daily intake value of 1pg TEQ/kg bw/day. Among exposure pathways, consumption of fish constitutes almost all the total intake, while contributions of other pathways are minimal.

Distribution, Source and Potential Risk Assessment of Polychlorinated Biphenyls (PCBs) in Sediments from the Liaohe River Protected Area, China

This study aimed to assess the occurrence, distribution, toxicity equivalency and health risks of dl-PCBs (dioxin-like PCBs) from nine sites collected in surface sediments from Liaohe River Protected Area. ∑dl-PCBs concentrations in sediments range from 79.2 to 365.1 pg/g. Sediment profiles showed that pentachlorobiphenyl is the most abundant congener among all sampling sites. The results of principal component analysis and cluster analysis indicated that PCBs were mainly derived from electronic waste and paint additives in the sediments of Liaohe River Protected Area. Toxic equivalent quantity (TEQ) values of the PCBs in the Liaohe River Protected Area sediments are at comparatively lower levels compared with the previously reported data. Hazardous ratio (HR) for human health risk assessment allied to cancer was found to be lower than the non-carcinogenic risk assessment within an acceptable range.

Levels of dioxins and dioxin-like polychlorinated biphenyls in seawater from the Hornsund fjord (SW Svalbard)

Knowledge of contaminant distribution is important, particularly in the vulnerable first results about the occurrence of seventeen polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and twelve dioxin-like polychlorinated biphenyls in arctic fjord seawater are reported. The contaminants were measured in 10 samples of suspended particulate matter collected in Hornsund (Svalbard). The ∑PCDD/F and ∑dl-PCB concentrations ranged from 0.066 to 231.47 pg/L and from 2.43 to 46.43 pg/L respectively. In terms of total PCDD/Fs, in general highly chlorinated PCDFs constituted the most significant fraction. Among dl-PCB compounds, PCB118 was the dominant congener. The toxicity equivalent for the samples ranged from 0.0008 to 1.90 pg I-TEQ/L for ∑PCDD/Fs, while for ∑dl-PCB it ranged from 0.0002 to 0.024 pg WHO05-TEQ/L. High concentrations of dioxins and dl-PCBs in some samples indicated that those contaminants could pose a threat to marine biota.

Spatiotemporal patterns of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in foodstuffs in air quality regions in Taiwan.

High-fat food intake is the main source of dioxin-like compounds for humans, such as consumption of meat, dairy and eggs, and seafood products. Fruits, vegetables, and cereals have relatively low levels of dioxin-like compounds, but because of high consumption they also contribute to the food-borne intake. It is necessary to clarify dietary dioxin exposure affected by different food contamination levels and dietary habits among different geographic areas. We aimed to evaluate chronic dietary PCDD/Fs and DL-PCBs exposure in 725 individual foods in 14 categories in 6 Taiwan air quality regions (AQRs) and a total of 2441 foods from 2004 to 2018. We estimated daily PCDD/Fs + DL-PCBs intake on the basis of sex- and age-specific foodstuff ingestion rate and PCDD/Fs+ DL-PCBs concentrations using a probabilistic approach. PCDD/F+ DL-PCB levels among the different sampling periods exhibited a decreasing trend in fish and aquatic products (from 0.384 ± 0.764 to 0.206±0.223pgWHO05-TEQg−1 w.w.) (p for trend=0.043), livestock products (from 0.133±0.298 to 0.035±0.043 pgWHO05-TEQ g−1 w.w.), eggs (from 0.221 ± 0.373 to 0.056 ± 0.048 pgWHO05-TEQ g−1 w.w.) (p for trend = 0.002), and dairy samples (from 0.066 ± 0.075 to 0.024 ± 0.026 pgWHO05-TEQ g−1 w.w.) (p for trend= 0.001). All lifetime average daily doses (LADD) were below provisional tolerable monthly intake (PTMI) but higher than the TWI for PCDD/Fs and DL-PCBs in food. The percentages of the contribution of each food group to the total dietary intake of TEQPCDD/F+PCB in different ambient air dispersion areas and age groups. The total daily intake of PCDD/Fs and DL-PCBs by Taiwanese differed between AQRs (0.188–0.397 pgWHO05-TEQ kg−1 b.w. day−1). The observed geographical variations were likely due to differences in food habits, cuisines, culture and levels of environmental contamination among various regions in Taiwan. By sensitivity analysis, we have identified the major contribution to LADD, which was the dioxin levels in marine fish, fresh water fish and fish related products, and followed by dioxin levels in duck eggs. In addition, marine and freshwater fish consumption rate accounts more than 10.2%. These major exposure variables was also consistent with the findings of total daily intake in different AQRs.

