Levels Of Polychlorinated Dibenzofurans Research Articles

DIOXINS, FURANS AND PCBS IN IMPORTED MARINE FISH – CONSUMER EXPOSURE

Background. Dietary guidelines recommend that fish should be consumed at least twice a week due to valuable nutrients they contain, like long-chain, polyunsaturated fatty acids, macro- and microelements, fat-soluble vitamins (mainly D3), amino acids and easily digestible protein. Apart from the benefits, fish consumption becomes a source of toxic compounds including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). The aim of our research was to investigate the levels of PCDD, PCDF and PCB in marine fish imported to Poland and assess the risk for consumers, taking into account the tolerable weekly intake (TWI) of 2 pg WHO TEQ/kg body weight (b.w.). Six fish species were investigated: turbot, mackerel, Atlantic salmon, tuna, pollock and hake. The method employed for the research was isotope dilution technique with high resolution gas chromatography coupled with high resolution mass spectrometry (HRGC-HRMS). Results and conclusions. The highest concentrations for the sum of PCDD/F/dl-PCB were determined in turbot muscles 1.25 pg WHO-TEQ/g of fresh weight (f.w.) and the lowest in pollock, hake and tuna muscles 0.02, 0.03, 0.04 pg WHO-TEQ/g f.w. respectively. Although the tested fish contained low PCDD/F/PCB concentrations compared to the permissible limits, the consumption of the recommended two portions of the most contaminated species resulted in TWI being exceeded even six times for children and two times for adults. Imported turbot, salmon and mackerel are significant sources of dioxins and PCBs for fish consumer.

Associations between Blood Levels of Polychlorinated Dibenzo-p-dioxins/Furans and Polychlorinated Biphenyls with Immune Systems

This study assessed the associations between blood levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) and humoral and cellmediated immune response. The subjects included 53 male workers who had worked at industrial waste incinerators for more than one year. The experimental groups were divided into indoor, field, and incinerator workers according to working process. Data on their lifestyles and occupational characteristics were collected using a survey, and blood levels of PCDDs, PCDFs, and PCBs were analyzed to determine their associations with T-lymphocyte subpopulations and immunoglobulin levels. The results showed that total blood dioxins PCB levels were higher in field and incinerator workers (20.46±22.21 and 21.97±18.05 pg toxic equivalence [TEQ]/g fat, respectively) than in indoor workers (7.69± 2.05 pg TEQ/g fat). CD3+, CD4+, CD8+, and CD4+ CD45RO+ cells among T-lymphocyte subpopulations and IgE and IgM levels among immunoglobulins were slightly higher in field and incinerator workers than those in indoor workers, with no statistical significance (p<0.05). Multiple linear regression analysis with Tlymphocyte subpopulations and immunoglobulins as dependent variables and PCDDS, PCDFs, and PCBs as independent variables showed that PCBs were negatively associated with CD3+ levels (B value=-56.890, 95% confidence interval [CI]=-104.39→ -9.392, p< 0.05) and were positively associated with the CD4+/CD8+ ratio (B value=0.149, 95% CI=0.001-0.297, p<0.05). In addition, PCB levels were associated with IgE (B value=248.703, 95% CI=153.79-343.62, p< 0.01), IgG (B value=52.078, 95% CI=0.344-103.812, p<0.05) and IgM levels (B value=53.153, 95% CI= 32.087-74.219, p<0.01). These findings was obtained from a small number of subjects; hence, further studies including more subjects are necessary to validate the associations between blood levels of PCDDs, PCDFs, and PCBs and immune function.

Declining trends of polychlorinated dibenzo-p-dioxins, dibenzofurans and non-ortho PCBs in Canadian Arctic seabirds

Polychorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) such as the non-ortho PCBs (nPCBs) persist in the environment despite international measures to ban their emissions. We determined congener patterns and temporal trends for PCDDs, PCDFs, nPCBs as well as their toxic equivalents (TEQs) in eggs of thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) sampled from Prince Leopold Island in the Canadian Arctic between 1975 and 2014. The dominant PCDD congeners were 1,2,3,7,8-PnCDD, 2,3,7,8-TCDD and 1,2,3,6,7,8-HxCDD, and the dominant PCDF congener was 2,3,4,7,8-PnCDF. The nPCB profile was dominated by PCB-126. The TEQ profile in the murre eggs was dominated by nPCB-TEQ whereas in the fulmar eggs, the PCDF-TEQ contribution to ΣTEQ was slightly greater than that of nPCB-TEQ. Concentrations of ΣPCDD, ΣPCDF, ΣnPCB and ΣTEQ declined between 1975 and 2014 in both murre and fulmar eggs. Based on TEQ thresholds in the literature for other species, and taking into account the trend towards declining TEQ levels, it is unlikely that current levels of PCDDs, PCDFs or nPCBs are affecting the reproductive success of thick-billed murres or northern fulmars in the Canadian Arctic.

The influence of electrodialytic remediation on dioxin (PCDD/PCDF) levels in fly ash and air pollution control residues

Fly ash and Air Pollution Control (APC) residues collected from three municipal solid waste incinerators in Denmark and Greenland were treated by electrodialytic remediation at pilot scale for 8–10 h. This work presents for the first time the effect of electrodialytic treatment on polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), and how these levels impact on the valorization options for fly ash and APC residue.PCDD/PCDF levels in the original residues ranged between 4.85 and 197 ng g−1, being higher for the electrostatic precipitator fly ash. The toxic equivalent (TEQ) varied ten fold, ranging 0.18–2.0 ng g−1 I-TEQ, with penta and hexa-homologs being most significant for toxicity.After the electrodialytic treatment PCDD/PCDF levels increased in the residues (between 1.4 and 2.0 times). This does not mean PCDD/PCDF were synthesized, but else that soluble materials dissolve, leaving behind the non-water soluble compounds, such as PCDD/PCDF. According to the Basel Convention, PCDD/PCDF levels in these materials is low (<15 μg WHO-TEQ kg−1) and the fly ash and APC residue could eventually be valorized, for instance as construction material, provided end-of-waste criteria are set and that a risk assessment of individual options is carried out, including the end-of-life stage when the materials become waste again.

A cross-sectional analysis of dioxins and health effects in municipal and private waste incinerator workers in Japan.

This cross-sectional study was intended to examine health effects of 678 male workers employed during an 8-yr period from 2000 to 2007 at 36 municipal and private waste incineration plants in Japan. Blood samples were obtained for analysis of concentrations of dioxins including coplanar polychlorinated biphenyls (coplanar PCBs) and evaluation of health effects. Health effects including diabetes were surveyed via a physician’s interview or clinical data from blood samples. There was a certain difference in serum concentrations of polychlorinated dibenzofurans (PCDFs) between the incinerator workers and Japanese general population, although no differences in the concentrations of total dioxins or polychlorinated dibenzo-p-dioxins (PCDDs) were found between the two groups. A few positive correlations between serum levels of PCDDs and PCDFs and the results of laboratory and physiological tests were found, but coplanar PCBs showed significant relations with 14 parameters of the tests. The background serum levels of PCDDs, PCDFs and total dioxins were significantly associated with the prevalence of diabetes. No essential differences in serum concentrations of total dioxins and in prevalence of diabetes between our subjects and the general population suggested that the incinerator workers were marginally exposed to dioxins in the workplace without any recognizable adverse health effects.

PCDD and PCDF concentrations in a traffic tunnel environment

In an effort to understand the fundamental aspects of air quality in traffic tunnel environments, field campaigns were conducted to measure polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and other important pollutants within two traffic tunnels in Nam San (NS) and Hong Ji (HJ) in Korea in 2009 and 2010. The mean concentrations of ∑PCDD/Fs (in fg/m3) at the two tunnel sites were 1270 (±880) and 1200 (±810), respectively. These values were moderately lower than those measured at a non-tunnel urban background site (1350 (±780) fg/m3) — selected as a reference in this study. In addition, seasonal patterns of dioxin concentrations were clearly evident at the traffic tunnels like the urban reference site, showing higher levels during the winter (and spring) than the summer (and fall). The observed seasonal variations were driven by changes in the concentrations of ∑PCDF congeners, while ∑PCDD concentrations showed little seasonality. The results of our study suggest that there is no significant difference in source characteristics between the two investigated tunnel sites and urban location, although the role of gasoline and diesel fueled vehicles are considered as the major source in determining the PCDDs and PCDF levels in a tunnel environment. However, given the relative increase in other important ambient pollutant (e.g. PM10) concentrations over ∑PCDD/Fs in tunnel air (compared to urban background air), the balance of sources in tunnels is clearly different from those in urban air overall.

