Concentrations Of PCDFs Research Articles

Diễn biến hàm lượng PCDDs/PCDFs và dl-PCBs trong không khí theo mùa ở một khu vực nội thành giai đoạn 2012-2020

The ambient air monitoring of PCDDs/PCDFs and dl-PCBs using passive air samplers in a residential urban area in Hanoi between 2012-2020 was deteminated. The seasonal variations of PCDD/PCDF and dl-PCB levels in ambient air in three periods: between Spring 2012 and Autumn 2015, from Winter 2015 to Autumn 2018, and between Winter 2018 and Autumn 2020 are similar to a V-shape with the highest peak in winter, then decreasing gradually in spring, bottoming in summer and rising again in autumn. The upward temporal trends of PCDD/PCDF and dl-PCB pollution, and total TEQD/F&DL, total TEQD/F and total TEQDL has been confirmed over time. The concentrations of total PCDFs were dominant and were approximately 1.0 to 9.3 times higher and 2.4 times higher on average than total PCDDs. Total dl-PCBs were 5.8 to 38 times higher and 17 times on average higher than the total toxic PCDDs/PCDFs. The PCDD/PCDF congeners contributed 83% to 95% of the total TEQ value. The phenomenon of temperature inversion not only causes seasonal air pollution but also increases the concentration of PCDDs/PCDFs and dl-PCBs with a narrower range but at a higher average levels.

Biomonitoring of the adult population living near the waste incinerator of Turin: Serum concentrations of PCDDs, PCDFs, and PCBs after three years from the plant start-up

In September 2013 a waste-to-energy (WTE) incinerator located in the Turin area (Piedmont, Northern Italy) started to produce energy by the incineration of municipal solid wastes. The plant, one of the largest WTE incinerator in Europe, burns up to 490,000 tons of waste per year. A health surveillance program was implemented in order to evaluate the potential health effects on the population living near the plant. This program included a biomonitoring study aimed at assessing levels of several environmental contaminants including, among others, PCDDs, PCDFs, and PCBs. Before the WTE incinerator start-up (T0), a group of 85 subjects (41 “exposed” and 44 “not exposed” subjects) was randomly selected for enrollment by the local health units among individuals aged 36–50 years who had been living in the same area for at least five years prior to the study. Subjects were balanced by exposure area, sex and five-year age classes. As from the study design, the same cohort was re-evaluated after three years of incinerator activity (T2). A parallel study was conducted on a group of 12 farmers living and/or working in farms located in an area in the range of 5 km around the incinerator. Results of this study did not evidence any impact of the WTE plant on human exposure to PCDDs, PCDFs, and PCBs. In fact, no significant differences were found in the concentrations of PCDDs + PCDFs, DL-PCBs, and NDL-PCBs measured in the population group residing near the plant after three years of activity (T2) with respect to the control group. A significant decrease of serum concentrations of all the analytes was observed at T2 in both groups compared to T0. Serum concentrations of PCDDs, PCDFs, and PCBs in the group of farmers were higher than those observed in the adult population under study.

Assessment of environmentally contaminated sediment using a contact assay with early life stage zebrafish (Danio rerio)

