Total TEQ Research Articles

Biodegradation of dioxin-contaminated soil via composting: Identification and phylogenetic relationship of bacterial communities

Aerobic composting was found to be successful in biodegrading dioxin-contaminated soil with a removal efficiency of 81% after 35 days. The highest biodegradation rate was observed during the thermophilic phase, where bacterial activity was at its peak. The presence of dioxins in the compost was also observed to affect the bacterial community structure. Based on the 16S rRNA sequences, the results indicated that Bacilli, Actinobacteria, Clostridia , Gammaproteobacteria , and Alphaproteobacteria were the main classes in the bacterial community. Bacterial species containing catechol 2,3-dioxygenase (C23O) and angular dioxygenase encoding genes were searched and identified using BRENDA database and previous studies. These genes code for the key enzymes in dioxin biodegradation pathways. Ten dioxin-degrading species and three potential dioxin-degrading species ( Pseudomonas sp., Burkholderia sp., and Ralstonia sp.) were identified in our compost. From the phylogenetic tree, candidate bacterial species for future dioxin degradation studies were also identified, with 99% 16S rRNA gene sequence similarities to previously reported dioxin-degrading species. These results provide novel insight into the bacterial community structure in the compost samples and phylogenetic relationship of the dioxin-degrading microorganisms that would be of benefit in pilot-scale composting of dioxin-contaminated soil. • After 35 days, the aerobic composting process biodegraded 81% of total TEQ dioxins. • Bacilli were the most abundant class of compost samples during the thermophilic phase. • Relationship of species with C23O and angular dioxygenase encoding genes were analyzed. • Ten dioxin-degrading and three potential species were identified in our compost.

Estimated PCDD/F TEQ and total TEQ concentrations in the serum of 7–10 year old Finnish children

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants that have detrimental health effects. As people are exposed to them mainly through the diet, EU has set maximum food dioxin and PCBs levels. EFSA CONTAM Panel made new risk assessment in 2018 that lowered the tolerable weekly intake (TWI) from 14 pg-TEQ/kg bw/week to 2 pg-TEQ/kg bw/week. Critical effect was decreased semen count at the age of 18–19 years if serum total TEQ at the age of 9 years exceeded the No Observed Adverse Effect Level (NOAEL) of 7 pg/g lipid. However, it is largely unknown to what extent NOAEL is exceed in European boys currently. We thus measured PCBs from small volume of serum in 184 Finnish children 7–10 years of age. To estimate the TEQ levels of children from measured PCB levels, we used our existing human milk PCDD/F and PCB concentrations to create a hierarchical Bayesian regression model that was used to estimate TEQs from measured PCBs. For quality control (QC), three pooled blood samples from 18 to 20 year old males were measured for PCDD/Fs and PCBs, and estimated for TEQs. In QC samples measured and estimated TEQs agreed within 84%–106%. In our estimate for 7–10 year old children, PCDD/F TEQ exceeded NOAEL only in 0.5% and total TEQ in 2.7% of subjects. Risk management following the decreased TWI proposed by the CONTAM Panel should be carefully considered if total TEQ in children is already largely below the NOAEL.

Assessment of PCDD/Fs, dioxin-like PCBs and PBDEs in Mediterranean striped dolphins

Bio-accumulation of high levels of persistent organic pollutants represent a serious conservation concern for Mediterranean marine odontocetes. In this study, blubber samples from 10 striped dolphins (Stenella coeruleoalba) stranded along the Italian coasts during 2015–2016 were analyzed. All specimens showed dl-PCBs > PBDEs ≫ PCDD/Fs. Median concentrations were 1820 ng/g l.w., 456 ng/g l.w. and 23.9 pg/g l.w., respectively. dl-PCBs accounted for 93.3% of total TEQs. PBDE concentrations suggest that the Mediterranean basin may be considered a hotspot for organobromine compounds. OCDD did not represent the greatest contributor to PCDD/Fs profile, most likely due to a change in dioxin environmental sources in the last two-three decades. Despite international regulations, the present study emphasized that POP exposure levels in Mediterranean striped dolphins have not declined significantly in recent years. Toxicological and risk assessment studies on this sentinel species may provide an early indication of potential adverse health effects on Mediterranean ecosystems.

