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Torrefaction constitutes one of the promising technologies for the management of waste biomass and the production of high-carbon products for combustion, gasification, adsorption of pollutants or soil treatment. Unfortunately, waste biomass may be contaminated with toxic persistent organic pollutants, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) and dioxin-like biphenyls (dl-PCB). Literature does not provide consistent measurements on how the low-temperature thermochemical processing, such as torrefaction, affects the toxicity of biomass. This contribution assesses how a torrefaction treatment, conducted at 200 °C, modifies the toxicity due to PCDD/PCDF/dl-PCB in biomass. We deploy the XDS-CALUX biotest on five types of waste biomass (sewage sludge, tree bark, cattle manure, spent coffee ground, common reed), before and after treatment. The content of total dioxin- & biphenyl fraction compounds in the raw biomass, investigated in this study, varies from 0.14 to 3.67 pg BEQ·g -1 d.m. ; BEQ stands for bioanalytical equivalent. This increase is statistically insignificant at p = 0.05, taking into account all types of examined biomass. This proves that low-temperature torrefaction cannot detoxify biomass, i.e., chars, produced from biomass characterized by elevated concentration of PCDD/PCDF/dl-PCB, will reflect the contamination of the feedstocks. With respect to heavy metals, we conclude that only the content of Cd in biomass, and, to a lesser extent, the abundance of Cu and Fe, modify the toxicity of this material during its thermochemical treatment at low temperature.-1 d.m. ; BEQ stands for bioanalytical equivalent. This increase is statistically insignificant at p = 0.05, taking into account all types of examined biomass. This proves that low-temperature torrefaction cannot detoxify biomass, i.e., chars, produced from biomass characterized by elevated concentration of PCDD/PCDF/dl-PCB, will reflect the contamination of the feedstocks. With respect to heavy metals, we conclude that only the content of Cd in biomass, and, to a lesser extent, the abundance of Cu and Fe, modify the toxicity of this material during its thermochemical treatment at low temperature., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study reports the data of polychlorinated dibenzo-p-dioxins (PCDDs), -furans (PCDFs), and polychlorinated biphenyls dioxin-like (dl PCBs) measured in a total of 260 samples of the dairy supply chain collected over a period of 7 years (2011-2017) in the Latium region (Italy). Levels and average profiles of congeners were reported for each group of the analyzed dairy matrices, and any differences between different sampling strategies were considered (around likely pollutant sources or casual sampling). Of the samples, 95.4% resulted compliant with the regulated levels; only samples belonging to the "sheep bulk milk" matrix were found to be above either the action levels or the maximum levels (tot. 12 samples). Raw milk of the sheep species showed the highest averages (PCDD/F 0.248 and dl PCB 0.966 WHO TEQ pg/g of fat) compared to the milk of other species. The buffalo milk showed a content of dl PCB significantly lower (dl PCB: 0.371 WHO TEQ pg/g of fat) than the sheep milk (p<0.05). Dioxins were found to be superior to furans in almost all dairy products, except in the noncompliant samples where furans were higher. The OCDD was found to be the most abundant congener in almost all dairy products. This study provides a first list of reference values for background contamination of the dairy supply chain in the Latium region. These pre-existing values will be useful in all cases of environmental pollution to identify critical situations., (© 2022. The Author(s).)