Levels of PCDDs, PCDFs and dl-PCBs in the blood of childbearing-aged women living in the vicinity of a chemical plant in Tianjin: A primary study

Several studies have suggested that maternal exposure to Polychlorinated dibenzo-p-dioxins (PCDDs), poly-chlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) may affect foetal growth and infant development. The aim of our study was to determine whether the childbearing-aged residents living near a chemical plant have a greater exposure risk. Concentrations of 17 PCDD/Fs congeners and 12 non-ortho and mono-ortho dioxin-like PCBs were measured using HRGC-HRMS in the blood of 30 non-occupational childbearing-aged women living near a chemical plant (Dagu) that had been producing chlorinated pesticides from 1958 to 2004. The factors that influenced the body burden were investigated based on responses to a questionnaire. Levels of PCDD/Fs+PCBs were in the range of 16.43–155.29pg WHO 2005-TEQg−1 lipid. PCDDs and PCDFs contributed 56.72% and 34.44%, respectively, to the total TEQ value. Total WHO-TEQ was approximately tenfold higher in the participants living in the vicinity of the plant (distance: 1.52±0.148km) than in the groups living farther away (distance: 4.93±1.124km). A negative correlation between total WHO-TEQ and distance to Dagu was observed by multiple linear regression models. The data provide basic information for monitoring dioxin-like chemicals in the district and for the future study of the relationship between POPs and pregnancy outcomes.

Yusho patients show increased serum IL-17, IL-23, IL-1β, and TNFα levels more than 40 years after accidental polychlorinated biphenyl poisoning

The Yusho poisoning incident, caused by rice oil contaminated with polychlorinated biphenyls (PCBs), polychlorinated quarterphenyls (PCQs), and polychlorinated dibenzofurans (PCDFs) generated by heat-denatured PCBs, occurred in 1968 in western Japan. Although severe symptoms are rarely observed today, the levels of PCBs and PCDFs in the sera of Yusho patients remain high. The aryl hydrocarbon receptor (AhR), which also acts as a dioxin receptor, is a transcriptional regulator that mediates dioxin toxicity. Recent studies show that dioxin mediates its immune toxic effects via AhR and that AhR activation induces dysregulation of interleukin (IL)-17- producing T (TH17) cells. This study therefore hypothesized that Yusho patients would show dysregulated TH17 cell-mediated immune responses. To validate the hypothesis, levels of IL-17 and IL-22, each secreted by TH17 cells, along with IL-1β and IL-23 were measured in serum samples from 40 Yusho patients and 40 age-matched controls. Levels of tumor necrosis factor (TNF)-α potentially secreted by TH17 cell-stimulated neutrophils and macrophages were also measured. The results indicated that serum IL-17 levels, as well as those of IL-1β, IL-23, and TNFα, were significantly higher in Yusho patients than in controls. In contrast, serum IL-22 levels were significantly lower in the Yusho patients. These results suggest that Yusho patients have dysregulated TH17 cell-mediated immune responses that may be linked to inflammation.

Blood levels of PCDDs, PCDFs, and coplanar PCBs in Yusho mothers and their descendants: Association with fetal Yusho disease

Maternal exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) may result in adverse health effects in their children. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease. Yusho mothers delivered descendants with low birth weights and hyperpigmented skin and mucosa, which are characteristic of fetal Yusho disease (FYD). The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on the development of FYD. Blood samples, obtained from 64 Yusho mothers (117 descendants: 10 with FYD and 107 without FYD), were analyzed for congeners of seven PCDDs, 10 PCDFs, and four coplanar PCBs. We investigated the association between the maternal estimated blood levels of dioxins at delivery and the risk of fetal Yusho disease. We also studied the differences in dioxin blood levels in 24 mother–descendant pairs (5 with FYD and 19 without FYD). The estimated levels of total PCDD TEQ, total PCDF TEQ, total coplanar PCB TEQ, and total TEQ in the maternal blood at delivery were associated with significantly increased risk of FYD. The odds ratios, which present the risk of FYD for a 10-fold increase in blood dioxin, were largest for 1,2,3,6,7,8-HexaCDD (odds ratio=28.6, 95% confidence interval=1.67–489.9, p=0.02). The levels of 1,2,3,6,7,8-HexaCDD in both the Yusho mothers and their descendants with FYD were higher than the levels in those without FYD. These findings suggest that 1,2,3,6,7,8-HexaCDD is the most important causative congener for the development of FYD.