Spatial distribution and source identification together with environmental health risk assessment of PAHs along the coastal zones of the USA.

Identification of polycyclic aromatic hydrocarbons (PAHs) sources and hot spot areas are the primary driving forces for their control in the environment. This study was performed in the US coastal areas to identify the major sources of PAHs and investigate the spatial distribution associated with carcinogenic PAHs (CPAHs) using a novel spatial forecasting method for the first time in environmental sciences. Diagnostic ratios of PAHs demonstrated the predominance of pyrogenic sources compared to petrogenic sources within the area of study. Five factors were extracted using positive matrix factorization method with respect to 16 priority PAHs, indicating the dominance of pyrogenic versus petrogenic sources mainly as a result of combustion products in the environment. The total toxic benzo[a]pyrene equivalency (TEQ) for all CPAHs ranged from 0.03 to 10,456ng/g containing a mean of 199ng/g. The contribution of each CPAH to the total TEQ varied according to the following order: benzo[a]pyrene (65.4%), dibenzo[a,h]anthracene (12%), benzo[b]fluoranthene (10%), benzo[a]anthracene (6%), indeno[1,2,3-c,d]pyrene (6%), benzo[k]fluoranthene (0.5%) and chrysene (0.1%). The spatial analysis by fixed rank kriging (FRK) highlighted a similar pattern associated with all of the CPAHs with higher values in the northern part of New Jersey State. In particular, Passaic River, Upper New York/New Jersey Harbor, Mullica River, Schuylkill River, Newark Bay and Christina River were the most contaminated stations regarding the observed values of CPAHs.

Dioxins and PCBs – Environment impact on freshwater fish contamination and risk to consumers

This paper reports polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCB) concentrations in sediment and fish collected from Polish rivers in agricultural and urban areas and the associated risk for fish consumers. Total TEQ concentrations in fish muscles were in the range 0.29–7.25 pg WHO-TEQ g−1 wet weight (w.w.). Generally, levels in sediment and fish muscles were low except for in the Vistula River in Cracow. In this fishery, total TEQ concentrations in sediments were high at 7.84 ± 1.73 pg WHO-TEQ g−1 dry matter and fish were non-compliant with Commission Regulation (EU) 1259/2011/EU (3.5 pg WHO-TEQ g−1 w.w. for PCDD/F and 6.5 pg WHO-TEQ g−1 w.w. for total TEQ). Dioxin congener profiles in sediments were dominated by OCDD, and in the most contaminated fisheries in Cracow additionally by OCDF and 1,2,3,4,7,8-HxCDF. The most accumulated PCDD/Fs congeners in fish were 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF except in Cracow, where 1,2,3,4,7,8-HxCDF dominated. The most abundant dioxin-like PCB (DL-PCB) and non-dioxin-like PCB (NDL-PCB) congeners were PCB 118 and PCB 153, respectively, both in sediment and fish muscles. The levels and profiles of contaminants in fish reflected the pollution of their environment. To characterize the potential health risk associated with dioxin and DL-PCB intake, doses ingested in two 100g portions of fish by adults and children were calculated and expressed as percentages of Tolerable Weekly Intake (TWI). Both values of TWI – that of 14 pg WHO-TEQ kg−1 b.w. and the newer value of 2 pg WHO-TEQ kg−1 b.w. established by the EFSA in November 2018 – were taken into account.It appears that regular consumption of some species could pose a health risk, especially those from urban areas.