In the marine food-webs, zooplankton is a key element in the transfer of persistent organic pollutants to higher trophic levels. We determined the congener-specific concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in offshore zooplankton (size from 0.2 to 20mm) collected in 2001, 2002 and 2010 in the northern and central Baltic Sea. Of the PCDD/Fs, the concentrations of 2378-TCDF were from 18 to 47 and of 23478-PeCDF from 7.9 to 29 pg g(-1)fat and showed little temporal differences. However, 1234678-HpCDF and OCDF were abundant in 2001-2002 especially in the eastern Gulf of Finland (average concentrations 50 and 89 pg g(-1)fat, respectively). In 2010 the concentrations of these two congeners were lower, 29 and 30 pg g(-1)fat, respectively, but still substantially higher than in the other surveyed areas. The principal components analysis (PCA) supported that area-specific patterns in pollution strongly contributed to the congener profiles particularly in surface sediment and in sediment trap material, but even in zooplankton. The concentrations of the PCBs were highest in the Gulf of Finland and in the Bothnian Bay. The concentrations of most PCBs were somewhat lower in 2010 than in 2001-2002. Of the dioxin-like PCBs, the concentrations of PCB-77 were highest (271-572 pg g(-1)fat) but PCB-126 (32-113 pg g(-1)fat) contributed from 85% to 91% of the total toxicity of PCBs due to its higher toxic potency. Of the PBDEs, the BDE47 and BDE99 were the most abundant (concentrations from 1.2 to 4.6 and from 0.4 to 3.3 ng g(-1) fat, respectively). The concentrations of most PBDEs were lower in 2010 than in 2001/2002 except in the eastern Gulf of Finland., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The objective of this study was to estimate the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (DL-PCBs and NDL-PCBs) in blood serum obtained from non-occupationally exposed volunteers living in the Naples area (Campania Region, southern Italy). The samples were taken from two geographical zones: one was an urban area of Naples and its surroundings and the other was located in an area deemed to be at high environmental risk. Total mean concentrations of these persistent pollutants proved to be in the range 1.43-17.38 pg WHO-TEQ1998 g(-1) lipid for PCDD/Fs, and 0.98-25.45 pg WHO-TEQ1998 g(-1) lipid for DL-PCBs. NDL-PCBs were in the range 316.57-482.90 ng g(-1) lipid. No significant differences were observed between women and men, nor between donors living in the two different areas. The mean levels of PCDD/Fs and PCBs in the population living in the Naples area were lower than those observed in some studies of populations living in exposed areas (near incineration plants or industrial sites) and urban or rural areas., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Dioxins are a family of persistent organic pollutants (POPs) listed under the Stockholm Convention, and include PCDDs, PCDFs, and dioxin-like PCBs. These toxic chemicals are carcinogenic, widely dispersed, and have long half-lives. They have contaminated the food web and, being fat-soluble, accumulate in adipose tissues and milk in the human body. To assess human exposure, we collected breast milk samples from 137 first-time mothers recruited from around Hong Kong. Samples were analysed by HRGC-HRMS in four pools, according to the subject's age and length of residency. Exposure was related to age, duration of stay, and possibly diet. Generally, older mothers, and mothers with a longer stay in Hong Kong, had higher levels of dioxins in their milk. This pattern was clearest for the PCBs, although deviations were observed for some of the PCDD/Fs. Mean concentrations, measured per gram of lipid weight in terms of WHO toxic equivalents (WHO-TEQs), were 7.48 pg/g for PCDD/Fs and 3.79 pg/g for PCBs, giving a total of 11.27 pg/g for PCDD/Fs and PCBs combined. Compared to an earlier Hong Kong study we conducted in 2002, the mean WHO-TEQ values in our latest findings were about 9% lower overall for PCDD/Fs and 19% lower for PCBs, with the mean total WHO-TEQ for PCDD/Fs and PCBs being around 13% lower in this study. This indicates a general declining trend in the levels of POPs in Hong Kong. However, our levels were still high when compared to those in some other Asian-Pacific countries. More stringent policies on reducing and eliminating POPs should help to lower these. Continued surveillance for POPs in human milk, as well as in common foodstuffs, will provide us with important information on human exposures that will be necessary for tracking our progress, and making future health risk assessments., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Temporal trends of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in mothers' milk are still quite rare. Data are particularly scarce when it comes to concentrations from the last decade, 2000 and onwards. The aims of the present study were to assess temporal trends of PCDD, PCDF and DL-PCB in mothers' milk from Stockholm, 1972-2011 and to compare the results with previous analysis of some of the older samples. The samples were analyzed by high resolution GC/MS and results were statistically evaluated for the periods, 1972-2011 and 2002-2011. The rate of which ∑PCDDs, ∑DL-PCBs and the ∑TEQ are decreasing (on pg/g fat WHO-TEQ2005) is higher in the last decade compared to the 40year period, 1972-2011. A similar trend is indicated, but not confirmed, for ∑TEQ of PCDFs, probably due to too many PCDF congeners below LOQ in the period 2002-2011. Concentrations of ∑PCDDs, ∑PCDFs, ∑DLPCBs and ∑TEQ, all expressed as pg/g fat on TEQ-WHO2005-basis, show a statistically significant decline over time, 5.8-6.8% per year, 1972-2011. The last ten years the annual declines for ∑PCDDs, ∑DL-PCBs and ∑TEQ are 9.2-11% and for ∑PCDF, 5.4%. Congener specific trend analysis, 2002-2001, of PCDDs and DL-PCBs showed the same pattern, while the PCDF congeners showed no such general trend. The results from the re-analysis showed good agreement with slightly lower ∑TEQ1998 pg/g fat concentrations in six out of seven samples and mean difference of 13% in ∑TEQ1998. The study shows that time series can be elongated from previous studies, as long as the sample population remains the same., (© 2013.)