Lake Saint-Louis, a shallow fluvial lake near the western tip of the island of Montreal, QC, Canada is an important spawning ground for many species of fish. Sediments in certain areas of the lake are known to be contaminated with high levels of metals and legacy organic chemicals. To improve our understanding of risk to native fish populations, we conducted a study evaluating levels of sediment contamination and potential effects on early life stage fish. Concentrations of PAHs, PCBs, PCDDs and PCDFs were several orders of magnitude higher at two industrial sites (B1 and B2) than at a nearby reference site (IP). Concentrations of 32 metals and metalloids were at least 5-fold higher at B1 and B2 than at IP. Moreover, all available interim sediment quality guidelines (ISQGs) were exceeded at the two contaminated sites, while none were exceeded at the reference site. Biological effects were evaluated using a sediment contact assay. Zebrafish (Danio rerio) embryos were exposed to clean water (control), or to sediment from IP, B1, and B2 until 120 h post fertilization (hpf). Mortality was significantly elevated in fish exposed to the B1, but not the B2 sediment. The frequency of deformities increased with increasing contamination, but this trend was not statistically significant (p > 0.05). Genes that are implicated in the response to PAHs, PCBs, dioxins and furans (cyp1a, cyp1b1, ahr2) were significantly elevated in the 120 hpf larvae exposed to the B1 and B2 sediments. Global DNA methylation, and mRNA expression of genes related to oxidative stress (maft, cat, hmox1, sod2), embryonic development (bmp2b, baf60c), metal exposure (mt2), and DNA repair (gadd45b) were unaffected. Our results suggest that the Beauharnois sector of Lake Saint-Louis is poor quality spawning habitat due to high levels of contamination, and the potential for harmful effects on early life stage fish.

Accumulation and temporal changes of PCDD/Fs and dioxin-like PCBs in finless porpoises (Neophocaena asiaeorientalis) from Korean coastal waters: Tracking the effectiveness of regulation

Temporal trend studies are useful to evaluate the effectiveness of regulations on local pollutants. The emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) has been regulated by the Korean government in accordance with the Stockholm Convention. The accumulation and temporal trends of PCDD/Fs and dioxin-like PCBs were investigated in finless porpoises (Neophocaena asiaeorientalis) collected in Korean waters. Median concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs were 1.0, 1.1, 0.1, and 1.8pgTEQ/g lipid weight, respectively, which were lower than threshold values for marine mammals. Age- and sex-dependent accumulation patterns were found for PCDFs and DL-PCBs. Temporal trends in finless porpoises collected between 2003 and 2010 showed significant reduction rates of 57%, 54%, 69%, and 60% for PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs, respectively. Our results suggest that the regulations on dioxin-like contaminants have been effective for marine mammals in Korea.

Trematomus bernacchii as an indicator of POP temporal trend in the Antarctic seawaters

The occurrence of POPs in remote areas, such as Antarctica, is the result of their ability to udergo Long Range Transport (LRT) in the atmosphere, precipitation and cold condensation.In this study, both recent levels of various POPs in Trematomus bernacchii and their changes in roughly three decades were determined in order to evaluate trends of POPs in Antarctic benthic seawaters. In fact, Trematomus bernacchii is considered a good sentinel bio-indicator for monitoring not only the extent of contamination by POPs in the Antarctic aquatic ecosystem, but also changes in Antarctic ecosystem quality and trends.A slight decreasing PCB trend was detected during 30-years time span (from early 1980's to 2010) in the circumantarctic seawaters. Two higher peaks of concentrations were reported in 2001 and 2005 in the Ross Sea and they may reflect the ice melting of icebergs.Because fire risk is very high in Antarctica due to the very dry air, a large use of flame retardants in buildings and furniture of stations is highly probable; moreover, many stations were built when there were no restrictions on flame retardants use. The PBDE levels in the T. bernacchii from 2001 to 2011 ranged 0.05–0.35 pg/g and were of the same order of magnitude in 2001/2011 and in 2002/2005, with a maximum value in 2005 (0.35 pg/g).Comparable concentrations of HCB, HCHs PCDDs and PCDFs are available only for few seasons: all these compounds showed a decreasing temporal trends and their concentrations were one or more order of magnitude lower in 2000s–2010s.

Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana)

Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18–520 and 83–3800ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000pg/g), with TEQ contributors in the order of PBDFs>>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93–540mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies.

Distribution of PCDD/Fs in the fly ash and atmospheric air of two typical hazardous waste incinerators in eastern China.