Emission characteristics of dl-PCNs, PCDD/Fs, and dl-PCBs from secondary copper metallurgical plants: Control technology and policy

This study investigated the characteristics of dl-PCNs, PCDD/Fs and dl-PCBs emitted from two typical secondary copper metallurgical plants processing copper sludge equipped with different sets of air pollution control devices (APCDs). Results indicated that the emission factors of dl-PCNs and PCDD/Fs of plant A are 0.00775 and 1.09 μg TEQ/ton, respectively, which are remarkably lower than those of plant B (3.12, 181 and 25.5 μg TEQ/ton for dl-PCNs, PCDD/Fs and dl-PCBs, respectively). Dl-PCNs contributed 0.7–2.7% of total TEQ for flue gases and up to 2.6% of TEQ for ash samples. The TEQ concentration of dl-PCNs in fly ash individually exceeds the regulated level of 1 ng TEQ/g regulated by Taiwan EPA, indicating that emission and discharge of dl-PCNs should be regulated. The combination of semidry scrubber and activated carbon injection (ACI) + baghouse (BH) is effective for simultaneous removals of dl-PCNs and PCDD/Fs in plant A; while the combination of cyclone, secondary combustion chamber, ACI + BH and wet scrubber (WS) is not optimal for removing dl-PCNs, PCDD/Fs and dl-PCBs. Memory effect occurring within BH and WS is responsible for low removal efficiencies of these POPs in plant B. This study suggests appropriate APCDs for simultaneous removal of three POP groups and recommends the inclusion of dl-PCNs in emission standard.

Free-range chicken eggs as a bioindicator of dioxin contamination in Vietnam, including long-term Agent Orange impact

Abstract PCDD/Fs contamination of free-range chicken eggs and soils from private Vietnam households was studied. The possibility of using free-range eggs as bio-indicators of dioxin contamination was considered as the soil-chicken-egg exposure pathway is considered to be the most sensitive exposure pathway of dioxins in soils to humans. A large territory from Dong Nai province in the south to Lao Cai province in the north was covered by the research. All analyses were performed by HRGC-HRMS method. PCDD/Fs levels in eggs from the majority of southern households exceeded the EC limit for eggs and egg products (2.5 pg WHO-TEQ2005 g−1 lipid). Total TEQs ranged from 0.4 to 361 pg WHO-TEQ2005 g−1 lipid in eggs and from 0.1 to 1272 pg WHO-TEQ2005/g in soil. 2,3,7,8-TCDD contribution was statistically significantly higher in both eggs and soils in sprayed with Agent Orange areas, indicating its long-term impact. In order to assess within site variation, a total of 62 individual eggs from 14 private households were analyzed. Mean relative standard deviation of total TEQ values in individual eggs within the separate households was 27%. Rather good correlation of PCDD/Fs concentration in eggs and respective soils was observed for all dioxin congeners and for hexa- and hepta-furans (except for 1,2,3,7,8,9-HxCDF). Higher bioaccumulation for lower chlorinated congeners was confirmed. The current study of using eggs as bio-indicators for large POPs contaminated sites may be suggested as a policy approach to evaluate human exposure to dioxin/POPs contaminated sites for known or suspected contaminated areas.

Comprehensive assessment of legacy organic contaminants and trends in lake trout from Cayuga Lake, New York: 2011–2017

A seven-year assessment of lake trout contaminants and statistical trend modeling was conducted on Cayuga Lake, New York as the reference monitoring site for the USEPA Great Lakes Fish Monitoring and Surveillance Program (GLFMSP). In all, over 200 individual compounds including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), polychlorinated napthalenes (PCNs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were monitored for the 2011–2017 study period. Legacy contaminants such as PCBs, OCPs, and PBDEs dominate the whole-fish lake trout contaminant profile in the 24–147 ng/g mean concentration range. Total dioxin-like contaminants monitored included PCDD/Fs, CP-PCBs, and PCNs with a mean concentration range of 2.0–516 pg/g. TEQ concentrations for the dioxin-like compounds ranged between 0.3 and 5.3 pg-TEQ/g, and total TEQ averaged 7.2 pg-TEQ/g for whole-fish lake trout. Contaminant trends were modeled using log-linear correlations for both whole-fish lake trout and lake trout eggs. All select compounds modeled for whole-fish lake trout showed significant decreases (average −53.4%) over the study period. Tissue residue guidelines for the protection of wildlife were uniformly exceeded for both mammals and birds based on mean 2011–2017 total TEQ concentrations measured. All lake trout skin-on fillets from Cayuga Lake analyzed exceed the USEPA human health screening value of 0.15 pg-TEQ/g-ww. Whole-fish lake trout from Cayuga Lake have significantly lower mean total TEQs (6.5 pg-TEQ/g) as compared with the average total TEQ in the Great Lakes (range: 21.9–50.8 pg-TEQ/g) (U = 10.000, p < 0.001), although rates of contaminant decline, contaminant ratios, and half-life (t1/2) are comparable.