Formation pathways of polychlorinated dibenzofurans (PCDFs) in sediments contaminated with PCBs during the thermal desorption process

Thermal desorption has attracted considerable interest as a remediation technology for the removal of dioxins and polychlorinated biphenyls (PCBs) from contaminated soils and sediments. Although several research groups have confirmed that polychlorinated dibenzofurans (PCDFs) are formed from PCBs during the thermal desorption of sediments contaminated with PCB, the formation pathways remain poorly understood. Herein, thermal desorption has been used to develop a greater understanding of the formation pathways of PCDFs from sediments contaminated with PCBs. PCB decomposition experiments of sediments contaminated with PCBs were performed over 5min at 450°C with a gas composition of 10% O2/90% N2, either in the absence (Run 1) or presence (Run 2–4) of one of three different 13C12-labeled PCB individual standards. The results of Run 1 showed that 99.96% of PCBs and 98.40% of polychlorinated dibenzo-p-dioxins (PCDDs) in the treated sediments had decomposed, whereas the concentration levels of PCDFs had increased by a factor of 31. The addition of different 13C12-labeled PCBs to the sediment sample yielded different 13C12-PCDFs isomer patterns, with formation pathways including loss of ortho-Cl2, loss of HCl involving a 2,3-chlorine shift, loss of ortho-H2 and dechlorination.

Maternal exposure to high levels of dioxins in relation to birth weight in women affected by Yusho disease

Background Studies on the association of maternal exposure to polychlorinated dibenzo- p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) with decreased birth weight in humans have produced conflicting results. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease. Objective The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on birth weight. Methods Blood samples, obtained from 101 Yusho women (190 births) who gave birth after exposure, were analyzed for congeners of seven PCDDs, ten PCDFs, and four non- ortho PCBs. Results Total PCDD TEQ (adjusted beta = − 161.9 g; 95% CI, −265.3 to − 58.6), total PCDF TEQ (adjusted beta = − 105.9 g; 95% CI, −179.5 to − 32.2), and total non- ortho PCBs (adjusted beta = − 178.4 g; 95% CI, −318.3 to − 38.5) levels were inversely associated with birth weight. Significant inverse associations with birth weight were also found for total PCDD TEQ, total PCDF TEQ, and total non- ortho PCB TEQ levels among male, but not female, infants. Significant inverse associations with birth weight were also found for nine congeners among all infants; the adjusted beta coefficients were largest for 1,2,3,6,7,8-HxCDD and smallest for 2,3,4,7,8-PeCDF. Conclusion In the setting of exposure to high levels of dioxins, maternal blood levels of PCDDs, PCDFs and PCBs are associated with lower birth weight in Yusho patients. The association exhibited gender-specific differences, as male infants are more susceptible than females to growth restriction induced by in utero dioxin exposures.

Dietary patterns and blood levels of PCDDs, PCDFs, and dioxin-like PCBs in 1656 Japanese individuals

The association between dietary patterns and blood dioxin levels has not been fully investigated. The present study population consisted of 755 men and 901 women (aged 15–73 years) living in 90 different areas of 30 prefectures of Japan. Dietary habits were assessed by inquiring about the consumption frequency of 28 foods, food groups and beverages. In addition, the blood levels of 29 polychlorinated dibenzo- p-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), and dioxin-like polychlorinated biphenyl (DL-PCBs) congeners were determined by high-resolution gas chromatography/mass spectrometry. The median total toxicity equivalent (TEQ) in the blood, which was calculated on the basis of the toxicity equivalency factors of WHO (2005), was 16 pg TEQ g −1 lipid. Principal component analysis identified five dietary patterns: Healthy diet (high intake of vegetables and fruits); Meat/High fat intake (high intake of meat, meat products, and eggs); Seafood and Alcohol (high intake of fish, shellfish, and alcoholic beverages); Miscellaneous; and Milk products and Alcohol intake (high intake of milk, Milk products, and alcoholic beverages). After adjusting for sex, age, body mass index, and smoking habits, the Seafood and Alcohol pattern scores were significantly related to higher blood levels of total TEQ and PCDDs/PCDFs/DL-PCBs, and the Milk products and Alcohol pattern scores were correlated with higher blood levels of DL-PCBs. More detailed analysis showed that the intake frequencies for alcoholic beverages and seafood were independently and positively associated with total TEQ and the TEQ of PCDFs and DL-PCBs. The association between alcoholic beverage intake and PCDDs was also significant. Analysis of dietary patterns may be useful for identifying the dietary characteristics of individuals with a high dioxin body burden.