Dioxin-like compounds in paired maternal serum and breast milk under long sampling intervals.

Serum and breast milk are both important biological samples to evaluate body burden of dioxin-like compounds which include polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs). We collected maternal serum at early pregnancy, and breast milk at 3-8 weeks after delivery from 55 mothers living in Beijing, China, and measured 29 dioxin-like compounds in these samples. The sampling intervals in this study were extended up to 10 months to analyze differences of contents between serum and breast milk under long sampling intervals. The results showed that mean TEq level of PCDD/Fs in serum (9.8pg TEq g-1 lipid) was 1.7 times higher than that in milk (4.5pg TEq g-1 lipid), while the TEq concentrations of dl-PCBs in serum (1.2pg TEq g-1 lipid) was significantly lower than that in milk (2.0pg TEq g-1 lipid). There were only two congeners, OCDD (r=0.32) and PCB105 (r=0.33), the correlations of which between serum and milk were significant. The differences in distributions of congeners in serum and milk might be influenced by number of chlorine substituents and structures of congeners. In addition, maternal age and BMI were positively and negatively correlated with mass concentrations of dioxin-like compounds in milk and serum respectively. These results suggest that, compared with serum, it is limited to use breast milk to assess long-term exposure for the wider population.

Environmental impact of co-combustion of polyethylene wastes in a rice husks fueled plant: Evaluation of organic micropollutants and PM emissions.

Co-combustion of biomass and plastic waste has emerged as one of the most promising approach at the plastic waste management challenge. This strategy is particularly attractive since it can simultaneously solve the increasing energy demand and reduce the plastic wastes volume. However, since the combustion of both plastic wastes and natural materials is a potential source of organic micropollutants, such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and of polycyclic aromatic hydrocarbons (PAHs), beside particulate matter, the environmental sustainability of the waste to energy (WtE) co-combustion strategy has to be assessed. To this end, the emissions of dioxin like (dl)-PCBs, PCDD/Fs and PAHs from a 4-MW thermal power plant fueled with rice husk, partially replaced by end-of-life polyethylene (PE) industrial waste (up to 15% of the thermal power of the plant), were investigated. GC-MS/MS analyses have demonstrated that the co-combustion of PE waste and rice husk presents a profile of environmental sustainability. The concentrations of dl-PCBs, PCDD/Fs and PAHs were extremely low and they have remained almost unaffected by introducing PE in feed. In particular, emissions of PCCD/Fs and dl-PCBs in flue gas were in the range 0.6-1.0 and 0.2-0.6pg TEQ/Nm3, respectively, while PAHs concentrations ranged from 410 to 825ng/Nm3. Furthermore, the emission factors of these organic pollutants were found to be lower with PE increasing rate while particulate matter emissions were not affected by co-combustions. Collectively, the investigation has demonstrated that the noils of the industrial PE, due to the low content in halides and metals, can be used as auxiliary fuel and energetically recycled through co-combustion with rice husk. This case of study represents an effective application of the WtE strategy and a concrete approach to mitigate the threat of plastic pollution.