Distribution of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in the fly ash and atmospheric air of one medical waste incinerator (MWI) and one industrial hazardous waste incinerator (IHWI) plants were characterized. The PCDD/F concentrations of the stack gas (fly ash) produced from MWI and IHWI were 17.7 and 0.7 ng international toxic equivalent (I-TEQ)/Nm(3) (4.1 and 2.5 ng I-TEQ/g), respectively. For workplace air, the total concentrations of PCDD/Fs were 11.32 and 0.28 pg I-TEQ/Nm(3) (819.5 and 15.3 pg/Nm(3)). We assumed that the large differences of PCDD/F concentrations in workplace air were due to the differences in chlorine content of the waste, combustion conditions, and other contamination sources. With respect to the homologue profiles, the concentrations of PCDFs decreased with the increase of the substituted chlorine number for each site. Among all of the PCDD/F congeners, 2,3,4,7,8-PeCDF was the most important contributor to the I-TEQ value accounting for ca. 43 % of two sites. The gas/particle partition of PCDD/Fs in the atmosphere of the workplace in the MWI was also investigated, indicating that PCDD/Fs were more associated in the particle phase, especially for the higher chlorinated ones. Moreover, the ratio of the I-TEQ values in particle and gas phase of workplace air was 11.0. At last, the relationship between the distribution of PCDD/Fs in the workplace air and that from stack gas and fly ash was also analyzed and discussed. The high correlation coefficient might be a sign for diffuse gas emissions at transient periods of fumes escaping from the incinerator.

Dioxin-related compounds in breast milk of women from Vietnamese e-waste recycling sites: Levels, toxic equivalents and relevance of non-dietary exposure

Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and polybrominated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and PBDD/Fs), human exposure to the latter has not been studied in details. This study investigated the accumulation levels and profiles of dioxin-related compounds (DRCs) in breast milk samples from women living in two Vietnamese EWRSs and estimated the intake contribution from e-waste-related exposure. Screening results using Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX) showed higher dioxin-like (DL) activities in samples from the EWRS Bui Dau than in those from the EWRS Trang Minh and a reference site (2.3–10 vs 1.7–4.8 and 0.60–5.7pg CALUX-TEQ/g lipid, n=10, 6 and 9, respectively). Chemical analysis results of selected samples show that the WHO-TEQ levels of PCDD/Fs, DL-PCBs and PBDD/Fs in EWRS samples were not significantly higher than in those from the reference site (0.22–7.4 vs 1.1–3.0pg/g lipid) and within the Vietnamese background range, but women involved in recycling accumulated higher concentrations of PCDFs (13–15 vs 2.3–8.8pg/g lipid) and PBDFs (1.1–1.5 vs <1.1pg/g lipid). By comparing the DRC profile in milk of these women with the reported profile in house dust from the same site, dust ingestion was estimated to contribute most of the intake for tetraBDF, 37 per cent to 55 per cent for penta–octaCDFs, but less than twenty per cent for PCDDs and DL-PCBs, and 26 per cent for total WHO-TEQs. The DL activities in some EWRS milk samples were not fully explained by chemical data, suggesting contribution from unidentified compounds. The estimated WHO-TEQ intake doses for breastfed infants (1.3–33pg/kg/d) mostly exceeded the tolerable value, especially for those living in the EWRSs; and unidentified DRCs might increase further the dioxin-related health risk.

Estimation of age- and sex-specific background human serum concentrations of PCDDs, PCDFs, and PCBs in the UMDES and NHANES populations