Placental DHA and ARA are negatively associated with body burden of polychlorinated dibenzofurans (PCDFs) in pregnant women

N‐3 and N‐6 polyunsaturates, DHA (docosahexaenoic acid, 22:6n‐3) and ARA (arachidonic acid, C20:4n‐6), are important in perinatal development. In contrast, increased body burden of polychlorinated dibenzo‐p‐dioxins (PCDD/Fs) or polychlorinated dibenzofurans (PCBs) lead to impaired neurological development. Because of similar chemical properties and origins of food sources, critical delivery of DHA and ARA to the fetus may also contribute to increased exposures to lipophilic organo‐chlorines. This study aimed to examine relationships between placental PCDD/Fs and PCBs toxic equivalent (TEQ) and DHA/ARA levels in 34 pregnant women from Taiwan. Trends of decreases in DHA (p=0.025) were observed as PCDF TEQ increased. Similarly, placental levels of ARA were reduced (p=0.020) as PCDF TEQ levels increased. In contrasts, DHA and ARA did not correlate with TEQ levels of PCDD or PCBs. After adjusting for confounders, increase in one PCDF TEQ were negatively correlated with decreases in 0.312% (wt%) of placental DHA (beta=−0.312, p=0.027) and 1.021% (wt%) of ARA (beta=−1.021, p=0.025). Thus, increases in body burden of PCDFs may alter placental DHA and ARA status. Mechanisms regarding placental DHA and ARA transfer which may be interfered by dioxin exposure warrant further investigation.

Hierarchical cluster analysis of polychlorinated dioxins and furans in Michigan, USA, soils: Evaluation of industrial and background congener profiles

As part of the University of Michigan Dioxin Exposure Study, soil samples were collected from 766 residential properties near the Tittabawassee River between Midland and Saginaw; near the Dow Chemical Facility in Midland; and, for comparison, in the other areas of Midland and Saginaw Counties and in Jackson and Calhoun Counties, all located in the state of Michigan, USA. A total of 2,081 soil samples were analyzed for 17 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). In order to better understand the distribution and sources of the PCDD/F congeners in the study area, hierarchical cluster analysis (HCA) was used to statistically group samples with similar congener patterns. The analysis yielded a total of 13 clusters, including: 3 clusters among the soils impacted by contamination present in the Tittabawassee River sediments, a cluster comprised mainly of samples collected within the depositional area of the Dow incinerator complex, a small cluster of samples with elevated 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD), and several clusters exhibiting background patterns. The clusters related to the Tittabawassee River floodplain contamination all contained elevated PCDF levels and were differentiated from one another primarily by their relative concentrations of higher-chlorinated PCDDs, a difference likely related to both extent and timing of impacts from Tittabawassee sediments. The background clusters appear to be related to combustion processes and are differentiated, in part, by their relative fractions of TCDD. Thus, HCA was useful for identifying congener profile characteristics in both contaminated and background soil samples.

Polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls levels in human breast milk from different regions of Turkey