Association between prenatal exposure to organochlorine pesticides and the intelligence at 7 years old children

TPS 731: Neurological effects in children, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Organochlorine pesticides (OCPs) are environmental contaminants that persist in the environment, and previous studies have shown associations between prenatal OCP exposure and subsequent neurodevelopment. However, it is still not clear how long this association could be prolonged. A prospective birth cohort study was conducted to examine the associations between prenatal OCP exposure and intelligence at 7 years children. Blood samples were analyzed using gas chromatography/mass spectrometry techniques to quantify 29 OCPs. The Wechsler Intelligence Scale for Children 3rd edition (WISC-III) was used to assess intelligence of children, which provided Verbal IQ (VIQ), Performance IQ (PIQ), and Full Scale IQ (FIQ). The test also has four subscales to represent more narrow domains of cognitive functions. We analyzed data from 95 singleton children without congenital anomalies, and who had both maternal OCP levels and WISC-III data. After multiple regression analysis adjusted by maternal age, education, parity, blood sampling period, children sex, we found OCPs had negative association with FIQ and PIQ, and positive association with VIQ. When prenatal total dioxin TEQ level was added to adjustment, however, positive associations between OCPs and VIQ disappeared, and negative association between FIQ and p.p’-DDD (β= -10.8: 95% Confidence Interval: -18.6 -2.9), p.p’-DDT (-19.26: -31.4 -7.1), and between PIQ and p.p’-DDD (-10.8: -18.6 -2.9), p.p’-DDT (-19.3: -31.4 -7.1) were remained. In the same analysis for subscale, the Perceptual Organization Index decreased with p.p’-DDD (-12.2: -20.2 -4.3), p.p’-DDT (-22.4: -34.6 -10.2), and Parlar-26 (-11.2: -21.7 -0.7). Additionally, Freedom from Distractibility Index, which reflects attention or working memory, decreased with p.p’-DDD level (-8.8: -16.8 -0.8). Although careful consideration is needed regarding other influential factors, and causal relationship between prenatal exposure to low-level OCPs and cognitive function of school aged children, prenatal OCP level may have prolonged effect on the children’s intelligence, especially perception, and attention or working memory.

Association of dioxin in maternal breast milk and salivary steroid hormone levels in preschool children: A five-year follow-up study of a Vietnam cohort

Recent studies have found elevated dioxin levels inside some former US military air bases in Vietnam, known as hotspots. The aim of the present study was to evaluate the association of dioxin exposure and steroid hormone in preschool children in Vietnam. In 2010, 2011, 52 primiparae mother–infant pairs in the hotspot and 52 pairs in a non-exposure region were enrolled. For the final analysis, 26 vs 26 pairs were selected, who participated at all three surveys. Univariable and multivariable linear regressions were used to evaluate associations between hormone and dioxin congeners. Geometric mean total TEQ of PCDD/DFs in the hotspot were significantly higher than in the non-exposure region, 8.7 and 3.4 pg TEQ/g lipid, respectively. In the hotspot, salivary dehydroepiandrosterone (DHEA) was significantly higher in 1-year-old children (Boys = 123 pg/mL, Girls = 120 pg/mL) than in the non-exposure region (Boys = 28 pg/mL, Girls = 27 pg/mL). In contrast, DHEA was significantly lower in 5-year-old children (Boys = 70 pg/mL, Girls = 106 pg/mL) in the hotspot than in the non-exposure region (Boys = 496 pg/mL, Girls = 654 pg/mL). Salivary testosterone was significantly lower in the hotspot (Boys = 1.9 pg/mL, Girls = 1.9 pg/m; Boys = 1.0 pg/mL, Girls = 1.1 pg/mL, respectively) than in the non-exposure region (Boys = 3.7 pg/mL, Girls = 3.8 pg/m; Boys = 5.7 pg/mL, Girls = 7.0 pg/mL, respectively) at 3 years and 5 years of age. Higher levels of highly chlorinated dioxins in breast milk were associated with higher DHEA in 1-year-old and lower DHEA and testosterone levels in 5-year-old children. Our findings indicated that dioxins were associated with changes of DHEA and testosterone levels in preschool Vietnamese children.