Age- and sex-specific estimates of serum dioxin concentrations are important for comparisons among populations. However, such comparisons are problematic because populations have different age and sex structures and values are typically reported only in broad age ranges that are not comparable across studies. There are few studies that report congener-specific serum concentrations, and none that provide these by sex for age as a continuous function. We combined the NHANES 2003–2004 data with the University of Michigan Dioxin Exposure Study (UMDES) referent population 2005 data to achieve stable and accurate estimates of mean and quantiles of serum dioxins by sex over ages 18–85. Survey-weighted linear and quantile regression models were fitted on the combined data with the log-transformed congener concentration as outcome and age, sex, and data source as covariates. Formulas are provided to allow calculations of age- and sex-specific mean and quantile estimates over ages 18–85. For instance, the geometric mean, median, 75th percentile, and 95th percentile of serum TEQ for men aged 50 can be estimated, respectively, from the formulas as 18.33, 19.02, 22.60, and 30.37pgg−1 lipids among the Michigan general population, and as 15.71, 15.89, 22.60, and 29.90pgg−1 lipids among US non-Hispanic whites. These methods and results are useful for comparing the congener-specific human serum dioxin concentrations in any individual to the general population mean, median, 75th percentile, and 95th percentile, and for comparing the serum dioxin concentration in any group of interest to the US and the Michigan general populations.

Concentrations and gas-particle partitioning of PCDD/Fs in the urban air of Dalian, China

PCDD/Fs in the urban air of Dalian, China were monitored with high-volume active sampler from November 2009 to October 2010. The concentration of Cl4−8DD/Fs ranged from 3065 to 49538 fg m−3, with an average of 10249 fg m−3. The international toxic equivalents (I-TEQ) value of that was 61.8–1182 fg m−3, with an average of 235 fg m−3, which was comparable to those in the other urban locations around the world. It was found that the Cl4−8DD/Fs appeared to be present mainly in the particle phase during winter, spring and autumn, while during summer which were dominantly in gas phase. The ratio of Cl4−8DD/Fs present in particle phase increased with the increasing level of chlorination. The concentrations of PCDFs and PCDDs decreased with the increase of chlorinated level, while the concentrations of 2,3,7,8-PCDDs congeners increased with the increase of chlorination level. The homolog profiles of the concentrations of PCDFs presented were higher than those of the PCDDs, which indicated the PCDD/Fs pollution source of the air in Dalian was characteristic for thermal source pollution. The correlation analysis of meteorological parameters with the concentrations of Cl4−8CDD/Fs was conducted using SPSS packages, and it was found that the ambient temperature and atmospheric pressure were important factors influence the concentration of PCDD/Fs in the air. The respiratory risk and intake dioxins of the residents around the sampling sites were studied in the paper. It was found that Junge-Pankow model was much more accurate in predicting the gas-particle partitioning behavior of PCDD/Fs homologues during winter, while the Harner-Bidleman model shows better agreement with the measured data during winter and summer.

Elevated concentrations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and polybrominated diphenyl ethers in hair from workers at an electronic waste recycling facility in Eastern China

Hair samples collected from e-waste recycling workers (n=23 males, n=4 females) were analyzed to assess occupational exposures to polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) at a large e-waste recycling facility in Taizhou, eastern China. Hair samples from a reference population composed of residents of Shanghai (n=11) were analyzed for comparison. The mean concentration of ∑PBDEs (range, 22.8–1020ng/g dw; mean, 157ng/g dw) found in hair samples from e-waste recycling workers was approximately 3 times higher than the mean determined for the reference samples. The congener profiles of PBDEs in hair from e-waste recycling workers were dominated by BDE 209, whereas the profiles in the reference-population samples showed comparable levels of BDE 47 and BDE 209. Total PCDD/F concentrations in hair from e-waste workers (range, 126–5820pg/g dw; mean, 1670pg/g dw) were approximately 18-fold greater than the concentrations measured in hair from the reference population. Concentrations of PCDFs were greater than concentrations of PCDDs, in all of the hair samples analyzed (samples from e-waste and non-e-waste sites). Tetrachlorodibenzofurans (TCDFs) were the major homologues in hair samples. Overall, e-waste recycling workers had elevated concentrations of both PBDEs and PCDD/Fs, indicating that they are exposed to high levels of multiple persistent organic pollutants.