Atmospheric concentrations and gas-particle partitioning of PCDD/Fs and dioxin-like PCBs around Hochiminh city

Atmospheric PCDD/Fs and dl-PCBs samples were collected in Hochiminh city, Vietnam to address the effect of meteorological parameters, especially rainfall, on the occurrence and gas/particle partitioning of these persistent organic pollutants. The results indicate that PCDD/Fs and dl-PCBs concentrations in industrial site are higher than those measured in commercial and rural sites during both rainy and dry seasons. In terms of mass concentration, ambient PCDD/F levels measured in dry season are significantly higher than those measured in rainy season while dl-PCB levels do not vary significantly between rainy and dry seasons. The difference could be attributed to different gas/particle partitioning characteristics between PCDD/Fs and dl-PCBs. PCDD/Fs are found to be mainly distributed in particle phase while dl- PCBs are predominantly distributed in gas phase in both rainy and dry seasons. Additionally, Junge-Pankow and Harner-Bidleman models are applied to better understand the gas/particle partitioning of these pollutants in atmosphere. As a results, both PCDD/Fs and dl-PCBs are under non-equilibrium gas/particle partitioning condition, and PCDD/Fs tend to reach equilibrium easier in rainy season while there are no clear trend for dl-PCBs. Harner-Bidleman model performs better in evaluating the gas/particle partitioning of PCDD/Fs while Junge-Pankow model results in better prediction for dl-PCBs.

Pollution Status and Risks of Dioxin-like Polychlorinated Biphenyls in the Soil of the Yellow River

The concentration levels, toxic equivalency (TEQ) concentrations, and carcinogenic and non-carcinogenic risks of dioxin-like polychlorinated biphenyls in shore soil from the 40 national key monitoring sections along the entire Yellow River were comprehensively studied. The results showed that the concentrations of ΣDL-PCBs in the soil were between 0.37-7.17 ng·g-1 (dry weight), and the mean value was 0.38 ng·g-1 (dry weight). The TEQ concentrations of DL-PCBs in the soil were between 0.00-30.31 pg·g-1 (dry weight), and the mean value is 13.63 pg·g-1 (dry weight), posing no significant risk to the ecological environment and human health. The carcinogenic and non-carcinogenic risks of DL-PCBs in this study did not exceed the limits set by the USEPA, and there were no obvious health risks. The residents in the middle reaches of the Yellow River were more vulnerable to DL-PCBs.

Sources of polychlorinated dibenzo-p-dioxins and dibenzofurans, and biphenyls in Chinese mitten crabs

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in Chinese mitten crabs from several areas were determined. The toxic equivalents (TEQs) for the mean PCDD/F and total PCDD/F and dioxin-like PCBs were 2.9 ± 2.7 and 5.7 ± 4.0 pg TEQ g−1, respectively. The mean concentrations of PCBs and dl-PCBs were 282 and 59 times the concentrations of PCDD/Fs, respectively. PCDD/F and PCB sources in the crab food web were assessed. The total TEQ of PCDD/F and PCB supplied by crab compound feed was 2.1 times the TEQ in crab meat. Broken corn, aquatic biota, and water contributed around 12% of the total TEQ inputs for crab meat. The contribution from sediment was around 164 times that from crab meat, and sediment may be the most important source of PCDD/Fs and PCBs in cultured crabs. Principal component analysis (PCA) and stable isotope ratios for nitrogen (δ15N) and carbon (δ13C) supported the TEQ results. The mean total PCDD/F and dl-PCB TEQ exposure for humans consuming crabs was 3.4 pg TEQ per kilogram of body weight per day. The PCDD/Fs and PCBs in >80% of the crab samples would not cause the tolerable daily intake to be exceeded.