Formation and toxicity of polycyclic aromatic hydrocarbons during CaO assisted hydrothermal carbonization of swine manure

The effects of temperature and CaO introduction on polycyclic aromatic hydrocarbons (PAHs) contents, distribution patterns and toxicity of the products from hydrothermal carbonization (HTC) of swine manure (SM) were investigated in this study for the first time. The results indicated that increasing temperature decreased total PAHs content of the hydrochar, while the PAHs toxicity firstly decreased and then increased during HTC of SM. For the aqueous product, the total PAHs content and toxicity gradually decreased with increasing temperature. CaO introduction during HTC of SM significantly suppressed the PAHs formation and promoted the transformation from higher molecular weight PAHs into lower molecular weight PAHs in HTC products, resulting in the remarkably decreased content and toxicity of PAHs. The lowest total PAHs content (1428.57 μg/kg) and TEQ value (21.33 μg/kg) of the hydrochar were obtained by 15% CaO introduction at 200 °C and 180 °C, respectively, and compared to SM, they were decreased by 73.73% and 79.51%, respectively. Moreover, 3-ring PAHs were the predominant PAHs in HTC products regardless of CaO introduction. The present study demonstrated that CaO assisted HTC at temperature lower than 220 °C was effective to reduce the total content and toxicity of PAHs in SM, and the prepared hydrochar was a promising soil amendment in view of the elimination of PAHs toxicity.

Polychlorinated Dibenzo-p-Dioxins, Polychlorinated Dibenzofurans, and Dioxin-Like Polychlorinated Biphenyls in Umbilical Cord Serum from Pregnant Women Living Near a Chemical Plant in Tianjin, China.

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (dl-PCBs) are bioaccumulative compounds that may affect fetal growth and infant development. The aim of this study was to determine whether the pregnant women living near a chemical plant in Tianjin had a risk of exposure to dioxins. Concentrations of PCDD/Fs and dl-PCBs in 24 umbilical cord serum samples collected from pregnant women were measured using a high-resolution gas chromatograph with a high-resolution mass spectrometer (HRGC-HRMS) and an isotopic dilution method. The levels of ∑(PCDD/Fs + dl-PCBs) were in the range 476–8307 pg·g−1 lipid, with a mean of 3037 pg·g−1. The mean World Health Organization toxicity equivalent (WHO-TEQ) for PCDD/Fs and dl-PCBs was 14.0 and 2.14 pg·g−1 lipid, respectively. The PCDD/Fs and dl-PCBs contributed 86.7% and 13.3%, respectively, to the total TEQ. The octa-CDFs and penta-CBs were predominant for the PCDD/Fs and dl-PCBs, accounting for 57.6% and 74.3%, respectively. Several PCDD/F and dl-PCB congeners were highly correlated, such as PCB 105 and PCB 118 (r = 0.982, p < 0.001). Although the results hint at decreasing trends for PCDD/F and dl-PCBs by comparison with a similar study in Tianjin, a total TEQ of 41.7% of study participants had a body burden that exceeded the biomonitoring equivalents for dioxins. It was shown that pregnant women and infants had a health risk of exposure to dioxins.

Organohalogen Contamination in Vietnamese Women Electronic Waste Recyclers Living and Working in Rural Northern Vietnam