Yusho disease, a polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) mixed poisoning caused by contaminated rice oil, occurred in Japan in 1968. The evidence on reproductive outcome is limited. We therefore evaluated the regional impact of the exposure to the PCB and PCDF mixture on stillbirth rate and secondary sex ratio among the residents in two severely affected areas. We selected the regionally-affected towns of Tamanoura (n=4390 in 1970) and Naru (n=6569) in Nagasaki Prefecture, Japan, for study. We obtained data on stillbirths (spontaneous/artificial) and live-born births (total/male/female) from 1958 to 1994. For a decade and a half after the exposure, an increase in the rate of spontaneous stillbirths coincided with a decrease in the male sex ratio. Compared with the years 1958-1967, the ratios for spontaneous stillbirth rates were 2.16 (95% confidence interval: 1.58 to 2.97) for 1968-1977 and 1.80 (95% confidence interval: 1.25 to 2.60) for 1978-1987. The sex ratio (male proportion) was 0.483 (95% confidence interval: 0.457 to 0.508) in the first 10years after exposure. Exposure to a mixture of PCBs and PCDFs affected stillbirth and sex ratio for a decade and a half after the exposure., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The Southwest Nigeria has witnessed tremendous increase in the output of municipal wastes in the recent years. Non availability of government policy on solid wastes management or its lack of effectiveness where it exists makes unabated open burning the predominant means of municipal solid waste disposal in the region. Open burning of municipal wastes being a major source of anthropogenic air emissions was investigated for atmospheric loading of some hazardous organic pollutants using the emission inventory method. The specific pollutants considered in this study were volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo -p-dioxin (PCDDs) and polychlorinated dibenzo furan (PCDF). The estimated release of VOCs, PAHs, PCBs, PCDD and PCDF from open burning of municipal wastes in the region over the 5-year period investigated were 64000 tonnes, 988 tonnes, 43 tonnes, 0.56 tonnes and 0.2 tonnes respectively. Given the serious human health implications associated with these hazardous organic pollutants, the study suggested conversion of wastes to energy as a possible solution since the region also faces energy challenges. [ABSTRACT FROM AUTHOR]

The levels of PCDDs, PCDFs and DL-PCBs were analyzed both in milk and adipose tissues sampled "in vivo" from lactating, drying off and heifer buffaloes from a Campania farm which had been impounded by the competent authority owing to the high dioxin levels found in bulk milk. The chemical determination was carried out by HRGC-HRMS using US EPA Method 1613b. The range of WHO-TEQ values for the PCDDs/PCDFs in adipose tissues was 1.79 to 68.64 pg g−1 fat and in milk was 8.33 to 13.95 pg g−1 fat. The contamination profile for dioxins and furans was given by 1,2,3,7,8-PeCDD; 2,3,4,7,8-PeCDF; 1,2,3,6,7,8-HxCDD and 2,3,7,8-TCDD. The levels of DL-PCBs in adipose tissue varied from 1.38 to 20.13 pg g−1 fat while ranged from 8.33 to 13.95 pg g−1 fat in milk. The pattern of DL-PCBs in both matrices was dominated by congeners PCB 126 and PCB 169. [ABSTRACT FROM AUTHOR]

Reductions in concentrations of persistent organic pollutants were observed for polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) in a comparison of two consecutive decades ending in December 31, 2015 (n = 413) and compiled from a 48-station long-term air-monitoring network in Catalonia, Spain. Reductions were observed in geometric mean concentration of total PCDD/Fs, decreasing at a rate of 11% yr −1 . Results reflect the relative success of improved pollution control measures at industry and traffic locations. At traffic and industrial locations, PCDD/Fs were reduced by around 68% (from 70 to 22 fg I-TEQ/m 3 ) and 66% (from 57 to 19 fg I-TEQ/m 3 ), respectively. The highest concentration of 1196 fg I-TEQ/m 3 was observed during the first decade at an industrial location. The highest concentration over the second decade was at a background location during winter (674 fg I-TEQ/m 3 ). Winter observations are generally higher than those recorded in summer, as evident in an 8-year period of moderate PCDD/F levels (<250 fg I-TEQ/m 3 , n = 143). PCDD/F congener profiles were identified has having less chlorinated PCDD/F, indicating the presence of nearby combustion sources at selected locations. More long-term sampling campaigns, combined with network optimization and integration into a meteorological model, can offer a tool for future PCDD/Fs control measures in not only Catalonia – but also applicable to other areas. [ABSTRACT FROM AUTHOR]

Abstract: The need for accurate thermodynamic data for the polychlorinated dibenzofuran family of isomers arises from the continued interest in the prediction of relative populations of these, and the lack of experimental data justifies the need for the calculation of these at a sufficiently accurate level. In order to add to the existing databases, specific heats have been calculated for the full 135 isomer set of PCDFs using B3LYP density functional theory calculations at the 6-31G(d) and 6-311+G(3df,p) basis set levels. These are calculated for temperatures up to 800K as well as the accompanying heats of formation and entropies at standard conditions. Knowledge of the specific heats up to this temperature gives greater confidence in the calculation of free energy values in the temperature ranges known to be important for PCDF formation and transformation. It is shown that a reduced set of quadratic functions can be used to represent the C p values for the eight isomer groups of the PCDF family and the methodology used is shown to predict the C p and entropy values with good accuracy for a number of other molecules for which experimental values are known. [Copyright &y& Elsevier]