Endocrine disruption and carcinogenesis: Evaluation of neoplasms in endocrine organs of rat in Carbendazim carcinogenic chronic study

This study presents the seasonal size distribution of particulate polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the atmosphere. Particles were sampled from October 2009 to October 2010 on a seasonal basis using a cascade impactor collecting six size fractions at a rural and urban site in the Brno area, Czech Republic. Higher concentrations of PAHs, PCDD/Fs and dl-PCBs were observed in cold seasons at both sites, attributed to the seasonality of the gas-particle partitioning, the increase of emissions and the lower boundary mixing layer in winter. All of the compounds showed a strong accumulation in the fine fraction, with, on average, 71% of ΣPAHs, 73% of ΣPCDD/Fs and 60% of Σdl-PCBs associated with particles <0.95 μm. The human risk assessment via inhalation was addressed and followed the same pattern as for concentrations, with 41 and 7 times higher risk in winter compared to summer at the rural and urban sites, respectively. More than 70% of cancer risks of PAHs, PCDD/Fs and dl-PCBs was associated with particles <0.95 μm. Moreover, an overestimation of the cancer risk via inhalation of up to 50% occurred when the size distribution of related compounds was not considered.

Polychlorinated biphenyls (PCBs) residues in commercial pasteurized cows\u2019 milk in Tehran, Iran

BackgroundTo date, despite the facts that pasteurized milk is the most consumed dairy product in Iran and its consumption has increased almost two fold during the last 10 years, no data are available concerning the concentrations of polychlorinated biphenyls (PCBs) in commercial cow milk in Iran market.MethodsThis study designed to determine the levels of PCBs in these products and to assess population exposure to PCBs by estimating the daily intakes. Pasteurized cows’ milk samples (10 brands) were collected from local markets at two different seasons and analyzed using sensitive and reliable methods.ResultsBased on the results all the indicator PCBs were detected and quantified in all of the samples, the mean ± SD concentration for the sum of the six congeners was 18.92 ± 14.36 ng g−1 fat. None of the samples surpassed the provisional value established by the EU of 40 ng g−1 fat. The sum of dioxin-like congeners, expressed as WHO-TEQ was 0.492 pg/g of fat which was considerably lower than the defined limit 3 pg/g fat, set for cow’s milk. Furthermore, a similar DL-PCBs profile as other studies was found for analyzed samples. The results indicated that concentrations of DL-PCBs were very low, and all of milk samples were compliant with EC legislation. In addition, seasonal variations were not observed for DL- and NDL-PCBs levels (p values >0.05).ConclusionsThe estimated dietary intake for target population was 0.06 pg TEQ/kg of body weight/day, much smaller than the amounts declared by the World Health Organization as tolerable daily intake.

Exposure Route of Dioxin-like Polychlorinated Biphenyls in Hair Based on Passive Sampling

The main exposure pathways of DL-PCBs in local population were studied by analyzing the levels, distributions and relationships of DL-PCBs in pooled tree bark samples and hair samples collected in Kaiyuan, Yunnan Province, China. The results indicated that the concentrations of DL-PCBs in bark and hair samples were 4.0 pg·g-1 to 88.9 pg·g-1 and 4.1 pg·g-1 to 19.3 pg·g-1, respectively, suggesting the pollution levels of DL-PCBs were relatively low in local environment and human body. The predominant PCB congeners in bark and hair was PCB-118, contributing 48% of the total DL-PCB concentrations in the bark samples and 61% of the total DL-PCB concentrations in the hair samples. The DL-PCB congeners in tree bark might had the same sources and these compounds might be derived from atmospheric long-range transport. External and internal exposures were responsible for the DL-PCBs concentrations in hair, and external exposure contributed more to low chlorinated PCBs than to high chlorinated PCBs.