Introduction:Electronic waste (e-waste) is increasing worldwide and is often shipped from developed to developing countries. Many of these products contain toxic levels of metals, organics, etc. When unsafe recycling approaches or methods are used (e.g., burning wire to reclaim copper), the resulting occupational exposures can adversely affect the health of e-waste recyclers.Aim:To identify which polybrominated and which polychlorinated dibenzo-p-dioxins/furans are higher in electronic waste recyclers when compared to non-recyclers.Methods:This study focused on female e-waste recyclers and non-recyclers that live in rural northern Vietnam. Whole blood, urine, and serum of forty e-waste recyclers and twenty Vietnamese comparisons and were evaluated for metals, organics, and dioxin-like exposure by the Center for Disease Control. This paper will be reporting on serum organohalogens. The Vietnamese cohorts were compared to the U.S. general population, using the National Health And Nutrition Examination Survey. TEQ’s were calculated and statistical significance was determined using Wilcoxon Rank Sum Test. The IRB of the University of Texas Health Science Center Houston and the Ethics Board of the Hanoi School of Public Health oversee this study.Results:12378-PeCDF, 123678-HxCDD, 123678-HxCDF, and 1234678-HpCDF were significantly different between recyclers and Vietnamese comparisons. Total dioxin TEQ was higher in e-waste recyclers than comparisons. Of the polybrominated dioxins and furans, 12378-PeBDD and 2378-TeBDF were significantly different between recyclers and comparisons.Discussion:This is the only study with data on polybrominated dibenzo-p-dioxins/furans in female electronic waste recyclers from rural Northern Vietnam, and the first to describe serum levels of both polychlorinated and polybrominated dibenzo-p-dioxins/furans in Vietnamese female e-waste recyclers. Improved occupational protocols may reduce potential adverse health effects such as cancer, endocrine, reproductive, developmental, and other disorders.

Background levels of dioxin-like polychlorinated biphenyls (dlPCBs), polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs & PXDD/Fs) in sera of pregnant women in Accra, Ghana

Human exposure data on dioxins and dioxin-like compounds (DLCs) in Ghana are limited. Based on health risks associated with dioxins and DLCs, the impact of maternal body burdens on foetal exposure is significant. This is the first study that assesses polychlorinated, polybrominated and mixed halogenated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs and PXDD/Fs), and dioxin-like polychlorinated biphenyls (dlPCBs) in sera of primiparous Ghanaians. Our sample selection includes 34 participants from two municipalities (Accra and Tema), and explores contributions from environmental and dietary exposures using questionnaire data. Sample preparation involved C18 solid phase extraction, purification with acidified silica and lipid removal cartridges, and detection with gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry. The calculated average toxic equivalent concentration was 5.3 pg TEQ/g lw, with contributions from dlPCBs (1.25 pg TEQ/g lw), PCDD/Fs (3.10 pg TEQ/g lw), PBDD/Fs (0.49 pg TEQ/g lw) and PXDD/Fs (0.50 pg TEQ/g lw). The calculated total TEQ concentration was lower than background TEQ concentrations reported in sera of pregnant women globally. Positive correlations were obtained for total dioxins and DLC concentrations with age and Body Mass Index (BMI). Dietary intake of seafood and dairy products had a strong influence on PCDD/F and dlPCB concentrations. Statistically significant differences were observed for dioxins and DLCs in participants from Accra (in close proximity to Agbogbloshie e-waste site) and Tema. Given the significant TEQ contribution of PBDD/Fs and PXDD/Fs (~20%), it is essential to explore these classes of dioxins and DLCs in future biomonitoring studies as they may pose health risks, and add extra diagnostic information in source exposure investigations.

Characteristics of PCDD/Fs in soil and sediment samples collected from A-So former airbase in Central Vietnam

A-So airbase, located in A-Luoi Valley — Central Vietnam, is a former military base occupied by US Special Forces between 1963 and 1966. The storage of Agent Orange in A-So airbase during the Vietnam War now poses a high potential for PCDD/F contamination in soils and sediments. In order to evaluate the occurrence and characteristics of PCDD/Fs in A-So former airbase, which has been reserved for a long time and suffered almost no significant anthropogenic impacts, soil and sediment samples were collected from 40 sites of two adjacent zones A and B in an area of 160,000 m2. Seventeen 2,3,7,8-substituted PCDD/Fs were analyzed using HRCG/HRMS (US EPA method 1613). Results indicate that concentrations of PCDD/Fs measured in zone A ranged from 95.0 to 4534 ng kgdw−1 (4.58 to 746 ng TEQ kgdw−1), while those in zone B were in the range of 80.8–4150 ng kgdw−1 (2.70–89.0 ng TEQ kgdw−1). The concentrations of PCDD/Fs observed in zone A are higher than those in zone B, suggesting that PCDD/Fs could be transported from zone A to zone B through surface soil erosion and runoff events. The main contributor to the total TEQ concentration was 2,3,7,8-TCDD, which was the indicator of Agent Orange contamination, accounting for 91 ± 9% and 72 ± 17% of the total TEQ concentrations measured in zones A and B, respectively. Comparison of PCDD/F concentrations in different soil layers reveals that the topsoil layer (at depth < 1 m) contributed 81–95% to the total PCDD/Fs in the study area, indicating that future remediation projects should focus on this topsoil layer. Since PCDD/F contamination in A-So airbase has not significantly improved for the last 20 years, remediation projects are urgently needed in order to mitigate the negative impacts of PCDD/F contamination on human health and wellbeing.