Human breast milk offers the optimal nutrition for all infants and have been widely used in biomonitoring programs to assess human exposure to lipophylic environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB). There are no previous reports from Turkey on chemically determined levels of PCDDs, PCDFs, and PCBs in human breast milk expressed as World Health Organization (WHO) toxic equivalents (TEQ). To get an overview of the levels of these contaminants in Turkish human milk, samples from 51 Turkish women living in the Ankara, İstanbul, Antalya, Kahramanmaraş, and Afyon provinces were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) throughout 2007. The mean concentrations of WHO PCDD/F-TEQ and WHO PCB-TEQ of all samples from the five regions were 7.5 and 3.1 pg g −1 on a lipid basis, respectively. PCDD/F concentrations ranged between 0.78 and 29.3 pg WHO-TEQ g −1 fat (1.7 and 36.2 pg WHO-TEQ g −1 fat, respectively, including PCB). Of the five studied locations, the lowest levels of ∑TEQs (PCDD/F + PCB) were found in the Afyon (6.8 pg WHO-TEQ g −1 fat) and the highest in the Antalya (15.6 pg WHO-TEQ g −1 fat) province. The results have been discussed in terms of regions and PCDD/F and PCBs for which analyses had been made. The mean levels of PCDD/Fs and PCBs in Turkish human milk are comparable to that found in other countries.

Effects of sulfur on PCDD/F formation under stable and transient combustion conditions during MSW incineration

SO 2 levels in the flue gas from a laboratory-scale fluidized bed reactor combusting artificial municipal solid waste (MSW) were varied (resulting in four different SO 2:HCl ratios 0, 0.2, 0.7 and 2.7 (by mass)) to study the effects of sulfur on the formation of polychlorinated dibenzo- p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzothiophenes (PCDTs). Sampling was performed simultaneously at three fixed points in the post-combustion zone with temperatures of 400, 300 and 200 °C, under normal combustion conditions and both during and after transient combustion conditions. The findings indicate that sulfur has a greater inhibitory effect on PCDF formation than on PCDD formation and that the PCDD/PCDF ratio in the flue gas depends on both the SO 2:HCl ratio in the flue gas and memory effects arising from transient combustion conditions. The results also indicate that the relative importance of different pathways shifts in the post-combustion zone; condensation products increasing with reductions in temperature and increases in residence time. However, these changes appear to depend on the SO 2:HCl ratio in the flue gas and combustion conditions. Sulfur seems to inhibit the chlorination of PCDFs. A tendency for increased SO 2 levels in the flue gas to increase levels of PCDTs was also detected, but the increases were much less significant than the reductions in PCDF levels.

Levels and Profiles of Polychlorinated Dibenzo-p-Dioxins, Polychlorinated Dibenzofurans, and Polychlorinated Biphenyls in Feedstuffs and Milk From Farms in the Vicinity of Incineration Plants in Tuscany, Italy

Levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorobiphenyls (PCBs) were determined in samples of bovine and ovine milk collected in farms located in the province of Grosseto, Tuscany, in the vicinity of two incineration plants as well as in farms located in areas with presumable background levels of contamination. Samples of feedstuffs of local origin used in the investigated farms were also collected and analysed. The cumulative levels of PCDDs, PCDFs, and dioxin-like PCBs (DL-PCBs) in feedstuffs ranged from 0.25 to 0.61 pg WHO-TE/g fresh weight (fw) in the farms under impact from incinerator emissions and from 0.21 to 0.34 pg WHO-TE/g fw in the control area farms. The sums of the six non-dioxin-like indicator PCB (NDL-PCB) congeners were 0.13 to 9.3 ng/g fw and 1.2 to 1.9 ng/g fw, respectively. In milk samples, the levels detected were 0.71 to 2.9 pg WHO-TE/g fat and 0.52 to 0.59 pg WHO-TE/g fat in farms under impact from the incinerators and in the control area farms, respectively. The corresponding sums of the six indicator PCB congeners were 1.4 to 8.2 ng/g fat and 0.90 to 1.6 ng/g fat. In all samples, contamination levels were below the limits set by the European Community (EC; Commission Directive 2006/13/EC and Commission Regulation 1881/2006/EC.) No relevant differences were found between samples collected in potentially exposed areas and control areas for total toxic equivalents and cumulative analytic levels of PCDDs, PCDFs, DL-PCBs, and NDL-PCBs (p > 0.05, Mann-Whitney U test). Observed levels were in agreement with those found in other countries in areas with background levels of exposure. Congener levels and profiles of PCDDs, PCDFs, and PCBs in feedstuffs and milk samples that were compared describe congener-specific transfer behavior.