Polychlorinated biphenyls (PCBs) are toxic and persistent chemicals produced between 1930s and 1980s primarily for insulating fluids in heavy-duty electrical equipment in power plants, industries, and large buildings. They persist in the environment and accumulate in plants and animals, and have been classified as probable carcinogens to humans. We performed a systematic review and meta-analysis of scientific literature on the relationship between PCB exposure and human cancer. Two cohorts of people highly exposed to PCBs through ingestion of contaminated rice oil and some cohorts of occupationally exposed workers failed to show a definite increase in total cancer mortality and provided inconsistent results regarding single cancers. Several cohort and case-control studies investigated the association between PCBs and specific cancers, showing an association between PCB serum levels and non-Hodgkin lymphomas (NHL), with a summary odds ratio of 1.5 (95% confidence interval: 1.1–1.7), but no consistent results for the other cancer sites and types. In conclusion, this review provides some evidence for the role of PCBs in the development of NHL, although the inconsistent results of studies performed on highly polluted people and occupationally exposed workers do not allow a firm conclusion to be drawn. [ABSTRACT FROM PUBLISHER]

Abstract: Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) bioaccumulate through the food chain and are therefore of public health concern. Exposure to these compounds was assessed in the second French Total Diet Study (TDS). Food samples (n =583) were collected to be representative of the whole diet of the population, prepared as consumed, and analyzed. Contamination data were combined with national individual food consumption data. Mean exposure (95th percentile) to PCDD/F+DL-PCBs was assessed to be 0.57 (1.29)pgTEQWHO-98 (kgbw)−1 d−1 in the adult population and 0.89 (2.02)pgTEQWHO-98 (kgbw)−1 d−1 in the child and teenager population. Less than 4% of the population exceeded the health-based guidance value for PCDD/F+DL-PCBs. Mean exposure (95th percentile) to the six indicator PCBs (PCB 28, 52, 101, 138, 153, 180) was estimated at 2.71 (7.90)ng(kgbw)−1 d−1 in the adult population and 3.77 (11.7)ng(kgbw)−1 d−1 in the child and teenager population. Only 2.6% of the adults [CI95%: 1.9; 3.3] and 6.5% of the children and teenagers [5.2; 7.8] exceeded the health-based guidance value for total PCBs. These results show that the contamination levels in food and therefore the exposure of the general French population to PCDD/Fs and PCBs have declined (by a factor of 3.2 for PCDD/F+DL-PCBs and about three for total PCBs) since the last evaluation, which was conducted using another methodology in 2005 and 2007, and show the efficiency of the European risk management measures which came into force after these evaluations. [Copyright &y& Elsevier]

Abstract: An extraordinary plan of official control was carried out in 2008 in Campania (Italy) with the aim to monitor polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) levels in buffalo milk and to detect the contaminated farms, most of which are located in Caserta province. For these companies has been ordered seizure and execution of additional analyses has been requested in farms falling in the nearness, within a distance of 3km, for a total of 304 farms examined. Moreover, all non-compliant farms were subjected to a periodic sampling in order to monitor trends in the levels of contamination. In this paper the distribution and the concentrations of 17 PCDD/Fs and 12 dioxin-like PCBs in 460 samples of buffalo milk collected in the province of Caserta (Italy) are presented. The range of WHO-TEQ values for the PCDD/Fs in milk was 0.17pgTEQg−1 fat and 87.0pgTEQg−1 fat with a mean value 3.63pgTEQg−1 fat and medium value 2.25pgTEQg−1 fat. The concentrations of dioxin-like PCBs in the analysed samples ranged from 0.21pgTEQg−1 fat to 15.9pgTEQg−1 fat and the WHO-TEQ values of sum of PCDDs, PCDFs and dl-PCBs ranged from 0.45pgTEQg−1 fat to 103.0pgTEQg−1 fat. The geo-referencing analysis allowed to individuate a restricted area of the region object of the present study where is located the majority of the non-compliant farms. The study of the congeners distribution has finally suggested that the likely cause of contamination is to be attributed to the illegal burning of waste. [Copyright &y& Elsevier]

Abstract: Mainstream cigarette smoke (MSS) from 12 US cigarette brands and two reference cigarettes was evaluated to determine concentrations of dioxins (i.e., polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs)). The study included three ‘tar’ ranges based on Federal Trade Commission (FTC) determination: Low Yield (LY)⩽5.5, Medium Yield (MY) 9.6–12.2, and High Yield (HY)⩾14.5mg/cig. Of the brands studied, the HY cigarettes yielded the greatest mean concentrations of 2005 World Health Organization Toxic Equivalents (WHO-TEQs) on a per cigarette basis. WHO-TEQ levels in LY cigarettes were significantly lower than for HY cigarettes (p =0.039) on a yield per cigarette basis and WHO-TEQ concentrations correlated with ‘tar’ yield (r =0.73, p =0.007), as did concentration on a WHO-TEQ per body mass per day basis (r =0.73, p =0.007). However, a statistically significant relationship was not observed between ‘tar’ yield levels and WHO-TEQ concentrations on a per mg Total Particulate Matter (TPM) basis. Concentrations for all brands tested ranged from 0.44 to 3.88fg WHO-TEQ/mg TPM. Maximum daily exposure estimates calculated from this range (0.004–0.074pg WHO-TEQ/kg bw/day) are below the current WHO Tolerable Daily Intake range of 1–5pg/kg bw/day. [Copyright &y& Elsevier]