PCDD/F Emission from Pharmaceutical Industries

ABSTRACT The emission levels and profiles of unintentionally formed polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) were comprehensively investigated in flue gases released from 16 regenerative thermal oxidizers (RTOs) belonging to 8 pharmaceutical industries (PIs) in China. The PCDD/F total concentrations and TEQ values with great variation, ranged from 0.148–9.051 ng m–3 and 0.008–0.255 ng I-TEQ m–3, respectively. Emission levels of most RTOs were lower than the emission standard of China (0.1 ng I-TEQ m–3), yet two were above 0.25 ng I-TEQ m–3. The PCDD/F concentrations in flue gases were in the order of HWIs > MSWIs > PIs. OCDD was identified to be the dominant congener in most RTOs, accounting for 21–71 wt%. In addition, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF and 1,2,3,4,7,8-HxCDF were effective TEQ indicators, especially for 2,3,4,7,8-PeCDF with a Pearson correlation coefficient of 0.995. The estimated annual emission amount (AE) of PCDD/Fs for PIs in this study was in the range of 0.435–11.016 mg I-TEQ year–1, with an average of 2.65 mg I-TEQ year–1. It was estimated that 19.96 g I-TEQ of PCDD/Fs were emitted from Chinese PIs to atmosphere in 2017. This is the first comprehensive investigation on the unintentional emissions of PCDD/Fs from PIs in China.

Emission of Unintentionally Produced Persistent Organic Pollutants from Some Industrial Processes in Northern Vietnam.

Concentrations of PCDD/Fs, dioxin-like PCBs (dl-PCBs), PeCB and HCB were determined in flue gas, fly ash and bottom ash samples collected from brick production, steel production, and zinc production plants, an industrial waste incinerator and a medical waste incinerator in northern Vietnam to understand the contamination levels, accumulation patterns and extent of emission. Total TEQs concentrations of PCDD/Fs and dl-PCBs in flue gas and ash samples from these industrial plants ranged from 0.304 to 50.55pg/Nm3 and 1.43 to 440pg/g, respectively. PeCB and HCB residues in flue gas samples ranged from 0.839 to 46.59ng/Nm3 and 1.16 to 60.5ng/Nm3, respectively. The emission factors of 4.8-740 ngTEQs/tonne for PCDD/Fs and dl-PCBs, 67.12-240.7µg/ton for PeCB and 11.64-889.3µg/ton for HCB were obtained in flue gas samples. This is among the first reports on the emission factor of PCDD/Fs, dl-PCBs, PeCB, HCB in brick production, zinc production and waste incineration in Vietnam.

Co-combustion of Shenmu coal and pickling sludge in a pilot scale drop-tube furnace: Pollutants emissions in flue gas and fly ash

Co-combustion of Shenmu coal and pickling sludge was carried out in a pilot scale drop-tube furnace. The effect of different pickling sludge amounts on the NOx, SO2, HCl, HF, PCDD/Fs and gaseous heavy metals emissions and fly ash behaviors was studied. The burnout section furnace temperature was 1250 °C, and the pickling sludge amount ranged from 0 to 20 wt%. The result indicates that the co-combustion of <20 wt% pickling sludge did not reduce the combustion efficiency. With increasing pickling sludge amount in the blended fuels, NOx and HCl emission concentrations were basically stable; however, those of SO2 and HF increased obviously. The total TEQ of PCDD/Fs emission was basically positively correlated to the sludge amount in the blended fuels, and the gaseous heavy metals emissions also increased obviously with the addition of sludge. To meet the national standard (GB18484-2001) on heavy metals emissions, the pickling sludge amount used in co-combustion must be <10 wt%. According to national standard (GB 16889-2008), because of the high leaching concentrations of heavy metals Cr, Ni, Cu and Pb, the co-combustion fly ash needs further treatment before being landfilled disposal as common waste.