Concentrations and accumulation features of PCDDs, PCDFs and dioxin-like PCBs in cetaceans from Korean coastal waters

Despite several studies that report accumulation of polychlorinated biphenyls (PCBs) and DDT in marine mammals worldwide, very few have examined polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like PCBs. In particular, no earlier studies have reported concentrations and accumulation profiles of persistent organic pollutants (POPs) in marine mammals from Korea. In this study, concentrations and accumulation features of PCDD/Fs and dioxin-like PCBs were measured in liver and blubber of minke whales and long-beaked common dolphins collected from Korean coastal waters. The concentrations of PCDFs and dioxin-like PCBs in blubber were 3–10 times higher than the concentrations measured in liver, but PCDDs were higher in liver than blubber. Total toxic equivalent (TEQ) concentrations in blubber of minke whales and common dolphins from Korean coastal waters were similar to, or higher than those reported for cetaceans and seals from other countries. Homologue and congener profiles of PCDD/Fs were different between livers and blubbers, while the profiles of dioxin-like PCBs were similar between the tissues. Concentrations of PCDD/Fs and dioxin-like PCBs in liver and blubber of dolphins were significantly higher than those measured in whales, due to differences in habitat and diet. The relative contribution of individual chemical groups to total TEQs was different between the two cetacean species, suggesting different exposures and metabolic activity. The TEQ levels in minke whales did not exceed the threshold level suggested for immunomodulation, while TEQs in all dolphin samples exceeded the suggested threshold level, implying potential adverse health effects from exposure to PCDD/Fs and PCBs.

An Investigation of Homes with High Concentrations of PCDDs, PCDFs, and/or Dioxin-Like PCBs in House Dust

As part of the University of Michigan Dioxin Exposure Study, the 29 congeners of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls that have World Health Organization consensus toxic equivalency factors were measured in house dust from 764 homes using a population-based sampling design over selected regions in five Michigan counties. Twenty homes had a total toxic equivalency in house dust that was more than 2.5 standard deviations above the mean (i.e., defined to be outliers). This follow-up investigation describes the outlier house dust measurements and corresponding soil measurements and explores possible sources of these toxins in house dust. The congener distributions in the house dust outliers varied and were dominated (i.e., >50% of the total toxic equivalency) by either polychlorinated dibenzo-p-dioxins (n = 9), polychlorinated dibenzofurans (n = 1), or dioxin-like polychlorinated biphenyls (n = 9). Likely sources of contamination of house dust were identified in only three cases. In two cases, dust contamination appeared to be related to contaminated soil adjacent to the home; in one case, contamination was related to a source within the home (a carpet pad). In most cases, the source(s) of contamination of house dust could not be identified but appeared likely to be related to uncharacterized sources within the homes. [Supplementary materials are available for this article. Go to the publisher's online edition of the Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing a summary of baseline and dust outlier interview questions and tables containing PCB, PCDD, and PCDF concentrations in various samples of house dust and soil.]

Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in the Atmosphere Around the Great Lakes

The atmospheric concentrations of PCDDs and PCDFs were measured in four sites near the shores of the North American Great Lakes. The sites included an urban site (Chicago, Illinois) and three rural/remote sites (Eagle Harbor, Michigan; Sleeping Bear Dunes, Michigan; and Sturgeon Point, New York). Sampling occurred every 24 days between November 2004 and December 2007. The concentration of PCDD/Fs averaged 2.3 +/- 0.2 fg WHO TEQ/m3 at Eagle Harbor, 35 +/- 3 fg WHO TEO/ m3 at Chicago, 7.4 +/- 1.4 fg WHO TEO/m3 at Sleeping Bear Dunes, and 13 +/- 2 fg WHO TED/m3 at Sturgeon Point. The total concentration of the 17 toxic PCDD/F congeners showed a significant seasonal trend at all sites, except Chicago. The date of maximum concentration averaged Dec 6 +/- 35 days, which is consistent with residential heating being an important source of PCDD/Fs to the atmosphere. A significant positive relationship between the logarithm of the total concentration of the 17 toxic PCDD/F congeners and the logarithm of the number of people within a 25 km radius around the sampling site was found. We suggest that urban and industrial areas, which are heavily populated, act as sources of PCDDs and PCDFs to the atmosphere.