PCDD/Fs and dl-PCBs concentrations in water samples of Taiwan

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (dioxin-like PCBs) have received much public concern worldwide due to their persistence and toxicity. The presence of these compounds in environmental matrices, especially in water bodies, enhances the risk of human exposure to these toxic pollutants. In this study, seventeen 2,3,7,8 chlorinated PCDD/Fs and twelve dl-PCBs were measured in 11 groundwater samples collected throughout Taiwan and 2 surface water samples collected in northern Taiwan. PCDD/F and PCB concentrations in two surface water samples are relatively low, with the average concentrations of 0.038 and 0.001 pg WHO-TEQ/L (7.474 and 1.862 pg L−1), respectively. As for groundwater samples, PCDD/F concentrations measured range from 0.005 to 3.963 pg WHO-TEQ/L, while dl-PCB concentrations range from 2.5 × 10−5 to 0.189 pg WHO-TEQ/L. Total WHO-TEQ concentrations range from 0.005 to 3.963 pg WHO-TEQ/L, reflecting serious contamination of PCDD/Fs and PCBs in groundwater at some sampling sites. In term of total PCDD/Fs, PCDDs constitute a significant fraction (77.3%), and OCDD is most abundant, followed by HpCDD/Fs and HxCDD/Fs. PCB 118 is dominant among 12 dl-PCBs measured, followed by PCB 105 and PCB 77. Solid-phase PCDD/Fs generally predominate in water samples and PCDFs are of slightly lower distribution in solid phase in comparison with PCDDs, while PCBs are mainly distributed in dissolved phase. Results of principal component analysis (PCA) indicate that use of PCP and Na-PCP, thermal processes and PCBs-containing products might be the major sources of PCDD/Fs and PCBs in water samples measured.

LEVELS AND CONGENER PROFILES OF DIOXINS, FURANS AND DIOXIN-LIKE PCBS IN CERTAIN EGYPTIAN COW’S MILK FARMS

Levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and dioxin like-PCBs (dl-PCBs) were determined in thirty five pooled raw cow milk and fifty nine animal feedstuffs samples including silage, hay, cereals and other farinaceous feed, premixes and mixed feeds were consequently collected from different regions of Egypt farms [Qaliubiya, Banha, Sharkia, Monoufia, Damietta, Kafr El-Sheikh, Gharbiya, Ismailia, Port Said, Noubaria (Beheira), Fayoum and Beni Suef]. The method performance used was assessed through successfully participation in specific interlaboratory studies (food and feed) organized by European Union Reference Laboratory for Dioxins and PCBs in Food and Feed. The obtained results showed that PCDD/Fs concentrations in cow milk ranged between 1.19 and 12.48 pg WHO TEQ g-1 fat weight (FW) and in animal feed ranged between 0.08 and 1.43 pg WHO TEQ g-1 dry matter (DM), however dl-PCBs concentrations in cow milk ranged between 0.14 and 3.7 pg WHO TEQ g-1 (FW) and animal feed ranged between 0.01 and 0.38 pg WHO-TEQ g-1 (DM). The mean concentration of PCDDs/PCDFs was 0.32 pg TEQ g-1 dry matter (DM) for animal feed, this level proved to be below the maximum (EU) limits (0.75 pg WHO TEQ g-1 DM). While the level of 3.9 pg TEQ g-1 (FW) for cow milk proved to be higher than the acceptable European (EU) standards limits for milk (3 pg WHO TEQ g-1 FW). However the mean concentration of dl-PCBs was 0.05 pg TEQ g-1 (DM) for animal feed which was below the maximum (EU) limits for feed (0.5 pg WHO TEQ g-1 DM). The obtained dl-PCBs level of 0.98 pg TEQ g-1 (FW) for cow milk was below the acceptable EU standards limits for milk (3 pg WHO TEQ g-1 FW). These finding showed that animal feed have often been reported as the major source to the PCDD/Fs and dl-PCBs intake into the cow milk chain, which characterized in parallel by the total TEQ (dioxin and dl-PCBs). Data revealed that the sum of furan (TEQ) was the predominant group with contribution by 49.96 and 42.51%; followed by the sum of dioxin (TEQ) with contribution by 29.66 and 44.46%; followed by the sum of non-ortho PCBs (TEQ) with contribution by 18.1 and 11.48% and then the sum of mono-ortho PCBs (TEQ) with contribution by 2.27 and 1.54% in cow milk and animal feed, respectively. Finally, the present results indicated that the general exposure of the population in Egypt to the main highest persistent organic pollutants was carried through cow milk and animal feedstuffs intake.