Abstract: The aim of this investigation was to evaluate the environmental impact associated to PCDDs/Fs and dioxin-like PCBs in the Ebro River basin. Sediments and fish from several species were sampled at three sites with different historical pollution records, including the Barbastro area with different industrial activities, and the Flix and Monzón sites, associated to heavy organochlorine compound pollution. Seventeen toxic PCDDs/Fs and 12 dioxin-like PCBs were analyzed by GC–MS. The results obtained indicated significant accumulation of dioxin-like PCBs, but not PCDDs/Fs, in sediments and fish at the Flix site compared to the other sites. Concomitantly, cytochrome p450 1A (CYP1A) expression, a known indicator for pollution by dioxins and dioxin-like PCBs, was significantly elevated in barbel (Barbus graellsii) from the Flix site, compared to the population from the Barbastro site. CYP1A expression correlated with the concentration of dioxin-like PCBs in the fish fat, whereas no significant correlation was found with PCDDs/Fs concentrations. Our data suggest a significant biological impact at the Flix site, closely related to the presence of dioxin-like PCBs, whereas the PCDDs/Fs contribution to this impact appears to be non-significant, at least in the studied sites. [Copyright &y& Elsevier]

Abstract: The toxic equivalency factor (TEF) approach was employed to compare immunotoxic potency of mixtures containing polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using the antibody response to sheep erythrocytes (SRBC). Mixture-1 (MIX-1) contained TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1-PeCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), and 1,2,3,4,6,7,8,9-octachlorodibenzofuran (OCDF). Mixture-2 (MIX-2) contained MIX-1 and the following PCBs, 3,3′,4,4′-tetrachlorobiphenyl (IUPAC No. 77), 3,3′,4,4′,5-pentachlorobiphenyl (126), 3,3′,4,4′,5,5N-hexachlorobiphenyl (169), 2,3,3′,4,4′-pentachlorobiphenyl (105), 2,3′,4,4′,5-pentachlorobiphenyl (118), and 2,3,3′,4,4′,5-hexachlorobiphenyl (156). The mixture compositions were based on relative chemical concentrations in food and human tissues. TCDD equivalents (TEQ) of the mixture were estimated using relative potency factors from hepatic enzyme induction in mice [DeVito, M.J., Diliberto, J.J., Ross, D.G., Menache, M.G., Birnbaum, L.S., 1997. Dose–response relationships for polyhalogenated dioxins and dibenzofurans following subchronic treatment in mice. I .CYP1A1 and CYP1A2 enzyme activity in liver, lung and skin. Toxicol. Appl. Pharmacol. 130, 197–208; DeVito, M.J., Menache, G., Diliberto, J.J., Ross, D.G., Birnbaum L.S., 2000. Dose–response relationships for induction of CYP1A1 and CYP1A2 enzyme activity in liver, lung, and skin in female mice following subchronic exposure to polychlorinated biphenyls. Toxicol. Appl. Pharmacol. 167, 157–172] Female mice received 0, 1.5, 15, 150 or 450 ng TCDD/kg/day or approximately 0, 1.5, 15, 150 or 450 ng TEQ/kg/day of MIX-1 or MIX-2 by gavage 5 days per week for 13 weeks. Mice were immunized 3 days after the last exposure and 4 days later, body, spleen, thymus, and liver weights were measured, and antibody response to SRBCs was observed. Exposure to TCDD, MIX-1, and MIX-2 suppressed the antibody response in a dose-dependent manner. Two-way ANOVA indicated no differences in the response between TCDD and the mixtures for body weight, spleen/body weight and decreased antibody responses. The results support the use of the TEF methodology and suggest that immune suppression by dioxin-like chemicals may be of concern at or near background human exposures. [Copyright &y& Elsevier]

Nineteen species of fish products caught and produced in the Russian economic zone of the Baltic region in 2002–2005 were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like biphenyls (WHO-PCBs). Freshwater fish had significantly lower PCDD/PCDFs levels than most saltwater fish, except cod''s fillet for which TEQ was comparable. In some cases pollutant levels of sea fish tissues essentially exceeded current regulatory values. Concentration of WHOPCDD/F-TEQ ranged from 0.06 to 0.57pg/g f.w. for freshwater fish, and from 0.16 to 17.83pg/g f.w. for sea fish. The special concern is caused by the high concentration of dioxin-like PCBs, whose contribution to the WHO-TEQPCDD/F,PCB considerably exceeded that of PCDDs and PCDFs. Concentration of WHOPCB-TEQ ranged from 2.56 to 124.40pg/g f.w. Profiles of PCDD/Fs congeners in fish were rather similar: in our opinion, the most probable sources of pollution were chlorine bleaching and outflow of PCBs. There is no real reason to assume that fish contamination was affected by the fungicide Ky-5 or similar chlorophenols mixtures. Relative contributions of each dioxin-like PCBs congener to total TEQ in fish tissue are presented in Fig. 2. Profiles of dioxin-like PCBs in general are close to Aroclor 1254, though in some cases there are essential differences. [Copyright &y& Elsevier]