Evaluation of PCDD/Fs, dioxin-like PCBs and PBDEs in sperm whales from the Mediterranean Sea

Numerous studies to date have reported concentrations of Persistent Organic Pollutants (POPs) in different marine mammal species worldwide. Yet data on sperm whales are scarce from rich and unique biodiverse areas such as the Mediterranean Sea. This work aimed to assess levels of dioxin-like polychlorinated biphenyls (dl-PCBs), polybrominated diphenyl ethers (PBDEs), and polychlorodibenzo-p-dioxins and furans (PCDD/Fs) in blubber of sperm whales stranded along the Italian coast between 2008 and 2016. POP mean concentrations (dl-PCBs: 6410 ng/g l.w.; PBDEs: 612 ng/g l.w.; PCDD/Fs: 57.8 pg/g l.w.) were mostly in line with what has been previously reported on the same species in the Mediterranean environment and tended to be higher than those reported from other geographical regions. The relative abundance followed the order dl-PCBs > PBDEs ≫ PCDD/Fs. Interestingly, the non-ortho dl-PCB pattern (126 > 169 > 77) was similar to that described in other studies worldwide and different from what is described in its main prey. This could be linked to particular metabolic activities in sperm whales against these highly toxic contaminants. Total TEQs ranged from 275 to 987 pg/g l.w. and showed the pattern Σnon-ortho-dl-PCBs > Σortho-dl-PCBs > PCDDs > PCDFs, with PCBs' contribution about 96%. These findings highlight the high abundance of PCBs still found in the Mediterranean environment despite having been banned for decades. All sperm whales analyzed in this study surpassed the threshold of 210 pg WHO-TEQ/g l.w. proposed as starting point of immunosuppression in harbour seals; a level of contamination that may have contributed to an impairment of their immune system.

Risk for animal and human health related to the presence of dioxins and dioxin-like PCBs in feed and food.

The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of dioxins (PCDD/Fs) and DL‐PCBs in feed and food. The data from experimental animal and epidemiological studies were reviewed and it was decided to base the human risk assessment on effects observed in humans and to use animal data as supportive evidence. The critical effect was on semen quality, following pre‐ and postnatal exposure. The critical study showed a NOAEL of 7.0 pg WHO2005‐TEQ/g fat in blood sampled at age 9 years based on PCDD/F‐TEQs. No association was observed when including DL‐PCB‐TEQs. Using toxicokinetic modelling and taking into account the exposure from breastfeeding and a twofold higher intake during childhood, it was estimated that daily exposure in adolescents and adults should be below 0.25 pg TEQ/kg bw/day. The CONTAM Panel established a TWI of 2 pg TEQ/kg bw/week. With occurrence and consumption data from European countries, the mean and P95 intake of total TEQ by Adolescents, Adults, Elderly and Very Elderly varied between, respectively, 2.1 to 10.5, and 5.3 to 30.4 pg TEQ/kg bw/week, implying a considerable exceedance of the TWI. Toddlers and Other Children showed a higher exposure than older age groups, but this was accounted for when deriving the TWI. Exposure to PCDD/F‐TEQ only was on average 2.4‐ and 2.7‐fold lower for mean and P95 exposure than for total TEQ. PCDD/Fs and DL‐PCBs are transferred to milk and eggs, and accumulate in fatty tissues and liver. Transfer rates and bioconcentration factors were identified for various species. The CONTAM Panel was not able to identify reference values in most farm and companion animals with the exception of NOAELs for mink, chicken and some fish species. The estimated exposure from feed for these species does not imply a risk.