A General Indication of the Contemporary Background Levels of PCDDs, PCDFs, and Coplanar PCBs in the Ambient Air over Rural and Remote Areas of the United States

Long-term measurements of the atmospheric concentrations of PCDDs, PCDFs, and coplanar PCBs were taken in rural and remote areas of the United States by the National Dioxin Air Monitoring Network (NDAMN). A total of 21 quarterly sampling moments occurred from June, 1998 to December, 2002 at 34 locations geographically distributed throughout the United States. Sampling sites were located in rural and remote areas to obtain background air concentrations of dioxin-like compounds. Results were reported as the toxic equivalent (TEQ) of the mix of PCDDs/ PCDFs (TEQDF) and the mix of coplanar PCBs (TEQPCB). At the studied rural sites the mean annual TEQDF for each of the NDAMN sampling years was 10.43, 11.39, 10.40, and 10.47 fg m(-3) for 1999, 2000, 2001, and 2002, respectively. There was no statistically significant difference in the rural mean TEQDF air concentrations across the sampling years (at 0.05 level of significance), although the mean concentration in sampling year 2000 increased 10% relative to the other sampling years. The 95th percent confidence interval of TEQDF air concentrations in rural areas of the United States is from 6.4 to 15.4 fg m(-3), indicating there is a 95% probability that the true mean falls within this range. Mean annual atmospheric concentrations (TEQDF) at the remote sites were 1.41, 0.99, 0.7, and 1.07 fg m(-3) in 1999, 2000, 2001, and 2002, respectively, The 95th percent confidence interval of TEQDF air concentrations suggest that the true mean annual atmospheric TEQDF concentration in remote areas of the United States is between 0.1 and 3 fg m(-3). The remote sites have average air TEQDF concentrations that are approximately 10 times lower than those of the rural sites. For the rural sites, there was close agreement in the mean annual air concentrations of coplanar PCBs (TEQPCB) among the years 1999, 2000, 2001, and 2002 (i.e., 0.62, 0.69, 0.59, and 0.7 fg m(-3), respectively). However, as is the case with PCDDs/PCDFs, there was a marked increase (i.e., approximately equal to 13%) in the annual rural mean air concentration in 2000 as compared to the other sampling years. The confidence intervals across the NDAMN sampling years suggests a 95% probability that mean TEQPcB atmospheric concentrations in rural and remote areas of the United States are within the range of 0.5-0.9 fg m(-3) and 0.1-0.5 fg m(-3), respectively. The congener distributional patterns of PCDDs/PCDFs in air were relatively constant at all locations, and match the profile of urban air. We propose the hypothesis that urban areas are regional sources of PCDDs/PCDFs and are affecting atmospheric levels in rural and remote areas of the United States.

Concentration changes of PCDDs, PCDFs, and dioxin-like PCBs in human breast milk samples as shown by a follow-up survey

Breast milk is known to discharge dioxins from the human body. However, to date, no direct comparison has been made of the concentrations of dioxin analogues in breast milk obtained from identical population after successive deliveries. We present here follow-up survey results of PCDDs, PCDFs, and dioxin-like PCBs concentrations in human breast milk samples from 35 women living in Tokyo from whom samples had been obtained and analyzed to determine the corresponding concentrations in the past. The average concentrations of total PCDDs, PCDFs, dioxin-like PCBs were 8.5, 5.5, 11 TEQ pg/g fat for the first samples and 5.4, 4.0, 6.6 TEQ pg/g fat for the second samples, respectively. The degrees of reduction of total PCDDs and total dioxin-like PCBs were higher than that of total PCDFs because 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3′,4,4′,5-PeCB (#126), which were the predominant congeners among PCDDs, PCDFs, and dioxin-like PCBs, respectively, had different degrees of reduction. Moreover we observed a significant increase of the concentrations of PCDDs, PCDFs, and dioxin-like PCBs in samples from three women in this follow-up survey, and the patterns of increased isomers differed among the three samples. It was conjectured that the increase of the concentrations was due mainly to dietary intake between deliveries. It is important for pregnant women to have a balanced diet to mitigate the exposure of infants to these chemicals.