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as well as polychlorinated biphenyls (PCBs) are widespread environmental contaminants. A French national survey was carried out in April 2006 to assess the concentrations of PCDD/Fs and dioxin-like PCBs (DL-PCBs) in raw cow’s milk. A random sampling scheme stratified by region was applied to collect 239 raw milk samples from 93 plants belonging to 17 dairy companies. Compared to a previous survey led in 1998 analyzing half-skimmed drinking milk in France, the PCDD/Fs level was cut by half, with an average concentration of 0.33pg toxic equivalent (TEQ)/g fat in 2006. The mean DL-PCBs concentration was 0.57pg TEQ/g fat and subsequently the sum of PCDD/Fs and DL-PCBs was 0.90pg/g fat, values below the thresholds defined by the European Union regulations. [Copyright &y& Elsevier]

This paper reports on an intensive study into releases of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated furans (PCDF) and polychlorinated biphenyls (PCB) from a diesel engine and the analysis of PCDD/F and PCB in crankcase lubricating oil. Experimental conditions were set and carefully controlled in order to maximize the possible impact of, and our ability to measure the effect of, changes in the levels of chlorine in the lubricant. Emissions to air were measured using modified EPA methods following the principles of the European EN 1948 standards. A series of 40 experimental runs were completed using three reference lubricants formulated to have three levels of chlorine present as a residual component (at levels of 12, 131 and 259mgkg−1 or ppm). The engine was run with and without the diesel oxidation catalyst. All lubricants were realistic oils and the use of unrealistic additives or doping of components – particularly chlorine – in the fuel and lubricant was carefully avoided. Analysis of fuel and lubricant (before and after testing) samples required strenuous attention to achieve acceptable recoveries and showed non-detectable levels of PCB and PCDD/F at a detection limit of around 1.5ng I-TEQ kg−1 (ppt), indistinguishable from the laboratory blank. The testing demonstrated the need for extreme care to be taken in developing measurement methods that are sufficiently sensitive for measuring chlorine content of fluids and PCDD/F in oils, the latter being particularly challenging. Mean emissions of PCDD/F with the diesel oxidation catalyst in place were 23 pg I-TEQ l−1 of fuel and with the diesel oxidation catalyst removed 97 pg I-TEQ l−1 of fuel. The results of this testing showed that the emissions of PCDD/F were greatly reduced by the presence of a diesel oxidation catalyst in the exhaust, a finding that has not been explicitly tested in previous work. They also show that emissions from the engine were not controlled by the level of chlorine in the lubricant and that emissions did not change in response to a much greater step change in the total chlorine entering the combustion chamber due to a change in the level of chlorine in the fuel. Emissions when the engine was configured with a diesel oxidation catalyst showed a consistent pattern that appears to be unique in the experience of the authors. [Copyright &y& Elsevier]

Abstract: Dioxin-like compounds (DLCs) are suspected etiological factors of endometriosis but their potential mechanisms of action remain elusive. Because endometriosis is an estrogen-dependent disease and since aromatase (CYP19), a key enzyme in estrogen biosynthesis, was recently demonstrated to be expressed in endometriotic lesions, we hypothesized that dioxin-like compounds could modulate local estrogen production through an up-regulation of aromatase. We tested this hypothesis by examining the correlation between serum DLC levels and CYP19 expression in endometriotic tissue obtained from 47 patients with peritoneal, ovarian endometriosis and/or deep endometriotic nodules of the rectovaginal septum. Aromatase expression was assessed by real-time RT-PCR in biopsied endometriotic tissues [peritoneal (n =19), ovarian (n =17) endometriosis and deep endometriotic nodules of the recto-vaginal septum (n =29)]. The relationship between aromatase expression and DLCs was traced by simple regression analysis. DLCs did not appear to be significant determinants of aromatase expression. CYP1A1 expression, measured as a positive control, was found associated with current smoking but not with DLCs. We conclude that DLCs do probably not facilitate the growth of endometriotic lesions by up-regulating the local expression of aromatase. [Copyright &y& Elsevier]

Abstract: The levels of polychlorinated dibenzo-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), coplanar polychlorinated biphenyls (coPCBs), and polybrominated diphenyl ethers (PBDEs) were measured in fish collected from San Francisco Bay in 2000 and from the California coast in 2001. The samples were composites of only the edible portions of the fish (skin on, skin off, or whole body minus head and guts) of comparable size and from distinct geographical areas. Sixty-five composite samples were analyzed for PCDD/PCDF/coPCBs, and 43 composite samples were analyzed for PBDEs. For all fish of all species from all sampling areas, the mean concentration of the sum of BDEs 47, 99, 100, 153, and 154 was 302ng/g lipid weight, with BDE 47>100>99∼154>153. For all fish of all species from all sampling areas, the mean PCDD/PCDF International Toxic Equivalent (I-TEQ) was 33.1pg/g lipid. For the three coPCBs (77, 126, 169), the mean I-TEQ for all fish of all species from all sampling areas was 109pg/g lipid. The highest concentrations of both PCDD/PCDF/coPCBs and PBDEs were found in the highly populated areas of San Francisco Bay, the Los Angeles area, and San Diego Bay. [Copyright &y& Elsevier]