Environmental variation of PCDD/Fs and dl-PCBs in two tropical Andean Colombian cities using passive samplers

Passive air-sampling data of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) taken in Manizales (a medium-sized city) and Bogotá (a megacity), Colombia, were analyzed in order to identify potential sources of pollution and the possible influence of meteorological variables like temperature and precipitation. The results indicate important differences in levels of PCDD/Fs and dl-PCBs between Bogotá and Manizales, attributed to differences in site characteristics and potential local/regional sources. Higher PCDD/Fs concentrations were observed in Bogotá (373fg/m3) compared to those observed in Manizales, with mean levels ranging from 64fg/m3 in a residential zone to 151fg/m3 around a vehicular-influenced area. Higher dl-PCBs concentrations were observed in the industrial area of Manizales compared to those observed in Bogotá, with mean levels of 6668fg/m3 and 4388fg/m3 respectively.In terms of PCDD/Fs congener distribution, there was a predominance of octachlorodibenzodioxin (OCDD) followed by 1,2,3,4,6,7.8-heptachlorodibenzofuran (HpCDF) congeners, with both cities showing higher levels in zones of high vehicular activity. Industrial influence was most evident in dl-PCB levels. In comparison to the mean levels of dl-PCB congeners obtained in the vehicular zones of Bogotá and Manizales, the industrially influenced sampling stations showed higher concentrations of dl-PCB congeners. Passive sampling results suggested that congener concentration profiles are characteristic of their different emission sources, and can be used to distinguish between their industrial or vehicular origins.

Levels and distribution of the dioxin-like polychlorinated biphenyls (PCBs) in the surface sediment of the Yellow River

The levels of DL-PCBs in the surface sediments collected in 15 different sampling sites from the Tibetan Plateau to the Yellow River estuary along the Yellow River were measured using the GC-MS. The concentrations of ∑DL-PCBs ranged from 2. 3 to 14.8 pg.g-1 and the TEQs of DL-PCBs were between 0. 001 4 and 0. 023 1 pgg-1 , with an average of 0. 007 3 pg.g-1. Compared with other domestic and foreign rivers, the DL-PCBs and TEQ levels of the Yellow River were at low levels. The main DL-PCBs congeners in the Yellow River sediments were tetra and penta chlorinated biphenyls. The DL-PCBs congener composition of rural and underdeveloped areas was similar, and there was similar congeners composition between the industry developed areas and the populous areas. Petrochemical industries and hydropower facilities may affect the distribution of DL-PCBs congener in the sediments. A significant correlation between concentrations of DL-PCBs and GDP per capita was found. It indicated that the contamination extent of DL-PCBs in the Yellow River was related with the local economic development, DL-PCBs levels in developed areas were higher than those in remote rural areas.

Size specific distribution of the atmospheric particulate PCDD/Fs, dl-PCBs and PAHs on a seasonal scale: Implications for cancer risks from inhalation

This study presents the seasonal size distribution of particulate polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the atmosphere. Particles were sampled from October 2009 to October 2010 on a seasonal basis using a cascade impactor collecting six size fractions at a rural and urban site in the Brno area, Czech Republic. Higher concentrations of PAHs, PCDD/Fs and dl-PCBs were observed in cold seasons at both sites, attributed to the seasonality of the gas-particle partitioning, the increase of emissions and the lower boundary mixing layer in winter. All of the compounds showed a strong accumulation in the fine fraction, with, on average, 71% of ΣPAHs, 73% of ΣPCDD/Fs and 60% of Σdl-PCBs associated with particles <0.95 μm. The human risk assessment via inhalation was addressed and followed the same pattern as for concentrations, with 41 and 7 times higher risk in winter compared to summer at the rural and urban sites, respectively. More than 70% of cancer risks of PAHs, PCDD/Fs and dl-PCBs was associated with particles <0.95 μm. Moreover, an overestimation of the cancer risk via inhalation of up to 50% occurred when the size distribution of related compounds was not considered.