Reduced expression of von Hippel–Lindau gene in subjects exposed to polychlorinated biphenyls and dibenzofurans

Polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) are ubiquitous pollutants found in the environment and human tissues. A cohort in Taiwan has undergone follow-up for 24 years after exposure to high levels of PCBs and PCDFs. The incidence of chloracne, hyperkeratosis, and abnormal nail was increased among exposed people. We conducted a study to identify the genes whose expressions were affected by such exposure. A cDNA microarray system consisting of 908 genes was used for pooled serum samples from non-smoking men exposed to PCBs and PCDFs ( n=15) and their matched referents ( n=15) in triplicate. After adjusting for background and housekeeping genes, genes with different expressions between the exposure and reference groups were determined by both regression and cluster analysis, and further confirmed by real-time RT-PCR. The tumor suppressor gene von Hippel–Lindau (VHL) was found to be down-regulated in the microarray analysis. VHL gene expression levels were also found to be positively associated with age, shown by real-time RT-PCR. Upon age adjustment, VHL gene expression was reduced in Yucheng (“oil disease”) subjects as compared to referents. Among Yucheng people, those with abnormal nails had lower VHL expressions than those without abnormal nails. These findings provide new insights into the potential role of VHL in health conditions associated with PCB and PCDF exposures.

Semipermeable membrane device (SPMD) for monitoring PCDD and PCDF levels from a paper mill effluent in the Androscoggin River, Maine, USA

Paper mill effluents may contain polychlorinated dibenzo- p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) that are normally generated due to chlorinated bleaching of pulp and paper. We used the semipermeable membrane device (SPMD) to monitor PCDD/F levels upstream and downstream of a paper mill on the Androscoggin River, in Jay (ME). Following the 36 day deployment, SPMD dialysis and cleanup, the samples were analyzed by HRGC/HRMS. Total concentrations of PCDD/Fs in SPMDs (sum of all tetra-through octachlorinated congeners) ranged from 4.71 pg g −1 to 26.26 pg g −1. Five out of the targeted 17 toxic congeners were detected, including: 2,3,7,8-TCDF; 1,2,3,7,8-PeCDF; 2,3,4,7,8-PeCDF; 1,2,3,4,6,7,8-HpCDD and OCDD. Permeability reference compounds (PRCs) were used for in situ calibration of the SPMD sampling rate ( R s). In all sites, water concentrations were the highest for OCDD (0.081–0.103 pg l −1), and the lowest for 1,2,3,7,8-PeCDF (0.005–0.009 pg l −1). There was not a consistent pattern of upstream–downstream gradient in the PCDD/F levels. This suggested that processes other than the mill in Jay (multiple sources, river dynamics) governed the flux of PCDD/Fs in the sampling locations. The SPMD results were validated by comparison to other studies on the Androscoggin River and elsewhere, confirming the potential of the device as a useful monitoring technique for PCDD/Fs in large river systems.

Serum levels of PCDDs, PCDFs and PCBs in non-occupationally exposed population groups living near two incineration plants in Tuscany, Italy

A pilot study was carried out in Tuscany, Italy, to provide preliminary information on the concentrations of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorobiphenyls (DL-PCBs), and selected non-dioxin-like PCBs (NDL-PCBs) in groups of subjects living in the vicinity of two incineration plants. Seventy-four volunteers were enrolled from areas identified as under a potential impact from incinerator emissions and from not exposed areas. No significant differences were observed between subjects living in the two types of areas. Total concentrations of PCDDs, PCDFs, and DL-PCBs resulted to be in the range 23–30 pg WHO–TEQ g −1, lipid base, for subjects in the 27–54 year age groups, while concentrations increased to 40–44 pgTEQ g −1 for the two 55–67 year age groups. The levels of PCDDs and PCDFs were in good agreement with those observed for unexposed population groups in Italy, while the contribution to total TEQ from DL-PCBs was appreciably higher than those currently observed in the general population in Italy and other countries. As to NDL-PCBs, serum levels of the six “indicator” congeners were in the range 240–300 ng g −1, lipid base, for subjects in the 27–54 year age groups. A raise in NDL-PCB body burden (430–470 ng g −1, lipid base) was observed for the two 55+ year age groups, in agreement with the expected age-dependent increase. The findings from this study do not show an incremental exposure to PCDDs and PCDFs in the samples from subjects living around the two incineration plants, whereas PCB congener profiles in all samples suggest a possible impact on the area of interest of industrial activities from near industrial settlements.