Residues of PCDD, PCDF, and PCBs in some marine organisms in Lake Temsah, Ismailia, Egypt

Residues of PCDDs/F, non-ortho, mono-ortho PCBs, and other PCBs were monitored in the tissues of mullet fish, bolti fish, bivalves and crab taken from Lake Temsah, at Ismailia, Egypt. Results showed that 2,3,7,8 Tetra CDD and 1,2,3,7,8 Penta CDD were the most frequently detected PCDD congeners. Similarly, 2,3,7,8 Tetra CDF, 1,2,3,7,8 Penta CDF and 2,3,4,7,8 Penta CDF were the most frequently detected PCDF congeners. No relationship was apparent between the concentrations of detected PCDDs congeners and the degree of chlorination, except with crab samples in which an increase in the chlorination coincided with a decrease in the concentrations of the congeners. In PCDF congeners, detected residues have had a reversed relationship with chlorination increase. In PCDD congeners, Octa CDD had the highest detected concentrations in the two fish species, while in the bivalves and crab, 2,3,7,8 Tetra CDD had the highest concentrations. The mullet fish had the highest total PCDDs concentration, at 0.398 pg/g fresh weight, followed by crab at 0.395 pg/g fresh weight, then bivalves and bolti fish at 0.187 and 0.062 pg/g fresh weight, respectively. In all the examined organisms, the total concentrations of PCDFs were much higher than the total concentrations of the PCDD congeners. The WHO–TEQ values were 11.92, 39.12, 25, and 3.6 pg/g fresh weight, for mullet fish, bolti fish, bivlaves and crab, respectively. The concentration of the mono-ortho congeners CB 118 was the highest detected of all non-ortho and mono-ortho PCBs congeners, with values of 0.382, 0.022, 0.231 and 0.357 ng/g fresh weight, in mullet fish, bolti fish, bivalves and crab, respectively. The WHO–TEQ concentrations were 0.799, 0.003 pg/g fw, 0.05 pg/g fresh weight, 0.676 pg/g, and 0.799 pg/g fresh weight, for the same species, respectively. The total concentration of PCBs 28, 52, 95, 99, 101, 105, 110, 118, 138, 146, 149, 151, 153, 170, 177, 180, 187 were 6.86 ng/g fresh weight for mullet fish, 0.2 ng/g fresh weight, for bolti fish, 2.72 ng/g fresh weight for bivalves and 2.8 ng/g fresh weight for crab, respectively.

Survey of persistent organochlorine contaminants (PCBs, PCDD/Fs, and PAHs), heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic in food samples from Huelva (Spain): levels and health implications.

Concentrations of PCBs, PCDDs, and PCDFs, heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic have been determined in a great variety of food samples purchased in different markets across the city of Huelva, located in southwestern Spain and under strong industrial activity. All samples analyzed presented concentrations below the maximum allowed by the European Community regarding PCDD/Fs, with the exception of samples within the meat group. An estimation of the daily intake resulted in 1.15 pg of WHO(PCDD/Fs)-TEQ/kg of body weight/day for a 70 kg person and 2.63 pg of WHO-TEQ/kg of body weight/day when PCBs were included, therefore accounting for a similar or even higher percentage than PCDD/Fs and showing the importance of their inclusion in monitoring studies. Meat and meat products, together with vegetable oils and dairy products, were the major food groups contributing to the estimated daily intake. For heavy metals and arsenic, the concentrations found were under the value proposed by European regulations, and estimated daily intakes were well below those proposed by the WHO for all metals investigated. PAHs have been analyzed in food samples from marine origin, values ranging from 8.22 to 71.4 ng/g of fresh weight. Pyrene was the most abundant compound, accounting for >80% in the samples investigated. The most carcinogenic PAHs, such as benzo[a]pyrene and dibenz[a,h]anthracene, were in all cases below the limits of detection. Therefore, the samples analyzed in this survey can be considered as safe with regard to the levels obtained and the in-force legislation.