Abstract: Concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) and of non-ortho-, mono-ortho- and di-ortho-substituted polychlorinated biphenyls (NO-CB, MO-CB and DO-CB) were measured in blubber of ringed seals sampled at Holman, NWT, in 1981, 1991, 1996 and 2000. Total PCDD and PCDF concentrations were usually below approx. 10 and 5 pg/g wet wt., respectively, and did not change significantly between 1981 and 2000, although there were sporadic temporal differences in some congeners. Total NO-CB, MO-CB and DO-CB concentrations were below approx. 1 ng/g, 250 ng/g and 1 μg/g wet wt. respectively; none of the total PCB concentrations changed significantly over the sampling period. Neither PCDD nor PCDF concentrations differed between males and females, nor did they increase with age in male samples. MO-CB and DO-CB concentrations increased with age in males, but not in females, and concentrations of total MO-CB and DO-CB were usually lower in females than in males. Changes in the distribution of PCB congeners between the 1980s and the 1990s are consistent with atmospheric transport processes becoming increasingly important in the introduction of PCBs to the Arctic in recent years. [Copyright &y& Elsevier]

Abstract: Background: Polychlorinated biphenyls (PCBs) and related compounds such as polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-dioxins (PCDDs) alter sexual maturation and endocrine function in animals. In 1978–1979, a mass poisoning occurred in central Taiwan from cooking oil contaminated by heat-degraded PCBs and oxidated compounds PCDFs. We tested the hypothesis that in utero exposed to PCBs/PCDFs alter sexual maturation, endocrine, and reproductive function in the human pubescent females. Methods: In 1997–1999, girls aged 13–19 years, born to mothers exposed to PCBs/PCDFs, was invited to participate in the study. Menstruation characteristic was recorded daily for 84 days and serum levels of estradiol, LH, FSH, and testosterone were measured on the 3rd day of menstruation. Results: A total of 17 exposed girls and controls participated, the exposed girls reported shorter mean duration of bleeding per cycle than 16 unexposed (5.5 vs 6.5 days, P =0.0055). There was a higher rate of irregular menstrual cycle in the exposed girls (40% vs 0%, P =0.018). Serum levels of estradiol (P =0.016) and FSH (P =0.061) were higher in exposed girls as compared to controls. Conclusions: We conclude that prenatal exposure to PCBs/PCDFs resulted in abnormal menstruation and higher estradiol and FSH levels in follicular phase of menstrual cycle in adolescent girls. [Copyright &y& Elsevier]

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are widespread environmental contaminants that exist as complex mixtures and are frequently detected at part-per-trillion (ppt) levels in humans. Using isotope dilution high-resolution gas chromatography/ high-resolution mass spectrometry (HRGC/HRMS), we measure the PCDDs, PCDFs, and PCBs in serum of a population of 78 women residing in an area near Seveso, Italy where a TCDD explosion occurred in 1976 and where furniture is manufactured. The average total dioxin-like toxic equivalents (TEQ) of these women was 25.3 ppt, lipid-adjusted, comparable to other parts of Europe. TCDD levels, however, were higher among the few women who resided in the exposed area in 1976. We examined the possibility of using the CALUX (chemical-activated luciferase gene expression) bioassay to estimate total TEQ in a small volume of plasma from this population. A total of 32 archived plasma specimens were selected for CALUX bioassay, based on the distribution of Total TEQ by HRGC/HRMS. The CALUX bioassay was performed blind to HRGC/HRMS results with 2 ml plasma per replicate analysis. Of 32 samples, 10 were below detection limits in the CALUX bioassay. For the 32 samples, the CALUX-TEQ averaged 25.4 ppt, lipid-adjusted (range: 0–127.6) and was not significantly different from the HRGC/HRMS Total TEQ average of 31.2 ppt, lipid-adjusted (range: 12.7–88.3) (t=0.88, P=0.38), however, the two measures were not significantly correlated (Rs=0.04, P=0.82). More validation of the CALUX bioassay with larger sample volume is needed before application as an exposure measure in large-scale epidemiologic studies of health effects of dioxin-like compounds.Journal of Exposure Analysis and Environmental Epidemiology (2005) 15, 310–318. doi:10.1038/sj.jea.7500407 Published online 22 September 2004 [ABSTRACT FROM AUTHOR]