Dioxins, furans, and non-ortho PCBs in Canadian Arctic seabirds.

This is the first account of PCDDs, PCDFs, and non-ortho PCBs in Canadian Arctic seabirds. Livers and eggs of thick-billed murres, northern fulmars, and black-legged kittiwakes were collected in 1975 and 1993 from Prince Leopold Island in Lancaster Sound, Canada. Detectable concentrations of PCDDs, PCDFs, and non-ortho PCBs were found in all the Arctic seabird samples analyzed. Of the PCDD congeners assayed, only 2,3,7,8-substituted PCDDs were detected in the samples, whereas non-2,3,7,8-substituted PCDFs were found in addition to 2,3,7,8-substituted PCDFs in some of the samples. The predominant PCDD/F congener found in the livers of all three species was 2,3,4,7,8-PnCDF, both in 1975 and 1993. Concentrations of most dioxins and furans decreased in the fulmars and kittiwakes between 1975 and 1993 but increased in the murres. Of the non-ortho PCBs measured, PCB-126 occurred in the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in all three species in both years. The highest concentrations of dioxins and furans as well as the highest TEQ values were found in the northern fulmar livers in both 1975 and 1993. Concentrations of some of the PCDDs and PCDFs are among the highest reported for Canadian Arctic biota.

Polychlorinated dibenzo- p-dioxins, dibenzofurans and polychlorinated biphenyls in polar bear, penguin and south polar skua

Concentrations of 2378-substituted polychlorinated dibenzo- p-dioxins (PCDDs), dibenzofurans (DFs) and non- and mono- ortho-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in livers of polar bears from the Alaskan Arctic and in eggs of Adelie penguin and south polar skua and weddell seal liver, fish and krill from Antarctica. This is one of the first reports to document the concentrations of PCDDs/DFs in polar bear livers from Alaska, and in penguin and skua eggs from Antarctica. Concentrations of total PCDD/DFs in livers of polar bears ranged from 8 to 66 (mean: 26) pg/g, on a lipid weight basis. Concentrations of total PCDD/DFs in Antarctic samples were in the increasing order on a lipid weight basis; weddell seal liver (8.9 pg/g)<fish (11–17 pg/g)<krill (27 pg/g)<penguin eggs (mean: 23 pg/g)<south polar skua eggs (mean: 181 pg/g). Concentrations of dioxin-like PCBs (including two di- ortho congeners) in polar bear livers were in the range of 1080–3930 ng/g, lipid wt. Concentrations of dioxin-like PCBs in Antarctic samples were in the following order on a lipid weight basis; south polar skua eggs (mean: 1440 ng/g)>>penguin eggs (30 ng/g)>seal liver (57 ng/g)>fishes (6.2 ng/g)>krill (0.9 ng/g). Concentrations of 2378-tetrachlorodibenzo- p-dioxin equivalents (TEQs) calculated based on the WHO TEFs were higher in the eggs of polar skua (mean: 344; range: 220–650 pg/g, lipid wt.) from Antarctica than in polar bear livers from Alaska (mean: 120; range: 69–192 pg/g). In general, concentrations of PCDFs were greater than those of PCDDs in polar organisms. 23478-PeCDF is one of the dominant congener found in several samples. Concentrations of TEQs in polar bear livers and skua eggs were close to those that may cause adverse health effects. Dioxin-like PCBs, particularly, non- ortho coplanar PCBs were the major contributors to TEQ concentrations in penguin and skua eggs whereas mono- ortho PCBs accounted for a major portion of TEQs in polar bear livers.