Abstract: To characterize the maternal–fetal transport of lipophilic endocrine disrupting chemicals, concentrations of polychlorinated (2,3,7,8-substituted) dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) were measured in maternal and fetal blood, and amniotic and allantoic fluids in cattle. Total toxicity equivalent quantity (TEQ) was highest in amniotic fluid on a fat-weight basis, whereas it was highest in maternal blood on a total weight basis. TEQ was lowest in allantoic fluid on either basis; 26 of 29 congeners analyzed in this experiment were detected in one or more samples. The largest number of congeners was detected in amniotic fluid. O8CDD, 2,3,4,7,8-P5CDF and 2,3′,4,4′,5-P5CB were the major congeners in PCDDs, PCDFs and PCBs, respectively. The O8CDD concentration was higher in fetal blood than in maternal blood on a fat-weight basis, whereas concentrations of other congeners were lower in fetal blood than in maternal blood. Furthermore, on a fat-weight basis, the O8CDD concentration was considerably higher in allantoic fluid compared with other samples. Concentrations of major PCB congeners were higher in amniotic fluid than in maternal and fetal blood on a fat-weight basis. In conclusion, it is suggested that lipophilic endocrine-disrupting chemicals contained in maternal blood are all transferred to the fetal circulation via the placenta in cattle. Furthermore, the results of this experiment imply that O8CDD has different transportation systems from other dioxins in the circulation, and that a considerable amount of PCBs is excreted and accumulated in amniotic fluid during the fetal stage in cattle. [Copyright &y& Elsevier]

Abstract: This work compares two lipid extraction methods for determining 24 polychlorinated biphenyls (PCBs), seven dibenzo-p-dioxins (PCDDs) and ten dibenzofurans (PCDFs) in human blood plasma. The first method was based on conventional liquid–liquid partitioning with chloroform–methanol and the other made use of a sorbent (Chem-Elut) to facilitate the partitioning of lipids into a mixture of hexane and 2-propanol. A multi-layer-silica column including acid- and base-impregnated silica gel was used to reduce the amounts of lipid present in the samples before a basic alumina clean-up step and activated carbon fractionation of planar analytes (PCDD/Fs and non-ortho-PCBs) and non-planar analytes (including ortho-chlorinated PCBs). Gas chromatography coupled to high resolution mass spectrometry was used to identify and quantify the analytes in the two fractions. The wet weight based concentrations obtained by the two methods were in agreement but both methods suffer from large organic solvent consumption. The toxic equivalencies derived for PCBs and PCDD/Fs using the two methods were also in agreement. However, the chloroform–methanol method gave slightly higher lipid recoveries, although with greater variation, than the sorbent-assisted method. Nevertheless, despite giving lower lipid recoveries, the sorbent-assisted method has advantages in ease of use and applicability to whole blood samples. The formation of emulsions was avoided with the Chem-Elut method, which probably explains the lower variability in the lipid determinations. [Copyright &y& Elsevier]

Abstract: Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCB) were determined in 23 soil samples collected at reference sites of the Swiss national soil monitoring network (NABO). Total PCDD/F and PCB concentrations are well correlated and proportional (R2=0.720). The total PCDD/F levels were between 72 and 703ng/kg corresponding to 1.1–11ng I-TEQ/kg, total PCB concentrations (sum of seven congeners IUPAC no. 28, 52, 101, 118, 138, 153, and 180) were from 1.1 to 12μg/kg. In all samples, the PCDD/F and PCB concentrations were in the range of background levels for these contaminants in Central Europe. Ninteen samples revealed PCDD/F levels below the guide value of 5ng I-TEQ/kg set by the Swiss ordinance relating to impacts on the soil (OIS); concentrations for the remaining four samples were below the trigger value (20ng I-TEQ/kg). All PCB concentrations were below the guide value of 100μg/kg. The elevated PCDD/F and PCB levels in some of the samples originating from forested sites could be attributed to the scavenging effect of forest canopies for semivolatile organic compounds. This interpretation could be substantiated by the observed distortion of the congener and homolog patterns of PCDD/F and PCB which is characteristic for forested sites. [Copyright &y& Elsevier]

Five fluidized bed incinerators combusting municipal solid waste were assessed for the impact of coplanar PCBs on total TEQ emission. In 17 stack measurements, the coplanar PCBs contributed on average less than 3% to total TEQ with a maximum contribution of 7.5% to total TEQ in one measurement. Differences in the design of the flue gas cooling section did not show an effect on the impact of coplanar PCBs on total TEQ.The effect of emission control devices on the impact of coplanar PCBs on the total TEQ was studied in more detail at one incinerator. The relative contribution of PCBs to total TEQ increased along the flue gas line. This was caused by a slightly higher removal efficiency for TEQ relevant PCDDs/PCDFs compared to coplanar PCBs by the bag filters and a higher destruction efficiency for PCDDs/PCDFs compared to PCBs by the SCR catalyst.Additionally, the removal efficiencies of the emission control devices (bag filters and catalyst) for other chlorinated aromatic compounds which have been proposed as TEQ indicator compounds (polychlorinated benzenes and polychlorinated phenols) were compared with those for PCDDs/PCDFs and coplanar PCBs. Removal efficiencies for polychlorinated benzenes or polychlorinated phenols considerably differed from those of PCDD/PCDF and coplanar PCBs. Implications for TEQ assessments using indicator compounds as proposed in the literature are discussed. [Copyright &y& Elsevier]

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo- p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed. [ABSTRACT FROM AUTHOR]